There is a new paper in Nature this week on recent trends in ocean heat content from a large group of oceanographers led by John Lyman at PMEL. Their target is the uncertainty surrounding the various efforts to create a homogenised ocean heat content data set that deals appropriately with the various instrument changes and coverage biases that have plagued previous attempts.
We have discussed this issue a number of times because of its importance in diagnosing the long term radiative imbalance of the atmosphere. Basically, if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere – and that somewhere is mainly the ocean. (Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).
The main problem has been that over time the network of XBT probes and CTD casts has been replaced by the Argo float network which has a much greater coverage and more homogeneous instrumentation. However, connecting up the old and new networks, and dealing with specific biases in the XBT probes is difficult. An XBT (eXpendable Bathy-Thermograph) is a probe that is thrown off the ship and whose temperature readings as a function of time are transferred to a profile in depth from knowledge of how fast the probe falls. Unfortunately, this function is a complicated one that depends on the temperature of the water, the depth, the manufacturer of the probe etc. Various groups – working with the same basic data – have shown that there were biases in the XBT associated with incorrect calibrations and have attempted to make better corrections.
The latest paper is a consensus effort from many of the people involved in the previous work and shows how robust the recent decades warming of the ocean has been. Indeed, the ‘best estimate’ for the changes in the top 700m seems to be a greater warming than seen in the NODC data and more than even the models were suggesting:
Update (May 2012): The scaling of the model output on the original graph was incorrect, and the graph has been replaced with a corrected version. The original can still be found here.
One thing that is interesting to note is that the interannual variability – particularly in the transition period between the two observing systems (1995-2005 say) is very dependent on exactly how you do the corrections, while the longer term trend is robust. This ties in directly with comments by Kevin Trenberth in this recent paper and in an accompanying commentary to the Lyman paper that while the energy budget changes over the long term are explainable, the changes over short time frames are still very difficult to quantify.
As usual, this is unlikely to be the very last word on the subject, but this is more evidence that the planet is basically behaving as the scientists think it is. And that isn’t necessarily good news.
Re ice loss – for sea ice loss, you’d have to take a time integral over the year of the latent heat of melting * ice mass anomaly to find an annual average heat (enthalpy in this case) anomaly.
Borrowing a few numbers from 39 Brian Dodge,
0.334 MJ/kg * 917 kg/m^3 * 10^12 m^3 = 306.278 * 10^18 J / (1 million km^2 * 1 m thickness) ~= 3.06 * 10^20 J / (1 million km^2 * 1 m thickness).
10^22 J / average (365.25 days) year
=
10^22 J / 31.5576 Ms
=
10^16 J / 31.5576 s
=
3.1688 * 10^14 W
3.1688 * 10^ 14 W / (510 * 10^12 m2)
~=
0.621 W/m2
I don’t know how accurate 510 million km2 is for Earth’s surface area; taking 4*pi*6371^2 km2 ~= 510.064 million km2; but I don’t know the formula for an ellipsoid (polar radius is slightly smaller than equatorial radius)(for what it’s worth, 4*pi*6381^2 km2 ~= 511.667 million km2, which gives a sense of why most of the mass of the atmosphere can be approximated as having the same horizontal area as at sea level (a 1 % increase in area is reached at a height of about 31.8 km)).
TheSea.Org, NOT selling anything, just a resource about the Oceans and Coral
Does this help put the units in context?
“the energy stored is enough to power nearly 500 100-watt light bulbs for each of the roughly 6.7 billion people on the planet.”
