I know nothing about climate science, but just reading your post I wonder if it is possible that the decrease in measured ocean heat content is mostly a factor of having better tools (the ARGO floating profilers)? That is, could it be possible that measurements in previous years, with lower quality measuring devices, consistently overstated the heat content?
Gavin, thank you for that thourough early analysis. As you point out, we should all be cautious over the next few months to see if these results are robust. Notwithstanding the continued rise in sea level (which Josh Willis has just commented on the Climate Science site), lets assume for a moment that this loss of heat is confirmed, and this heat is not still in the deep ocean (no evidence of this). I honestly do not understand assigning this magnitude of heat loss to “natural tropical variability”. Can you ellaborate? 21% loss of the heat that was accumulated between 1955-2003, in just two years? This will need some good research to show why natural variablity would be this large over these time spans. Would not such a finding largely invalidate the heat budget equations as they are now understood? The Levitus and Pielke papers show that averaged out for these types of time intervals (>1 year), this analysis provides a snapshot of the net radiative imbalance at the top of the atmosphere. There has virtually been no dispute about this from the community (that I have read about). How can this actual radiative imbalance be negative, even for these short(2 year) periods of time?
The real question in my mind is, given the continued increase in GHG forcing, what could have allowed such a loss of heat? If we isolate the ocean for diagnosis, there is a rather short list of suspect forcings and feedbacks (ie changes in shortwave reaching ocean surface possibly from strong negative aerosol feedbacks, net positive rate change in loss of longwave from the ocean (which would have implications for the positive WVF), net positive heat loss through evaporation without balancing compensation (with other implications for positive WVF). Another voodoo possiblity would be a net change in shortwave reaching the top of the atmosphere. No evidence of this either, but lets get all of them out on the table.
If this heat has been lost to space, and the models have not accounted for it, it would seem to me that it must have an effect on the model “projections” because the non-equalibrium forcing has changed (the system has been reset at a lower temperature).
In earlier threads I”ve posted links to several studies showing increasing abysal temperatures (Nordic sea, and north Pacific). You say above “sea level however has continued to rise unabated according to the altimeter satellites. The only way to reconcile the results would be to have had a sharp compensating increase in freshwater …”
Isn’t deeper mixing so the abyss is warming sooner another explanation that would keep ocean expansion the same overall?
I am just a reader, no competence in the science, don’t know if the magnitudes are at all comparable for mixing and warming/cooling.
Thanks providing the full context. The paper is very new and it takes some time for the scientific community to examine closely and to judge how important it is.
Its hard for someone with some but not a lot of scientific training (like myself) to fully understand how significant a study is without hearing from scientists.
If the measurements are shown to be very accurate and they represent a change in heat content of the oceans, is the magnitude of the change significant? Is the reduction in heat content itself significant?
Comment by Joseph O'Sullivan — 16 Aug 2006 @ 12:43 PM
Could there have been a lare net transfer of energy from the oceans to the atmosphere during 2004-05 due to the very active tropical storm seasons in the Northern Hemisphere?
year-to-year fluctuations in any of the key metrics of planet’s climate are
mostly a function of the weather and cannot be expected to be captured in climate
models, whose ‘weather’ is uncorrelated with that in the real world.
Seasonal weather is correlated since it is mostly a function of energy inputs. Seasonal weather patterns are also correlated (between models and the real world) to an increasing extent and there is a high degree of correlation between circulation changes based on SST’s between the models and the real world.
What is lacking is mainly the correlation between the models and real world in local and regional weather but this is also ever improving as the model time and spatial resolution improves. The ability of the models to forecast weather is neither possible nor necessary, but the models must have adequate weather feature modeling to determine a realistic horizontal and vertical water vapor pattern to be able to model the warming effects of that water vapor.
As this is my first post to you, firstly let me congratulate you on an excellent site, which I regularly recommend to my fellow forum members on Netweather.TV.
I posted Climate science on the subject of the undersampled Arctic, and Roger Pielke kindly responded, but said that, as the Arctic was only 10% of the oceans, the sample difference would probably not be significant. Evidently, though, if the NOAA/NESDIS anomaly graphics are to be believed, whilst being ‘small’ in area, the size of the anomalies would surely raise the overall temperature by a measurable/ quantifiable amount; it was not the remit of the paper to include this, but shouldn’t such an adjustment be taken into account in a discussion of its implications?
Secondly, you mention the possibility of a large freshwater influx over the past three years as a possible explanation. From recent research, I would suggest that this is entirely plausible; I could cite several examples of substantial increases (runoff, glacier melt, precipitation, sea-ice loss) which, collectively, amount to a real net increase in the Arctic freshwater budget. If this water is finding its way into the ocean areas sampled, we really could be in trouble with the THC. What do you think?
Re: #9 These are really excellent questions. Lyman and Willis took a look at both of these and comment on them in their paper. The earlier heat changes had long been suspect due to sampling. Lyman asserts that the 1960’s change is subject to a much larger error, but both the one in the 1980’s and most recent are statistically significant. I would suggest that the reasons for these are not understood at this time.
In respect to heat transport to the deeper ocean, Lyman also took a look at heat changes below 750 meters, and the cooling signal was still quite strong. This does not invalidate the deep ocean hypothesis, but with no viable mechanism proposed to transport this heat, it looks unlikely at this time to be the answer.
Icecaps are melting faster now in the Arctic, Antarctica, Greenland, and glaciers. So some heat is being transferred to the cryosphere. How much?
Latent heat to melt ice: 355,000 joules/kg x 1,000 kg/cubic meter x 10^9 cubic meter/cubic km
= 3.55 x 10^17 joules to melt one cubic kilometer of ice.
Thus, melting 1,000 cubic km absorbs 3.55 x 10^20 joules.
That’s 1% of Lyman’s heat loss (if the arithmetic and logic are right). Then there is more heat to warm all that ice, first to melting point and then to the average temperature of the ocean. This accounts for some of the heat loss, sea level rise, and decreasing salinity at high latitudes. Plus, the remaining ice may also be warming.
The cryosphere is small relative to the oceans, but not relative to Lyman’s drop in heat content.
Clearly more analysis will clarify the uncertainties in the ocean heat estimates – which are very large and, I believe, may be understated in the Lyman et al paper since they address random but not systematic sources of error. Having done a variety of global-ocean heat flux calculations recently, I can say with confidence that the systematic error, even if VERY small, can rectify significantly onto the global heat integral when integrating to depths of 700m. It is likely that the systematic error will shift as new data are incorporated into their analyses (you’ll note that they get nearly ALL of their cooling below 200 m!)
It is also worth mentioning that the results of this study (which imply a recent ~0.5 PW ocean cooling) are, in my view, entirely inconsistent with the best available fluxes at TOA – CERES retrievals- which actually show a NET INCREASE in the net downward flux at TOA of at least 0.4 PW (depending on which sensor is used) between the 2001-2 and 2003-4 periods. The error bars on the CERES retrievals, particularly when all 4 sensors are available are significantly less than the (reported) error bars on the ocean heat content data in the Lyman et al work.
Accounting for this anomalous ~1 PW sink WITHIN the climate system between the 2001-2 and 2003-4 periods I think will prove to be a bit of a reach, don’t you think?
Recent Cooling of the Upper Ocean
by John M. Lyman, Josh K. Willis, and Gregory C. Johnson
Submitted 26 May 2006
to Geophysical Research Letters
Accepted 31 July 2006
…The recent cooling of the upper ocean implies a decrease in the thermosteric component of sea level. Estimates of total sea level [Leuliette et al., 2004; http://sealevel.colorado.edu], however, show continued sea-level rise during the past 3 years. This suggests that other contributions to sea-level rise, such as melting of land-bound ice, have sccelerated. This inference is consistent with recent estimates of ice mass loss in Antarctica [Velicogna and Wahr, 2006] and accelerating ice mass loss on Greenland [Rignot et al., 2006] but closure of the global sea level budget cannot yet be achieved.
New satellite observations from the Gravity Recovery and Climate Experiment (GRACE; launched in March, 2002 and administered by NASA and Deutsches Zentrum fÃ¼r Luft-und Raumfahrt, GRACE will map Earth’s gravity field approximately once every 30 days during its lifetime) should soon provide sufficient observations of the redistribution of water mass to more fully describe the causes of recent sea-level change.
Finally, the estimates presented here are made possible only by recent improvements in the global ocean observing system. The sharp decrease in error since 2002 is due to the dramatic improvement of in situ sampling provided by the Argo array of autonomous profiling CTD floats, and the real-time reporting of Argo data made it possible to extend the estimate through 2005. Characterization of the error budget, which is of paramount importance in the estimate of such globally averaged quantities, was made feasible by the long-term maintenance of high quality altimeter missions such as TOPEX/Poseidon and Jason.
The issues relating to sea level rise and the global water budget can only be addressed when the record of satellite gravity measurement from GRACE achieves adequte duration. GRACE, Argo, and satellite altimetry are core components of the global ocean observing system. Failure to maintain any one of these observing systems would seriously impair our ability to monitor the World Ocean and to unravel its importance to the climate system.
