Dr. Roy Spencer sent me a notice of his most recent post in email. He offers an invitation for anyone to help “figure this one out”. The result could be “worse than we thought”. – Anthony
(edited 8/23/09 0710 CDT: Changed plots & revised text to reflect the fact that NCDC, not CRU, is apparently the source of the SST dataset; also add discussion of possible RFI interference in satellite measurements)
(edited 8/22/09 1415 CDT: added plot of trend differences by month at bottom)
By Dr. Roy Spencer
In my previous blog posting I showed the satellite-based global-average monthly sea surface temperature (SST) variations since mid-2002, which was when the NASA Aqua satellite was launched carrying the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). The AMSR-E instrument (which I serve as the U.S. Science Team Leader for) provides nearly all-weather SST measurements.
The plot I showed yesterday agreed with the NOAA announcement that July 2009 was unusually warm…NOAA claims it was even a new record for July based upon their 100+ year record of global SSTs.
But I didn’t know just HOW warm, since our satellite data extend back to only 2002. So, I decided to download the NOAA/NCDC SST data from their website — which do NOT include the AMSR-E measurements — to do a more quantitative comparison.
From the NOAA data, I computed monthly anomalies in exactly the same manner I computed them with the AMSR-E data, that is, relative to the June 2002 through July 2009 period of record. The results (shown below) were so surprising, I had to go to my office this Saturday morning to make sure I didn’t make a mistake in my processing of the AMSR-E data.
As can be seen, the satellite-based temperatures have been steadily rising relative to the conventional SST measurements, with a total linear increase of 0.15 deg C over the 7 year period of record versus the conventional SST measurements.
If the satellite data are correct, then this means that the July 2009 SSTs reached a considerably higher record temperature than NOAA has claimed. The discrepancy is huge in terms of climate measurements; the trend in the difference between the two datasets shown in the above figure is the same size as the anthropogenic global warming signal expected by the IPCC.
I have no idea what is going on here. Frank Wentz and Chelle Gentemann at Remote Sensing Systems have been very careful about tracking the accuracy of the AMSR-E SST retrievals with millions of buoy measurements. I checked their daily statistics they post at their website and I don’t see anything like what is shown in the above figure.
Is it possible that the NCDC SST temperature dataset has been understating recent warming? I don’t know…I’m mystified. Maybe Frank, Chelle, Phil Jones, or some enterprising blogger out there can figure this one out.
UPDATE #1 (8/22/09)
Here’s the trend differences between the satellite and in-situ data, broken out by calendar month. The problem seems to be mainly a Northern Hemisphere warm season phenomenon.
UPDATE#2 (8/23/09)
Anthony Watts has suggested that the radio frequency interference (RFI) that we see in the AMSR-E 6.9 GHz data over land might be gradually invading the ocean as more boats install various kinds of microwave transmitters. While it’s hard for me to believe such an effect could be this strong (we have never seen obvious evidence of oceanic RFI before), this is still an interesting hypothesis, so this week I will examine the daily 1/4 deg. grids of AMSR-E SST and compute a spatial “speckle” statistic to see if there is any evidence of this kind of interference increasing over time. I should note that we HAVE seen more RFI reflected off the ocean from geostationary TV communication satellites in the AMSR-E data in recent years.
UPDATE#3 (8/24/09)
OK, gang, this is what I found out today before having to leave work. I downloaded the monthly grids of SST from NCDC (both their v2 and v3b products), and I computed the monthly anomalies at each gridpoint relative to the June 2002 through July 2009 period (since that is the period we have AMSR-E measurements for).
I then differenced the later part of the period (since 2007) with the earlier part (during and before 2004), separately for the NCDC and AMSR-E products.
Then I differences THOSE differences.
What it shows is that AMSRE has either spuriously warmed, or NCDC has spuriously cooled, by 1 to 2 deg C over all of the ‘warmer’ waters of the globe. The problem seems to diminish and then go away poleward of about 30S latitude, and poleward of 45N latitude.
This does NOT look like an RFI issue…it is too uniform spatially. Someone has made a major boo-boo…and I hope it isn’t me. 🙂
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Roy Spencer (17:53:54) :
There seems to be some confusion here…..The issue is that two global SST datasets that should show very similar behavior over that period of time have DIVERGED by so much….and fairly consistently over time.
(Quick break from work) Beyond my expertise and ken but looking at the 3 graphs above I’d say black one satellite minus in situ is believeable. Red and Blue – nah.
Ocean temperatures go up by over 0.35 C in a year and a half? Has there been a supervolcano going off under the sea? Mass die off of marine life? Something not quite right there
Leif Svalgaard (11:34:17) :
If you tell us which station(s) are used for the graph then we can accurately calculate the component for any time half of the last 1000 years, so can extend the graph that far.
