NASA Aqua Sea Surface Temperatures Support a Very Warm January, 2010
by Roy W. Spencer, Ph. D.
When I saw the “record” warmth of our UAH global-average lower tropospheric temperature (LT) product (warmest January in the 32-year satellite record), I figured I was in for a flurry of e-mails: “But this is the coldest winter I’ve seen since there were only 3 TV channels! How can it be a record warm January?”
Sorry, folks, we don’t make the climate…we just report it.
But, I will admit I was surprised. So, I decided to look at the AMSR-E sea surface temperatures (SSTs) that Remote Sensing Systems has been producing from NASA’s Aqua satellite since June of 2002. Even though the SST data record is short, and an average for the global ice-free oceans is not the same as global, the two do tend to vary together on monthly or longer time scales.
The following graph shows that January, 2010, was indeed warm in the sea surface temperature data:
But it is difficult to compare the SST product directly with the tropospheric temperature anomalies because (1) they are each relative to different base periods, and (2) tropospheric temperature variations are usually larger than SST variations.
So, I recomputed the UAH LT anomalies relative to the SST period of record (since June, 2002), and plotted the variations in the two against each other in a scatterplot (below). I also connected the successive monthly data points with lines so you can see the time-evolution of the tropospheric and sea surface temperature variations:
As can be seen, January, 2010 (in the upper-right portion of the graph) is quite consistent with the average relationship between these two temperature measures over the last 7+ years.
[NOTE: While the tropospheric temperatures we compute come from the AMSU instrument that also flies on the NASA Aqua satellite, along with the AMSR-E, there is no connection between the calibrations of these two instruments.]
Putting aside some valid points about sampling and drift in satellite instrumentation (in which a phrase such as “we qualified and accepted it to make sure four types of things wouldn’t go wrong, then we launched it, and found a fifth” comes up a lot) has anyone calculated the amplification factor between the troposphere and the surface?
I believe one of the ‘fingerprints’ of AGW is an increasing amplification trend, such was the heated debate about the Santer v Douglass papers
“FYI this video is even more amazing”
Sure. We don’t expect helicopters with stationary main rotor blades to fly. And they tend to make less noise than that one in your video. These are physically implausible observations. To an uninformed observer, it appears that they do, but fortunately we all know where the problem lies.
Equally, we know that propellers do not continually shed solid aerofoil blades – as one of the videos I posted seems to suggest . So we are fortunate enough to get straight to the root of the problem in that case.
Now take a leap away from those cases. We are trying to observe global temperature trends from sampled data systems.
What do we to conclude when we see a significant step change in global average temperature? Not just the principle of such a step change, but a step change in a *monthly average* value!
How many petajoules appear to be suddenly “changing hands” in the atmosphere when before there were none? What physical short-term mechanisms do we beleive can produce such a change? Is this feasible within the variability we can normally expect from the atmospheric system?
If we have surveyed the characteristics of the global temperature field and designed a “sampling strategy” with that in mind, we can take comfort that we are not observing an artefact of aliasing (this is more a reference to spatial alisasing).
It is quire easy to show that the absolute maximum spacing between temperature samples is about 1000 km for a “weatherless” climate where atmospheric temperature continuously varies beteeen the poles and equator. But the climate has weather patterns at much finer resolution. So the spatial distribution of samples must be much finer than 1000 km to avoid aliasing (=or a “modulated signal”).
I don’t have enough information (the “spectral analysis”) of the spatial climate system to suggest a minimum spacing between samples to capture the variations in the climate across the global temperature field (at a particular elevation). This requires a detailed survey of the physical system prior to sampling.
George: “And unfortunately the central limit theorem, will not buy one a reprieve from a Nyquist violation.”
So true.
George: “Of course sampling theory predicts that if you sample at the correct Nyquist rate, that you can (in theory) exactly reconstruct the original continuous function. ”
I agree, but I think the difference is that the theory has the luxury of infinite time to gather informaton about the signal.
