[Last update Nov 11, 2024] There were a number of media reports today [May 11, 2024] related to Yuan et al. (2024), for instance, New Scientist, The Guardian etc. However, this is really just the beginning of what is likely to be a bit of a cottage industry in the next few months relating to possible causes/influences on the extreme temperatures seen in 2023. So to help people keep track, we’ll maintain a list here to focus discussions. Additionally, we’ll extract out the key results (such as the reported radiative forcing) as a guide to how this will all eventually get reconciled.
We’ll split the papers up by process/topic, or if the paper is general or integrative. Let us know in the comments if there are relevant papers we’ve missed. [Update: it should go without saying that we are not discussing the reason why recent years have been so much warmer than the pre-industrial, that is well known and should be uncontroversial (ha!), rather we are focused on the specifics of what happened in 2023 compared to other recent years].
Update 10 August 2024: We are convening a session at the Fall AGU meeting in DC (Dec. 9-13, 2024) entitled “GC053: Cracking the puzzle of the Anomalous Temperatures in 2023: Observational and modeling studies to identify and understand potential factors and future implications.“. We got 20 abstracts submitted, and so there will be an oral and poster session. See you there!
General
- The Carbon Brief discussion of the 2023 anomaly, and inability of the CMIP6 models to capture the strangeness in the anomalies in the fall.
- My commentary from March: Schmidt (2024), which suggests that there is roughly 0.2ºC in the global annual mean and more in the second half of the year, that appears anomalous (compared to simple expectations based on the long term trend and the state of ENSO at the beginning of the year).
- There is in fact a Nature special collection for 2023 climate. Ha.
- Rantanen and Laaksonen (2024) show that the September 2023 anomalies are unlike anything seen in the CMIP6 model ensemble.
- Kuhlbrodt et al. (2024) has a summary of all the interesting climate events in 2023.
- Tippett and Becker (2024) assess the skill of initialized predictions for 2023 and find that while their skill is largely related to ENSO, they uniformly underestimated predictions of 2023 warmth.
Impacts of Hunga-Tonga Hunga Ha’apai (HTHH)
The eruption of HTHH in January 2022, reached 56km high in the stratosphere and increased stratospheric water vapor by ~10% while also depositing SO2 in the stratosphere. The mix of warming and cooling effects and different timescales for each, makes calculating the impact hard.
- Schoeberl et al (2024) “HTHH produced a global forcing of -0.17±0.07 W/m2 over 2022-2023″. (i.e. a net cooling!).
- Sellito et al, 2024 estimate the SO2 burden from HTHH as ~1.6 Tg sulphate.
Impacts of IMO2020 (Marine shipping emission changes)
- Overview of the pre-existing results from CarbonBrief (July 2023). They estimate 0.08 W/m2 forcing, and a warming in 2023 of ~0.04ºC.
- Yuan et al. (2024). First chemical transport model runs with an 80% reduction of SO2 from marine emissions. They find a radiative forcing 0.2±0.11 W/m2 over the ocean (which translates to 0.14 W/m2 globally). Though see Zeke’s comments as well.
- Quaglia and Visioni (submitted) CESM2 response to 90% decreases in shipping emissions (4.2 TgS/yr) in historical/SSP370 runs. Radiative forcing is 0.2 W/m2 and temperature increase in 2023 is ~0.1ºC.
- Skeie et al (submitted) a multi-model estimate of the radiative forcing from the shipping emission change, of 0.06-0.09 W/m2.
- Yoshioka et al (submitted) use HadGEM3-GC3.1 and find 0.13 W/m2 forcing, and only a 0.02ºC warming this decade.
- Jordan and Henry (2024) find a forcing of 0.14 W/m2
Impacts of other aerosols
- Wang et al. (2024) Looked at the impact of Chinese aerosol emission decreases from 2010 to 2020 and saw increases in North Pacific ocean temperatures. Not immediately applicable to 2023, but perhaps indicative of what might come.
- Global mean emissions in the new CEDS data (only to 2022) compared to what was used in CMIP6. Note that the drop in shipping SO2 in 2020 is 7.4 TgS/yr, but the difference to CMIP6 scenarios is a bit less.
Impacts of the solar cycle
- Nothing published yet, but here is a graph of the observed annual solar irradiance compared to what was used in the CMIP6 models (courtesy of T. Zhou). Solar cycle 25 is both a little faster and a little more active than predicted. The difference in TSI in 2023 is around 0.55 W/m2 which is around 0.1 W/m2 in global radiative forcing above what the CMIP6 models used.
Impacts of ENSO variability
- Samset et al (2024) argue that the atmospheric response in 2023 to SST variability was not unusual.
- NEW Raghuraman et al. (2024) argue that the jump in 2023 is not inconsistent with El Niño (from looking at pre-industrial control runs). (But they don’t demonstrate that the 2023 is actually predictable from this relationship).
Other sources of Internal variability
- This could involve the NAO, Southern Annular Mode, anomalous behaviour of Saharan dust etc. but we haven’t seen much published yet.
Expressions of forced climate change
- Tselioudis et al. (2024) suggest that the dynamic feedbacks effecting clouds are a big part of the signal in the albedo change, and thus a contributor to recent anomalies.
- NEW (10/1/2024): There is a follow-on preprint from Tselioudis and colleagues estimating that the impact of the dynamic cloud changes on the effective planetary albedo and absorbed SW radiation is about 80% of the CERES trend.
We will keep this thread active as we update the lists to the papers.
References
- T. Yuan, H. Song, L. Oreopoulos, R. Wood, H. Bian, K. Breen, M. Chin, H. Yu, D. Barahona, K. Meyer, and S. Platnick, "Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming", Communications Earth & Environment, vol. 5, 2024. http://dx.doi.org/10.1038/s43247-024-01442-3
- G. Schmidt, "Climate models can’t explain 2023’s huge heat anomaly — we could be in uncharted territory", Nature, vol. 627, pp. 467-467, 2024. http://dx.doi.org/10.1038/d41586-024-00816-z
- M. Rantanen, and A. Laaksonen, "The jump in global temperatures in September 2023 is extremely unlikely due to internal climate variability alone", npj Climate and Atmospheric Science, vol. 7, 2024. http://dx.doi.org/10.1038/s41612-024-00582-9
- T. Kuhlbrodt, R. Swaminathan, P. Ceppi, and T. Wilder, "A Glimpse into the Future: The 2023 Ocean Temperature and Sea Ice Extremes in the Context of Longer-Term Climate Change", Bulletin of the American Meteorological Society, vol. 105, pp. E474-E485, 2024. http://dx.doi.org/10.1175/BAMS-D-23-0209.1
- M.K. Tippett, and E.J. Becker, "Trends, Skill, and Sources of Skill in Initialized Climate Forecasts of Global Mean Temperature", Geophysical Research Letters, vol. 51, 2024. http://dx.doi.org/10.1029/2024GL110703
- M.R. Schoeberl, Y. Wang, G. Taha, D.J. Zawada, R. Ueyama, and A. Dessler, "Evolution of the Climate Forcing During the Two Years After the Hunga Tonga‐Hunga Ha'apai Eruption", Journal of Geophysical Research: Atmospheres, vol. 129, 2024. http://dx.doi.org/10.1029/2024JD041296
- P. Sellitto, R. Siddans, R. Belhadji, E. Carboni, B. Legras, A. Podglajen, C. Duchamp, and B. Kerridge, "Observing the SO2 and Sulphate Aerosol Plumes from the 2022 Hunga Tonga-Hunga Ha'apai Eruption with IASI", 2023. http://dx.doi.org/10.22541/essoar.169091894.48592907/v1
- I. Quaglia, and D. Visioni, "Modeling 2020 regulatory changes in international shipping emissions helps explain 2023 anomalous warming", 2024. http://dx.doi.org/10.5194/egusphere-2024-1417
- R.B. Skeie, R. Byrom, . Hodnebrog, C. Jouan, and G. Myhre, "Multi-model effective radiative forcing of the 2020 sulphur cap for shipping", 2024. http://dx.doi.org/10.5194/egusphere-2024-1394
- M. Yoshioka, D.P. Grosvenor, B.B.B. Booth, C.P. Morice, and K.S. Carslaw, "Warming effects of reduced sulfur emissions from shipping", 2024. http://dx.doi.org/10.5194/egusphere-2024-1428
- G. Jordan, and M. Henry, "IMO2020 Regulations Accelerate Global Warming by up to 3 Years in UKESM1", Earth's Future, vol. 12, 2024. http://dx.doi.org/10.1029/2024EF005011
- H. Wang, X. Zheng, W. Cai, Z. Han, S. Xie, S.M. Kang, Y. Geng, F. Liu, C. Wang, Y. Wu, B. Xiang, and L. Zhou, "Atmosphere teleconnections from abatement of China aerosol emissions exacerbate Northeast Pacific warm blob events", Proceedings of the National Academy of Sciences, vol. 121, 2024. http://dx.doi.org/10.1073/pnas.2313797121
- B.H. Samset, M.T. Lund, J.S. Fuglestvedt, and L.J. Wilcox, "2023 temperatures reflect steady global warming and internal sea surface temperature variability", Communications Earth & Environment, vol. 5, 2024. http://dx.doi.org/10.1038/s43247-024-01637-8
- S.P. Raghuraman, B. Soden, A. Clement, G. Vecchi, S. Menemenlis, and W. Yang, "The 2023 global warming spike was driven by the El Niño–Southern Oscillation", Atmospheric Chemistry and Physics, vol. 24, pp. 11275-11283, 2024. http://dx.doi.org/10.5194/acp-24-11275-2024
- G. Tselioudis, W.B. Rossow, F. Bender, L. Oreopoulos, and J. Remillard, "Oceanic cloud trends during the satellite era and their radiative signatures", Climate Dynamics, vol. 62, pp. 9319-9332, 2024. http://dx.doi.org/10.1007/s00382-024-07396-8
Great idea. Will look forward to what the pursuit uncovers!
In the graph for Recent temperature anomalies, what happened to the disappearing 2023-10 band?
I have previously recorded many related papers incl new ones and articles on the Much Ado, and May UV pages during the past months.
I’m a little mystified by the conclusions of Yuan et al (2024).
The nub of the mystery is how they convincingly convert their +0.2Wm^-2 ocean forcing (+0.13Wm^-2 global, a value that doesn’t appear very controversial) into a warming of “around 0.16 K of warming with a timescale of 7 years.” They use a model as per Geoffroy et al (2013) which finds a forcing of +3.9Wm^-2 would result in some +1.7ºC (Fig 1b) suggesting a forcing one-thirtieth the size would result in [1.7/30 =] +0.6ºC warming over 7 years. While this is still a significant warming to expect 2020-27, it is also a significant difference from the Yuan et al result.
I also note the Geoffroy et al (2013) model also yields a warming of roughly +0.42ºC/decade under a linear forcing increasing at +0.55Wm^-2/decade, this perhaps 25% higher than the increasing GHG forcing shown by NOAA AGGI thus suggesting GHG forcing should show a warming of +0.34ºC/decade, a value which I would find very difficult to reconcile with the +0.19ºC/decade in the SAT record to 2015.
I would suggest that these problems do need addressing before anybody starts waving Yuan et al (2024) as a serious analysis.
MAR, did you drop a decimal point in this bit:
“suggesting a forcing one-thirtieth the size would result in [1.7/30 =] +0.6ºC warming over 7 years…”
Per my math, that should be +0.06. (0.0567, to be a bit more exact.) Or am I missing something in the background that explains this 10-fold difference?
Indeed. Mind, the decimal point is still there. It’s the zero that ran off.
Pesky devils! They do do that on occasion.
Very good indeed! May I suggest to include:
1) Consequenses of accelerating meltwater (freshwater) influx in the north-western Atlantic, the sea between western Greenland and Baffins Land and maybe the Barents sea? Why the tendency to cooler weather conditions in parts of these regions, contrary to the warming of especially the north Atlantic except for the “cold blob”? How does this connect with
2) The tendency for more SSW (sudden stratospheric warming) episodes in the northern winters? (If there is such a tendency – it seems so to me)?
3) Effects of accelerating methane releases – from a) thawing permafrost, b) the fossil industry and c) agricultural production.
Sorry to be off topic (admin pls delete if you want/need to) but — the page design seems to have changed again — text now appears to be a very faint grey colour and almost unreadable. (Firefox on Windows on a proper computer.)
It wouldn’t be quite so bad if you were still using a serif font for body copy, which is what they’re for! Serif fonts are far more readable, sans-serif should really only be used for headlines and the like.
[Response: we haven’t changed anything. Is there a way to see what font it is rendering at? Maybe we can add a different font to the list. – gavin]
(No need to post this) Further to previous comment just posted — OK well that’s weird, when the page redisplayed after I hit “post comment” the font colour’s back to the usual dark grey.
Comments about serif / sans-serif still stands, though!