Yes, thanks. I will take up your offer. Here is the location: nearest to 60 S, 60 W, half way between Ushuaia and Larsen Ice shelf.
E.M.Smith (15:21:58) : While it’s “anecdotal” my son reports significant increases in interference with various wireless equipment since the “Digital TV” cutover hit.
The US switched over on June 12, 09. Other countries have been switching over since before that.
http://en.wikipedia.org/wiki/Digital_television#Timeline
Richard (15:26:52) :
Ocean temperatures go up by over 0.35 C in a year and a half? Has there been a supervolcano going off under the sea? Mass die off of marine life? Something not quite right there
The sea surface temperature has risen, ocean heat-energy content hasn’t. In fact it’s been “slightly falling” since 2003.
We are witnessing heat energy leaving the oceans.
Lucy Skywalker (15:13:35) “[…] Do buoys generally cool more due to wind evaporating spray […]?”
That’s a good one.
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Lucy Skywalker (15:13:35) “[…] are land, sea-above-surface, and sea-below-surface affected differently by a changing Sun? Does land cool with quiet sun while oceans warm? The hemispheric difference is surely a big clue.”
That’s an interesting one (that risks triggering thread-derailing semantic/technical-nitpicking – let’s hope not!) I suggest working shifts in global-distribution-of-water into this.
– –
– –
For those who do not have access to Sidorenkov (2003), Sidorenkov (2005) provides an overview in section 3:
Sidorenkov, N.S. (2005). Physics of the Earth’s rotation instabilities. Astronomical and Astrophysical Transactions 24(5), 425-439.
http://images.astronet.ru/pubd/2008/09/28/0001230882/425-439.pdf
Strongly suggested:
Compare Figure 7 with Bob Tisdale’s Southern Ocean graphs.
http://bobtisdale.blogspot.com/2009/04/closer-look-at-ersstv3b-southern-ocean.html
Again: Good work Bob. This is getting interesting.
Question: Do you know of any related literature? – or other time series that show the same general pattern?
Tom in Texas: You wrote with regards to the correction by Aaron Wells, “Yes, sorry. My point was that its easier to compare the wiggles when the trends originate at the same point (much the same thing as using anomalies).”
But the intent of the graph wasn’t wiggle matching. It was intended to show that the trends were fundamentally the same, that the TLT anomaly trend wasn’t elevated like the AMSR-E data. But this ONCE I will respond to your curiosity:
http://i31.tinypic.com/8y5dvl.png
Bob Tisdale (16:26:26) : “But this ONCE I will respond to your curiosity”
Thanks Bob. It looks to me like ERSST Feb.(?) 2005 is a bad data point.
It wouldn’t affect the trend much, and if anything would make their agreement even closer.
tallbloke (16:02:38) :
Richard (15:26:52) :
Ocean temperatures go up by over 0.35 C in a year and a half? Has there been a supervolcano going off under the sea? Mass die off of marine life? Something not quite right there
“The sea surface temperature has risen, ocean heat-energy content hasn’t. In fact it’s been “slightly falling” since 2003.
We are witnessing heat energy leaving the oceans.
Still doesnt ring right. In over a century the sea surface temps rise matches that. The red and blue curves – seems to be some mistake there.
Why should more energy leave when the energy content is in fact getting less? But indeed if the sea surface gets slightly warmer as is probable this would warm the atmosphere by convection ands radiation.
Yes, anecdotal.
Observation of the TV spectrum shows things are normal with no large-scale, area-wide mixing problems present (equipped with the tools to ‘troubleshoot’, measure, identify and such interference here on this end). Dorothy needn’t click her heels together quite yet and return back to Kansas and analog broadcasts quite yet.
And no oddities to report on other bands either (VHF, UHF incl ham bands, poh-leece, wx service, WiFi, etc) since the switch either. But don’t let that compel anyone from otherwise blaming that which is not observable ‘without instrumentation’.
Reminds me of the sage advice to the newbie ham operator wishing for a tower:
Construct that new tower and wait a fortnight plus a week or so for ‘interference’ reports from the neighbors and town council to pour in … only then is it safe to add the antenna (or beam) of choice to the tower and then wait another fortnight for a repeat of the cycle once more before actually operating …
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vukcevic (15:30:45) :
Yes, thanks. I will take up your offer. Here is the location: nearest to 60 S, 60 W, half way between Ushuaia and Larsen Ice shelf.