37 CRS: Average coal contains 1 or 2 ppm uranium. Illinois coal contains up to 103 parts per million uranium. A 1000 megawatt coal fired power plant burns 4 million tons of carbon per year. Coal is 25% to 96% carbon. That multiplies out to 412 tons of uranium in the cinders and ash [Illinois worst coal] plus 14.7 million tons of CO2 per 1000 megawatts per year. 3% of the fly ash gets into the air. The cinders have to be trucked away. If you can’t convince them on the CO2, work on the psychological angles. See:
http://www.ornl.gov/ORNLReview/rev26-34/text/coalmain.html
for other pollutants in coal, such as thorium, lead and arsenic. Licking the GW problem is going to take a lot of psychology, marketing, and other skills. Tell the truck drivers who haul the ash that it contains uranium, thorium, arsenic, lead, etc. Unburned coal contains Benzene and benzene is an extremely strong carcinogen. Tell that to the miners. Shaft [underground] mines also have radon, the radioactive gas, in them because radon is a decay product of uranium. The higher the percentage of uranium in the coal, the more radon is in the mine air. Illinois coal miners may be in violation of the standards for radiation workers. Radon decays in about a day into polonium, the super-poison. If I had your email address, I would send some analysis sheets for several mines. If you could visit some union chiefs and slip them the information it could help. Get help wherever you can.
As far as India and China are concerned: That argument has been used before, and it is bogus. China and India will fall in line as soon as the US does because China and India are already on the edge of famine and the situation in both is getting worse. Remember, all that 10 to the 23rd power joules of heat in the ocean is causing the wind to blow the wrong way over India and China and everywhere else. Agriculture is suffering in many more places than it is benefitting. The comments on the previous post on this web site have a lot of discussion on floods and droughts. Both are happening to farms in many places and both curtail food production. The problem is all that excess heat in the ocean, of course.
GeoEngineering: The popular GeoEngineering solution is to put SO2 into the stratosphere. The problem is that SO2 is a poison gas. SO2 + H2O=H2SO3
H2SO3+O=H2SO4=sulfuric acid=battery acid. If it forms in your lungs, your lungs dissolve. The best and cheapest thing to do is to make it illegal to take coal, oil shale and tar sands out of the ground.
Good luck, agent 37. :) :)
Very ‘a propos’ Gavin. We know that sea ice doesn’t necessarily form when outside air temperatures are just below zero, for instance Eastern sea board is largely ice free during the coldest of winter. I also know that Arctic sea ice starts forming with about -11 C air temperatures, when its especially not windy. This is the current Arctic balance of sea ice formation. When the ocean warms further, this balance likely means that sea ice onset will start at even colder temperatures, with the warming atmosphere this will make a refreeze of the Arctic Ocean well into the long night. From the get go, at current Arctic warming rates,
we have less than 20 years before the Arctic pack ice becomes seasonal like Antarctica. But if the sea warms further, as it does relentlessly, just like the atmosphere, may be in a few years there will be hardly any second year ice. Even so, most in this world worry not about a dark blue North Pole, each coming summer brings us closer to a different planet seen from space, may be most have never thought about simply this look.
Whenever there are revisions made to estimations and/or projections of quantities such as ocean heat content…..why, oh why is it always in the direction of “things are worse than we expected”? Unlike many here, I will actually be around to see the ramifications….
Norbert: if you include both land and sea temperatures combined then we are likely to see consecutive records broken month in-month out from now on until there is a large prolonged trend in land/air temps the other way which at the momenmt seems increasingly unlikely.
Still for March and April 2010 land temps were I think 8th hottest on record and 15th respectively or something around there…so we are not fluctuating to anywhere near normal range on the ‘troughs’. Every year that the air temps are near record highs it will push ocean temps that little higher and that’s not withstanding the affects of ice albedo either. It seems to me the comb. land/sea temps are taking more of an exponential curve and the natural variabilty is getting narrower as well.
Gavin: I read that the land of iceland and greenland is measurably moving upward as the ice sheets that have been compressing the land are melting and thus getting lighter….my question..could the recent eruption of Eyjafjallajökull have been triggered by slight changes in the tectonic forces in the area caused by the progressive loss of ice thickness?
Thanks!