Thanks for your time…
Thanks Gavin, very useful !
probably worth adding this link to an upcoming special collection on the topic, deadline submission October 2024, from, well, Nature publishing itself!
https://www.nature.com/collections/ahbedcfifa
[Response: Ha! I had no idea. Thanks. – gavin]
Suggestion for the TSI plot: label the right-hand y axis with the corresponding global radiative forcing.
Wording fix: It should go without saying that we are NOT discussing…
Thanks! I was a little intrigued by a recent update on Hunga-Tonga Hunga Ha’apai which reversed earlier conclusions about noticeable cooling. I’m not finding it: in fact the above reference is the most recent, and looks to be sufficiently clear about what we do and don’t know (unlike some people here who overflow with certainty, which imnsho does not reflect the workings of science).
So I will continue as I began, only to emphasize that more recent work has reduced the exaggerated conclusions which appeared earlier as observations are clarified over time. Now that’s science!
Perhaps you’re referring to this?:
Long-term climate impacts of large stratospheric water vapor perturbations.
https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-23-0437.1/JCLI-D-23-0437.1.xml
Key conclusion:
Global mean surface temperature anomalies (including SSTs) are 0.032±0.022◦C with this model, which is again very close to the 0.035◦C estimated by Jenkins et al. (2023).
Thanks for the specifics. Being an amateur, my comment was more generalist, as I wrote; I try to learn and limit my remarks to my understanding.
Though it is grey literature, please also include this May 1 policy paper by Transport & Environment in your reporting: “Non-CO2 MRV in EU ETS, a no-regret step to mitigate aviation’s full climate impact”.
See especially the graphical data in Fig. 1 concerning the effect of contrails over the same oceanic areas that are primarily being discussed regarding reduced sulfur in shipping fuels.
The graphic is a map of the full extent of the northern hemisphere, and it shows the most intense effect of contrails is over the north Atlantic and north Pacific Oceans (although the caption, misleadingly, is “Percentage of flight distance forming persistent over the EU and surrounding areas.”)
https://www.transportenvironment.org/articles/position-paper-non-co2-mrv-in-eu-ets-a-no-regret-step-to-mitigate-aviations-full-climate-impact
(“MRV ” means the Monitoring, Reporting and Verification framework required by the EU ETS in 2022.)
Keep in mind that the oceanic indices have a biennial component in that there is an underlying periodicity paced at 2 years. This is mentioned frequently, often also as a quasi-biennial mode.
https://meetingorganizer.copernicus.org/EGU24/EGU24-10200.html
Mention this because back-to-back-to-back La Nino in the years 2020-2022 may have an impact on the discharge characteristic of an ensuing El Nino. Perhaps it may be much more intense. That could also extend to AMO.
I continue to look at tidal forcing of a biennial mode, with an identical forcing shared between ENSO and AMO https://gist.github.com/pukpr/2326fba3f5061ed2a8cec58b43db8308
If g(t) is the biennial impulsed tidal forcing then ENSO= f1(g(t)) and AMO = f2(g(t)) where f1 and f2 are different LTE standing wave mode modulation functions. What’s LTE? That stands for solutions to Laplace’s Tidal Equations, a simplified form as described in Mathematical Geoenergy (Wiley/AGU, 2018).
As I have asserted before, banging heads against the wall until El Ninos and the other oceanic cycling modes can be predictably forecast
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Dear Dr. Schmidt,
There are fierce fights about the question if the role of aerosols is or is not underestimated in climate models analyzing the Earth climate evolution during the anthropocene, during the industrial era and especially during the last decade.
I would like to ask how well the sides of the dispute can rely on data. I noted that a satellite that should detect aerosols globally was launched just this year, am I right?
And a further question. I assume that the speed of Earth warming in terms of the global mean surface temperature may strongly depend not only on the changing power input (Earth energy imbalance, EEI), but also on the extent in which the absorbed excess energy is dissipated / distributed in the ocean. If the speed of ocean mixing accelerates of, oppositely slows down, I can imagine that it could change the speed of the surface warming significantly even in case that the power input would have not changed at all. Can the foreseen analysis of the observed changes in global surface temperature rely on a solid picture of the trends in ocean heat content (OHC), or is the available data, e.g. from Argo buoys, in fact still too fragmentary to support these analyses properly?
Finally, a third question regarding global precipitation data. My previous questions on this forum pertaining to this topics have not brought a clear answer yet – if a long-term reconstruction of trends in global annual precipitation and its distribution between land and sea does already exist, or not yet at all. And, in case that if a such analysis already does exist, can it serve as a basis for reconstruction of global trends in latent heat flux and its distribution between land and sea? I am asking because I assume that in such case, it could perhaps provide a further fixed point on which the reconstruction of Earth energy balance and its temporal trends could rely.
It appears that nobody of regular readers and discussion participants on Real Climate can answer these questions with a reasonable certainty. Could you? And, if there perhaps are no clear answers yet, are there at least ideas how the level of our knowledge could be improved?
Thank you in advance and best regards
Tomáš Kalisz
Thank
Tomas Kalisz:
“If the speed of ocean mixing accelerates of, oppositely slows down, I can imagine that it could change the speed of the surface warming significantly even in case that the power input would have not changed at all. ”
Research has been done on this issue and it is likely to speed up warming:
“CLIMATE CHANGE IS CREATING A SIGNIFICANTLY MORE STRATIFIED OCEAN, NEW STUDY FINDS”
https://news.ucar.edu/132759/climate-change-creating-significantly-more-stratified-ocean-new-study-finds
“The ocean has become significantly more stratified over the last half century as the climate has warmed, inhibiting the ability for heat, oxygen, and carbon dioxide from the surface to be transported deeper into the ocean, according to a new study. The decrease in ocean mixing could amplify warming due to human-caused climate change at the Earth’s surface, intensify ocean acidification, and impact the marine food chain, among other impacts.The study, published this week in the journal Nature Climate Change, found that stratification in the upper 200 meters (656 feet) of the ocean increased by about 7% between 1960 and 2018. ”
A more recent study finds much the same:
“Climate change has reduced ocean mixing far more than expected”
https://www.cnrs.fr/en/press/climate-change-has-reduced-ocean-mixing-far-more-expected
So we can already see what’s happening and what is most likely to continue to happen.
.
“Can the foreseen analysis of the observed changes in global surface temperature rely on a solid picture of the trends in ocean heat content (OHC), or is the available data, e.g. from Argo buoys, in fact still too fragmentary to support these analyses properly?”
The argo network has comprehensive coverage. Refer UCSD:
“Argo is a global collaborative partnership where contributing nations maintain an array of ~4000 autonomous ocean floats that each profile vertically from 2000m once every 10 days. Data from Argo allows for unprecedented spatial coverage of the world’s oceans, with approximately one float per 3-degree box across the global ocean, where it is deeper than 2000 meters. Before Argo, ocean and climate scientists relied on sparse temperature and salinity measurements from commercial and research vessels, as well as from a limited number of stationary moorings. Unlike measurements from ships, Argo data minimizes spatial biases (such as oversampling in heavily-traveled shipping lanes) and temporal biases (such as mostly summer time data in high latitudes where harsh winter conditions limit ship access). This global coverage is crucial for detection of climate change signals because within (and between) major ocean basins, heat is constantly transferred around different areas and seasonal cycles in some regions can overshadow interannual variability. Therefore, a continues global coverage is needed in order to accurately quantify longer-term changes happening in the ocean.”
https://argo.ucsd.edu/science/argo-and-climate-change/
I’m not not sure why you didn’t just google answers to your questions, rather than ask someone very busy like Gavin. Its very easy to find all this information. I was curious and and retired, so I had a look anyway. I can certainly see why Piotr accuses you of sea lioning: (Sealioning (also sea-lioning and sea lioning) is a type of trolling or harassment that consists of pursuing people with relentless requests for evidence, often tangential or previously addressed, while maintaining a pretense of civility and sincerity (“I’m just trying to have a debate”), and feigning ignorance of the subject matter. Wikipedia).
in Re to nigelj, 1 Jun 2024 at 5:48 PM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822528
Dear Nigel,
Thank you for the provided links and for your comment to that I, however, respectfully disagree.
I think that if Wikipedia or other publicly accessible sources represented a sufficient information about climate science, there would be no incentive for Dr. Schmidt and his colleagues to run Real Climate forum.
I am afraid that the links you provide do not answer my question how the leading climate scientists assess the completeness of the available data, and their suitability for the explanation of the presently disputed observations, namely, of the global temperature anomally of the last year.
I have not mentioned the aerosol data only, because I think the climate system does not include aerosols and greenhouse gases only. I am afraid that in a new reader, some discussions herein may evoke a feeling that nothing else than greenhouse gases and aerosols needs to be taken into account, and that climate science does not deal with anything else. That is why I dared to address in my questions directly Dr. Schmidt.
If you know the answers, on my questions, please share them, even though you may feel a discomfort from replying to a sea lion. I do not think that general public knows these answers, and I believe that it might be useful to extract them from specialized scientific litearture and make them more accessible to the public this way.
Best regards
Tomáš Kalisz
Tomas Kalisz: “I am afraid that the links you provide do not answer my question how the leading climate scientists assess the completeness of the available data, and their suitability for the explanation of the presently disputed observations, namely, of the global temperature anomally of the last year.”
I dont know the answer to that and I doubt Gavin Schmidt would know offhand, given he didnt design the argo network. If you want to know why 4000 argo floats at a certain spacing of one float per 3-degree box across the global ocean, was considered sufficient, (it looks good to me) contact the argo organisation. I have already given you their home page in my previous comment, and it has full contact information on it ( argo@ucsd.edu and other contacts).
TK & nigel, for ARGO, Woods Hole Oceanographic Institution (WHOI) is an excellent resource.
https://www2.whoi.edu/site/argo/
[I hesitate to refer TK to them, as he seems to have a problem absorbing the information presented to him without proliferating queries which demonstrate an incomplete (and sometimes odd) understanding, but will have to hope their wonderful organization provides him with a wealth of material if he really wishes to know more.]
Tomas Kalisz: ” I think that if Wikipedia or other publicly accessible sources represented a sufficient information about climate science, there would be no incentive for Dr. Schmidt and his colleagues to run Real Climate forum.”
The Real Climate is NOT run for the benefit of the full of themselves ignoramuses, who are too lazy to do their homework: to take a basic course in climate sciences, to read a textbook, to find and read Wikipedia entries, or to do an elementary literature search on Google Scholar, and who unwilling to do any of the above, expect … the top scientists in the world to waste their time to explain basic to them, even though in the HUNDREDS of their earlier posts – they have shown that they are unable or unwilling to understand what is explained to them and/or cherry-picked only these parts of the explanation that support their a-priori beliefs.
Nor is Real Climate run for climate change denier trolls, applying the sealioning trolling technique, to paralyze the debate and tie down the opponent experts:
Wikipedia:
“Sealioning: trolling or harassment that consists of pursuing people with RELENTLESS REQUESTS for evidence, often tangential or previously addressed, while maintaining a pretense of civility and sincerity. […] It may take the form of “incessant, bad-faith invitations to engage in debate”, and has been likened to a denial-of-service attack targeted at human beings”.
In re to Piotr, 2 Jun 2024 at 3:27 PM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822537
Dear Piotr,
If the answers to my questions were already published in hundreds of previous Real Climate posts, I believe that one of regular readers finally helps and provides a reference.
I hope that this way, even lazy ignoramuses like me can benefit from this website.
Greetings
Tomáš
Tomas Kalisz “ If the answers to my questions were already published in hundreds of previous Real Climate posts I believe that one of regular readers finally helps and provides a reference
What are you talking about? “Regular readers” have already REPLIED to HUNDREDS of your posts on this forum – proving again and again your ignorance of climate science, your inability to understand, or unwillingness to accept, what was explained to you, or your cherry-picking only these parts of the answers that support your a priori beliefs.
Not to look far, see:
– May 4 post where I indicated TO YOU that YOUR proposed increasing 1000-FOLD current global desalination, then spreading and evaporating all this water over 5 mln km2, to achieve after 100s? 1000s? of operation – at most 0.3K cooling – is NOT a “feasible” solution to AGW.
– or my May 24 PROOF that your accusations (TK; “you twist and misinterpret what I said ”) was based on a lie: TK:“I have never proposed acive water cycle management as an alternative to GHG mitigation”.
I proved it to be a lie by QUOTING your May30 and May 31, 2023 posts in which you calculated that extra evaporation of “12750 km3 water” we cancel the ENTIRE radiative forcing of GHGs, or even:
“ REVERSE the sign of EEI – in other words, we might be able to COOL the Earth this way” Tomas Kalisz, May 31, 2023
What MORE of a reference do you need???
I wonder if this reduced oceanic mixing is connected with the weakening AMOC, as argued here on realclimate several times by Stefan Rahmstorf, latest i february this year https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/ ?
It seems to me obvious that such a connection must exist, maybe combined with more freshwater from melting glaciers and ice-sheets, melting/thinning sea ice, more rapid runoff from land resulting from more extreme precipitation events (which, combined with more extreme droughts and desertification, loss of rainforests/deforestation etc., tends to dampen infiltration a lot) in important regions. Freshwater is less dense than salty water. On the other hand, a more windy climate should enhance the ocean mixing, one would expect.