Elsewhere you have claimed that your graph was based on many stations. Why do you think that that particular location is important? And what does ‘nearest to 60S, 60W’ mean? Anyway, the variation of the Z-component at that location is nowhere near what your graph shows: http://www.leif.org/research/Z-Component-1595-2010.png
But, that’s our job, E.M., to understand the RF environment and understand the propagation of those signals, plan for the signal levels (for receive) and also what is necessary in the way of transmit signal purity so as not be a ‘nuisance’ on the band to adjacent ‘services’ either within our own service-band or whether adjacent to other ‘bands’ that must be protected from RF that might otherwise cause harm (defined often as ACP or ACPR measurement – adjacent channel power [ratio]).
I have yet to see, except under really, really adverse conditions that the atmosphere and to a slightly lesser extent the ionsophere acts as anything but a linear, passive bi-directional ‘medium’ when it comes to signals; oh, it may change a signals phase (apparent to a receiving party on the shortwave bands as ‘selective fading’) and amplitude (then there is Faraday rotation; let’s save that for another time), but I have yet to witness ‘mixing’ (convolution: two time-varing signals of different wavelength producing a plethora of others) or other obvious non-linear behavior.
So far, for this RF engineer, if you respect the channel plan, build equipment for the dynamic range of the signals expected, restrict or control emissions from one’s transmitters per established or industry standard norms, everything works out (at least to the degree that the system design engineers planned for). I suspect there are other issues as yet unexplained affecting those > 200 MHz wide, AMSR 6.9 GHz ‘receivers’ e.g. as malfunctioning equipment (and that does happen; I have stories in that category too).
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OT, yet more scaremongering in the media;
http://www.smh.com.au/environment/record-hot-spots-all-in-nsw-20090823-ev52.html
http://www.smh.com.au/environment/wild-weather-woman-injured-during-galeforce-winds-20090824-evf6.html
Govn’t and industry can’t have it both ways, something has to give;
http://www.smh.com.au/environment/global-warming/industry-warns-of-carbon-trading-backlash-20090821-etss.html
Well how about this:
At Least 1 Dead from Rouge Hurricane Wave
Those red hurricane waves are pretty bad.
Bob Tisdale (03:27:12) :
“maksimovich: You asked, “Can you separate signals by say firstly nh/sh ratios…”
And create maps? No.”
No problem I have what I need for an example.
This example separates the signals,interanually and geographically well (and imparts a substantial amount of information)
Southern ocean
http://i255.photobucket.com/albums/hh133/mataraka/sstspectraltopography.jpg
Richard (17:10:54) :
Why should more energy leave when the energy content is in fact getting less?
It’s easier if you consider it the other way round.
Energy leaves the ocean raising SST’s on the way, therefore the remaining energy is less. Why it does it is an interesting question, but the SST record shows that this is what happens when the sun gets quieter, like at the end of the C19th, and now. Big el ninos occur when the sun is at minimum, especially after a run of high cycles.
To me, the simplest and most obvious answer is that the oceans absorb and retain energy when the sun is strong, and release energy when the sun goes quiet.
This seems to happen both at decadal and multidecadal timescales. i.e. over the ~11 year solar cycle and after a run of a few high cycles.
Leif Svalgaard (18:04:05) :
———
It was not necessarily meant to. 60S 60W is an area well known for the high speed currents, where warm water currents of Pacific and (cold saline) Circumpolar current squeeze trough into South Atlantic.
Recent study suggests that oceans’ currents may have an effect on geomagnetic intensity. Chart from NOAA (Dec 2005) shows mag S pole drift for period 1590-2005. Comparing two, it might give an indication if there is an effect.
tallbloke (01:11:06) :
Energy leaves the ocean raising SST’s on the way, therefore the remaining energy is less. Why it does it is an interesting question, but the SST record shows that this is what happens when the sun gets quieter, like at the end of the C19th, and now. Big el ninos occur when the sun is at minimum, especially after a run of high cycles.
To me, the simplest and most obvious answer is that the oceans absorb and retain energy when the sun is strong, and release energy when the sun goes quiet.
This seems to happen both at decadal and multidecadal timescales. i.e. over the ~11 year solar cycle and after a run of a few high cycles.
This sounds reasonable. The radiative balance becomes negative? More is being radiated out than in. Another analogy would be a bucket of water with a heater on top. As you turn up the controller the water absorbs radiation and heats up, when you turn it down it radiates more than it absorbs and cools, but while doing so the surface layer gets hotter? Wonder if anyone has done such an experiment to confirm this?
And where is the data to confirm your statement this happens? This would explain the sudden increase in the SST. But by that much? Still doubtful
To square the circle one really needs to propose independent variability within the oceans i.e. independent of direct forcing from either sun or air.
I say that because there are no cycles in air or sun to explain 25 to 30 year oceanic phase shifts and often oceanic cycles either oppose or supplement solar cycles so I’m a little doubtful about the suggestion that El Ninos dominate when the sun is at solar minimum.