…The loss of ice has been occurring about five times faster from Greenland’s southeastern region in the past two years than in the previous year and a half. The dramatic changes were documented during a University of Texas at Austin study of Greenland’s mass between 2002 and 2005.
The study was published today in the journal Science. Related results on the significant loss of ice from Antarctica were published in Science in March by other researchers participating in the Gravity Recovery and Climate Experiment (GRACE) mission. The GRACE mission is funded by NASA and the German Aerospace Center, and led by Aerospace Engineering Professor Byron Tapley at the university.
Dear Gavin (and all commentors), Thanks to you all for your interest in and discussion of our manuscript.
For those that are interested, I have posted some further discussion of the sea level budget and the possibility of errors caused by the introduction of Argo data on Roger Pielke Sr.’s Climate Science weblog.
Gavin, thanks for the thorough discussion you provided at the outset. I did want to make a minor comment about your post, though. I don’t think I would put the increase of the freswater input into the “unlikely” category. As I mention in the post linked above, adding up the various reports of melting rates found in the literature, you can arrive at rates of freshwater input as high as 2 mm/yr. Considering the error bars on all of these estimates, I don’t think that is too far removed from our rate of total minus thermosteric sea level rise of 2.9 mm/yr between 2000 and 2005.
[Response: Hi Josh, Thanks for dropping by. My use of ‘unlikely’ was really in relation to the change from 0.7 mm/yr to 2.9 mm/yr in such a short time. That is a rather large increase and prior to it being raised as a possibility here is not a magnitude of rapid change I had ever heard considered before this. However, this issue should be decidable with available data. First off, we have the altimeter data which should be able to validate the relative changes in steric height implied by the heat content changes on a regional (or zonal mean) basis (maybe you’ve done that already?). Secondly, salinity measurements should be able to assess the amount of freshwater inputs for this period relative to the years before, though these have probably not yet been collated. On another tack, it should be possible to track the heat anomalies month by month (at least in the basin mean) – that would make it clearer where the heat is going/coming from. Unconnected subsurface anomalies would be a sign of a problem, while advected anomalies and surface generated anomalies shoul dbe easy to spot. – gavin]
The ocean’s surface begins to warm, but before it
can heat up much, the surface water is mixed down and replaced by colder
water from below.
Mixed down from the water streams of the ocean current.
I think this process the decrease in heat could be a mix of water fluctuation caused from melted/fresh(cold) water streams and the ozean current .
Isn’t heat also compensated from the fact of still rizing sea levels(expanding ozean floods coast land)?
And maybe weather anomalys have also a impact (eg. air movement caused from hurricanes).
Transporting warmer air to higher areas – cooling the surface.
Re #7 and hurricane-driven heat transfer: I tried to look up differences in tropical convection heat transfer to the atmosphere between high-hurricane and low-hurricane years and couldn’t find a clear answer, other then that the topic is complex. Hurricanes do have a deep surface mixing effect that normal tropical convection doesn’t produce, and that would be expected to result in greater transfer of heat to the atmosphere, but it gets complicated in a hurry; see the realclimate discussion of the Walker circulation for example, as well as the link between hurricanes and sea surface temps.
Re #9 and space loss vs. deep ocean loss: It does seem that if radiation to space was the loss, you’d see a correlated increase in the temperature at the top of the troposphere, which is some -73 C. If loss to the deep ocean was responsible, well the data doesn’t go below 700m. Undersampling in the Arctic could be far more important then the 10% cited by Pielke because the polar regions are where deep water formation (sinking of cold, salty water) occurs; this drives the deep circulation and also oxygenates the deep ocean. Warmer water hold less dissolved gases (the classic example is to shake up a can of warm cola and a can of cold cola, and open both at the same time – try it!); that includes both O2 and CO2. If a warming deep ocean starts releasing CO2…
In this respect, the continuing hypoxic trend off the Oregon coast is important. See http://www.sciencedaily.com/releases/2006/07/060727090749.htm ; “Marine ‘Dead Zone’ Off Oregon Is Spreading”; that’s the 5th time in 5 years (my previous post on this topic linked to the 2004 event). Here’s the brief report:
“A fundamental new trend in atmospheric and ocean circulation patterns in the Pacific Northwest appears to have begun, scientists say, and apparently is expanding its scope beyond Oregon waters… This year for the first time, the effect of the low-oxygen zone is also being seen in coastal waters off Washington,”
Re#10 and the freshwater input: That will require better data, according to the authors of this paper. I cut and pasted some sections out of their preprint that relate to this:
“This suggests that other contributions to sea-level rise, such as melting of land-bound ice, have accelerated. This inference is consistent with recent estimates of ice mass loss in Antarctica [Velicogna and Wahr, 2006] and accelerating ice mass loss on Greenland [Rignot et al., 2006] but closure of the global sea level budget cannot yet be achieved. New satellite observations from the Gravity Recovery and Climate Experiment (GRACE; launched in March, 2002 and administered by NASA and Deutsches Zentrum fÃ¼r Luft-und Raumfahrt, GRACE will map Earth’s gravity field approximately once every 30 days during its lifetime) should soon provide sufficient observations of the redistribution of water mass to more fully describe the causes of recent sea-level change…..
…..The issues relating to sea level rise and the global water budget can only be addressed when the record of satellite gravity measurement from GRACE achieves adequate duration. GRACE, Argo, and satellite altimetry are core components of the global ocean observing system. Failure to maintain any one of these observing systems would seriously impair our ability to monitor the World Ocean and to unravel its importance to the climate system.”
What I think they are referring to is the widely noted failure of NASA to keep up Earth system satellite research programs. Perhaps pressure on Congress to earmark funds for an Earth System branch at NASA would be the best strategy for making sure the data continues to be collected. One of my advisors once told me “Science is politics.” Darn it – she was right.
I’m not sure I totally understand this post, but if the ocean has cooled slightly as part of natural fluctuation “noise,” and if last year’s hurricane season (with Katrina, et al.) happened during this natural cooling fluctuation, and if the ocean is on a general track of getting warmer, then we probably have much much worse to expect in future hurricanes….
Comment by Lynn Vincentnathan — 16 Aug 2006 @ 7:11 PM
I think it’s not a good idea to try to link the global upper ocean heat content result to hurricanes. The recent cooling, if real, is largest at 400 m depth or so where it is less than 0.1 degC. The implied global average heat flux is ~1 W/m2. These are not large numbers compared to the seasonal and interannual variations for any given region. Eg see the map in LWJ06’s Fig 2, which shows regional heat content changes, expressed as fluxes, on the order of +/- 50 W/m2.
I haven’t thought much about the THC although I’ve expressed doubt about seeing large regional cooling if it did shut down or change direction, mainly because global warming is so rapid that any cooling effect with time would be dampened by warming factors going on.
“Establishing A Connection Between Global Warming And Hurricane Intensity
Climate change is affecting the intensity of Atlantic hurricanes, and hurricane damage will likely continue to increase because of greenhouse warming, according to a new study. It provides for the first time a direct relationship between climate change and hurricane intensity, unlike other studies that have linked warmer oceans to a likely increase in the number of hurricanes.
I’ve been living here not quite 3 years now, so I can’t comment, but the only times I’ve seen ocean water look so ugly–like green pond scum, but in motion–are associated with effluent being dumped into the ocean without being properly treated. Yes, and it’s smellier than usual too. SSTs are higher here now too, and oldtimers are saying that the summer wind and weather patterns are different. The real unfortunate part of this is the area where this is happening is one of several along the Oregon coast we’re trying to have proclaimed marine sanctuaries.
Upwelling to me implies greater thermal mixing that should result in SSTs decreasing, but ours are rising, and the experts all seem perplexed.
From my reading, it seems that we are seeing a spread of the warm water sea life. Have there been any findings that contradict the trend (of spreading warm water sea life)? If there has not, then any assertions of confidence with the delta values should be withheld.
I would be suprised if the increased flow of cold water from the melting polar icecaps could decrease the total heat content of the oceans, given the amount of additional heat that must be in the oceans that is causing the coral bleaching episodes throughout the tropics. It may turn out to be the case, however, my gut feel is that something is wrong with the measurements (now or more likely then!)
Comment by Lawrence McLean — 17 Aug 2006 @ 9:33 AM
This is a bit off-topic, but I’ve read about the ocean off Oregon, where it is oxygen-depleted with large marine animal die out. They are saying it is due to changes in currents or upwelling of low oxy waters.
Could it also be due to anoxia happening when methane clathrates melt — the methane combines with oxygen, forming CO2 and such, depleting the oxygen. Or is it too early (& not warm enough yet) for that?
I understand this has happened in past severe GW episodes, mainly in the oceans.
I also read that there could be massive releases of hydrogen sulfide caused by the warming, toxic levels — but how warm would it have to get for that?