KV Johansen: “ I wonder if this reduced oceanic mixing is connected with the weakening AMOC
if it is – then it would be the result, not the cause. Warming, stronger in high-lat Atlantic because of Arctic amplification, and freshening from glacial and sea-ice melting – make the surface waters less dense and therefore less likely to vertically overturn in winter -> weaker AMOC, and less likely to vertical mix during the rest of the year.
One could argue that a weaker AMOC means LESS of the very cold winter water sinks – so more of it stays at the surface and if not dispersed by currents – is likely responsible for most of the observed Cold Blob there. Now, colder than usual water at the surface should increase vertical mixing, but weaker AMOC means ALSO less export of salt into deep ocean (only the coldest and saltiest water sink deep enough)
So if the Cold Blob is also Less Salty Blob – then the stratifying effect of lower S is likely to outweigh the effect of lower T in the opposite direction ^*
^* Vertical stratification in high latitudes ocean tend to be more vulnerable to changes in S than in T (the latter not having much room for changes, both vertically, and seasonally).
In Re to Piotr, 4 JUN 2024 AT 8:35 PM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822566
Dear Piotr,
When reading the articles mentioned above by KV Johansen, and the following discussion, I got an impression that the concerns about possible changes in the intensity of ocean mixing / conveyor belt are mostly based on theoretical assumptions and models.
I would like to know if there are also data / methods allowing to compare modelling of these currents with observations. Based on your contributions I assume that you are an oceanographer or at least that you work in a field that has some links to oceanography. It is my feeling that e.g. Argo buoys do not track ocean currents, or at least not the deep and/ or ascending/ descending currents. Could you comment?
Thank you in advance and best regards
Tomáš
Tomas Kalisz: “possible changes in the intensity of ocean mixing / conveyor belt are mostly based on theoretical assumptions and models. I would like to know if there are also data / methods allowing to compare modelling of these currents with observations”
Why? what would you do with an answer? You don’t know even the basics (theory and models) of vertical mixing and Thermohaline Circulation (THC), you don’t know the observational methods in physical oceanography, hence you can’t interpret their data – much less use your interpretation of data to compare with theory and models.
Given that – your request looks like another example of your sealioning ( “incessant, bad-faith invitations to engage in debate” and has been likened to a denial-of-service attack targeted at human beings“) AND following denialist tropes: in this case the line: the so-called climate change is ONLY A THEORY, based on theoretical assumptions and theoretical models .
And it’s fighting an opponent whose hands you tied behind their back: you demand the observation data to verify models exploring FUTURE scenarioes, ” future” meaning that the observational data for those don’t exist yet.
Even if the changes in the mixing caused by AGW are already under way – the observation signal to noise ratio is likely to be very poor – ocean inertia makes the signal weak, while the confounding variables, i.e. the noise – are massive since we deal with a much more complex system than the much more mixed, vertically and horizontally, atmosphere.
in Re to Piotr, 22 Jun 2024 at 12:15 PM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822887
Dear Piotr,
I think that if there was a similar global reconstruction of past precipitation as is available for temperature, the models could be tested by starting e.g. in year 1980 and predicting next 44 years. The same could be perhaps possible for models predicting intensity of ocean currents / heat storage in ocean, if we had a similar data showing if and how the speed of global ocean mixing changes / changed.
I supposed that models that create various future scenarios should be capable to predict the present state, if they start in the known past, or am I wrong?
Greetings
Tomáš
WRT to Tomas’s comment here, my sense is that the idea of using a validating hindcast on precipitation is, if not exactly wrong, at least more challenging than the comment would suggest.
Recall that modeled temperature results cannot be expected in most cases to exactly match an historical temperature trajectory–there may be one or more model runs that come quite close, but most runs will not, due to the statistically chaotic nature of the system. So assessments are based on congruence with the ensemble mean, not particular runs.
Precipitation seems to be a thornier issue; it’s quite highly localized, and moreover there isn’t necessarily (and AFAIK) a global-scale trend analogous to the warming trend we’ve observed. Some areas will get wetter, some will get dryer, and globally there might not be much change in amounts. But of course the effects will still be felt, and if you are flooded out of your home, your concern for the global average will be vanishingly small.
Anyway, there is and has been work on this matter, as a Google Scholar search reveals:
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C18&q=hindcasting+global+precipitation&oq=hindcasting+global+precip
Tomas Kalisz June 24: I think that if there was a similar global reconstruction of past precipitation as is available for temperature, the models could be tested by starting e.g. in year 1980 and predicting next 44 years.”
Ocean mixing and overturning, have incomparably larger inertia and complexity than atmospheric processes averaged globally, hence the observations of the former have a much higher noise to signal ratio than the latter.
And with your ignorance of the fundamentals you wouldn’t understand a thing anyway. Not to waste more time on that – I’ll just repost one the parts of my original answer you decided to ignore:
=== Piotr, June 22: ===
” what would you do with an answer? You don’t know even the basics (theory and models) of vertical mixing and Thermohaline Circulation (THC), you don’t know the observational methods in physical oceanography, hence you can’t interpret their data – much less use your interpretation of data to compare with theory and models.
Given that – your request looks like another example of your sealioning ( “incessant, bad-faith invitations to engage in debate, and has been likened to a denial-of-service attack targeted at human beings“)
AND you are again following denialist tropes, along the lines:
the so-called climate change is ONLY A THEORY, based on theoretical assumptions and theoretical models, [so we can burn as much fossil fuels as Russia and Saudi Arabia would like us to burn]
=====================
Kevin McKinney 27 JUN “, Precipitation seems to be a thornier issue
Comparing to globally averaged temperature – yes.
Compared to changes in the ocean vertical mixing and overturning, which is what Kalisz is talking about – it is a child’s play*. Then again it’s all beyond the point – since doesn’t have even the basics to understand anything from neither precipitation nor oceanographic models
—-
*given incomparably larger thermal inertia of the ocean, and the complexity of the vertical mixing of the ocean compared to the atmosphere, and on top of that technical complexity of the observations of ocean dynamics compared to globally averaged air temperature or precipitation.
“Maybe we can add a different font to the list. – gavin]”
As long as it’s not ‘Climate Crisis’ , which is seriously illegible:
https://vvattsupwiththat.blogspot.com/2024/05/cliche-trigger-warning-its-as-bad-as-it.html
One should perhaps consider the idea that Hunga Tonga would have a significant impact on the equatorial stratosphere behavior. From this NASA link, the introduction of a huge amount of water vapor is obvious, but it has virtually no impact on the QBO cycling. Look at the darkened contours and note that the temporal structure is preserved
https://acd-ext.gsfc.nasa.gov/Data_services/met/qbo/qbo.html#water
Why is that? Probably because the QBO is purely a fluid mechanical effect which doesn’t respond to minor changes in temperature or gas composition.
In fact all the quirky anomalies/perturbations observed in the QBO observed in the past few years are more likely the expected behavior due to the more erratic pattern of tides (a purely mechanical forcing on a fluid) over the span of decades. The QBO periodicity is compatible with a mix of tidal cycles that can be cross-validated by keeping training intervals separate from testing intervals.
https://github.com/orgs/azimuth-project/discussions/11#discussion-6778948
Previous discussion here.
https://geoenergymath.com/2024/03/16/are-the-qbo-disruptions-anomalous/
The bottom-line is that anomalous patterns may not be anomalous if the correct underlying model is applied. That of course may well be the case for the 2023 temperature anomaly, but we won’t know until oceanic cycles such as ENSO and AMO are understood inside and out. IMO, these are also likely a fluid mechanical effect, i.e. orbit tidally forced.
Paul Pukite: “ we won’t know until oceanic cycles such as ENSO and AMO are understood inside and out.”
Area of research in search of ….societal relevance? ;-)
For the existential threat to our civilization, global climate CHANGE, only the things that do CHANGE significantly over climatological time scale – count. Short-term OSCILLATIONS around the mean – don’t. Thus ROI in studying them for climate change is likely to be low – they are merely a NOISE, practically disappearing (by being averaged out), when climatological time scale is used.
To become important to climate CHANGE, these oscillations would have to:
1. be CHANGING in a systematic way (say, El Nino phase longer and stronger)
2, have the climate’s effect of that change from p. 1 should be at least in the same ballpark as that of the GHG forcing
3. those changes have to have an external source, i.e., cannot be just a result of GHG forcing
– because then they are not drivers of, but merely feedbacks to, GW. And with you favouring the tidal explanations to ENSO – this may be a tough mountain to climb – I don’t think gravitational attraction by the Moon has changed, and in one direction, all that much over last several decades …
But then again, you heard this before, and obviously … nothing landed. I don’t expect this time to be any different …
P: For the existential threat to our civilization, global climate CHANGE, only the things that do CHANGE significantly over climatological time scale – count. Short-term OSCILLATIONS around the mean – don’t.
BPL: This is a central point I have many times tried to explain to deniers. A whole bunch of them think they can get away with “it’s just a cycle!” One guy who used to pop up on ResearchGate (an otherwise respectable venue) insisted the present warming was due to a “60-year cycle.” When I pointed out that it wasn’t this hot 60 years ago, he changed the subject.
Piotr: “For the existential threat to our civilization, global climate CHANGE, only the things that do CHANGE significantly over climatological time scale – count. ”
BPL: “ This is a central point I have many times tried to explain to deniers. A whole bunch of them think they can get away with “it’s just a cycle!”
…and it applies on BOTH ends of the AGW time-scale:
– at a shorter end: 3-7 years of Paul Pukite’s ENSO, or the 22-year cycle of the “ It’s the Sun stupid” folks,
– at a longer end – the same Pukite lecturing me: “ Common misconception here” and then coming up with a cycle …. “measured in millennia“. and then trying to gain credibility by association (with Keeling, “yes that Keeling” [(c) P. Pukite]
As they say in the US: “ If the time-scale doesn’t fit, you must acquit“. Or something like that.
The interesting thing about the “it’s a cycle” folk is that the longer the warming goes on, the longer the cycle has to be. This is because all they are doing is Fourier approximation of the temperature series. The problem, of course is that they can get agreement only for a portion of the curve. Denialists are a classic example of stupidity sent to college.
Naively extracting Fourier series only works for obvious situations and not for cases such as Brillouin zone folding and Mach-Zehnder demodulation, where cross-harmonics essentially encrypt the frequency spectrum. Whenever you run across a Fourier approximation that doesn’t express obvious periodic factors, don’t give up and attribute it to noise. It could be encrypted information that needs to be demodulated from a carrier frequency or otherwise un-aliased or decoded in some fashion. A high percentage of sticky unsolved problems would likely benefit from using this class of signal. processing techniques.
(was this directed at me or Gavin?)
“But then again, you heard this before, and obviously … nothing landed. I don’t expect this time to be any different …”
Piotr, Your misguided crusade to stop science from advancing continues. The topic of the RealClimate post is essentially on the origins of the 2023 heat spike. Nothing in the models of GHG-assisted climate change can explain a spike in temperature — it really can only project a secular warming trend. Now, it’s possible that the current elevated temperature is actually a permanent step change or that GHG’s somehow amplified a natural peak in a cycle. But we won’t get that resolved until the heat spike finishes. In fact, Bob Henson at Yale Climate Connections said:
https://yaleclimateconnections.org/2024/06/research-on-earths-raging-fever-of-2023-24-is-picking-up/https://yaleclimateconnections.org/2024/06/research-on-earths-raging-fever-of-2023-24-is-picking-up/
So it’s not just me, instead you’re singling me out as a whipping boy. You seem to be implicating everyone that is asking the question that Gavin above and Henson are posing:
Science marches on and it’s futile to stop scientists from asking questions. Yet I’m sure you will find something in my perhaps indelicate phrasing as another gotcha.
Piotr said:
Common misconception here. Because of the incommensurate nature of the major long-period orbital cycles, the gravitational forcing with respect to the Earth is continuously changing and the repeat pattern is measured in millennia, see Keeling & Whorf, 2000 — yes that Keeling. Consider the lunar and solar declination and perigee cycles (4 possibilities right there), the approximate least common multiple repeat period is about 1000 years for just 2 of these. Take the 18.6 year lunar nodal declination cycle and 8.85 year lunar perigee cycles and that only repeats every 1097.4 years. But then that does not align on an annual cycle which is required for ENSO, so that 5 x 1097.4 = 5487 years is repeat for a hypothetical ENSO cycle that is triggered by a seasonal impulse modulated by a lunar tidal forcing.
In practical terms, this means that if ENSO behavior is aligned to a nonlinear response of the fluid dynamics to the precise tidal forcing (ala Laplace’s Tidal Equations used in GCMs) then the 150 years of measurements is not even close to being enough data to discern a pattern from inspecting the data alone.
That’s why I think that machine learning neural network experiments that are trying to extract patterns from only the data are potentially misguided. The evaluation of NNs occurs from fitting nonlinear interactions within the data to the data itself, but if the important external forcing component is not included then the real pattern won’t be discovered.