[Response: Not as far as I know. – gavin]
[Response: Actually, there is some literature on this sort of thing. In fact, the release of stresses following ice unloading are significant enough to matter. There is evidence, for example, that Mt. Rainier experienced this following the last glacial maximum, as the large glaciers retreated from it’s flanks. This doesn’t in any way suggest one can meaningfully attribute the eruption of Eyjafjallajökull to ice unloading though. At best, it is a contributing factor to the exact timing – i.e. at the scale of “this month, rather than next year”. This is one of those straw-the-broke-the camels back sort of things.–eric]
Does anyone have the formula to calculate the ocean heat content from temperature data. I am looking at ARGO data for the Indian Ocean basin. The raw temperature data show a significant (from 2003 to present) decline in ocean temperature in the upper 700m.
I would like to convert the temperature data to heat content.
Gavin #21,
On being more specific about what seems contradictory about this piece and the Pielke/Trenberth/Willis (PTW) exchange, I suppose, as a non scientist, it seems to me that the conclusion at the end of PTW is that the measurements of OHC seem to be completely contradictory to model predictions, whereas this present RealClimate post has the opposite conclusion, namely, that measurements perfectly confirm the model predictions.
The exchange I refer to is this one: http://pielkeclimatesci.wordpress.com/2010/04/19/further-feedback-from-kevin-trenberth-and-feedback-from-josh-willis-on-the-ucar-press-release/
There were others at the time, i.e. follow ups by Roy Spencer, and Pielke Jr., but this was the one that really grabbed my attention.
It is my impression that Willis completely agrees with Pielke whilst politely disagreeing with Trenberth (et al) throughout that exchange.
But, if what RealClimate has posted here is true, it would be unfortunate that by completely ignoring this recent blog exchange, RealClimate has given the impression of burying its head in the sand and throwing inconvenient analyses under the rug. Because you make no mention of this exchange, a reader like myself who is unable to crunch the numbers himself is free to simply choose the one he likes best. And I have to admit that I do like the Pielke/Willis view better.
So wouldn’t it be good to comment on where you disagree with Pielke/Willis?
Best, Alex
[Response: That conversation is talking about closing the budget for very short time periods – which everyone acknowledges is not well constrained due to the uncertainties in the radiation flux calculations and the OHC measures. For the long term changes, the numbers have tracked model estimates (Hansen et al, 2005; Domingues et al, 2008) and continue to do so (see above). Differences in analyses for short periods are large, and I have been consistent in stating that they are too large for dramatic conclusions to be drawn. – gavin]
It is largely because science is conservative and errs on the side of moderation.
Keep that in mind when some ignorant fool claims that scientists are being sensational in their statements.
Kate@56,
Whenever there are revisions made to estimations and/or projections of quantities such as ocean heat content…..why, oh why is it always in the direction of “things are worse than we expected”?
It cuts both ways. Hansen 88’s, climate sensitivity has been reduced by about 25% (~4C down to ~3C for double atmospheric CO2). GISS adjustments result in a lower centennial temp trend than raw for global surface stations, and lower for the last 50 and 30 years than raw. I guess we don’t hear much about that sort of thing, but it’s there for anyone to look up. Global sea level and Arctic sea ice projections appear to have been underestimated (IPCC AR4). This is less to do with revision of data and more with recent observations (the data is processed, of course), but care must be taken when trying to prognosticate from short-term trends.
54 Ed: We think alike! I’ve been bitching/moaning about the radionuclide burden of coal since the 1970’s. Nobody seems to care…it’s a non-issue except to a handful of folks like on this blog.
When I was Sr. Env. Scientist to the Gas Technology Institute, we disparagingly referred to coal as “the fuel that won’t go away.” That’s just the way it is, we have to find some way around the problem. I’m working on it as we speak….if we can’t regulate/legislate coal out of existence, we have to make it economically unattractive and offer better alternatives. After all, we don’t burn wood/dried cow pies for fuel as much as we used to!
Have faith, everyone. Kate 56, I hear you! Some of the brightest minds are working on these problems right now, you will hear a flood of news (patent announcements mostly) in the coming months.
so, everyone knowing CO2 blocks a band of IR no other gas blocks believed the missing heat went into oceans and this had to be confirmed by sizing it up. and as CO2 is a part of carbon cycle, the fast component of which is enzymatically driven (by plants) and obeys (most of the time (during summer days)) Michaelis-Menten kinetics and gives a similar non-linear response that is harder to prove than a linear one. looks like the acceleration has started and i’m thinking will anthropocene be like pliocene or early miocene-paleocene.
