If my previous post I included a link to a Gavin Schmidt comment:www.realclimate.org/index.php/archives/2011/10/global-warmin..."Two further points have come in comment threads recently that are related to this. The first is whether the changes in deep ocean heat content have any direct impact other than damping the surface response to the ongoing radiative imbalance. The deep ocean is really massive and even for the large changes in OHC we are discussing the impact on the deep temperature is small (I would guess less than 0.1 deg C or so). This is unlikely to have much of a direct impact on the deep biosphere. Neither is this heat going to come back out from the deep ocean any time soon (the notion that this heat is the warming that is ‘in the pipeline’ is erroneous). Rather, these measures are important for what they tell us about the TOA radiative imbalance and it is that which is important for future warming."His last sentence got me looking for recent TOA satellite measurements. I came across a paper by Loeb et al. on TOA variability and Figure 2f shows the CERES monthly TOA radiation anomalies for the 10-year period 2000-2009.Advances in Understanding Top-of-Atmosphere Radiation Variability from Satellite Observationshttp://meteora.ucsd.edu/~jnorris/reprints/Loeb_et_al_ISSI_Su...While there are ups and downs, my eyeball indicates that over the decade was was little or no net radiation imbalance at the top of the atmosphere and certainly not a 1 W/m2.A couple of questions. How does this square with the standard radiation budget? How is this near zero imbalance related to the surface temperature plateau? What is cause and what is effect?DB2
Looking at another TOA paper by Loeb et al. one can find the CERES data graphed for ten years, 2001-2010, in figure 2b. The curve is smoothed but shows the same pattern: starting high in 2001, dropping in 2002, then leveling near zero until the dip in 2008 and a rise in 2009, finishing negative in 2010.http://xa.yimg.com/kq/groups/18383638/336597800/name/ngeo137...http://meteora.ucsd.edu/~jnorris/reprints/Loeb_et_al_ISSI_Su...However, I am puzzled as to how the authors then show in Figure 3 that the net TOA flux is positive over the entire ten-year period, with an average of 0.5 W/m2.How do they get from Figure 2b to Figure 3?DB2
DB2: How does this square with the standard radiation budget? How is this near zero imbalance related to the surface temperature plateau? What is cause and what is effect?All good questions.In fact, this paper is an excellent example of what I consider to be the primary research question in the entire field of statistics: How can we correctly separate out all the cause-and-effect relationships that may exist between several 2D and 3D random fields?The "random fields" in question here are:(a) Top-of-atmosphere long-wave radiation(b) Atmospheric temperatures(c) Atmospheric transparency (cloud cover)(d) Humidity(e) Ocean heat content(f) Land heat content(a) and (c) are essentially two-dimensional, being spheres. The others are all three-dimensional random fields. All are time-varying, and affect each other in interesting ways. The authors gloss quickly over the statistical challenges in sorting out causes from effects, but for me this is the central question.Noel Cressie, in France, is grinding his way slowly towards a formal solution, building on the theory of kriging, but I think there are better ways. It will be interesting to present this to my seminar this summer, to see what some really bright minds might be able to produce.Loren
How do they get from Figure 2b to Figure 3?I don't understand all the details but Figure 2 shows the "anomaly" while Figure 3 shows the "net". The paragraphs on page 2 describe the difference:"A limitation of the satellite data is their inability to provide an absolute measure of the net TOA radiation imbalance to the required accuracy level. The net TOA radiation imbalance is the difference between incoming and outgoing radiation, quantities that are well over two orders of magnitude larger than the net TOA imbalance. It is thus necessary to anchor the satellite data to an absolute scale using other data."They then go on to talk about various datasets different authors use to anchor the data, and describe their choice. The result is these other datasets are combined with the data in Figure 2 to get Figure 3.
"The net TOA radiation imbalance is the difference between incoming and outgoing radiation, quantities that are well over two orders of magnitude larger than the net TOA imbalance. It is thus necessary to anchor the satellite data to an absolute scale using other data."I get the impression that they have already done the 'anchoring' before Figure 2. At any rate, in discussing Figure 2 they write:"During La Niña conditions (negative Multivariate ENSO Index, or MEI), the Earth tends to gain more energy....The two-year period following mid-2007 is characterized by strong La Niña conditions that result in a maximum in net radiation gain into the climate system in late 2008, followed by a sharp decline (of up to 2Wm-2 in the tropics) when a transition to El Niño conditions occurs in mid-2009."And yet despite the changes just mentioned, Figure 3 shows a remarkably even Net TOA flux that varies from 0.1 to 1.1 W/m2. I send any enquiry to Dr. Loeb; we'll see what he replies.DB2
It will be interesting to present this to my seminar this summer, to see what some really bright minds might be able to produce.It would be interesting to read a summary of their solutions after the class.DB2
Things I am aware of are that absolute TOA from CERES is not reliable though the deltas are quite reliable, and that Spencer does a lot less speculative fiction in his published science than he does in his blog entries, and still generates papers that are... "subject to considerable argument" shall we say... which is understandable given his interpretations. You might be interested in this guy who seems to have pulled together some of this information as well. Don't be too put off by the blog title, there's science here, much more than opinion... http://scienceofdoom.com/category/measurement/
I send an enquiry to Dr. Loeb; we'll see what he replies.In an e-mail Loeb explained that Figure 2 shows anomalies for the ten-year period and averages, by definition, to zero. Figure 3 shows the net TOA imbalance.DB2
In an e-mail Loeb explained that Figure 2 shows anomalies for the ten-year period and averages, by definition, to zero. Figure 3 shows the net TOA imbalance.Thanks.
It would be interesting to read a summary of their solutions after the class.On a problem this difficult?Here's the way it usually works. I take some time out of a regular seminar to give my perspective on a *really* hard problem, and wave my hands a little to try to convey why this is also an interesting problem whose solution might be extraordinarily valuable to many people. I get a few questions, but not much more than that. Then, a month or two later, some student will wander into my office and say, "Remember that idea you presented a while ago...?" It will turn out that he or she has been turning it over and pondering it. I offer to set up an independent study, or thesis credits, or something so that the student can get academic credit for further work. Maybe six months to a year later this results in a formal presentation to the department, and possibly a publication.I have been through this little dance many times, and it is one of the most enjoyable parts of my job. It's also why students keep coming to my lectures, and why the department keeps rehiring me for another year.Loren
It would be interesting to read a summary of their solutions after the class.---On a problem this difficult?I was thinking of first approximations, enhanced back-of-the-envelope sorts of things that often arise in graduate seminars.DB2
I was thinking of first approximations, enhanced back-of-the-envelope sorts of things that often arise in graduate seminars.You are thinking of physics. This is math -- we seldom (if ever) do actual calculations with numbers, even when we are studying numerical algorithms or statistical procedures. In category theory, for example, we are working with exotic algebraic systems that do not even resemble ordinary numbers. In my kind of statistics, space itself is warped or twisted, with infinite dimensions. What we call a "calculation" is typically a complex series of inequalities leading to an asymptotic result -- not a number in sight. It's what give math its innocence and charm.Loren
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