Now here’s where the breakthrough is: consider that ocean cycles are pinned to specific Earth geographic configurations, which enforce certain lunar and solar orbital cycles (think in terms of frequency of eclipses in a certain region VS occurring anywhere in the world). However, an atmospheric cycle such as QBO has longitudinal invariance which means that some of the incommensurate periods are removed from consideration. In fact, because of this higher topological symmetry and thus reduced DOF involved in the QBO behavior , the lunar+solar cycles are more easily revealed in a short time-series. And that’s exactly the case as I have published previously; as a succinct overview, here is a mathematical explanation that I recently wrote up: https://geoenergymath.com/2024/03/25/proof-for-allowed-modes-of-an-ideal-qbo/
That’s why I haven’t given up on ENSO, as I realize that the lunar +solar patterns have to be more complex. Perhaps the more trivial nature of QBO gave me too much hope of finding a related pattern in ENSO, yet I haven’t thrown in the towel yet and blamed it on chaos or randomness. It’s getting easier to fit the data and the cross-validation results are improving so there is light at the end of the tunnel. Yet, I still remain mystified by the climate research effort being expended assuming internal variability and the big guns at Google and NVIDIA that are doing machine learning w/o including the external factors. And in the context of this RC post, it’s possible that the 2023 heat spike may be the result of a confluence of lunar + solar factors with a nonlinear response that emerges from a comprehensive analysis.
Piotr claims:
You said “I don’t think gravitational attraction by the Moon has changed”. Again, what do you mean by this? From the text by Pugh and Woodworth (2014), “Sea-Level Science: Understanding Tides, Surges, Tsunamis and Mean Sea-Level Changes,”
This value is often chosen because two perigean cycles of 8.85 years will fit into this 18.6 year nodal precessional interval, But of course this is not an exact commensurate match, which is why the tidal analysis has to be updated regularly. See also country-specific guidelines such as the NOAA Tech Report NOS CO-OPS 068 https://tidesandcurrents.noaa.gov/publications/NOAA_Technical_Report_NOS_COOPS_68.pdf and Figure 1 inn particular.
And from a recent article, it’s worse than this :
IMO it is straightforward to model ocean indices such as ENSO and AMO using a common tidal forcing. The periods of 18.6 years or 18 years (Saros) and ~4.5 years (about 1/2 of the perigee cycle because of the antipodal tide) always appear in the forcing modulation patterns. Yet, one has to understand that these ocean cycle instrumental records extend for over 100 years, and the challenge is to keep track and calibrate these so-called long-period tidal factors. Yet, I think the reason that it will be hard to get buy-in to the significance of this approach is because ocean cycle events occur on a interannual basis, which is the calibration scale, a far cry from the daily tidal patterns that most don’t even blink an eye over.
Paul Pukite June 10: “You said “I don’t think gravitational attraction by the Moon has changed”. Again, what do you mean by this ?”
So…, on June 10 you ask me what I meant by the very same sentence you … had already dismissed two days earlier: “Common misconception here PPukite June 8″.
Shouldn’t you dismiss other people’s argument only AFTER you have learned what they mean?
And as for your question – wasn’t the meaning OBVIOUS from the rest of the sentence that you didn’t quote? You know:
Piotr June 6: “ [ I don’t think gravitational attraction by the Moon has changed] , and in one direction, all that much over last several decades …”
AND from the preceding sentence in which I explained … what I meant by “all that much“:
Piotr June 6: “ To become important to climate CHANGE, these oscillations would have to:
[…] 2. have the climate’s effect at least in the same ballpark as that of the GHG forcing
You have read that, and instead of showing that the CHANGES in the Moon gravitation “ over the last several decades” had at least COMPARABLE radiative forcing to that of the GHGs over the same period – you … lecture me on the changes in Moon’s gravitational forcing over time ….. “measured in millennia” ???? “Millenia” are NOT “several decades”. Mr. Pukite.
And no, my pointing to YOUR limitations in YOUR comprehension of the posts to which YOU reply, and to YOUR attempts to make YOUR research area, and by extension YOU – more important (e.g. your famous claim that a better prediction of timing of next ElNino “ would save countless lives“) – is NOT a “crusade to stop science from advancing” nor trying ” to stop scientists from asking questions.
PPukite: “ So it’s not just me, instead you’re singling me out as a whipping boy. ”
No, it is your posts that single you out. Gavin or Henson haven’t claimed that the anomalously warm 2003 represents a climatic change forced by the Moon’s gravitational cycle “ measured in millenia, you did. So it is on you, not on them.
Piotr does get upset — ain’t that something? No skin off my nose, I enjoy working on this stuff and dabbling with machine learning. If I came across someone trying something innovative, my curiosity would draw me in. Guess that doesn’t apply to everyone.
Today I just finished a first-pass peer-review of a Copernicus paper submission. The fluid dynamics meshed computational model included a fit to sea-level readings, which is what the author claimed would validate the model. I suggested that it might be a good idea to work with more than 10 days + finer sampling of the time-series data to better discriminate against the forced tidal response. Despite that, still recommended the paper, as it does add to scientific knowledge
Paul Pukite: “ Piotr does get upset ”
And you have deduced that from …. which part of my post? ;-)
No skin off my nose, I enjoy working on this stuff and dabbling with machine learning.
NOBODY is discussing your machine learning – the discussion was about your pathetic search for relevance of your area of interest (ENSO) to the society at large -when you claimed that a better prediction of the timing of ElNino “ would save countless lives . and to the science of climate change: “ we won’t know until oceanic cycles such as ENSO and AMO are understood inside and out”.
I have listed the necessary conditions under which your claim to relevance can be defended:
– on “saving countless lives” – show a plausible mechanism in which knowing the more precisely the date of the next El Nino “would save countless lives ”
– on the critical importance of ENSO to climate change – I listed 3 necessary conditions your oscillations would have to meet:
=====
1. be CHANGING in a systematic way (say, El Nino phase longer and stronger)
2, have the climate effects of these changes comparable to that of the GHG forcing on the climate, i.e. multidecadal, scale.
3. those changes have an external source, i.e., cannot be just a result of GHG forcing– because then they are not drivers of, but merely feedbacks to, GW.
===
On “saving countless lives” – you tried to weasel out on … semantic – that you didn’t mean “too many to be counted“, but merely an … “impossible to count” who knows, maybe many, maybe nobody at all, impossible to say. In other words, to save your face, you sacrificed your initial thesis.
On the importance to climate change science – you patronizingly lectured me that ENSO can be changed by Moon gravitational cycles ….”measured in millenia“.
To which I pointed time-scale discrepancy – a cycle lasting “millenia” cannot explain the global T increase over … the last several decades.
You have never addressed this criticism, but instead – tried to drape yourself in the authority of science, by portraying my SPECIFIC criticisms of your SPECIFIC claims as … an attack on science:
PPukite Jun 8: “ Your misguided crusade to stop science from advancing continues.” and Science marches on and it’s futile to stop scientists from asking questions ”
All of which tells nothing about science or about me, but tells quite a lot about you.
I don’t really get that upset by Piotr’s histrionics, it’s more amusing and quaint than anything else. My stuff is out there and published — go ponder why he’s not citing that instead of harping about some random RC comment I made on the societal benefits of predicting the climate.
In Mathematical Geoenergy (Wiley/AGU, 2018), chapter 12, I describe an ENSO model that includes a bi-annual impulse. That was over 5 years ago so I have been able to experiment with it more, trying to falsify and/or cross-validate the results as one should do with any scientific hypothesis. The recent insight may be that all the oceanic indices may have collectively reached a peak last year. Is there something modulating the bi-annual impulse, perhaps only isolating the tidal forcing signals that are longitudinally invariant? Can’t be the tropical lunar cycle because that depends on longitude (see my interactions with RC commenter Patrick27 the last few months here). How about applying only the draconic and anomalistic lunar cycles acting together, which has a beat frequency of very close to 6 years :
1/(1/Drac-1/Anom)/Year = 1/ (1/27.2122-1/27.5545)/365.242 = 5.9975 years
This is a nearly perfect even number with which to sustain/synchronize a 2-year impulse. One of the big issues with a bi-annual impulse is that it’s a metastable state. There’s nothing preventing a bi-annual cycle from missing a beat and resynchronizing on an annual cycle that’s offset by a year. IOW, there are 2 possible bi-annual pulse trains to synchronize on — say the years 2020, 2022, 2024, etc or the odd years 2019, 2021, 2023, etc. Thus the 6-year cycle — intimately tied to the 18-year Saros eclipse cycle — synchronizes the bi-annual delay and stabilizes the metastable state. For 5.9975 years, the stabilization will continue for 1/(1/5.9975 -1/6) = 14,394 years, which is the time it will take to get out of phase and flip to an odd alignment.
That’s all well and good but this approach indeed works to model all the ocean indices, including ENSO, PDO, AMO, and IOD. I have a scratch pad GIST on GitHub here, where I am collecting cross-validation experiments https://gist.github.com/pukpr/3a3566b601a54da2724df9c29159ce16
Each one of these takes a few minutes to obtain a decent fit. The insight I have as to why some of the indices have multidecadal behavior (such as AMO and PDO) has to do with the sensitivity of the anomalistic lunar cycle with respect to a bi-annual cycle. The anomalistic cycle has an implicit beat of 1/ (2*365.242/27.5545 mod 1) = 95 years, which will cause the lagged integrated response to wander about the mean value of 0. As it happens, by modeling a shorter lag response for ENSO, the multidecadal response is not as apparent. IOW, it has a faster reversion to the zero mean, and the fluctuations do not wander as much, staying interannual for ENSO instead of multidecadal.
So the fact that all the oceanic cycles have a common-mode for tidal forcing suggest that the Earth can experience a collective response that can generate an amplified peak as we measured last year. The longitudinal invariance of the specific tidal factors reinforce this behavior, much like it does for atmospheric QBO (see ibid, Chapter 11).
Perhaps the reason that this analysis has been overlooked, I looked into the etymology of the words anomalistic and draconic => an “anomalistically draconic approach” in simpler terms refers to an approach that considers irregular or unusual cycles or patterns, typically in a scientific or observational context. It implies studying phenomena that occur irregularly or deviate from the norm, focusing on their unique characteristics or occurrences rather than regular patterns. Draconic implying dragons and their remote plausibility – “don’t go there, here be dragons” – https://en.wikipedia.org/wiki/Here_be_dragons
The fact that the majority of tidal analysis concentrates on the tropical tidal factor obscured the fundamental nature of the behavior, and no wonder the draconic and anomalistic cycles have been overlooked.
Bottom-line is that this idea of tidal cycles controlling the natural variation of the ocean is not going away. It really should be considered as the default hypothesis (replacing the null), much like the earth’s orbital declination cycle is the consensus prevailing hypothesis for explaining why seasons exist. And why Milankovitch has been adopted as the consensus hypothesis for glacial cycles. Orbital forcing should always be considered before all other rationales, including the ridiculous sunspot models, which never seem to die.
Paul Pukite: I don’t really get that upset by Piotr’s histrionics, it’s more amusing and quaint than anything else.
Those who can falsify opponent’s arguments – do. Those who can’t – assure the reader how they are amused, and then their mind drifts away on a tangent – they explain something nobody asked about.
PP: “ My stuff is out there and published — go ponder why he’s not citing that ”
Have you published there:
1) the mechanism by which a better prediction of the timing of next ElNino “ would save countless lives“ [(c) Pukite, P., 2024]?
2) how a Moon gravitational cycle with a period “measured in millennia” [ (c) P.Pukite] drives the AGW temperature trend over the last …. several decades?
If not, then … keep pondering why oh why am I not citing these publications on OTHER topics that nobody was commenting on.
See also Wikipedia: “ Tangential speech or tangentiality is a communication disorder in which the train of thought of the speaker wanders and shows a lack of focus, never returning to the initial topic of the conversation.“
The popular physicist Sabine Hossenfelder (@skdh) has recently received much grief for simply pointing to the lack of agreement in global temperatures and whether the Earth has crossed a threshold. This here top-level RC post is also indirectly adressing the question by pointing out that there’s no agreement to what caused the current temperature spike. Neither is there a consensus for the causative mechanisms behind El Nino & La Nina transitions, of which this lack of understanding is not routinely pointed out. So both wobbbly baselines and wobbly understanding are coming under scrutiny. Scientists ask the tough questions because solving challenging problems is how they earn their stripes. So she’s kind of doing what she was trained to do. OTOH, the gatekeeping that Piotr is trying to do is reaching the absurd levels of the Monty Python unladen swallow Bridge of Death skit.
Out now in Earth System Science Data journal the final version (June 5, 2024) report by Forester et al on 2023, plus links to a guest post in Carbon Brief on June 5th by Prof. Forester & Dr. Debbie Rosen on the findings and the June 5th AP News article that first alerted me to the report on their findings:
.
https://essd.copernicus.org/articles/16/2625/2024/essd-16-2625-2024-discussion.html
.
https://www.carbonbrief.org/guest-post-tracking-the-unprecedented-impact-of-humans-on-the-climate/
.
https://apnews.com/article/climate-change-accelerating-record-hot-deadly-434881547b4585a32fa906cf5495d3f0
.