That’s probably the reason why practical systems need to exceed the absolute theoretical minimum by a factor of 5 or 10. Otherwise we can get that hideously distorted “modulated signal” in the first video,
It would possibly be more enlightening to see the total atmospheric column charted in the same manner (hint, hint, Dr. Spencer). If the troposphere is warmer but the stratosphere is cooler, is the net change null? Hmmm. Cooler gasses occupy less volume?, pressure increases slightly?, nacreous clouds form further south?, and all that jazz.
BTW, a lot of the instrument descriptions and tech specs (including calibration and validation methods), as well as the calculations leading to the final data product, are readily available (although a little difficult to sort through) from within the AIRS website and links there. I’m sure they are doing the best they can considering the challenges involved.
And yes, they are not actually measuring “temperature” from over 600 km in orbit, they are measuring “channel brightness” (or peak line intensity in my field) of O2 emissions in far IR and microwave frequencies. Considering everything that could have an impact on those measurements, I’m glad my lab is safely enclosed in a climate-controlled facility on the surface of the planet, where most of the variables can be comfortably controlled.
And I will not stop saying THIS about CO2 radiative emissions, because some people simply refuse to quit believing that it is a gas species with magical properties – absent collision, the only molecule that can absorb at CO2 emission wavelengths is ANOTHER CO2 molecule.If this were not true, it would not be possible to measure molecular emission lines from a satellite that is orbiting the planet at nearly 700 km. Luckily, the ground I walk on is not composed of CO2. No, CO2 “reradiation”, or “back-radiation”, or whatever they are calling it today, CANNOT heat the surface.
1997 was a solar minimum followed by a temperature spike in 1998 due to el nino; 2009 was a solar minimum followed by a temperature spike in 2010 due to el nino.
i’m not a scientist, but…
Jordan (15:51:08) :
…”It is quire easy to show that the absolute maximum spacing between temperature samples is about 1000 km for a “weatherless” climate where atmospheric temperature continuously varies beteen the poles and equator. But the climate has weather patterns at much finer resolution. So the spatial distribution of samples must be much finer than 1000 km to avoid aliasing (=or a “modulated signal”).
I don’t have enough information (the “spectral analysis”) of the spatial climate system to suggest a minimum spacing between samples to capture the variations in the climate across the global temperature field (at a particular elevation). This requires a detailed survey of the physical system prior to sampling.
As our non-linear climate displays deterministic chaos, the scale of sampling to get any sort of accuracy of global temperature would need to be incredibly small. I’ve seen estimates that say that even if a 3-D 1m grid over the entire volume of the atmosphere across the globe was to be used, with a 1 minute sampling rate, the accuracy would still only around 0.1of a degree C.
Not sure what this means in terms of Nyquist frequency?
ps I should add that the videos I attached to my posts are not *my* videos. I searched YT for them – credits due to their authors
“It turns out this is what applied mathematicians call an “ill-posed” problem, meaning that small errors in your radiation measurements — and no sensor is ever perfect — result in big, random-looking errors in your temperature measurements. The satellite people decades ago came up with a solution to this difficulty, and it involves forcing the computer programs calculating the atmospheric temperatures to take into account what we expect the atmospheric temperatures to be. The computer tries to find the closest match to the radiation data from the satellite while making small and reasonable changes away from the average “expected” atmospheric temperatures at the place and season it is looking at. By now I’m sure you can see what the problem is… if someone in a position of authority changes what the computer’s expected atmospheric temperatures are, the satellite measurements will produce different temperature estimates for the same measured heat radiation.”
Thank you D. Ch.
Do I interpret this correctly if I say that when certain climate anomaly happens where troposphere temperature is for one reason or another warmer than surface actually is, this creates disconnect between satellite temperature and surface temperature?
So if we have this exception in place “making small and reasonable changes away from the average “expected” atmospheric temperatures at the place and season it is looking at” this algorithm might not adapt to situation and end up producing warmer surface temperatures that might not represent the actual surface temperatures?
So the satellites really measure the troposphere and use some kind of static formula which should give the surface temperature if standard / expected conditions exist?
I’m no means trying to criticize the satellite measurements; I’m merely trying to understand better the complexity of doing these conversions and situations which might lead into situations where mismatch might be created between satellite data and surface data.