Comment by Lynn Vincentnathan — 17 Aug 2006 @ 2:50 PM
Re#26, Hi Karl. So called ‘dead zones’ exist in other areas as well; a better term is oxygen minimum zones. A well-studied example is the oxygen minimum zone that develops off the west coast of South America and is generally thought to be due to the high nutrient inputs and the very productive fisheries in the region; in addition in this region the bottom waters tend to stay oxygenates – the zone develops in the mid-ocean depths. An image of this system can be seen at http://omz.udec.cl/files/esquema_surgencia.gif Similar zones exist off the Arabian peninsula, and they are important areas for studying nitrogen cycling.
In contrast, the Oregon zone appears to be linked to low O2 levels in upwelling subarctic bottom water; you are correct in that high effluvient outflow would also produce such effects, but that would look more like the Peruvian system. It is certainly possible that both effects are occuring in synergy.
Regarding the anectodal article that you linked to, there are a couple of issues involved here. Terry Thompson (the author) is a retired commercial fisherman and I doubt that he’s was out taking measurements of bottom water dissolved O2 from his boat. Surface water anoxia, as you point out, can happen due to effluvia and the 50’s were not exactly an environmentally conscious era – paper/pulp mill effluvient in particular is known to cause fish kills. From his article: “I have my own memories of the 1950s. I recall seeing whiting floating in Yaquina Bay, gasping for air. This wasn’t a rare occurrence. People who lived here will remember the dead fish that littered the beaches.” See also http://www.ocean.us/node/235 . Political activisim is fine, but attacking science for political reasons is not.
“The lack of wide-scale ocean monitoring makes determining the size and movement of the dead zone difficult, although some new instrumentation being used this year by OSU scientists is helping. Dissolved oxygen sensors have been deployed on the sea floor both close to shore and in 260 feet of water off Newport, some of which are sending data in near real-time.”
Bryan Sralla had this to say about my previous comment on this issue:
“Ike, I am glad you are finally talking about hydrocarbons. FYI, the Middle East hydrocarbon source rocks were deposited in the Tethys Sea. This was a shallow inland sea, that generated restricted anoxic marine source rocks. The massive carbonate reservoirs of the Middle East oilfields are mainly shallow water karsted and fractured dolomites. You are so far off base on this, that it is really hard to even begin to take what you said seriously. Wrong tectonic setting, wrong source rock environment, wrong reservoirs, wrong structural setting. Try again! Global ocean stratification forming oilfields? I have never heard of this in my career as a petroleum geologist. There is way too much junk science on this website.”
Ummm – perhaps it is time for an apology for the ‘junk science’ comment?
My comments were indeed needlessly harsh, and for that, you have my apology. To the valuable Real Climate website, I also retract my statement about the “junk science”. Although my interpretations of some data may differ, it will be my intention to attempt a more diplomatic tone in the future.
Old crusty, tough guys like Bill Gray have always been my heros in science though, but I see that these kinds of tactics have their drawbacks and occasionally hurt feelings. I will do better.
Thanks for the response, Bryan. However it was less the tone of your comments and more their lack of scientific accuracy that I was concerned with. If you link to the last link in my post, you will find the following statement; there are many such examples available and any decent petroleum geologist would agree with this:
“Examples of modern sapropel formation within the oxygen minimum zone beneath upwelling high productivity surface waters can be found on the continental slope of the Arabian Peninsula and in the California borderlands. Upwelling in the northwest Indian Ocean provides sufficient surface productivity to provide an excess of organic matter to sediments on the continental slope of the Arabian Peninsula where the oxygen minimum zone intersects the slope. Off California, the combined effects of sluggish circulation in semi-isolated basins, continental margin depths within the oxygen minimum zone, and high surface water productivity all contribute to accumulation of laminated, organic-rich sediments in the Santa Barbara basin.
Anoxic sediments have been widespread in the past and are of great economic importance as source rocks for hydrocarbon deposits. Expansion and intensification of the oceanic oxygen minimum zone, probably during times of reduced thermohaline circulation, is one mechanism that seems to account for many sapropels. Deep basins connected only by shallow connections, which resulted in restricted bottom circulation, were especially common during early stages of continental rifting that formed the Atlantic basin.”
As you point out, the Mideast oilfields source rocks were produced in the Tethys Sea; to quote,
“This was a shallow inland sea, that generated restricted anoxic marine source rocks. The massive carbonate reservoirs of the Middle East oilfields are mainly shallow water karsted and fractured dolomites. You are so far off base on this, that it is really hard to even begin to take what you said seriously. Wrong tectonic setting, wrong source rock environment, wrong reservoirs, wrong structural setting.”
However, my comment was strictly related to the conditions under which source rock would form, not the myriad other factors that allow for the development of productive oilfields – the porosity, the presence of cap rocks, etc. What I’d like to see is an acknowledgement of the scientific inaccuracy of your ‘unnecessarily harsh criticism”.
Re: #34 If you or anyone else would like, I would really enjoy continuing our discussion of petroleum geology off line. Petroleum source rocks and geochemistry are facinating, but really not the subject of this thread.
For a massive source of published, peer-reviewed work on the subject, I would suggest an associate membership in the American Association of Petroleum Geologists. The AAPG Bulletin is published online each month, and is a world-class source for technical papers involving petroleum systems. I look forward to visiting with you further via e-mail.
The set of Comments and the original posting on Real Climate have advanced the discussion of the signficance and the issues associated with the observed recent upper ocean cooling. I have just two comments here:
The 60S-60N averaged sea surface temperatures have been relatively flat since 2001 as shown in a personal communication from NOAA, that should be widely available soon. The current value is significantly lower than it was in 1998.
Secondly, unlike the global average surface temperature trend, which has a lag with respect to radiative forcing, there is no such lag when heat content is measured in Joules (see http://blue.atmos.colostate.edu/publications/pdf/R-247.pdf). The upper ocean heat content in mid 2005 was about equal to that in mid 2001. This means that the heat content was “reset” to this earlier value, whereas the multi-decadal global climate model projects a more-or-less monotonic increase in ocean heat content. There clearly is a problem with the models and the IPCC-type understanding of the human- and natural-climate forcings and feedbacks.
[Response: Well, according to the Hadley/Reynolds analysis, SST has risen from 1998 onwards, and so I’m not sure what the NOAA analysis has done differently (see http://data.giss.nasa.gov/gistemp/maps/ for yourself). Obviously though on any short time scale of a few years, there is significant local variability as would be expected from a dynamic ocean environment. I don’t know why that appears to be a surprise. I agree that the models tend to show less decadal ocean variability than observed (given the obvious caveats on the observational side), but absolutely disagree that this implies that longer term estimates are off. The model used in Hansen et al (2005) for instance, does not have a good representation of ENSO variability – conceivably leading to this underestimate of decadal variability, but other models do a better job and it would be good to see what their variability looked like in this metric. By the way, it is the same quantity whether it’s measured in total Joules or converted to W/m^2. The latter makes it much more convenient to compare to the radiative imblance, and so is the way I prefer to think about it. – gavin]
Hello, everyone. Interesting discrepency. I wonder if the original paper describes how interpolation was done over the missing data – I apologize in advance, as I haven’t access to the paper. Slide 7 of the PowerPoint deck over at http://www.clivar.org/organization/pacific/south_pac_workshop/presentations/SPac_Intro_ignaszewski.ppt shows the global data coverage of Argo as of 30 September 2005. As you can plainly see, North of 60 there is only data basically for the Greenland and Norwegian Seas. The data from the large Barents, West Siberian, East Siberian, Chukchi and Beaufort Seas, the Baffin Bay and the Denmark strait as well as the polar Arctic Ocean appear not to exist. Normally this couldn’t influence the results overmuch, as the Arctic Ocean is only ~10% of the polar ocean. But if we consider the mean polar temperature anomalies (see http://en.wikipedia.org/wiki/Image:Global_Warming_Map.jpg for a map), the missing data seem to be experiencing much greater warming then the sampled North Polar data, at the ocean surface at least. The Beaufort Sea and areas north appear particularly striking, with some of the highest mean temperature anomalies observed on the planet, around 1.5 oC for the region. Compare this with the modest surface temperature changes of ~0.5 oC for the sampled region, and you the sense of my post. (It’s not my idea, tho’ – credit goes to Fergus Brown, post #10 over at RealClimate: http://www.realclimate.org/index.php/archives/2006/08/ocean-heat-content-latest-numbers/). In terms of power integrated over area, only northern Eurasia has a higher regional warming in absolute terms – which suggests to me that sea surface warming in the Arctic west of the Canadian archipelago might change the total sea energy balance by quite a bit. Any thoughts? (crossposted to Roger Pielke’s Climate Science blog at http://climatesci.atmos.colostate.edu/2006/08/14/more-information-on-the-geophysical-research-letters-article/)
Comment by Steffen Christensen — 17 Aug 2006 @ 6:12 PM
The geologists are interested in, and talking about, the way oil used to be formed in the past; the marine biologists are saying that developing conditions can kill off a lot of organisms, and that would cause sedimentation making layers rich in organic material — at present, in a very different world.
I don’t see any contradiction. Looking at the difference between limestone and dolomite tells us whether calcium shells of the organisms was soluble at the depth and temperature where the sediment was laid down at the time. The issue today is what happens today.