Good for Sallie Baliunas! I’m quite surprised. Some of that scientific training didn’t go to waste. She’s also about 176% more personally honest than most public deniers.
“49
Frank Giger says:
22 May 2010 at 7:58 PM
Mr. Benson, where can I find a frostline/treeline map, ”
Just a wee shot in the dark, but couldn’t you ask your country forestry commission? They kind of need to know this sort of thing, even if they get the info from another source.
Frank Giger, #49–
http://instaar.metapress.com/content/u11w07513410j694/
http://www.jstor.org/pss/1552625
http://www.taiga.net/yourYukon/col439.html
http://www.esajournals.org/doi/abs/10.1890/06-0265
http://aob.oxfordjournals.org/cgi/content/full/90/4/537
(This last is the best resource I found, as it is a review of the relevant literature as of 2002.)
It seems unlikely from these that a comprehensive map exists yet–but following up on these, perhaps you can tell us more?
Frank Giger, thanks for the calculation. You have the relationship between calories and joules inverted. I would rather work with yearly figures, which reading from the graph is about 10^22 joules per year. This is my calculation:
10^22 Joules x 0.24 Calories/Joule = 2.4 x 10^21 Calories
1.3 x 10^9 km^3 of ocean x 10^15 ml / km^3 = 1.3 x 10^24 ml of ocean.
But we are working with the top 700 m of ocean. Given an average depth of 3790 meters, we get
1.3 x 10^24 ml x 700 m / 3790 m = 2.4 x 10^23 ml of ocean.
2.4 x 10^21 Calories
—————————– = 1.0 x 10^-2 degrees
2.4 x 10^23 ml ocean
By this calculation, the top layer of the ocean is gaining one hundredth of a degree per year. That seems too low. Can someone show what I am doing wrong, if anything?
A very succinct and accurate assessment of the entire AGW denial culture.
Ike # 28 were you making a joke?
“…Baliunas was so surprised by this result that she threw in the towel….”
Google news gives me only this comedy site.
68: the average surface temp increase is a couple of tenths of a degree C per decade. Your 700M number of .01C/year is about half that. Since the oceans are warming more slowly than the land this sounds about right. If you had dropped a decimal point I don’t think the agreement would be that close.
Hmmm… with the understanding that news has roughly the same relationship to data (i.e., history), that weather has to climate, I ask Mr. Benson @45 (/et alia/):
“Briefly, the only (moderately substantial) clathrate dissolutions are in/near the Arctic Ocean at shallow depths. The vast majority of the methane released remains in the ocean.”
That would appear not to be the case – or do I misunderstand the relative quantities of methane being released into the ocean (Gulf of Mexico) by the British Petroleum (BP) Deepwater Horizon/oil volcano there? One to two million gallons per day of stuff (oil+gas), at pressure. Even with a 50/50 breakdown (low), that’s a *lot* of methane.
And yes, BP’s lack of transparency /in re/ those quantities makes this all somewhat difficult. Hopefully that lack will change quickly, and already is, but:
What *is* this oil spill likely doing to the Gulf, purely in terms of methane? How much goes in before a practical saturation point is reached?
What are people not asking, that they ought to be – strictly as this spill might affect AGW generally (ocean heat-uptake specifically?)? I am not asking about the biology of the situation – those answers are unfortunately more clear – just about what long-term physical processes we may have unleashed (and cannot, apparently, stop) which relate to Global Warming.
I dunno. Maybe it’s a dumb question, and the quantities involved are small and irrelevant. It doesn’t seem that way though.
By the way – in reference to my previous post; I note that the oceans of the world *emit* about 15.5 million tons of methane per year – and that the Arctic Ocean itself (an area of considerable and increasing concern) accounts for half of that. This would be as reported, March of this year, by “…an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov.”
http://galaxymachine.de/climate/78-arctic-seabed-methane-stores-destabilizing-venting.html
Compared to 15.5 million tons/year, what is anecdotally spewing out of the Deepwater Horizon well *per day*, doesn’t seem to be inconsequential.