If so, would I be correct if I interpret this so that satellite data is quite accurate information about temperature of troposphere, but while certain conditions exist, it might not be the actual representation of surface temperatures?
And, by the way, this hasn’t been that cold a winter. People just like to say that it is. I guess it makes them feel good.
If you want to persuade people, then admitting the obvious is a first step. It has plainly been a cold winter, on average, in the land portions of the Northern Hemisphere. To deny that is to deny what is plainly in front of your face. And it makes anyone reading think “what other facts is this person prepared to wave away”.
Just as you don’t want the non-alarmists to wave away what you regard as important data, you cannot do it either. Accept that it has been a cold winter on land in the NH, and deal with it, if you want us to accept that it has been a record warm one at sea.
(BTW is has, from my point of view, been a fairly coolsummer. It would also help your cause if you did not leave half the world out of any arguments.)
Btw: About the data flow: Do universities get the raw satellite data, or has it been pre-processed by NASA?
From my specialty (hot water heating).
A one inch copper water line can transport about 60,000 BTUH’s with a 20* delta T.
Compare that with forced air, the duct size needed to transport the same amount of energy with air is about 8″ X 14″.
George E. Smith (15:10:38) :
I would say that all “climatology” is statistics AND that they are practising statistics without a license!
Dave.
[quote JP (16:56:22) :]
Btw: About the data flow: Do universities get the raw satellite data, or has it been pre-processed by NASA?[/quote]
It goes to NASA or JAXA (Japanese NASA) first.
http://magicjava.blogspot.com/2010/01/aqua-satellite-data-processing.html
Jordan,
I come to these blogs to learn things and you taught me something today – thank you. I agree completely whatever we think we are seeing it is certainly effected by spatial aliasing.
If Dr Spencer is out there – or anyone else for that matter. Is there a response to this issue?
D. Ch.
“The satellite people decades ago came up with a solution to this difficulty, and it involves forcing the computer programs calculating the atmospheric temperatures to take into account what we expect the atmospheric temperatures to be. The computer tries to find the closest match to the radiation data from the satellite while making small and reasonable changes away from the average “expected” atmospheric temperatures at the place and season it is looking at. By now I’m sure you can see what the problem is… if someone in a position of authority changes what the computer’s expected atmospheric temperatures are, the satellite measurements will produce different temperature estimates for the same measured heat radiation.”
—–
Fascinating. While I am prepared to believe that this January’s UAH lower tropospheric temperatures are the hottest on record, D. Ch.’s post reminded me of how NASA’s Nimbus 7 satellites failed to detect the ozone hole over the Antarctic. The British Antarctic Survey’s head of the Geophysical Unit, Joseph Farman, made Dobson spectrophotometer readings of the Arctic atmosphere from the time of IGY (International Geophysical Year 1957-58) onward, at Halley Bay, and detected a sharp drop in ozone in 1981. His first instinct was to distrust his instrument, so he ordered a new one. Even with his new Dobson specrophotometer, which arrived in 1982, the ozone hole was evident. Still skeptical, he travelled to McMurdo station 1,000 miles away to take another series of readings in 1983. He would not publish his results until he eliminated all the possibilities. He refused to accept his results partly on account of how anomolous they were compared with the ozone readings from NASA’s Nimbus 7 satellites. It turned out that NASA scientists programmed the Nimbus computers to analyze only ozone data that fell between 180 and 650 Dobson units, which atmospheric models had indicated were well outside of realistic ozone variables. Data falling outside the parameters were considered to be due to instrument malfunctions – and put aside (but fortunately not discarded). This led to a non-detection of the ozone hole by scientists monitoring the most sophisticated technology of the day, while Farman and his more empirical approach using older technology was able to detect the anomoly and in the end draw attention to it.
I can see parallels, but doubt that anything similar has occurred with the UAH satellites. Still, it’s worth thinking about asking to see the raw data, as you recommend to Steve McIntyre.
Aagh – I should, proofread more carefully! Joseph Farman worked only in the Antarctic, not in the Arctic as indicated in one of the sentences of my previous post.