Someone above said methane reacts with oxygen to make carbon dioxide in water.
I believe that reaction takes much longer than bubbles require to reach the surface; the methane released in these bubble sites or in rapid events like underwater landslides) either dissolves in water or reaches the atmosphere in a matter of minutes, according to what was posted here earlier.
My mistake: When one looks at ANNUALLY averaged SSTs, e.g., at http://www.jisao.washington.edu/data_sets/global_sstanomts/ (the link given in Lyman, et al.), rather than multi-year averages, the disagreement disappears. (The Washington data indicates a drop of 0.02 degrees C between 2003 and 2005.)
My thanks to Bryan Sralla, Pat Neuman and many others, who responded to my somewhat naive questions(#10). The Wunsch paper in particular (see #29), being from an oceanographic perspective, was instructional. A striking comparison can be made by reading Schlesinger et. al. (Illinois)’Assessing the Risk of a Collapse of the Global Thermohaline Circulation’ (sorry, no link), or the recent paper published by Curry et. al. (WHOI) in Science magazine.
Let’s agree that a simple ‘Global Conveyor’ is an inadequate, even misleading model of circulation. Let’s also agree that the Laurentide ‘hosing’ of the Atlantic was not a causal agent in the YD. We still end up with a bucketful of freshwater. Curry suggests an Arctic-Atlantic flux of 5000km3/an mean 1965-95, + 19000Km3 from the three ‘salinity anomalies’ in that period. This must be having an effect on the ocean circulation, on the upper levels, if nowhere else. Therefore, it must be having an effect on the climate. So, two more naive questions: What effect do you think this is having? and; What are the current AOGCMs which incorporate the Polar regions (I am certain there is one) showing as a consequence (in climate terms) of this, assuming it were a forcing mechanism?
I’m not married to the idea of thermohaline weakening or even less, shutdown; at the moment, the numbers don’t add up. But I do wonder how seriously the models, and thus the humans who interpret them, are taking this.
Once again, thank you for letting me contribute to your discussions.
John, thanks for the comments. It is certainly true that a very small temperature bias that is not random from instrument to instrument, but instead is the same over a large number of profiles can create systematic error in global estimates of ocean heat content. However, we felt that by testing the different datasets independently, as I discussed in post to Roger Pielke’s blog that was linked in #16. Since tossing all of the Argo data, or using ONLY Argo data to make the estimate did not get rid of the cooling, we felt that it was not a result of systematic bias.
I would also comment that it is important not to read too much into the depth v. temperature change figure. Having the peak in the cooling occur at depth rather than at the surface is not that suprising considering how that figure was calculated. Remember, this represents a global averaged of temperature changes over many regions of the ocean that are governed by vastly different dynamics. The peak in the cooling, for instance, (about 400m) coincides with the depth of the thermocline in the subtropical Pacific. The ocean moves heat around internally in complicated ways, and the 1-D view provided in figure 4 is simply not sufficient to descirbe its global heat budget. In other words, the ocean is not a simple 1-D slab that diffuses temperature anomalies down from the surface.
Finally, you are correct that 1 pW heat sink in the climate system would be problematic. My understanding of the CERES TOA fluxes, however, were that the 1-sigma error bars were still on the order of 2.4 W/m^2, or about 1 pW. This is still a bit too large to be contradictory to our ocean cooling findings, I think. Perhaps you have newer references or info. on the satellite data, though. If you do, I would love to hear more.
Another type of observation is that there seems to be a virtual plague of droughts world-wide. Too little precipitation has cut agricultural production in the U.S. and in Europe, Australia and southern Africa. The Amazonas is drying too. Abnormally high rains have been reported only in North Korea, Ethiopia and Poland, but these areas seem to me very small. Grain market prices have risen 20% and the stocks are reaching new lows.
Is this just biased news reporting, or is there something else?
Colder sea surface, less evaporation, less rain would be logic, but should be visible on satellite surface temperature measurements. It is the surface temperature that has immediate impact.
Questions, wouldn’t increasing ocean acidification impact formation of carbonate-based rock? What would this altered rock strata look like to a future geologist? Lastly, several articles I’ve read regarding current and near future grain production say yields are likely to drop because of an impending el nino; is this correct, or are these writers just trying to continue the bull market in food commodities?
Re #12: Perhaps the ice isn’t all melting, which would throw off your calculation. There have been reports of increased shedding of ice from Greenland and I think Antarctica. Sea level can go up without the ice melting.
It is not surprising for there to be SST variability. If you ever see a good time series animation of SSTs, you will know that there is significant movement of water and temperatures within the world’s oceans (like there is with polar ice extents.)
Here is a good animation of the Pacific over the past year (August 05 to August 06 centred over the El Nino formation region.)
These animations should tell you that you shouldn’t get worked up about one little area of the acean warming for a period of time. Carribean temperatures cooling slightly over a 2 year period is normal given the nearly chaotic heat transfer that occurs in a system as large as the world’s oceans (the biggest surface system there is of course.) A few bouys in the North Atlantic showing warmer temperatures compared to the measurements of 30 years ago is not “evidence” etc.
RE: #50 – Of course, I must make mention of the seeming paleo correlation between ice ages and expanded arid regions. Not sure which is in the driver’s seat. Consider dust. Does dust, in concert with other factors, trigger ice advances? Fast forward to today. Consider impacts of the “Chinese dust mennace” on the big picture.
If the loss of heat by the oceans is caused by a change in radiation balance, the primary source of the change should be a change in (mainly tropical) cloud cover.
There is a strong negative correlation between the solar cycle and (low) cloud cover, but the resulting change in cloud cover from the current solar minimum may not be strong enough to explain the fast change in ocean heat content. Neither is there much change in (cooling aerosol) SO2 emissions in the past years around the equator (China, India), compared to the previous period.
There were indications of a longer-term decrease in (sub)tropical cloud cover (1985-2000), leading to increased insolation (2-3 W/m2) in that period. This may be reversed in recent years. The earthshine project expects such a stabilisation/reverse since ~2000. But what do cloud measurements indicate for the ocean regions with most cooling?
in regards to hurricane transport of of surface through approximately 80 meters of solar insolation may be supportable by a number of sources. First, the NCDC 250mb NH analysis does indicate an increased aberration of the Northern Jet Stream. Second, the indication of the changes of the Walker ITCZ circulation may be an associative indication of a strong northward movement of the normal ITCZ hydrologic cycle and the saturated adiabatic latent heat release of the tropical water vapor in the higher latitudes. Third, the recent NASA articles indicating the increased high altitude (20-26km) air temperatures above the polar regions. In any case, if there is an indication of polar terrestrial IR emissions into space they should be evident as IR flares near the polar regions and observable using the IRAS or GEOS satellite system.
Regarding the oceanic change whether this is related to fresh water infusion, satellite orbital aberration, or even an average global air pressure or gravitational aberration remains for further review. I would be much more inclined to believe it is a measurement error when dealing with such fine changes. With longer term measures hopefully more of these issues can be clarified.
As an agricultural meteorologist, I wanted to provide some clarification on the linked news story from China. The mention in the story of the city of Chongqing not receiving rain for the past 70 days is inaccurate. This weather station has actually received 4 inches of rain since the beginning of July (~40% of normal). In fact, rains were near normal during May/June, with better than 12 inches of rain falling. It is also worth noting that the mentioned area is on the far western edge of major Chinese growing areas. The main growing areas in the North China Plain and Manchuria have had a very good growing season. There certainly are very dry areas at the moment in growing areas of Australia, Argentina, West Africa, and Russia, while much of the Central U.S. & Europe are starting to see a significant reversal this month of earlier dryness. The scattered problem areas have certainly led to a downturn in global production for some crops, but most are still at relatively high levels versus historical norms.
Ferdinand, are you referring to Shaviv’s work on Cosmic Ray Flux and global temperature variance? As I understand it, Knud Jahnke of the Astrophysikalisches Institut Potsdam found major flaws in the analysis.
I suggest it may not be cloud cover alone. Though in my estimation they play a very large role.
The condition that Ferdinand mentioned may be more likely related to very small aerosols. I would suggest these small aerosols have a large effect on the saturated adiabatic cooling and heating cycles and the transport of water vapor latent heat poleward. The problems with the clouds is not only the altitude; but also the time of day for various cloud classes. Reflectiveity versus the insolative mid-tropospheric heating that can result versus the tendency to reduce terrestrial IR re-emission into space seem to be the three primary characteristics of clouds in relation to surface and atmospheric temperatures. We also have the issue with the class cloud and the time of day and duration that a class of cloud may be overhead.
We also have the condition regarding air pressure and the character of the cloud cover during certain cyclonic or anti-cyclonic conditions. In another post Ferdinand suggested that there also is the issue of atmospheric saturation and the temperature in the air column. It appears that there are possibly many contributors related to the variation in SSTs and the 20 Deg. C isotherm depth that have yet to be examined before including the variations beyond basic meterologic issues.