EarthSystemDynamics
@EGU_ESD
5h
Discussion open for comments on @EgUsphere:
Modeling 2020 regulatory changes in international shipping emissions helps explain 2023 anomalous warming
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1417/
NK: Discussion open for comments on @EgUsphere:
Modeling 2020 regulatory changes in international shipping emissions helps explain 2023 anomalous warming
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1417/
BPL: Thanks to Ned for posting this interesting link.
Dan Visioni
@DanVisioni
54m
Here we are: our discussion paper estimating the climatic impact of reduced shipping emissions in fully-coupled CESM simulations is out. We find a substantial contribution that can largely explain most of the 2023 anomalous temperatures…
First, we find that CESM finds a consistent radiative forcing contribution of 0.2 W/m2, perfectly in line with most estimates already out there. We also find that this can much better explain TOA imbalance compared to current CMIP6 scenarios…
We then look, month by month, at how likely the anomalous 2023 temperatures would have been leveraging the variability of the CESM large ensemble: for instance, we estimate that August 2023 temperatures have been made 9 to 27 times more likely to occur by the reduction (of IMO SOx Aerosols).
Lastly, by 2030, the overall contribution in GM temperatures is estimated in CESM at +0.2K: quite a lot! But we think the response is quite solid: what was most striking is that our results show a good match with observations, manifesting the temperature signal only after 2023..
This is still under discussion: if you think we did something wrong you’re welcome to leave a public comment in @EGU_ESD. There’s a lot more in the letter where we explain our methodology and compare against available observations.
Finally, let me remind of my discussion about who’s wrong and who’s right: it’s good to be skeptical of single modeling results, and only time will tell
But it is clear to me that there should have been much more discussion of this potential impact pre-2020: while the air quality impact is large, and there’s no doubt the IMO decision was correct, we knew since 2013 of its potential climatic impact, and yet it was seldom mentioned.
Imagine if we had been much more prepared and treated this as an opportunity to study the climate system more, by improving our observational & modeling capabilities and be ready in January 2, 2020. Or how it would have affected discussions of “every tenth of a degree matters”…
Includes figures graphs
https://nitter.poast.org/DanVisioni
Assistant Prof @CornellEAS studying Climate Intervention & aerosols across disciplines.
Yale Climate Connections Masters and Henson have a new post which covers some of the same material listed here (and cites this article). Research on Earth’s raging fever of 2023-24 is picking up: La Niña will most likely quell a stretch of global record heat, but human-produced greenhouse gases loom as large as ever.
https://yaleclimateconnections.org/2024/06/research-on-earths-raging-fever-of-2023-24-is-picking-up/
I just reread them both right through, and for this science-interested partially informed layperson struggling to internalize understanding of all this weirdness, it seemed to help. The crossover between theory and understanding is particularly rich in interest, even were the problems hypothetical.
But the problems are not hypothetical, they are urgent. What we need is not crypto and AI and more products selling convenience and consumption, but a wholesale return to caring and sharing with respect for our finite planet’s limits. Billionaire envy and quick buck influencers need to be cut loose from access to power. We are not going to be rescued by quick fixes but by the hard work of cultivating our garden. Oh well … I digress.
Can you add Rantanen et al (2024; https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/asl.1216) among papers focusing on internal variability?
Here is an accounting of some other recently released papers that are yet to be listed, as of the afternoon EDT on June 6.
——————————–
Related to Hunga Tonga Hunga Ha’apai
The one I posted above (one downside of this one is that they do not include the contribution of aerosol negative forcing, they say that the effect is negligible):
Long-term climate impacts of large stratospheric water vapor perturbations.
https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-23-0437.1/JCLI-D-23-0437.1.xml
Key conclusion:
Global mean surface temperature anomalies (including SSTs) are 0.032±0.022◦C with this model, which is again very close to the 0.035◦C estimated by Jenkins et al. (2023).
——————————–
Related to IMO shipping aerosol reductions:
Courtesy of Zeke Haufather on Twitter
https://nitter.poast.org/hausfath/status/1798406091543650376, he did post one of the listed ones above in the OP (Quaglia and Visioni), but also added these:
Multi-model effective radiative forcing of the 2020 sulphur cap for shipping (Preprint)
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1394/
From abstract:
The model means of the ERF range from 0.06 to 0.09 W m-2 corresponding to the ERF due to the increase in CO2 concentration over the last two to three years.
and notes of another paper by Gettelman et al that should be out shortly in Geophysical Research Letters:
Gettelman, A., Christensen, M. A., Diamond, M. S., Gryspeerdt, E., Manshausen, P., Sieir, P., Watson-Parris, D., Yang, M., Yoshioka, M., and Yuan, T.: Has Reducing Ship Emissions Brought Forward Global Warming?, Geophys. Res. Lett., submitted, 2024
finds 0.12 w/m^2 forcing and a relatively small temperature effect (~0.03C in 2023)
From: Simulations and Analysis In Support of “Has Reducing Ship Emissions Brought Forward Global Warming?”
https://zenodo.org/records/10724917
The comparison with the annual increase in CO2 forcing (which has been running at +0.03Wm^-2/y for the last decade) should also account for all the extra long-lived GHG forcing (thus the total boosted to +0.04Wm^-2), and presumably a reduction in negative forcing from reduced global pollution would also add to an underlying increase in annual forcing.
This total solar irradiance (TSI) graph in the opening text should be obligatory reading to all those “ It’s not us, it’s the Sun, stupid!” folk. Although we shouldn’t count that they will read the fine print, so we should divide the [numbers] by 4 and multiply by 0.7″ for them, and then ask them how do they reconcile:
1. the 0.8C difference between 2023 and 2000, with the increase in solar irradiance/m2 of Earth over the same years of … 0.05 W/m2.
2. that 0.05 W/m2 being about 60 times SMALLER than GHG forcing.
3. the fact that TSI oscillates/i> over that period, yet global T anomaly shows a clear rising trend – i.e. that global T rises when TSI increases, and global T rises when TSI decreases.
Maybe our experts in correlation, Victor and Keith Woollard, will explain it?
Inconvenient truths?
Ed Hawkins @ed_hawkins
Climate scientist, NCAS/University of Reading | IPCC AR6 Lead Author
In discussing M Mann’s recent sojourn on YT says about the errors and confusion presented:
“Baselines are one of the largest sources of confusion when trying to compare observations & models, and in thinking about how to produce projections. There is no perfect choice, mistakes are easily made & it is never as simple as often implied. Clarity & transparency is critical.
hi Gavin
i see only the html text when I clink on this link
https://svs.gsfc.nasa.gov/4908/
Gianpaolo
[Response: Weird. I get the full page. Maybe try a different browser? or reload? If it persists, contact them since it might be a problem with their site. – gavin]
Published: 15 March 2001
Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997
https://www.nature.com/articles/35066553
Um, like Doh!
Tomáš Kalisz 1 JUN 2024 AT 2:35 PM “temperature may strongly depend not only on the changing power input (Earth energy imbalance, EEI), but also on the extent in which the absorbed excess energy is dissipated / distributed in the ocean”.. I dislike this Backwards Logic I’ve heard from climate scientists for 11 years. Let’s stay close to Basic Physics.”absorbed excess energy” is Backwards Logic. I just happened yesterday on GoogleyTube to complain in comment about that for a nice Levke Caesar talk (not much coincidence, I complain non stop everywhere). Here’s cut’n’paste: My “colder than 15 degrees” is rough, it’s a comment for concept with approx.. quantity to give it clarity.
——–
I’m going to complain about the Junk Thermodynamics Public Outreach of oceanographers which Levke gives at 27:04 to 27:15 here. It’s the standard dumbing-down for the public that oceanographers do, a totally-nonsensical meme that’s so obviously incorrect that a person would need to have no physics education and minimal brain function not to instantly recognize it as nonsense. I heard Heidi Cullen say that same rubbish (to politicians I think) about the “pause” or “hiatus” and that annoyed me. The “pause” or “hiatus” was NOT “More heat going into the ocean instead” but was “More coldness coming OUT OF the ocean”. The oceanographers for decades insist on saying the thermodynamics arse backwards in the most appropriate crude way because the digestive system is the perfect analogy. If you push something in then something comes out because space is limited. If you push more water into the deep ocean then more water must COME OUT OF the deep ocean. It is NOT the pushing of heat into the ocean “instead of using it to warm the surface” that cools the surface but rather it is the pushing of WATER VOLUME (not heat) into the ocean that cools the surface by forcing colder deeper water out of the ocean to the surface. This is so patently obvious that it’s annoyed me for 11 years that oceanographers like Levke here, Heidi Cullen 10 years ago and all of them in talks always say this nonsense rubbish anti-physics meme. They should stop doing that thermodynamic rubbish and get some accurate phrasing to say. Sheeesh. The air and land have ~no thermal capacity so if the heat is going into ocean instead of heating air then its preventing Earth’s air from heating to 200 degrees or 300 degrees or something, it ABSURD rubbish. The surface-air temperature is actually set on multi-decadal to a few centuries time scales by these 3 simple things:
– Power of “sunlight” absorbed
– Power of Earth’s radiation to space
– Power of water colder than 15 degrees rising to surface
And nowhere in those is “getting heat from the atmosphere, extracting that and getting it into the deeper ocean so in a way it’s also important for cooling the atmosphere” so stop that rubbish you oceanographers, review your school physics notes.
On ultra-short time scales such as 18 months the surface-air temperature is geatly adjusted upwards by an El Nino but that’s blips that soon go back to where they were. I think perhaps those “ocean heatwaves” probably do that also, but again sporadic and short lived. I’m considering the surface-air to include 90 m top layer of ocean because “sunlight” mostly gets absorbed into the ocean film of several metres and then quickly exits to warm air so my “Power of water colder than 15 degrees rising to surface” is actually “Power of water colder than 15 degrees rising to ~90 m or less below surface”. The “ocean” for these circulation topics is the ocean below 90 m (97.5% of it).
Nice rant, Barry. From a physics/thermodynamics perspective, the cooling from La Ninas is much easier to understand than the warming from El Ninos. During a La Nina, the deeper colder water nears the surface as the thermocline is raised in the eastern Pacific (i.e. upwelling). This creates a huge heat sinking effect thus dropping the temperature in that region. El Nino is the opposite of this. There is a natural tilt in the thermocline that exists east to west, independent of El Nino/La Nina, due to Earth’s rotation and the Coriolis effect. So during El Nino events, the natural tilt in the thermocline across the equatorial Pacific Ocean is partially compensated (i.e. thermocline flattening), leading to less heat sinking overall and an increase in temperature.
In this qualitative context, cold is a heat sinking effect, and so hot is a lack of heat sinking.
Yet, these are mere words and thus lacking in quantitative value — to that end, the exact dynamics of the ENSO behavior can be solved via the solution of Laplace’s Tidal Equations applied to the equatorial thermocline waveguide. Everything, including the erratic cycling of the standing wave dipole & higher mode harmonics, can be modeled and cross-validated via this approach. Bottom-line is that an external mechanical force is required to achieve the cycling and that’s the long-period tidal forces applied to the reduced gravity environment at the thermocline.
A general query (not dedicated to the proffered topic):
now that LLMs and AI modeling are off and running, who has been charged with (or who is taking up the challenge of) training an LLM or AI model in all the relevant metrics and analyses pertaining to climate change–everything (atmospherics, biospherics, cryospherics, hydrospherics, lithospherics), and using all the histories of data refinement and refined and proper methodological applications and analytics?
Is this task only something the IPCC has the personnel and the deep pockets for? Is some kind of collaborative academic project underway?
Will any such system be contributing substantively to forthcoming IPCC (and RealClimate) publications and notifications sooner rather than later?
Edward Burke
That would be Google (w/GraphCast) and NVIDIA (w/FourCastNet) , the latter just annoited the most valuable company in the world, with a market cap of $3.3 trillion (https://www.nytimes.com/2024/06/18/technology/nvidia-most-valuable-company.html). In China, it’s the IT conglomerate Huawei with their PanguWeather AI technolgy.
Of course, together they don’t stand a chance against me, as MNFTIU.
As I understand it, the IPCC has neither. Their headquarters and permanent staff occupy a small space donated by the WMO, and per this document their annual budgets run from ~5 million to ~10 million Swiss francs. (Which, in turn, are worth about $1.10 US.)
The Assessment and Special Reports are produced pro bono by volunteer scientists, who are reimbursed for costs.