On the other hand tallbloke has said he has noted that the phase shifts occur around minimum on every third cycle and someone else suggested a mechanism but I’ve no idea whether that stacks up.
What does seem clear is that if the oceans are releasing energy faster as during an El Nino event then unless the solar input is more than compensating for the energy lost then the ocean energy content falls even as the air warms.
tallbloke (16:02:38) :
Richard (15:26:52) :
Ocean temperatures go up by over 0.35 C in a year and a half? Has there been a supervolcano going off under the sea? Mass die off of marine life? Something not quite right there
The sea surface temperature has risen, ocean heat-energy content hasn’t. In fact it’s been “slightly falling” since 2003.
We are witnessing heat energy leaving the oceans.
But surely it’s been leaving the oceans since 1997/98 at least. Why are the high SSTs still at the same level as they were then. This ocean cooling stuff just doesn’t stack up.
vukcevic (01:46:01) :
60S 60W is an area well known for the high speed currents, where warm water currents of Pacific and (cold saline) Circumpolar current squeeze trough into South Atlantic.
Why is your curve different from mine?
Could satellite data be systematically high? The idea is they don’t ‘measure’ water temperature but the air “immediately” above. Could Wingo’s surmise be on track with rising albedo throwing calibration studies. Light is a wave as well as quanta.
“We are witnessing heat energy leaving the oceans.
But surely it’s been leaving the oceans since 1997/98 at least. Why are the high SSTs still at the same level as they were then. This ocean cooling stuff just doesn’t stack up.”
The only way for it to stack up is to set the rate of solar energy going into the oceans against the rate of (former) solar energy leaving the oceans for the air.
Thus throughout the 30 years up to 2000 there was a predominance of El Ninos releasing high levels of energy to the air but the ocean energy content nevertheless rose most likely because the solar cycles 21, 22 and 23 were all at historically high levels of activity.
I know that is at odds with what Leif Svalgaard tells us about the smallness of solar variability from cycle to cycle but it’s all we have to go on unless one accepts the CO2 forcing scenario. To my mind the CO2 scenario cannot be right because the flexibility and speed of the hydrological cycle always deals effectively with any attempted deviation of the air temperature above or below ocean SST temperatures globally.
The period 1945 to 1975 is instructive because then we had a very active solar period during cycles 18 and 19 ( at peak, even higher than during 21,22 and 23) but there was a some of cooling of the air globally because of a negative oceanic phase.
Then solar cycle 20 was a bit weaker and the oceans remained negative and the combination gave a more significant downward trend in temperatures during the early 70s.
Now all that suggests a pretty high responsiveness of the global air temperatures to combined solar and oceanic trends but that remains at odds with what we think we know about the energy quantities involved.
I have suggested that the answer is that there is a very fine balance between energy entering the oceans and energy leaving it and additionally the oceans themselves have their own internal characteristics independent of sun and air which periodically accelerate and decelerate the speed of the flow of energy through the Earth system. In the process of accelerating and decelerating the flow of energy the oceans themselves generate a variation in the amount of heat energy produced within the system which is independent of the solar contribution.
When the oceans slow down the rate of energy flow more energy is converted to heat and when the oceans speed up the rate of energy flow then less energy is converted to heat. Just like a resistor in an electric circuit.
I don’t expect that description to be readily accepted by many at this point but I am hopeful for the future.
Richard (02:06:01) :
water absorbs radiation and heats up, when you turn it down it radiates more than it absorbs and cools, but while doing so the surface layer gets hotter? Wonder if anyone has done such an experiment to confirm this?
And where is the data to confirm your statement this happens? This would explain the sudden increase in the SST. But by that much? Still doubtful
The oceans, their varying salinity, and their currents both lateral and vertical are a good deal more complex than a bucket experiment, but be my guest. 😉
What explains the sudden fall in SST’s by the same sort of amount previous to the 0.35C rise? And is 0.35C really all that much anyway?
John Finn (03:46:39) :
But surely it’s been leaving the oceans since 1997/98 at least. Why are the high SSTs still at the same level as they were then. This ocean cooling stuff just doesn’t stack up.
According to my calcs, the oceans gain heat whenever the sunspot count exceeds around 40/month. So the oceans gained quite a lot of heat during solar cycle 23 after the big el nino heat release during the cycle22/23 minimum. Once the sunspot count dropped after 2003, the oceans started releasing heat energy.
You need to understand SST’s can be high for different reasons: energy entering from above, energy welling up from below.
Richard (02:06:01) :
And where is the data to confirm your statement this happens?
SST data, OHC data, sea level data, LT data.