Jaime, Shakhova’s methane paper was discussed here at the time:
https://www.realclimate.org/index.php/archives/2010/03/arctic-methane-on-the-move/
I have been wondering about the interannual variability in the OHC data.
Is this thought to be a real variability in OHC or is it thought to be mostly due to the not so good accuracy in the year to year numbers ( as Gavin hinted in response to #21)?
Are there single drivers big enough to explain this variability?
Jaime Frontero – Escaping methane in the Gulf is being examined. One consideration might be the fact that some/much of the exiting methane may be forming clathrates as it hits the cold water as demonstrated by the [foolishly unanticipated?] problem using the containment dome.
Blair Dowden (68) at quick glance I think the volume of the top 700m of the sphere is more than your 700/3790 ratio would say; though that aggravates not helps your problem. Maybe there’s something else.
Frank Giger (49) — I don’t know about maps. I just try to keep up on several blogs devoted to aspects of climate and climate change.
Any comments on the relevance of this update to the plausibility of the mass extinction scenario described in Peter Ward’s Under A Green Sky ?
[Response: None. -gavin]
RS 59,
heat content H = m cp T
where H is in Joules, m the mass of the object in question, cp the specific heat capacity at constant pressure, and T the absolute temperature. I would divide the ocean into horizontal layers with different mean pressures and temperatures and figure it that way. You might try a model using lapse rates and see if your total converges as you try more and more thinner and thinner layers, calculus-style.
#68
The main problem is that you are assuming thermodynamic equilibrium, which would certainly not hold for such a short period. You need to take into account the time required for a temperature anomaly to diffuse downward. This would require dividing the ocean into a minimum of two layers and solving a partial differential equation (the “heat equation”)with appropriate boundary conditions.
Anyone know what the denialist blogs are saying about Deepwater Horizon? Are they demanding transparency from the BP hierarchy ;-)
This is off topic but I need help.
I’m visiting a friend who’s a radio host, and I’m sitting in on the show tomorrow morning. The special guest is “a monkey who can predict the weather better than NOAA”
I googled it, it’s a publicity stunt by the Center For Public Policy. The chimp is “Dr. Hansimian”, and by having him randomly roll dice or whatever, he can predict hurricanes just as well as NOAA. This supposedly disproves climate change, I guess.
I’m a mere art major with no climate expertise, but I do have a healthy skeptic streak, and I smell a rat. What can I bring to the table tomorrow morning?
Yes, where is the Baliunas quote from?
The 1999 part of the Baliunas quote may be from this:
http://oldfraser.lexi.net/publications/books/g_warming/solar.html
For the rest, nothing found trying
Baliunas +”Rational scientists can no longer support that position”
— citation needed
Kaje says: 23 May 2010 at 8:32 PM
Bypass the chimp and go directly for the issue of what sort of policy improvement can be expected from a think tank generating sophomoric cheap shots. So, drill in on “How did you choose a name for your ape stuntman?” Don’t let it go.
Re #83, Kaje, you can predict Summer will be warmer than winter!
“What can I bring to the table tomorrow morning?”
Loaded dice
Thanks all. I called my friend, and she says that they know the chimp folks are nuts, and they’re just baiting them. Also, this blog seems to address most of their arguments.
If you want to call in and decimate them on-air, the station is Road Dog on Sirius (147) and our show starts at 11 am eastern.
http://www.sirius.com/servlet/ContentServer?pagename=Sirius/CachedPage&c=Channel&cid=1104779630449&flash=noflash
80
Barton Paul Levenson says:
23 May 2010 at 4:33 PM
“RS 59,
heat content H = m cp T”
Thanks Barton for the formula and analysis advice.