Piotr 6 JUN 2024 AT 7:03 PM “To become important to climate CHANGE, these oscillations would have to: 1. be CHANGING in a systematic way (say, El Nino phase longer and stronger)”. There is my broken-record 1-trick-pony thing I been posting since late 2013 (updating a tad):
In late 2013 I found a tropical Pacific wind speed plot which was absent trend for many decades and trend started 1995. In early 2013 I had plotted GMST 1962-2012 with separate symbols La Nina, ENSO-neutral & El Nino and found
+0.165/decade with a nice eye ball it for La Nina, ENSO-neutral but a (messy) 0.20/decade 196?-1995 & 0.23/decade 1995 for El Nino. Then February 2014 this was published: Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus Nature Climate Change 4, 222–227 (2014) doi:10.1038/nclimate2106 Corrected online 14 February 2014 Matthew H. England, Shayne McGregor, Paul Spence, Gerald A. Meehl, Axel Timmermann, Wenju Cai, Alex Sen Gupta, Michael J. McPhaden, Ariaan Purich & Agus Santoso “Here we show that a pronounced strengthening in Pacific trade winds over the past two decades—unprecedented in observations/reanalysis data and not captured by climate models—is sufficient to account for the cooling of the tropical Pacific and a substantial slowdown in surface warming through increased subsurface ocean heat uptake.”
——–
Quote: “Atlantic warming turbocharges Pacific trade winds Date:August 3, 2014 Source:University of New South Wales. New research has found rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds. Currently the winds are at a level never before seen on observed records, which extend back to the 1860s. The increase in these winds has caused eastern tropical Pacific cooling, amplified the Californian drought, accelerated sea level rise three times faster than the global average in the Western Pacific and has slowed the rise of global average surface temperatures since 2001. It may even be responsible for making El Nino events less common over the past decade due to its cooling impact on ocean surface temperatures in the eastern Pacific. “We were surprised to find the main cause of the Pacific climate trends of the past 20 years had its origin in the Atlantic Ocean,” said co-lead author Dr Shayne McGregor from the ARC Centre of Excellence for Climate System Science (ARCCSS) atthe University of New South Wales.”
——-
I tried to find that wind speed plot or an updated one but I’d lost the reference and can’t find anything extended beyond 2012 anyway so I don’t know what the situation was after 2012 but it was an ongoing trend 1995-2012 at least, covering some ENSO cycles.
Wind is what’s referred to as a confounding variable in the attribution of ENSO events. The initial changes in SSTs and thermocline levels are more likely driven by oceanic processes, primed by external influences such as tidal and seasonal forcing. Wind patterns respond to these initial changes and then act to amplify and sustain the SST anomalies through a positive feedback loop. Therefore, while winds play a role in the development and intensification of El Niño and La Niña events, they are part of a feedback mechanism rather than the primary causative factor. At best, the interplay between oceanic and atmospheric processes creates a more complex system where multiple feedbacks, including perhaps global warming, contribute to the overall dynamics of ENSO. As everyone in this forum is highly aware of the role of GHGs such as CO2 acting as a feedback mechanism in climate change, it’s odd that wind is not treated the same way with respect to ENSO.
But of course, these are just words. If g(t) is a seasonally impulsed tidal forcing then ENSO = f1(g(t)) and AMO = f2(g(t)) and PDO = f3(g(t)), where f1, f2, f3 are different LTE standing wave mode modulation functions. LTE standing wave modes are solutions to Laplace’s Tidal Equations, a simplified form as described in Mathematical Geoenergy (Wiley/AGU, 2018). Oceanic climate indices are a rich source of data for cross-validating such models. I don’t even treat wind as a driving factor, as it is subsumed as an amplifying scale factor, to first-order invariant across the time interval that ENSO and the other indices have been measured.
in Re to Paul Pukite, 24 Jun 2024 at 8:05 AM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822907
Dear Dr. Pukite,
If I understood your posts correctly, your theory enables a more precise accordance between predicted and observed tides (particularly on sites with extreme tides like Bay of Fundy) than other models, am I right?
Further, it is my understanding that you assume that tides contribute to mixing of the less dense surface water with deeper layers and thus to the pace of heat distribution in ocean, am I right?
If so, I could indeed imagine that periodical changes in tide intensity might trigger more-less periodical changes in heat exchange between land and ocean known as ENSO, PDO, and influence also further processes linked to ocean streams and climate.
I am, however, uncertain if you already explained (or not yet) if the assumed relationship between tides and ocean mixing intensity on one hand and the climate on the other hand is relatively simple and straightforward (e.g., that in a situation when the Earth releases less heat than absorbs, a stronger mixing causes heat accumulation in the ocean, whereas a weaker mixing causes heat release from the ocean), or if it is much more complex.
Furthermore, I would like to ask if your theoretical models of ocean fluid dynamics already are mature enough for an implementation into climate models?
I think that it could be very interesting to see if such “tidally upgraded” climate models, when tested on predictions of the present climate starting from more or less distant past, will achieve a better fit with observations than state-of-art models.
Could you comment on a quite basic level?
Thank you very much in advance and best regards
Tomáš Kalisz
Paul Pukite: As everyone in this forum is highly aware of the role of GHGs such as CO2 acting as a feedback mechanism in climate change, it’s odd that wind is not treated the same way with respect to ENSO.
that’s because that “everyone” knows that GHGs such as CO2 acted as a feedback mechanism ONLY during some NATURAL climate changes – like those during the glacial cycles. For the CURRENT AGW, on the other hand, feedbacks of GHGs with temperature are dwarfed by the increases in GHGs due to human activities (“forcing”).
And there is an obvious test to verify the truthiness of your claim:
if CO2 and CH4 were indeed mainly feedbacks then the same increase in T must have resulted in the same increase in CO2 and CH4. It hasn’t: during the peak of the last interglacial, with temp. almost identical to today’s,:
CO2 was = 285 ppm, now is = 420 ppm,
and CH4 was = 700ppb, now is = 1930 ppb
Ergo, the vast majority of the increases in CO2 and CH4 was NOT due to feedbacks. but caused by an external force (humans) and thus CO2 and CH4 are a major forcing, NOT a merely a feedback
A classic feedback is where the strength of a specific time-series response doesn’t change it’s pattern but is simply amplified, or that peaks or valleys are specifically amplified/attenuated. The latter would be a non-linear effect.
CO2 does this by self-amplifying through the Arrhenius temperature rate laws or cross-amplifying H2O which is also fed-back via outgassing rate laws,
As for ENSO, there could be some feedback with wind, and obviously Bjerknes atmospheric cycling feedback, but one has to realize that this will not necessarily change the underlying time-series pattern. Perhaps this is over-simplifying, but HiFi audio gear is a feedback-based amplifying system where you pay big $ so that the input time-series is not distorted as an output. There are also non-linear companding systems that are used to reduce noise — tho the underlying pattern is not changed.
That being said, the foundation of my Laplace’s Tidal Equation (fluid dynamics) formulation applies non-linear manifold mapping on the input forcing — on the verge of being unrecognizable but retaining vestiges of the input pattern. I cut my teeth on this kind of stuff early on in my lab research and am not intimidated by these kinds of problems. CO2 forcing is child’s play in comparison.
Barry E Finch: “ the cooling of the tropical Pacific
Interesting. Unfortunately for our Paul, this change points in the exactly wrong direction – ENSO and the tropical Pacific were supposed to be indispensable to explain global WARMING, not cooling.
Paul Pukite 24 JUN 2024 AT 8:05 AM Could be what you say as far as I know (not much) because I can’t find it nonsensical. What’s missing from yours is wind-driven sea surface height (SSH) of the western tropical Pacific wrt eastern tropical Pacific. In an ENSO talk in 2014 Kevin Trenberth mentioned that western SSH was 1.2 m higher than eastern SSH due to the wind push and Kevin implied that something’s gotta give (of course there was a 2015/2016 El Nino. I can only run to an opinion that it’s physically impossible for wind to push western SSH to a couple kilometres higher than eastern SSH so there are 2 only possible outcomes (1) A steady state evolves for centuries-millennia with western SSH x metres higher than eastern SSH and a deep return current as per the thermohaline circulation but the wind-driven word or phrase that scientist lady used in a Webinar talk I heard few years when she was apportioning AMOC to thermohaline and the snazzy wind-driven word or phrase that I’ve forgotten (2) A Boom’n’Bust cycle becomes the situation. The other end to the starting ENSO tidy thing is what causes collapse because if there’s collapse then the wind doesn’t have to push as hard to pile up the water, so it can therefore get going again; I have a vague recollection of somebody saying something out of the Indian Ocean collapses the La Nina phase.
Barry,
The proof is in the pudding. Tides have a built-in reference point in which to compare models against data. No such reference for winds — anytime wind is mentioned as a cause, all that one can do is do a contemporaneous correlation and say “yup, the wind agrees with the buildup east vs west”. So what … that’s like invoking something as elementary as the ideal gas law, as wind will automatically flow from a high-pressure cold region to a neighboring low-pressure warm area. Local sea level will also rise or lower according to the inverse barometer effect, so don’t need wind to “push” anything. (Yes, me being a lake person from Minnesota, I’m well aware of water piling up on the windward shore of the lake but, jesus, that’s not the same as an ocean).
Bottom line wind doesn’t explain an underlying cause, just an invariant of a thermodynamic system, with likely some feedback implied but not as a root cause.
In contrast, I solved Laplace’s Tidal Equations and applied a particular formulation of seasonal-assisted tidal forcing to see if it could actually match the patterns in ENSO/PDO/AMO/QBO observed. As I pointed out in my late 2018 Wiley publication, it’s not difficult to generate realistic tidal forcing, but more to the point, one can do cross-validation by fitting to any interval of the time-series and extrapolate an excellent correlation elsewhere.
https://geoenergymath.com/wp-content/uploads/2024/06/image-18.png
Barry said:
Same here, as I admit to going on and on about my findings, starting in 2014 in my case. Believe me, I would have given up on this crusade long ago, if it was just a rhetorical narrative re-iterated over and over again. That’s tiresome stuff and don’t understand how people can keep that up on a long-term basis (unless they were being paid to do it). But quantitative results are different — if the numerical cross-validation keeps getting better over time, it becomes more and more interesting, and far from being a tedious exercise in rephrasing talking points.
One thing I do is place all my results and model data on GitHub or GitHub’s GIST. I understand how machine learning and web-scraping works and look forward to an ML experiment grokking all the info and spitting out something even better. I will likely pull the trigger at some point and see what comes out. Exciting times ;)
in Re to Paul Pukite, 28 Jun 2024 at 11:30 AM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822947
Dear Dr. Pukite,
I would like to remind you of my questions asked on 25 Jun 2024 at 10:39 AM,
https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/#comment-822918
I suppose that you could comment also with respect to present contributions by Jan Umsonst who cites among others also three publications pertaining to increased heat accumulation in ocean surface waters and increased ocean stratification:
https://www.nature.com/articles/s41467-023-42468-z
https://www.nature.com/articles/s41467-024-48381-3
https://www.nature.com/articles/s41558-024-01958-8.epdf?sharing_token=B2dI0Ns1CrjwZLvlwyD9mNRgN0jAjWel9jnR3ZoTv0MItjsDAN0Drhv6DBIA9rRX0cef0k6BZE8GL0sADVWWx9DFC6CWo-3mi6B5xXdxPb6delUYKOpCC86DAihKC0z086r2Iy6hV-jJsaQzEwTHdSC8ePQ79d_mM6aiU17csnpGgCT_98yJ_tphkOJxnwXyXN7qbElOV49ybLzyBEbbci4yfviZzzeyyDDT6_Rt4jY%3D&tracking_referrer=www.realclimate.org
Best regards
Tomáš Kalisz
Hi all, thx Gavin, here two studies I think important to solve the issue:
The first a preprint: “Recent global temperature surge amplified by record-low planetary albedo”; https://arxiv.org/abs/2405.19986 – they estimate the effect of increased shortwave absorption that went through the roof in 2023 to be around 0.2°C – likely sea ice and clouds.
And this one is a complementary:
“Observational Assessment of Changes in Earth’s Energy Imbalance Since 2000”; https://link.springer.com/article/10.1007/s10712-024-09838-8?fbclid=IwZXh0bgNhZW0CMTEAAR3yxlEJwGCiPcaKayLfx8FPNOvA5GSISGvKRVeaM-gceSrdGgB1G5c0VhY_aem_ATHBHHmAlfdxAT0aKxjcBCbmTmv_YfQVih5uJ2MXsVrKzhaAz3jyM4U_CNF0R5bMGBzVXBiAZMVtF1o6RzAeYSn2
They tie the cloud feedback to higher SST’s and we had widespread marine heatwaves across the oceans in 2023.
Further, we had a cloud feedback over the drying out Amazon in 2023 and over Northern Canada.
Another aspect is the the postive Indian Dipole in 2023 which increases the latent heat loss from the Indian Ocean – should have also contributed to the warming in 2023. Further, in the Albedo study it is shown that also cloud cover declined over the colder part of the positive Indian Dipole – so an additional effect.. Think it should be included.