Comment by L. David Cooke — 21 Aug 2006 @ 10:59 PM
Re: Rhampton #55, In the past Ferdinand has intended the work of Kristjansson not Shaviv that he cites in this post:
…This study uses the GFDL GCM in conjunction with monthly mean sulfate climatology from the MOZART chemistry-transport model and relates cloud droplet number concentrations to sulfate mass concentrations using an empirical relationship [Boucher and Lohmann, 1995]. It predicts an annual global mean first indirect forcing of -1.5 W m-2 from an anthropogenic sulfate burden of 0.59 Tg S. Most of the cooling occurs in norhtern hemisphere (NH), where most anthropogenic sources of aerosol are located. Owing to long-range aerosol transport, higher cloud frequency and susceptibility, the cooling over ocean is stronger than over land, resulting in an ocean-to-land ratio of 1.3. Some of the strongest forcing is located off the coasts of east Asia, Europe, and northeast United States. As a result of persistent marine stratocumulus, the oceanic regions off the west coasts of Africa and North America are responsible for the rest.
Indeed I was referring to Kristjansson (thanks Martin), who indicated a good reverse correlation between low cloud cover and (TOA) solar radiation (but worse for GCR – galactic cosmic rays).
In the longer term, there was (1985-2000) a decrease of high (cirrus) cloud cover over the (sub)tropics, caused by faster Hadley/Walker cell circulation, leading to more insolation (2-3 W/m2) and more escape of heat to space (~5 W/m2). See the works of Wielicki, 2002 and Chen, 2002. This was expanded by J. Norris, 2005 in time, back to 1952 for sea level clouds and 1971 for land based clouds, and in latitude by surface based cloud observations.
The change in radiation balance is more heating of the oceans at one side (specifically high in the subtropics, as expected), but more heat released at higher altitudes, thus somewhere acting as a net negative feedback to higher sea surface temperatures.
Further, the change in radiation balance is huge, some order of magnitude larger than what can be calculated from the theoretical increase in LW reradiation by the increase of GHGs in the same time frame. Even with water vapor feedback, this can not be explained.
Now we (probably) see some reversal of the previous warming of the oceans. So my first thought was clouds, as these can give huge changes in radiation balance in a short time.
Regarding fine aerosols, as suggested by David, there are huge increases in industrial activity in SE Asia since 1975, but that is a rather linear expansion, where SO2 emissions are in lockstep with more dirtier aerosols. As far as I know, the rate of increase of the emissions didn’t change much in last years, therefore I don’t think that man-made aerosols are responsible. And I have not read of extreme conditions for natural aerosols (Mongolean desert…) either. But I have to admit that I didn’t digest yet all the links about aerosols that David send to another list (UKweatherworld)…
The solar-cloud connection is quite real (after two satellite measured sun cycles), but can’t explain the rather fast and huge changes in radiation balance over the previous period. There may be self sustaining internal oscillations which feed the changes in SST / air circulation / cloud cover / radiation balance, back and forth (AMO?). But this needs to be resolved.
Based on the decrease in SO2 emissions in Europa, there should be a huge difference in temperature increase between less polluted areas and more polluted areas, downwind from the main sources. But that is not measurable, see here.
Based on the increase of aerosols in SE Asia, one should expect less warming in the NH Indian Ocean than in the SH. But that doesn’t fit reality, see here
And aerosols off the Chinese coast should induce more reflecting, longer lasting clouds, but there was a decrease of cloud cover in the 30N-30S band with increasing aerosol releases (I have no specific figures for the Eastern Pacific).
And last but not least: ocean heating is larger for the NH part (if corrected for area), while most anthropogenic aerosols are released in the NH (and most stay there until raining out).
China’s coal-fired electric generation stations emitted 26 million tons of sulfur dioxide in 2005. Prior to the 1990 US acid rain program implementation, American generating stations emitted 24 million tons of SO2 and current emissions are about 10.5 million tons.
Comment by John L. McCormick — 23 Aug 2006 @ 11:06 PM
Here is what we must assume:
1.) Conservation of volume (aka sea-level) during energy loss.
2.) Heat transfer to space without massive heat transfer to intermediate atmosphere.
3.) Heat transfer to space directly by water vapor. (Seriously?)
4.) Release of massive amounts of water vapor that then somehow does not behave as a greenhouse gas.
Or, we could look again at the map on page 11. It is very hard to miss the blue line from the tip of africa to tasmania. This is part of the MOC. In fact, you’ll see the rest of the MOC outlined in red and blue.
What could cause this? The MOC streams could be diverging and resistance to it increasing as it diverges. As it diverges it mixes with the surrounding water.
Here is Josh Willis (one of the authors) on the issue:
“… it is true that transport of heat to deeper layers my be a part of the signal(MOC shutdown), but in my opinion, the magnitude and speed of the cooling are too large to be entirely explained this way. The upper 750 m of the ocean cooled by about 3 x 10^22 J in 2 years. This is equivalent to a heat flux of about 0.48 pW, or a circulation change of 116 Sverdrup * degrees C. The difference in mean temperature above and below 750 m is about 7.7 degree C. That means that in order to achieve a sufficient downward heat flux, the circulation would have to change by 15 Sv, more or less instantaneously, and remain that way for 2+ years. 15 Sv is the same order as the mean magnitude of the overturning circulation itelf. That
would mean that the entire MOC would have had to have shut down instantaneously in 2003 and remained shut down for the past two years. This conflicts with Harry Bryden’s estimate of the MOC that he published in Nature last year, which he computed to be about 15 Sv. from his hydographic cruise in March of 2004.”
Sure, but the requirements are much less if you use the much cooler temperature of the deep MOC currents, and not just the “below 750 m” temps.
Michael Winton has also suggested another possibility. He postulated that upward thermal buoyancy flux induced by surface cooling could become insufficient to overcome the stratifying effect of surface freshening, creating a thermal inversion in the oceans. Visually, it would probably have an effect like the north atlantic as pictured on page 11.
In addition to the clouds item, J. Norris has a paper in preparation about cloud trends vs. climate change.
On page 58, there is a calculation of cloud feedback, assuming that the change in cloud cover is solely a response to increased forcing. The net response is -0.8, which is a very strong negative feedback…
Of course this is the response, if nothing else is influencing cloud properties/cover, but important enough for further investigation.
The paper in preparation gives a very detailed overview of cloud properties and influence and observed SSTs over time. Of interest are pages 62 and 63, where cloud cover changes roughly coincidence with SST changes.
Okay – back to ‘radiative imbalance’. The only way the Earth can lose heat to space is via radiation, but the redistribution of heat within the oceans, atmosphere and ice sheets can occur via conduction, convetion and radiation. Under steady-state conditions, the total radiation absorbed by the Earth must match the total radiation emitted by the Earth; that’s what radiative balance or imbalance means in the climate literature. This is a very different notion than that of a model of radiative absorption and emission in the atmophere, which is a very specific physical process. See the discussion of the microwave satellite temp. measurements (a major discussion that was initiated by climate skeptics who claimed that the satellite record showed tropospheric cooling), at Realclimate: http://www.realclimate.org/index.php/archives/2005/08/et-tu-lt/
The internal heat transfer beween the oceans, atmosphere and ice sheets can be modelled far easier than it can be measured, but models need real data for comparison. To account for their results, the authors (Lyman et. al) suggest radiative loss to space, but they also include references relating to warming bottom water, deepening tropical gyre warm bowls, and increased mass loss from the Antarctic and Geenland ice sheets. They acknowledge that the altimetry data seems to contradict the notion of radiative heat loss to space.
Looking at their global map, it seems that the majority of the cooling was from fairly isolated regions centered around 30N and 30S. One thing I would have liked to see in the paper is a quantitative side-by-side comparison of sea-surface temperatures and upper ocean heat content; all the paper says is that only “a small amount of cooling is observed at the surface, although much less than the cooling at depth” though they do report that it is consistent with 2-yr cooling SST trend – but again, no actual data analysis of the SST trend is reported. This seems sloppy to me, since the SST dataset is far more reliable than the upper ocean heat content dataset, and as far as I can tell the Arctic is underrepresented in the data. The global ice-free ocean seems to exclude the Artic and Antarctic ocean regions, since ARGO floaters wouldn’t be likely to survive the sea ice – which is why remote bottom-moored data collection systems are a good idea, esp. for the Arctic. I’d like to see a global map of SST next to their global map of OHC; that might reveal patterns of interest.
Limited data from the Arctic and Antarctic (the regions that are expected to warm the fastest and the earliest) means that warming in these regions could have offset the rest of the reported trend. The fact that the cooling trend is reduced when the ARGO data is excluded seems to support this notion.
Incidentally, I just found that the Reynolds SST weekly report has been removed from the NOAA website: here is the old location: http://www.cdc.noaa.gov/Datasets/reynolds_sst/ I’ve been looking at that on a weekly basis for years, and now it’s suddenly gone? There is something odd going on at NOAA and NWS, as far as I can tell – perhaps the climate denialists have found a new home in the federal government. I’d very much like to know why that page has been removed!