Regards
Re #83
Kaje, with all due respect, I think it would be a mistake to engage the monkey people in argument. They’ll come with a bag of well honed arguments which will sound like science and which will only be effectively debunked by someone with a firm grasp of the science. IMO the fact that they stoop to this kind of stunt is potentially more illuminating to your listeners than a failed attempt to discredit them. Res ipsa loquitur.
76 flxible: Please keep us posted on the air analysis over the gulf oil spill. Altitude, distance and wind need to be reported along with substances found.
Does anybody have a graph of the methane coming out of the oceans over many years? How does what is coming out now relate to 50 or 100 years ago?
Gavin (or anyone else in the know),
Can the NODC data in recent years (since circa 2003) be trusted? I think that Richard’s question @30 is an important one, especially since (as far as I know) the NODC site is the only place where one can obtain OHC data which are updated regularly.
Unfortunately, Lyman et al. do not shed any light on why the NODC data are so much lower, and in fact showing a short-term decline whereas the other data (from Lyman et al.) are not. The NODC revised their OHC estimates down earlier this year, but provide no explanation on the site.
Anyhow, an explanation as to why the data sets differ and which one is more trustworthy (Lyman et al’s vs. NODC) would be very much appreciated.
Thanks.
[Response: The difference is in the corrections to the XBT data, which is obviously part of the systematic error. Lyman shows that these issues make a difference in the transition period to the Argo floats mainly. Thus the NODC numbers should still be useful as long as this uncertainty is acknowledged. I imagine that Levitus et al are trying to improve their analysis on an ongoing basis and they will be working on the best approach to the issue. -gavin]
Kaje 83,
“Doesn’t surprise me. Weather is chaotic and is predicted by weathermen. Climate is statistical and is predicted by actual scientists. When you can understand how a ca sino makes a consistent profit, despite the fact that you can’t predict any individual hand of blac kjack or spin of the roul ette wheel, you’ll understand the difference between weather and climate–and why your stunt does nothing to disprove global warming.”
Gavin #60,
I am still left with the impression that you are evading the question of the meaning and significance of the Pielke/Willis/Trenberth exchange.
We all know, of course, Trenberth’s now famous behind the scenes remark that it is a travesty that we can’t account for the lack of recent global warming, and his exclamation that the observing system must be inadequate (which I guess is reference to the satellite radiation budget measurements?). Trenberth later claimed that there is heat missing and that it must lie beneath >700m in the deep ocean and that it may come back “to haunt us”. But Willis then agreed with Pielke that it is probably impossible and that it’s unlikely we’ll find any missing heat below 700m. Pielke Jr spelt it out for us the next day that this means the “missing heat” is probably missing because it has been radiated out into space, or in layman’s terms, because it’s just not there.
Now a few weeks later we find ocean heat has been adjusted upwards by Lyman et al. and we find Josh Willis one of the coauthors. Yet Willis already agreed that he thought the existing measurements were pretty good. Pielke has used Willis’s data to show a decline in OHC since 2003 which doesn’t appear in this the new Lyman et al analysis. (In fact, it looks like Willis has frankly got his own name on two of the curves in your diagram, both the NODC data and the Lyman et al data. Is that right?)
So what is the conclusion for this? There is missing heat below 700M or there isn’t?
Best, Alex
[Response: There is clearly some heating going on below 700m. But this discussion of ‘missing’ heat is very confused. The satellite records are not good enough to say what the year-to-year imbalance is and so are not able to say whether any heat is missing or not. So what is the ‘missing’ idea based on? Model estimates – but as I showed above, the estimates of OHC change are in line with the models, and so I don’t see why anyone thinks that any heat is missing. If the satellite data were better, there might be something to this, but right now the issues are all in the noise, and thus pretty unresolvable. – gavin]
On monkeys predicting hurricanes: it’s a funny stunt, and nothing more. It’s an old gag with a different punchline. Over the years we’ve seen horses that predict weather by stomping hooves, pigeons that predict the stock market by pecking on stock listings, etc. If birds were really consistent and better than people at forecasting stocks we wouldn’t have stock brokers as such; we’d have bird keepers.