Next aspect is that we had an increase in water vapor by about 5% during the exceptional warm months in 2023 – here from NOAA there you can see it: https://psl.noaa.gov/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Precipitable%20Water&level=2000&lat1=90&lat2=-90&lon1=0&lon2=360&iseas=0&mon1=0&mon2=0&iarea=1&typeout=1&Submit=Create%20Timeseries&fbclid=IwZXh0bgNhZW0CMTAAAR1YNlLwrCP8mvTkKTMWH3kLaX6qVpa3uIr5VbriKMsuoDnrisJWd49gY4Y_aem_Ad7JdELRSpOsWMlBmq-ezvxrbOHR8MNkdRJcV1CeQbiMkHGyOoVrCeBQbjNqAliajsZQlsuv2tF7bbzDRKhecX6D maybe also a noteworthy contribution.
Then I think the temperatures across the Antarctic had an effect which should be included – just the heat wave in September was mindblowing – and this is connected to sea ice losses – so sea ice losses in 2023 get leveraged by supporting warm air intrusions into Antarctica – had been several exceptional warm months over Antarctica – so this should be included.
Then there exist studies on an increase latent heat loss over the western boundary current regions due to cold and warm core eddies – maybe also something. “Midlatitude Mesoscale Thermal Air-sea Interaction Enhanced by Greenhouse Warming”; https://www.researchsquare.com/article/rs-3932615/v1
Then there exist a study on how marine heatwaves across the mid-latitudes release heat during autumn when the atmosphere gets colder and winter storms start to form over the North Pacific and Atlantic. And as these marine heatwaves had been exceptional in 2023 this should have also had some effect..
Another candidate is the non-linear soil-moisture temperature cascade over the dried out continental regions in 2023 which had been quite strong in 2023 – e.g. Amazon and northern North America.
If you are interested in any of these where I did not link the studies I can look for the studies which I have somewhere :D
An unlikely candidate are expanding mode waters that warm and freshen across the mid-latitudes at depths of >150m which could have been mixed to the surface to some extent as the low-pressure systems had been quite strong in autumn winter of 2023 – but like I sad unlikely but still also a possibility. Here they raise the possibility: “Recent acceleration in global ocean heat accumulation by mode and intermediate waters”; https://www.nature.com/articles/s41467-023-42468-z – interesting here that we do now understand that the intensifying ocean fronts of the western boundary current fuel the formation of low and high pressure systems and the hydrological cycle over these regions – so this could be connected to intensifying low pressure systems over the mid-latitudes in the autumn and winter of 2023 – if they had been exceptional strong during 2023 in this season – do not know but at least in the North Atlantic they seemed quite extreme in 2023.
I think the warming in 2023 can only be explained by taking an holistic stance on the Earth system as there had been many systems contributing so some extent to the warming.
Further I think the effect of the El Nino was quite small in 2023 – this is explained in this study:
“Forecasting Tropical Annual Maximum Wet-Bulb Temperatures Months in Advance From the Current State of ENSO”; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL106990
Just some speculation from me – but one thing is for sure: the temp. jump in 2023 was driven by many systems which marine heatwaves and the cloud feedback and latent heat release towards the colder months maybe the largest reason – really strong cloud feedback…
Lots of observational studies now out there…
All the best
Jan
Hi Gavin, a headline “marine heatwaves” is warranted to explain the heating in 2023 – SST’s had been exceptional and marine heatwaves where to blame. And here are two studies which I waited for some years now to be published as it is observed my various studies on MHW’s that a shallower mixed layer depth and increased stratification is one of the meta causes of marine heatwaves. And both studies argue that we amplified the seasonal cycle of mid-latitude oceans via increased upper ocean stratification and mixed layer depth.
Here we go:
“Human-induced intensified seasonal cycle of sea surface temperature”; https://www.nature.com/articles/s41467-024-48381-3
“The emerging human influence on the seasonal cycle of sea surface temperature”; https://www.nature.com/articles/s41558-024-01958-8
There exist studies that found an increase in mixed layer depth over the oceans. But they can not explain how it is possible while upper ocean stratification increases which they state (at least one does it). So its likely a reanalysis dataset chaos.
There exist also another study on mixed layer depth in the North Atlantic and North Pacific which saw an increase in mixed layer depth – but the graphs showed an increase till the Hiatus and then an increase.
Just want to say that the increases in stratification of the upper ocean is serious stuff especially in regard to the non-linear expansion of marine heatwaves that covers during 2023 at their peak more than >40% of the global ocean surface.
Just from the signal its obvious that marine heatwaves are a feedback of global warming likely because we warmed then too fast from the surface as heat takes more time to reach the deeper ocean than it is accumulated over the first 300m (0-700m).
Its a simple realization that a slow global warming has nothing to do with a fast one, as the speed of the warming is non-linear related to the strength of the positive feedbacks that speed up the warming. And upper ocean stratification, mixed layer depth, marine heatwaves, reduced heat uptake, and accumulating warm blobs of water freshening which come up again to the surface (happened already two times) are at the forefront of the above principle. And 2023 was likely the first strong signal which will increase in magnitude as we continue our mad course…
All the best
Jan
Ok a last one as it is also important – in 2023 stratification of the upper ocean went through the roof –
“New Record Ocean Temperatures and Related Climate Indicators in 2023”; https://link.springer.com/article/10.1007/s00376-024-3378-5
Important info here: the marine heatwave off the west coast of Africa that formed in end of March 2023 that persisted till two weeks ago could have produced the signal of OHC anomalies which increased in exactly the area over the first 300m by 0.36 Gjm2, but over the first 700m only by 0.4 Gj/m2 accordingly to Copernicus and ORAS5.
“Ocean heat content”; https://climate.copernicus.eu/climate-indicators/ocean-heat-content
Just for the ones who are interested in this interesting signal we had there – just to underline the importance marine heatwaves could have.
Here I have some pictures of this marine heatwave in the eastern North Atlantic persisting off west Africa well into the Atlantic…
https://www.facebook.com/Erdsystemforschung/posts/526740883039493?ref=embed_post
Just to make my point why marine heatwaves should be included as one of the causes for the extreme warming in 2024!
My reasoning is simple. Without understanding the further development of the marine heatwave signal at the surface and subsurface oceans and their cascading effects it won’t be possible to model global warming… So better include it in the discussion…
All the best
Jan
Umsonst Jul 8: Without understanding the further development of the marine heatwave signal at the surface and subsurface oceans and their cascading effects it won’t be possible to model global warming… So better include it in the discussion…
You may be inventing a wheel – AOGCMs (Atmosphere/Ocean General Circulation Models) used in most of the current climate modelling – already contain many layers of the ocean, hence the penetration of the heat into the surface and subsurface layer and its influence – are being modelled and compared with available observations.
There are dozens of threads on Real Climate and 100s? , 1000s? publications – on where the heat goes in the ocean.
See also pages for the general public, like https://climate.nasa.gov/vital-signs/ocean-warming/?intent=121
Just on fun fact here as I always go with the scientific literature:
Today’s ocean models can only simulate less than 5% of the currents at 1,000-meter depth
“Widespread global disparities between modelled and observed mid-depth ocean currents”; https://www.nature.com/articles/s41467-023-37841-x
Another fun fact: we just started recently to really check in how far models simulate the spatial pattern of the observed subsurface ocean heat accumulation – at least it was mentioned by one recent study…
And if I learned one thing than that the most important ability is to realize ones mistakes, correct them, and move on as ones mistakes are the most important part of the learning process…
All the best
Jan
Umsonst: “ Just on fun fact here as I always go with the scientific literature: Today’s ocean models can only simulate less than 5% of the currents at 1,000-meter depth”
Fun fact – horizontal currents at 1000m have only marginal relevance to vertical penetration of heat from the atmosphere into the ocean, particularly to your “ the marine heatwave signal at the surface and subsurface oceans”
U: Another fun fact: we just started recently to really check in how far models simulate the spatial pattern of the observed subsurface ocean heat accumulation – at least it was mentioned by one recent study…
Another fun fact – “ one recent study” proves nothing. Come back when you read MANY studies and you are able to prove that their observations have spatial and temporal resolution to be sufficient to test the models.
U: If learned one thing than that the most important the most important ability is to realize ones mistakes, correct them, and move on
You have skipped the most important FIRST step – being able to PROVE that these are indeed mistakes.
So far – you have not proved that.. What you proved, with your confident yet unsubstantiated claims, that you haven’t learned arguably the most important thing in science: humility and self-skepticism (see Socrates: “I know I know nothing”)
When I see something that looks to me like other people making mistakes – my FIRST response is to check whether I am not making mistakes, NOT to assume that I am so clever that without knowing much about subject I still have figured out what the experts in the field failed.
You, like some others before you (T. Kalisz, JCM, Killian, Shurly), seem to operate on the opposite principle. Not a particularly constructive, nor endearing you to the readers, approach.
Hi Gavin, as i find this temperature jump in 2023724 so important and the feedback cascade highly fascinating just some more points and studies which I find important:
1: Earth-system science is at a cross road – SSTs drive global warming or they do not! If its the later MHWs expansion and related feedbacks ongoing till today have to be included in the assessment of the ongoing temperature jump.
2: The temperature jump of the last 12 months has to be studied by the months as otherwise important monthly signal are left out of the assessment e.g. sea ice losses around Antarctica and the related exceptional heatwave over the entire ice shield, and the exceptional temperature jump in Sep. 2023.
3: If you go by the month the exceptional temperature departures in the single ocean basins have to be studied, as we have in single months other regions that developed exceptional temperature peaks, most noteworthy the astonishing signal across the tropical oceans of the Atlantic and Indian Ocean which are likely feedback driven.
4: Intensifying ocean fronts and temperature patterns in several ocean regions are known to produce a latent heat release signal operating also on a seasonal basis with related peaks. Also this global warming signal is intensifying which should be included on a seasonal base, as it could have had a non-neglect temperature signal.
5: Global warming now increasingly overcoming natural variability of SSTs is another component that should be put into focus. Not only that currently close to the entire North Pacific and Indian Ocean are above the 1981-2011 average, also the same we have over close to the entire Southern Ocean.
6: The possibility of a heat release by expanding, warming, and freshening mode waters during the winter months in both Hemispheres should be explored as we could also have had here a signal, especially in 2023/24 across the mid-latitudes and subpolar oceans of the NH. They accumulate in >150 depths. So maybe here a signal possible. This falls under in how far warming in the pipeline in the oceans had been involved in the current temperature jump.
And last some more studies which I see important to solve this puzzle:
“Attributing daily ocean temperatures to anthropogenic climate change”; https://iopscience.iop.org/article/10.1088/2752-5295/ad4815
“Long-term ocean temperature trend and marine heatwaves”; https://link.springer.com/article/10.1007/s00343-023-3160-z
As we had this astonishing SW signal in 2023:
“Energy Imbalance in the Sunlit Ocean Layer”; https://www.researchsquare.com/article/rs-3979671/v1
While SOx emisison cuts in 2020 can be ruled out to produce such SW signal in 2023, they con not ruled out to have amplified the MHW signal in some areas (SOx leveraged cloud feedback by expanding MHWs):
“Distinct anthropogenic greenhouse gas and aerosol induced marine heatwaves”; https://iopscience.iop.org/article/10.1088/2752-5295/ad13ac
SSTs produce a lagged non-linear land temperature signal on the land masses (this will not only count for the tropics but also for the e.g. mid-latitude ocean fronts intensifying thereby producing a strong latent heat release signal):
“The influence of global sea surface temperature variability on the large-scale land surface temperature”; https://link.springer.com/article/10.1007/s00382-014-2332-0
Preprint of this possible important monthly signal for this exceptional temp. jump:
“Midlatitude Mesoscale Thermal Air-sea Interaction Enhanced by Greenhouse Warming”; https://www.researchsquare.com/article/rs-3932615/v1
This one is important piece to understand that marine heatwaves produce also a soil-moisture-temperature cascade which was quite strong in 2023 across the tropical to NH land masses:
“Drying of Indian subcontinent by rapid Indian Ocean warming and a weakening land-sea thermal gradient”; https://www.nature.com/articles/ncomms8423
This whole scientific discussion should be included as it has to be ruled out or included in the temps assessement of 2023/24 (for example the drying out Amazon in 2023 is clearly related to Ocean surface temperature pattern of the equatorial Pacific and Atlantic ocean in 2023 (other studies):
“Trends in continental temperature and humidity directly linked to ocean warming”; https://www.pnas.org/doi/10.1073/pnas.1722312115
This one is important to understand the the soil-moisture atmosphere coupling is able to produce a substantial warming signal over the land masses during the boreal warm months and tropics for the whole year:
“Soil moisture–atmosphere coupling accelerates global warming”; https://www.nature.com/articles/s41467-023-40641-y
In my opinion Earth system science has to face the reality that understanding the feedback character of 2023/24 is at best a messy business as the local to global operating feedback character of dozens of interacting subsystems has to be taken into account to understand the current development in the Earth system…
All the best
Jan
p.s. sorry for my äh writing but I’m not interested in grammar or spelling but just to understand the Earth system from a mechanistic perspective, therefore Gavin you have my livelong gratitude as it had been your blog some 20 years ago that showed me that studies are nice short and easy reads which then led to me, reading all these scientific discussions that seemed important for me to understand Earth as one system operating via thousands of subsystems – the easy part changed with time as all these physical ocean mixing stuff, atmospheric circulation mechanics gave me some real headaches ;)
U: SSTs drive global warming or they do not!