So, the loss of heat from the upper ocean could be an artifact of undersampling in polar regions. I also don’t understand why the authors didn’t separate out SST’s and apply their statistical method to that dataset as well as to their complete ocean heat dataset. How have SST’s changed in polar regions? Furthermore, their globally averaged depth profile (something I’ve never seen before) of ocean heat content is remarkably devoid of any practical information; a latitudinal display at every 10 degrees would be more useful.
In general, these datasets are supposed to be made available for analysis by other researchers, and there was no mention in the paper of access to the actual data used. It would be nice to see a global map of data density next to the OHC global data map. While restricting access to raw data is common practice in pharmaceutical industry research, this should definitely not become the standard for climate research.
Even assuming that the dataset is comprehensive: Considering that the upper-ocean cooling is seen mainly at 30N and 30S, another explanation for this cooling is increased ocean – to – atmosphere heat transfer in these regions (possibly aided by hurricane-mixing of the upper ocean layer, and advection of deeper cold water as a result). If so, then it could be that the heat was lost to space, but given the rapid redistribution of heat in the atmosphere via convection, isn’t it also possible that the heat was transferred to the ice sheets, resulting in increased freshwater runoff to the oceans? What makes this scenario unlikely?
[Response: One minor point. As far as I understand it, hurricanes actually warm the deeper layers (though they do temporarily cool the surface which adjusts through air-sea exchange very quickly after the storm has passed). This is because even the cooled surface waters that are mixed down are still much warmer than the thermocline waters. – gavin]
My apologies for stepping in earlier; I was trying to bring into the discussion your earlier comment regarding the effect of lack of saturation in the Arctic regions from UKweatherworld. And to share that I am seeing aerosols as a significant participant; however, not the SO2s as much as the SiO.
In the period of 2001 through 2004 I had observed a very interesting trend in the character of aerosol precipitants along the Eastern Divide of the Appalachian Ridge. A very fine aerosol that appeared to be almost like talc was faily widespread throughout Western NC. At first I thought it was simply dust due to development work in the area. I hung several tape strips across a wide area of NW N Carolina and got some interesting data not only was the aerosol very fine; but, about 1/2 of the aerosols appeard to have a spherical character to them. As I did not have an outlet to share this information I had simply reserved it as a personal observation.
It was not until the NASA study regarding the Sahara Dust in Florida that I thought about it again. (I wish I still had those samples.) It made me curious if there might not have been a relationship to the volcanic activity in the Caribbean in the late 90’s and the possible character of the hydrologic cycle in the early 90’s. That most aerosols precipitate out in only a few years was clear; but, what happens to the aerosols that reach the Tropopause and lower Stratosphere if they are very fine? The question became; Is it possible that these very fine aerosols were responsible for the change in the hydrologic cycle in that the state change and the normal saturated adiabatic/adaibatic cycle could be interrupted? And that was the balance of the links I had shared with you in reference to the effects of areosols.
When you and Ike began discussing the the Energy Imbalance and you mentioned the “missing heat”, it brought back the question of what if there is an interruption to normal water vapor latent heat transfer and it is not corrected in the models? As you are pretty busy I had not thought to pursue this with you earlier; but, here there be an opportunity. Has anyone seen anything that would seem to support my observations?
(*Note, I had not seen that the Walker circulation had increased, I had seen a study that in the N. Pacific it had decreased about 3%. Later I have seen what appears to be an indication of an increase of northern movement of the air mass what was dominated by the Walker circulation. Coupling this effect with the increasing Arctic Easterlies, the warmish high altitude Polar temperatures, the NH 250mb isotherm analysis indicating an abnormal increased deviation of the Northern Jet Stream (http://nomads.ncdc.noaa.gov:9091/ncep/NCEP ) and the “broken” hydroligic changes all seem to point to a similar process.)
Comment by L. David Cooke — 24 Aug 2006 @ 10:24 PM
In the Eastern N. Pacific the isotherms are getting shallower and the 20 Deg. C depth apppears to be getting shallower over the last 3 years at a number of buoys. However, it is not universal and depending on latitude can be more or less pronounced. (It appears to be a shallower observation closer to the equator and the further east you measure.)
Comment by L. David Cooke — 24 Aug 2006 @ 10:37 PM
Incidentally, I just found that the Reynolds SST weekly report has been removed from the NOAA website: here is the old location: http://www.cdc.noaa.gov/Datasets/reynolds_sst/ I’ve been looking at that on a weekly basis for years, and now it’s suddenly gone? There is something odd going on at NOAA and NWS, as far as I can tell
Ike, I think the Reynolds SST weekly report is still available here . NOAA’s web pages appear to be undergoing extensive re-disorganization. So far, everything I thought was gone, I was able to find in a different place by dropping the right keywords into google, followed by ‘site:noaa.gov’ .
RE #65: The GRACE data makes that unlikely. The total for Antarctica and Greenland is only about 1 mm/yr, still a considerable increase from just a few yesrs ago. Josh Willis thought that other contributions might bring it to 2 mm/yr total.
I find that this particular thread is very interesting – thanks to all.
A question please.
I understand that ocean circulation is complicated but I have been trying to find out how much is known about the flows of underground rivers and where they enter the ocean. Significant flows of fresh water are involved : for example, one single source with its outlet in the deep Mediterranean is reputed to have sufficient fresh water to supply the needs of Marseilles. The technology for supply is like capping an oil well – at least that is the way I prefer to look at it.
It occurred to me that there must be similar flows into all the oceans of the world and particularly from melting ice-caps where temperature changes may have exposed previously blocked outlets. Are there any maps of the flows of this fresh water or any other information on this subject which is readable and reliable please, for a non-expert like me. I can persist with the idea of run-off from land, acting as an umbrella as it were, but it doesnt seem correct to me.
I am actually more familiar with the Florida submarine springs; however, the last link I provided below indicate a number in the Med. as well. I did not find any in the Indian Ocean though there are several references to arabian coastal sources. I would be inclined to expect a large amount in SE Asia; however, I have no references.
Overall I would not expect these to be a profound effect. Though there is a large volume, most can easily be compared to a large stream or small river. Total ground water including the known major rivers that empty into a saline body is likely less then 3-5% of the total volume that evaporates daily whether from land or oceanic sources. I hope this can assist you in your endevors.
You are a good man Dave Cooke thanks. I understand your point about evaporation but I was also thinking of the impact on undersea currents, temperature and salinity. I shall read your links and continue. Thanks again.
Anyone else out there with info all gratefully received.
This link to the US Geological survey site gives you information about ground water dischare. There is twice as much ground water as there is fresh water. http://ga.water.usgs.gov/edu/watercyclegwdischarge.html In fact all rocks, except for a small section above the water table are saturated. Since water is heavier than oil, when an oil resevoir is penetrated, the water forces the oil out of the ground causing a gusher.
I think most of the groundwater enters the oceans through seeps driven by osmosis. The salty water draws the fresher water out of the rocks, due to the same process that your skin wrinkles in the bath. The salty fluids in the skin soak up the fresh bath water. See http://www.loc.gov/wiseguide/jun05/toes.html
I think you will find that salinity near the coasts is lower than that at the same depth further from shore, even at great depth.
Do the oceans offer an engineering oppertunity?
“Since the ocean component of the climate system has by far the biggest heat capacity” , I’ve been wondering if the cool waters of the deep ocean could be used to mitigate the effects of global warming for a few centuries until we have really depleated our carbon reserves and the system can begin to recover on its own. As repugnant as it is to suggest engineering solutions for mans’s folly – this is one I haven’t heard bantied about – so please shoot it down! IF cool deep sea water were mixed relentlessly with surface water by some engineering method – (e.g. lots of wave operated pumps and 800m pipes) could that enouromous cool reservoir of water a) mitigate the thermal expansion of the oceans because of the differential in thermal expansion of cold and warm water, and b) cool the atmosphere enough to reduce the other wise expected effects of global warming? My back of the envelope calculation suggests that we should be able to do this for several centuries without warming the deep waters very much while maintaining constant surface water temps. (you need about 100 liters/s/km^2 to cool present forcings)- during which time we kick the carbon habit. Besides all of the horrible unknowns, the biggest problem is pumping that much water up and down.
Regarding comment 74: That would be a horrible idea to attempt, even if it is feasible (and using OTEC it might be, since that will actually generate a little usable energy in the process), for at least three very big reasons:
1 – The colder surface water would mean that far less energy is being lost to space, making the energy imbalance even worse.
2 – Cold water at the bottom of the ocean holds a lot of dissolved carbon and bringing it to the surface will both acidify surface waters and emit carbon into the atmosphere. The amounts of carbon would be vast, on a scale comparable to current human emissions.
3 – It would involve messing with the environment on an unprecedented scale, and such things generally cause a lot of other effects which we didn’t even imagine could happen.
Google and my brother brought me to this page. I believe you all have explained the heat loss from the surface of the world’s oceans. Ideas that I thought of (solar cycle now at solar minimum, transfer of heat from the oceans to the atmosphere via recent active hurricane seasons, and ice melt runoff) were all taken.