MattN (13:56:37) : You wrote, :About that warm pool in the south Pacific. Might this have somethign to do with it,” and posted this link:
http://www.iceagenow.com/Undersea_volcanic_eruption_in_Tonga_heating_the_water.htm
There’s a link at the bottom of the page to the full post with comments here at WUWT:
http://wattsupwiththat.com/2009/03/19/undersea-volcanic-eruption-in-tonga/
If you were to run through the thread looking for my name you’d find my 13:14:06 comment on 3/19 with the following map, pointing to the location of Tonga. Steve missed the mark by a thousand miles or so.
http://s5.tinypic.com/25kohg1.jpg
The big red blob (scientific term) in the South Pacific is a common response during El Nino events.
http://bobtisdale.blogspot.com/2010/01/south-pacific-hot-spot.html
It also occurs at other times.
Jordan (13:40:58): Jordan, there should be a contact link at Dr. Spencer’s website.
http://www.drroyspencer.com/
He would be the person with the answers to your questions.
Dave in Canada (13:27:54) : You wrote, “Anyone else find it curious that hurricanes down, ocean temps up?”
El Nino events suppress Atlantic hurricanes, so, in effect, it’s the other way around.
SJones (13:03:56) : You wrote, “But if the heat is a result of an El Nino – what’s that got to do with CO2?”
Not a thing. Climate scientists misrepresent the effects of El Nino events. Refer to the following posts that also ran here at WUWT:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of.html
And:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of_11.html
And:
http://bobtisdale.blogspot.com/2009/06/rss-msu-tlt-time-latitude-plots.html
You wrote, “The heat is released by warming in certain parts of the oceans (and which then subsequently warms the atmosphere) – but what has that got to do with AGW?”
Not a thing. There is no evidence that anthropogenic greenhouse gases warm the oceans. Refer to these posts:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
And:
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html
And:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html
Is anyone saying CO2 causes El Ninos?
They try on occasion.
If you have any questions, feel free to ask here or at my website.
“While the tropospheric temperatures we compute come from the AMSU instrument that also flies on the NASA Aqua satellite, along with the AMSR-E, there is no connection between the calibrations of these two instruments.”
But since they fly together there must be a close correlation with the surface track they are observing. So some level of connection might be expected?
Bob, I don’t get it. Is the whole planet warmer this month than it has been for a few decades? Because the sun has been in a funk.
Tom in Florida (12:41:14) : Will someone please make the definite statement that when SST goes higher it is either:
1. due to the release of heat from the oceans and they are cooling
or
2. due to the accumulation of heat in the ocean and they are warming
Which is it?
************
It depends on the time frame. If you’re talking about year-to-year variations, the rises are typically associated with El Nino events. During El Nino events, the tropical Pacific releases heat into the atmosphere, and through changes in atmospheric circulation, the El Nino events cause sea surface temperatures to warm outside of the tropical Pacific. The release of heat in the tropical Pacific also reduces the ocean heat content there.
Then there are multiyear time frames. There are also multiyear aftereffects of strong El Nino events that can cause significant step increases in lower troposphere temperature anomalies of the Northern Hemisphere. Discussed here:
http://bobtisdale.blogspot.com/2009/06/rss-msu-tlt-time-latitude-plots.html
There are also multiyear aftereffects to strong El Nino events in a significant part of the global oceans, Discussed here:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of.html
and here:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of_11.html
If the El Nino causes a multiyear La Nina event, Ocean Heat Content will rise in the tropical Pacific and in many other ocean basins as well during that multiyear La Nina:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
And then there are multidecadal timespans, and the major variable is the Atlantic Multidecadal Oscillation.
http://en.wikipedia.org/wiki/Atlantic_multidecadal_oscillation
Some try to say the Pacific Decadal Oscillation (PDO) has a similar effect but the PDO is an aftereffect of the El Nino and La Nina events.
“Is anyone saying CO2 causes El Ninos?”
RealClimate has all but said those exact words. I beilieve the context was they did not think the Pacific would ever go back to a negative phase.