BPL: They do not. They are part OF global warming, by definition.
Hi Barton,
so we can rule out that surface oceans suddenly covered by >40% by marine heatwave did not produce a surface air temperature signal in 2023/24? Also a delayed one possible, as SSTs produce a lagged continental temp. signal (guess I linked the study in my former post).
If we can rule it out, and its proven by the existing scientific literature that marine heatwaves are only weakly related to surface temperatures, that they do not produce a significant positive cloud feedback, and do not enhance latent heat loss to the atmosphere when they dissolve, then I agree, and the MHW signal in 2023/24 should be discarded as a possible driver of 2023/24 temperatures.
But if this is not clear then we should include MHWs in our analysis, as we have to be sure before we rule them out or does science not function like that? I mean I wasn’t in University so I do not know, how could I?
All the best
Jan
p.s. four more studies which I find important to understand the complexity behind the 2023/24 temperature signal and why some possible feedbacks should be included as they feed on one another:
Two studies on the non-linear soil-moisture-atmosphere cascade and their warming potential (if the warm months from 2023/24 are analyzed on a monthly or seasonal basis then this feedback could become important – e.g. Amazon, North America, Arctic)
First study states that the soil moisture cascade could produce some 0.5°C of additional warming till 2100. This means that the effect could have been significant on a seasonal basis in 2023/24 (and be it 0.01°C – the different secondary feedbacks could add up in 2023/24.
“Soil moisture–atmosphere coupling accelerates global warming”; https://www.nature.com/articles/s41467-023-40641-y
Here a similar finding for the permafrost regions – also here a strong signal possible:
“Permafrost Cloud Feedback May Amplify Climate Change”; https://https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109034
Then why MHWs cause secondary feedbacks and thereby increase their effect on warming: warmer ocean surface temperatures could support declining humidity over the continents thereby strengthen the non-linear soil-moisture-atmosphere cascade:
“Trends in continental temperature and humidity directly linked to ocean warming”; https://doi.org/10.1073/pnas.1722312115
And here the third study I found that links the expansion of marine heatwaves during summer also on increasing stratification and declining mixed layer depth – this time a model study – this would make out of marine heatwaves a feedback of global warming, which behaves non-linear till today. So maybe better to study their effects on warming:
“Future Amplification of Sea Surface Temperature Seasonality Due To Enhanced Ocean Stratification”; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL098607
Just would be very happy if the temperature jump in 2023/24 would be studied by dividing it in shorter periods – or that the influence of the single feedbacks operating in different months would be studied over the seasons when they operate.
All the best
Jan
p.s. from a mechanistic perspective the first 12 month above 2°C are now well within reach of the Earth system to happen around 2030. One precondition has started now as ENSO went into recharge mode again (but maybe it will stop soon again, but I have my doubts). And if all the above holds to some extent true (further sea ice losses included) combined with mean warming the chances for a “year” warmed by 2°C are not too bad, as we speak here about a forced signal by various subsystems of Earth. And its inside the model spread if the running hot models are included or not?
Hi Gavin, sorry for my post – if I tyre you just do not publish is and I will stop :D
Here another important piece why the cloud feedback over drying out continents during the warm season is so important to include in the 2023/24 temperature feedback – this time permafrost regions:
“Here, we use simulations with the ICON-Earth System Model to show that such a drying increases regional temperatures via an atmospheric feedback: During the warm season, dryer conditions at the surface reduce the moisture transport into the atmosphere. This decreases the relative humidity in the boundary layer and the low-altitude cloud cover. Since clouds reflect more sunlight than the snow-free land surface, the reduced cloudiness increases the available energy, hence, temperatures and advances the thawing of the ground. Higher temperatures in the Arctic and subarctic zone, in turn, have important consequences for the net energy exchange between equatorial and polar regions. Thus, the effects of a large-scale drying of high-latitude soils may not be limited to the regional scale but could notably increase global mean temperatures.”
“Permafrost Cloud Feedback May Amplify Climate Change”; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109034
Umsonst: “the reduced cloudiness increases the available energy, hence, temperatures and advances the thawing of the ground.
But wouldn’t the thawing of the ground … increase the supply of liquid water for evaporation which by increasing cloudiness would offer a negative feedback, therefore limiting the potential to “notably increase global mean temperatures”?
P: wouldn’t the thawing of the ground … increase the supply of liquid water for evaporation which by increasing cloudiness would offer a negative feedback, therefore limiting the potential to “notably increase global mean temperatures”?
BPL: I think the latest evidence is that cloud cover is a positive feedback; the hotter it gets, the less cloud cover. I’ll see if I can find some citations.
BPL: “ I think the latest evidence is that cloud cover is a positive feedback; the hotter it gets, the less cloud cover – I’ll see if I can find some citations
I think this was the conclusion of the papers about CERES data. Further, one can deduce that from Lague et al 2023 we have discussed to death on RC in the last few months.
But that’s beyond the point, since I didn’t question this positive feedback between the reduction in clouds and warming, QUITE THE OPPOSITE – I actually based my criticism of Jan’s post on the reality of this feedback – by indicating that Jan’s “ the thawing of the ground ” is a negative feedback with T, because by providing moisture from melted permafrost for an INCREASE in clouds – it WEAKENS the positive feedback between reduction in clouds and T.
Globally there is an increase in water vapor. Not sure how this is represented by cloud cover. Floods are certainly getting much worse, and the distribution of drought/wet, often only a few miles apart, has increased, making dry drier and wet wetter.
Clement, A.C., Burgman R., and J.R. Norris 2009. “Observational and Model Evidence for Positive Low-Level Cloud Feedback.” Science 325, 460-464.
Dessler, A.E. 2010. “A Determination of the Cloud Feedback from Climate Variations over the Past Decade.” Sci. 330, 1523-1527.
“Estimates of Earth’s climate sensitivity are uncertain, largely because of uncertainty in the long-term cloud feedback. I estimated the magnitude of the cloud feedback in response to short-term climate variations by analyzing the top-of-atmosphere radiation budget from March 2000 to February 2010. Over this period, the short-term cloud feedback had a magnitude of 0.54 ± 0.74 (2s) watts per square meter per kelvin, meaning that it is likely positive. A small negative feedback is possible, but one large enough to cancel the climate’s positive feedbacks is not supported by these observations.
Both long- and short-wave components of short-term cloud feedback are also likely positive. Calculations of short-term cloud feedback in climate models yield a similar feedback. I find no correlation in the models between the short- and long-term cloud feedbacks.”
Just interpreting/guessing here, but I note the earlier conditional statement “during the warm season.” Perhaps that indicates a time when the ground has already thawed and dried, and the resulting humidity advected away? Seems plausible at first blush, at least.
Kevin McKinney: “ Perhaps that indicates a time when the ground has already thawed and dried, and the resulting humidity advected away?
Highly unlikely, given what Jan wrote:
1.Jan Umsonst: “ During the warm season, dryer conditions at the surface reduce the moisture transport into the atmosphere. This […] advances the thawing of the ground. advances the thawing of the ground. ”
I.e. he makes the point of ADVANCING thawing through the warm season, i.e. NOT something that was completed early on and as such – no longer takes places in warm season.
2. Plus the fact that he talks specifically about “the Arctic and subarctic zone” – i.e. the places where warmer summer temperatures WILL continue “ thawing of the ground until the cold season.
Good points! Continuing along the consideration of this scenario, though, if a warmer atmosphere is what’s thawing the frozen ground, then it must thaw from the top down. Which leads me to wonder in turn at which point or points in the process liquid water availability to the atmosphere is enhanced, and when it is not.
So, a scenario. I well remember spring ‘break up’ in Sault Ste. Marie, Ontario; humidity was high, and so was runoff. (A fact that nearly killed my brother, when he ended up in a raging torrent where normally a placid little creek trickled.) And I must imagine that one facet of this time is the fact that the ground surface is frozen, making the surface pretty impermeable. Water can’t be absorbed, which is the more subtle reason (after all that obvious snowmelt) why runoff is enhanced so much. During such a phase, you clearly did not have “dryer conditions near the ground.”
But fast forward a couple of weeks, and all that drama is over. The top several inches of ground are thawed and permeable; plants are growing at a rapid clip, and of course taking up water to do it. The frost line is sinking deeper and deeper into the ground, and continues until it reaches whatever depth the local frost line resides at. (In the Arctic, of course, it may reach the permafrost zone instead.) Either way, the soil is more and more permeable. Runoff decreases. The soil surface tends to dry, and dry the more readily the higher the temperature.
Snow may still exist in patches–even in the Sault, which is coldish but temperate, you might find–or at least, might have found when I was still a kid–snow patches in sheltered places with northern exposure well into June. Farther north, these are more common. But as such patches melt, the runoff reaches either streams, or permeable soils.
Perhaps this scenario can ‘square the circle’ we are facing with this seemingly counterintuitive model result of Jan’s. Please turn your analytic capabilities on it and see what you think!
Kevin: Jul 19: “ Please turn your analytic capabilities on it and see what you think!”
;-) I’ll try my best:
K: “ plants are growing at a rapid clip, and of course taking up water to do it.
Most of the water plants take up is not used up, but evaporated. Hence the growth of the plant INCREASES, not decreases evaporation.
K: “ The soil is more and more permeable. Runoff decreases.
except both are a good thing from the point of view of cloud formation: The runoff ends up in rivers and oceans. Evaporation from there depends on the SURFACE area, not the volume – and the surface area does not change all that much in rivers and almost not at all in the lakes and oceans. Therefore, the runoff is the MISSED opportunity to evaporate. Contrast this with the water absorbed by the soil – kept locally and gradually released into the atmosphere by the soli or plants growing there, thus allowing increased cloudiness. and providing negative feedback to temperature.
Or if you prefer an analogy – think of the Arctic ground as a sponge. If the sponge is frozen – all the water you pour in – just flows from its surface toward a sink. If the sponge is not frozen – it can absorb quite a lot of water and then gradually release its water into the air as evaporation – with very little, if any, lost to the sink.
In both cases – conclusion OPPOSITE to those proposed by Jan.
Thanks, Piotr! Well-reasoned once again.
But the ‘rapid plant growth’ slows down, too, with evaporation slowing down as it does. Call this “phase 2a.”
Then we get to “phase 2b,” in which we may–
Fair enough, but one may also contrast this basic case under two conditions: an average daily temp of 15C over an arbitrary nominal month, versus, say, 20C. I think I may have to break down and actually read the paper Jan posted–I have so far neglected that elementary step. I blame an invigorating discussion. But now I’m really curious about this. Your qualitative logic seems sound, if not necessarily covering the entire possible scope of the scenario, but then why would the putative effect show up in model studies? One question I want to look at now: what actually was the ‘independent variable’ in their experiment? “Drying?” Or temperature?
Kevin: “ But the ‘rapid plant growth’ slows down, too, with evaporation slowing down as it does. Call this “phase 2a.”
it’s still more evaporation (and more clouds) that you would have with the control case – the water not being there in the first place because it had run off into rivers and ocean.
Kevin Fair enough, but one may also contrast this basic case under two conditions: an average daily temp of 15C over an arbitrary nominal month, versus, say, 20C.
except it won’t test Jan’s claim about thawing of the ground being a positive feedback to AGW via reduced evaporation – for that would be unthawed ground.
Kevin Your qualitative logic seems sound, if not necessarily covering the entire possible scope of the scenario, but then why would the putative effect show up in model studies?
I am not sure it does – the idea of thawing of the ground being a positive feedback to AGW via reduced evaporation seems to be Jan’s interpretation of the paper results and as such, I have challenged it within its own logic.
_If_ the model study makes the same claim – then my challenge would apply there as well – to make a claim of a particular feedback – they need a proper control for that particular feedback (here: non- or less-thawed ground). Simply having a model showing that the cloudiness in the Arctic decreases with temperature does not offer such a control – since the possible effect of thawing is conflated with the effect of increasing temperatures on relative humidity and though it – ability to form clouds (the same evaporation from ground would produce less clouds at 20C, than at 15C).
Piotr, I’m going to have to read that paper to pursue this farther. Thanks for your analysis all the way along. If I actually get around to reading it, and if it provides more grounding for thought, and/or clarity regarding Jan’s hypothesis, I’ll report back.
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Dessler’s paper (Schoeberl et al.) recently moved from a pre-print to a peer-reviewed publication:
https://doi.org/10.1029/2024JD041296
https://doi.org/10.22541/essoar.171288896.63010190/v1
Commentary:
https://x.com/AndrewDessler/status/1816172792267551065
https://artsci.tamu.edu/news/2024/07/new-study-disputes-hunga-tonga-volcanos-role-in-2023-24-global-warm-up.html