One point that was not fully considered was the contribution of the melting of the artic ice sheet. It is not only smaller in area, but thinner as well. This, when added to the contributions of the Antarctic, continental glacier, and Greenland melting should account for the discrepancy.
It goes without saying that melting ice cools the water.
With climate and Greenhouse Gas thoeries of Global warming, it appears to me that of most interest is the interface between the Earth’s atmosphere and space and the flow of radiated heat from the sun, what’s reflected back from Earth’s surface and the consequences of any change in that balance.
So what do the Astrophysicists suggest? The most compelling arguments to me are from the variablility of the earth’s orbit around the sun and the Sun’s variable output of radiated energy. Based on this, energy of all sorts from the sun is predicted to decrease from now until 2030 when it will slowly increase again.
Since the oceans are massive heat sinks, they cause delays (around a decade or more) in observed temperature changes from changes in radiated energy from the sun. The slight drop in net ocean heat from 2003-2005 fits what the Astrophysicists predicted some years ago. Some of them have also successfully predicted El Nino phases and some of the recent droughts. This tends to lend a certain amount of credibility from my view point as no other branch of science appears to be able to!
It would be very interesting, to say nothing of it being potentially very useful if Astrophysicists and Climate Scientists got together for a brain storming session. Is this doable?
Barton, may I disagree? There are two points in this: the sun is since ~1940 higher in intensity than ever in the previous +/- 400 years and probably 8,000 years. This anyway may explain most of the warming in the 1900-1940 period. Second: solar intensity on short term is inversely correlated with low cloud cover (see the reference here), which intensifies the variation and probably the long-term trend too. If the same happens for GHGs remains to be seen (but the trend over the last decades is the other way out for cirrus clouds).
And even if there is little trend of solar in the past decades (there still is some discussion about an upswing in minimum solar strength), the impact of the higher-than-past level of solar intensity is delayed by the oceans and only now may come into equilibrium…
Ferdinand, have you an explanation in your theory for why none of the other factors act as forcings during the same time period? It sounds like your theory is that somehow only the sun, and nothing else, contributes to the observed change.
Do you have a way to show that the rest — such as aerosols +co2 +AGHG — somehow sum to zero?
Hank, I never said that CO2 has no influence at all. But I have doubts about the height of the influence, as currently implemented in climate models.
As already said in previous discussions:
– the theoretical influence of doubling CO2 is rather well known, based on radiation absorption bands. But that gives less than 1 C warming without feedbacks.
– the influence of aerosols is highly uncertain and IMHO overestimated. If this is the case, then the influence of GHGs (including feedbacks) is also overestimated, or it is impossible to fit the 1945-1975 temperature trend.
– the influence of water vapor feedback itself is positive, but clouds seems to act as a strong negative feedback (while current climate models see clouds as a neutral to positive feedback!).
– the influence of solar variations IMHO is underestimated, as these are accompanied with a positive cloud feedback (and specific influences in the stratosphere).
This has implications for future scenario’s, as a lower sensitivity for CO2 (and a higher for solar) means that there will be less warming for the same CO2 emissions (assuming no large excursions of solar).
With halve the sensitivity for CO2 (~1.5 C for 2xCO2, including feedbacks), reduced influence of aerosols (1/4th) and increased solar sensitivity (~1.5 times), one can fit the temperature trend of the last century…
Based on what I have read about aerosols, cloud behaviour and solar, in my opinion the real response to 2xCO2 may be at (or even below) the low-end scenario of the IPCC…
Re the Sun — I’ll repeat my calculations here. Please let me know if I made a mistake or mistakes.
The emission temperature of a planet, the temperature as measured from some distance away, can be found with this equation:
Te = (S (1 – A) / (4 sigma)) ^ 0.25
where Te is in kelvins, S is the Solar constant, A the Earth’s bolometric Bond albedo, and sigma the Stefan-Boltzmann constant. S at Earth’s orbit averages 1367.6 Watts per square meter, the Earth’s albedo is about 0.3 (assume this is exact for the moment), and sigma has the value 5.6704 x 10^-8 in the SI, which gives an emission temperature for Earth of 254.9 K.
Global warming since 1880 or so has been about 0.6 K. How much would the Solar constant have to have risen to provide that much of an increase? Solving for S, we have
S = 4 sigma Te^4 / (1 – A)
Plugging our results for Te back into this equation, it gives S = 1367.9 (which shows the problems of using significant digits). If we take Te = 254.9 – 0.6 = 254.3, we get S = 1355.1. In other words, the Solar constant would have to have increased by 12.8 Watts per square meter to get the observed warming. The Solar constant has, in fact, risen by about 1 Watt per square meter over this time period. Solar can’t do it alone without violating conservation of energy.
Now, there may be some feedback in the Earth system that “multiplies” changes in the Solar constant. But until the Solar freaks identify what that feedback is, their theory fails on basic scientific grounds.
What you did forget is to include the greenhouse effect. Of the 1370 W/m2 solar radiation, some 240 W/m2 is reaching the surface. There must be an equilibrium at the TOA, but part of the outgoing radiation from the surface is retained by GHGs, including water vapor. That lowers the ratio between TOA solar radiation and what reaches the surface as solar SW + LW + greenhouse LW.
This is far better explained by Dr. Scafetta in this RC discussion…
And please reread the solar-cloud connection of fig.1 of Kristjansson, where over a solar cycle (+/- 0.5 W/m2 TOA), the observed change in low cloud cover is within +/- 2%. I have no figures yet what this means in radiation budget (expect some answers in a few weeks). But a change of -1.7% in (high level) clouds over 1 decade caused a change of 1.2 W/m2 in reflected SW and ~3 W/m2 more IR radiation to space over the 30N/S band. Or a pretty significant change in radiation budget…
Has anyone considered the possibility that the Earth’s heat balance is externally driven by a phenomenon related to solar activity.
Most climatologists limit the solar interaction with climate models to changes in solar insolation. This is understandable, since it is the only form of interaction that is easy to understand and quantify.
However, it may be possible that slight changes in solar input (eg. UV radiation levels in the stratosphere or cosmic ray influences on low level cloud formation) may be amplified by natural resonance matching to the overall climate system. This may lead to long term heating and warming cycles in the oceans that are the result of upwheling of cool water from deep within the oceans.
Indeed, historical data shows that about every 30 – 60 years the Nothern Pacific ocean undergoes sustained periods of cooling which by their scale and magnitude must influnece the overall heat balance of the planet.
Though it still considered very controversial, evidence is emerging that regime changes in the Pacific ocean (the last of which was in 1977) may be caused by small variations in the rotation rate of the Earth that are forced by changes in the level of solar activity.
[Response: The answer to your first question is, yes, of course. The conclusions from those studies do not support the idea that solar activity (which has been roughly stable since the 1950s) has anything to do with the ongoing rise in temperatures. We are among those climatologists who have explored the intereactions of UV forcing as a mechanism to enhance the solar impact and that is a valid idea (we have some new results which I’m sure you’ll find interesting under review at the moment). However, the lack of solar activity trend in recent decades makes it very difficult for any solar mechanism (even unknown ones) to account for the recent climate changes. As to your last point, the idea that Pacific climate is affected by tiny changes in the Earth’s rotation is ridiculous (and not controversial at all). The causality is the other way around if there is any connection at all. -gavin]
I don’t usually write on internet forums, and neither I like to call attention upon myself. But when talking about the recent cooling of the Earth’s ocean, one of the physical reasons that should immediately pop on our minds are changes in the earth’s reflectance. And there are indeed some indications that the Earth’s albedo has changed in the recent times, in ways consistent with the ocean’s behavior. This is depending on which albedo dataset you are using of course, as they not all agree.
RE: #91 – some of us simply want to understand and account for all components of the energy equations, no agenda aforethought. To allude to an oft overused quote, that which cannot be measured cannot be improved.
I’ve been following the discussion both here and at Pielke’s Climate Science. Little attention seems to have been paid to the geographical distribution of the changes in figure 2 of Lyman(I think – not got the paper on me). Apologies if this has been answered here – but if it is I’ve somehow missed it (been doing loads of reading to get up to speed on it).
I assume therefore that we’d expect to see the cooling manifest itself on the Western regions of the Atlantic and Pacific basins, also in a ring around the Antarctic.
Can someone tell me why this would be expected and would not be a diagnostic?
Has anyone read the full text of this recent article from GRL? All I can see is the abstract, and can’t understand it as a nonspecialist. I wondered if it relates to the ocean heat content change described.
GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L17604, doi:10.1029/2006GL026826, 2006
Relaxation of central Arctic Ocean hydrography to pre-1990s climatology
_Upper ocean hydrography in the central Arctic Ocean has relaxed since 2000 to near-climatological conditions that pertained before the dramatic changes of the 1990s. The behavior of the anomalies of temperature and salinity in the central Arctic Ocean follow a first-order linear response to the AO with time constant of 5 years and a delay of 3 years._
Barton, sorry for the delay (had no Internet access the whole past week)…
If we accept the figures of Scafetta and West, the practical (observed in different ways) influence of solar changes within the 11 year cycle is ~0.11 K/W/m2 (the W/m2 at the TOA, the K at the surface) and for changes within the 22 year cycle, that increases to ~0.17 K/W/m2. For longer cycles (or non-cyclic trends) this must be substantially higher, as there is no relaxation due to opposite trends in a cycle. Anyway over 0.2 and maybe over 0.5 K/W/m2. Or the increase of 0.6 K over the past century may have been caused for at least for 33% by solar up to maybe over 80%, if one assumes a 1 W/m2 TOA solar energy increase over the past century. But the latter is quite uncertain, as that is based on proxies. We only have real measurements for one 22 year solar cycle…
That is based on practical evidence, including all feedbacks (thus including cloud feedback). Clouds are such a strong factor in the whole equation, that any theoretical calculation fails if the real feedback of clouds is not included…
RE #7 and 18: the missing 10^22 joules — Hurricanes could do that…
Dad was a hurricane forecaster in Grady Norton’s day. He instilled in me a respect for their order of magnitude.
Given that a hurricane removes something like 5*10^19 joules per day from the ocean (http://www.aoml.noaa.gov/hrd/tcfaq/D7.html), I too am curious as to hurricanes’ purpose in Mother Nature’s scheme of things. 200 hurricane days in three years is not much of a stretch and it’s all the energy you’re missing. Ten a year at a week apiece…. Have I mis-read that noaa page?
Looks to me like hurricanes are Mother Nature’s safety valve that blows excess heat right around the insulating layer of GHG, exhausting to the troposphere. From there I assume it’s an easy hop to space.
I’m an old boiler guy, so the safety valve analogy is natural to me. Others might prefer the analogy of fire sprinklers.
Old Jim Hardy, an interesting post and thanks for the link; helpful facts.
I like the safety vavle analogy. Makes me think Dr. Lovelock has a keen sense of perception. I am not a Gaia guy, but one can think of the planet using the hurricane, cyclone safety valve to dump excess heat. But, it appears to be limited in its capacity to cool things down.
As a boiler man, you know the safety valve will keep whistling a bit as the pressure diminishes. If pressure rises again, the safety valve might again come into play. Too much extra heat might overpower the safety valve and chaos ensues. One could say too much extra heat at the earth surface will greatly excite the hurricane safety valve (maybe too much, too often) but not enough heat will be jettisoned to the troposhere and will remain to melt glaciers, warm air currents, disrupt preciptation patterns and, in general, muck up the system
Comment by John L. McCormick — 13 Sep 2006 @ 8:37 AM
Dear Mr. Hardy;
I wanted to thank you for your post. I have been playing here for only a few weeks and there seems to be a loss of familiarity in the data that has been discussed. It was almost a matter of dumbfoundedness after what I had learned in my youth, (From a Miami NHC Eyewall Flight Specialist).
I reviewed your reference and was amazed to see the logic of old return. Dr. Landsea clearly demonstrated in the FAQ what I thought was apparently news here. (I did not see your reference to the 200 hurricane days in your link; however, what you demonstrated is reasonable.)
It is kind of amazing that this “new” generation appears to have to start all over again. (See: http://namma.msfc.nasa.gov/index.html ) to learn what the “Gray Heads” have known for decades. I cannot wait to see the new data that they have gathered on this junket.
Under most conditions, the stratosphere puts a lid on heat exhaust from hurricanes in the troposphere making it to outer space. Unlike the troposphere, temperature in the stratosphere increases with height – similar to warm air aloft in the troposphere putting a cap on cloud formation.
However, it is quite possible that the Hadley Cell could transport the latent heat to the Ferell cell for exhaust at the Poles. If you look at some of the recent posts on NASA’s Goddard site regarding the upper altitude (@700mb) polar air temperatures and the NCEP NESDIS Jet Stream/Barometric data the transport appears to be possible. It just may be that the transport is occurring at the tropopause or an intermediate layer of around 6-7 Km, based on some recent data coming out of the NAMMA research. (I would possibly keep my eyes on data regarding the Calipso/CloudSat data as well. Just because vertical movement may be limited, a horizontal transport may be available instead. Or put another way, “Just because the door is closed does not mean that an open window is not available.”)
Comment by L. David Cooke — 13 Sep 2006 @ 12:18 PM
Thanks guys, for your kind remarks.
I assumed, perhaps naively, that heat rejected by a hurricane to the troposphere would upset the equilibrium and quickly radiate away, the stratosphere being comparatively transparent to longwave.
“The spectrally averaged effective emission temperature of the earth is about 252 K, which corresponds to the physical temperature near the 6 km level. This is also then the approximate location of the spectrally averaged TAU = 1 level from which most of outgoing flux can be said to originate from.” (http://www.realclimate.org/index.php?p=58, comment #17)
old jim himself
Comment by old jim hardy (aka analog) — 13 Sep 2006 @ 12:52 PM
Re: Gavin’s response to #86
Solar activity does have to have increased since 1940 to explain a significant part of the recent warming. All that is needed is unrealized climate commitment from continuation of the high levels of solar forcing reached by 1940. A constant forcing applied to a pot of water, can still result in an increase in the temperature of the water. The realization of the temperature increase from the high level of solar activity was delayed/interrupted by a period of aerosol cooling, and there was also a significant, but not necessarily large, contribution from the increase in GHG forcing, and perhaps a contribution from internal climate variation as well.
Current models are not good enough to dismiss one of the highest levels of solar activity in 8000 years as a mere coincidence, or to apportion attribution.
[Response: Think about it as a simple heating function with a large heat capacity. If you increase the heating and then keep it steady, you expect a delay in the response, but than an asympotoic trend to the new warmer state. Responses get smaller as time goes on. Now in the real world the temperature response is increasing through time – this is inconsistent with solar being the dominant driving. -gavin]
I agree it would be asymptotic to the new warming state if it were a simple heating function, however, if that was the case for the climate, we wouldn’t need the models. The climate commitment studies show that temperature increases are significant for the first century and equilibrium sea level rise can take a millenium. We know that an aerosol cooling period interrupted the warming trend. The same feedback mechanisms that are proposed to enhance the CO2 warming are also applicable to solar forcing, including warming induced increases in methane release. Non-linear positive feedbacks from reductions in ice and snow cover can also be operative.
If we had better sea level rise data for the whole period, we might see that the heat storage curve into the ocean had a shape that better matched the simple function approximation than the land surface data does, or we might have better information on internal climate modes that confused or delayed the temperature response.
If climate senstivity to CO2 is eventually shown (rather than just assumed) to be close to the sensitivity to solar, I think a case can then be made that the GHG attribution should be equal or higher than the solar attribution, despite the large uncertainty in our knowledge of the increase in solar forcing. I am hopeful that breakthroughs in the physical realism of the models, such as incorporating a parameterized version of the skin effect, will allow us to get confidence in this climate sensitivity to CO2, even if we still don’t have the data needed to validate the models to the accuracy needed for longer range projections.
“… Sami Solanki and his team at the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany, have looked at the concentrations of carbon-14 in wood and beryllium-10 in ice as far back as back 11,000 years ago. ….”It’s a boom-bust system, and I would expect a crash soon.”
“…. the most recent calculations by Solanki’s team suggest that the sunspot crash could lead to a cooling of the Earth’s atmosphere by 0.2 Â°C …. as big as the most optimistic estimate of the results of restricting greenhouse-gas emissions until 2050 in line with the Kyoto protocol.”
“… “What might happen is that the sun gives the planet a welcome respite from the ravages of man-made climate change – though for how long, nobody knows. During the Little Ice Age, the fall in average global temperature is estimated to have been less than 1 Â°C and lasted 70 years. The one before that persisted for 150 years, but a minor crash at the beginning of the 19th century lasted barely 30. For now, we will have to keep watching for falling sunspot numbers. “The deeper the crash, the longer it will last,” Weiss says.
“There is a dangerous flip side to this coin. If global warming does slow down or partially reverse with a sunspot crash, industrial polluters and reluctant nations could use it as a justification for turning their backs on pollution controls altogether, makingmatters worse in the long run. There is no room for complacency, Svalgaard warns: “If the Earth does cool during the next sunspot crash and we do nothing, when the sun’s magnetic activity returns, global warming will return with a vengeance.”
END EXCERPT, taken from CCNet 123/06 – 15 September 2006
[My comment: the possible cooling from the Kyoto protocol alone has long been described as trivial by opponents, and as only a bit of what’s needed by proponents. It appears all agree that the sun’s effect over 11,000 years looks — like Kyoto — tiny compared to the anthropogenic warming expected -hr]
It would be interesting to know what climate model and scenarios Solanki’s 0.2 degree C temperature drop is based upon. This might be being achieved in the face of significant CO2 forcing in a model with significant anti-solar bias in its surface albedo. Even with these possible issues, it buys us 50 years of economic growth and technological development and a net reduction in the heat content of the ocean, that the future warming must overcome. A richer and more technologically capable civilization may not only be able to better afford to address warming, but may also be able to do it more cheaply and insightfully.