The best counter isn’t a counter at all. It’s a laugh at it along with tales of similar stunts, and then a big “so what.”
Let’s say a magical monkey could predict the number of hurricanes in a given season accurately. To be honest, whup-de-do. It’s nice information, but not critical – and easily trained, since we know roughly the number of hurricanes each year due to the cyclic nature of their appearance.
Where hurricanes are forming, their track and intensity is actually more relevant. And for that I’ll trust the trained metorologists over Bubbles.
A Category 3 hurricane isn’t a big deal in the scheme of hurricanes, until they hit the wrong spot. Brush the coast as it peters out and not much damage. Hit the shore over a city that is built in a bowl that is below sea level with a levee system plagued by 30 years of mis-management and its a disaster.
Barton 94-
You misunderstand, I’m not the anti-science nut trying to discredit AGW with the chimp. I’m just confronting the person who is.
I think I’m good, thanks to commenters here, at Pharyngula, and also the handy Skeptical Science app. Mmmmm, debunking denialists…
It’s worth noting that there are still some lingering instrumentation issues w/the later equipment. Here’s a synopsis of troubles leading to the present:
“In 2003, it was found that problems with the Druck Pressure Sensor were causing some floats to stay at the surface for prolonged periods and eventually to become surface drifters. The Druck Pressure Sensor is the successor to the Paine pressure sensor in Seabird CTDs. Even when not severe, the problem may have caused errors in the salinity measurement due to increased biofouling due to prolonged surface exposure. When the problem was found, the CTDs were recalled and the source of the problem was fixed, but this was not possible for floats already deployed. A large number of SOLO floats with FSI CTD packages deployed in the Atlantic Ocean between 2003 and 2006 were found to have a pressure offset problem due to a software error. This error caused pressures to be paired with the temperature measurements from the next lower level, creating the illusion of a cooling ocean. Once the problem was found, a list of such floats was compiled. An effort was made to correct the problem, successful in some floats, not in others. All data from all these problem floats are included in WOD09. For those data which could not be corrected, all float cycles are flagged. More recently, in early 2009, a problem with the Druck pressure sensor has been found (J. Willis and D. Roemmich, minutes of 10th meeting of International Argo Steering Team). This problem causes pressure sensor drift after deployment. Deployment of new floats was halted temporarily, until the pressure sensor design could be altered. Already deployed APEX floats are being monitored closely for sensor drift. The full extent of this problem is not yet apparent”
From this fascinating document:
World Ocean Database 2009
81: Jerry Stevens said: You need the heat equation and diffusion.
I don’t agree. Diffusion is not how heat gets buried in the ocean. If it were the top of the ocean would be hot and the depths would never get heated. The diffusion time for heat in water is L^2/D with D~=10^-5 m^2/s. Thus for heat to diffuse 1000m takes 10^11 seconds ~=10^4 years. Simply considering the time it takes to heat up the water a given amount with a given heat flux is far more telling, which basically assumes that the transport is instantaneous.
If you really want to consider thermal transport you need a model of the velocity field. People write down heat equations for the ocean but then they pretend that they’re not really talking about molecular heat transfer but some sort of effective heat transfer so they use much larger thermal diffusion coefficients than the molecular ones. Then you have to pick a thermal diffusion coefficient out of your … hat and argue for the value you chose. There are cases in which folks have derived “effective” diffusion coefficients for particular hydrodynamic flows but there is no rote procedure for doing this. I would argue that you either can assume instantaneous transport or you use an ocean model and advect the heat away. I believe that if you check you’ll find the two give roughly the same answer.
You can predict the next day’s weather with about 75% accuracy (in temperate zones) by merely saying “same as today”.
Skill with weather models increases that to 85%. However, that is quite significant if you’re looking for the prediction horizon (where you’ve got a 50-50 chance). With continuity, your prediction horizon is less than 3 days. At 85% you can extend it to over 4 days (more, because the skill is in asserting change, therefore the 85% is not completely independent).
Therefore a monkey randomly bashing away gets it WORSE than the even LESS clever “same ol’ same ol'”.