Guest Post by Willis Eschenbach
I’ve been thinking about the Argo floats and the data they’ve collected. There are about 4,000 Argo floats in the ocean. Most of the time they are asleep, a thousand metres below the surface. Every 10 days they wake up and slowly rise to the surface, taking temperature measurements as they go. When they reach the surface, they radio their data back to headquarters, slip beneath the waves, sink down to a thousand metres and go back to sleep …
At this point, we have decent Argo data since about 2005. I’m using the Argo dataset 2005-2012, which has been gridded. Here, to open the bidding, are the ocean surface temperatures for the period.
Figure 1. Oceanic surface temperatures, 2005-2012. Argo data.
Dang, I like that … so what else can the Argo data show us?
Well, it can show us the changes in the average temperature down to 2000 metres. Figure 2 shows that result:
Figure 2. Average temperature, surface down to 2,000 metres depth. Temperatures are volume-weighted.
The average temperature of the top 2000 metres is six degrees C (43°F). Chilly.
We can also take a look at how much the ocean has warmed and cooled, and where. Here are the trends in the surface temperature:
Figure 3. Decadal change in ocean surface temperatures.
Once again we see the surprising stability of the system. Some areas of the ocean have warmed at 2° per decade, some have cooled at -1.5° per decade. But overall? The warming is trivially small, 0.03°C per decade.
Next, here is the corresponding map for the average temperatures down to 2,000 metres:
Figure 4. Decadal change in average temperatures 0—2000 metres. Temperatures are volume-averaged.
Note that although the amounts of the changes are smaller, the trends at the surface are geographically similar to the trends down to 2000 metres.
Figure 5 shows the global average trends in the top 2,000 metres of the ocean. I have expressed the changes in another unit, 10^22 joules, rather than in °C, to show it as variations in ocean heat content.
Figure 5. Global ocean heat content anomaly (10^22 joules). Same data as in Figure 4, expressed in different units.
The trend in this data (6.9 ± 0.6 e+22 joules per decade) agrees quite well with the trend in the Levitus OHC data, which is about 7.4 ± 0.8 e+22 joules per decade.
Anyhow, that’s the state of play so far. The top two kilometers of the ocean are warming at 0.02°C per decade … can’t say I’m worried by that. More to come, unless I get distracted by … oooh, shiny!
Regards,
w.
SAME OLD: If you disagree with something I or anyone said, please quote it exactly, so we can all be clear on exactly what you object to.
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So…the thermal capacity of the oceans is 1000 times that of the atmosphere. The upper 2.5m layer of ocean has the same heat capacity as the entire atmosphere above.
48% of the oceans volume is found in the top 2000m
Yet, warming the top 2000m at a rate of 0.02°C per decade is described as “trivially small”?
I think the amount of heat stored could be described as “quite a lot”, especially as we’re being lead to believe that the Earth is undergoing a statistically significant and rapid cooling.
What’s especially interesting, is that the two animations suggest, within the limits of variation in the data, that the heat dynamic is homeostatic. Unfortunately none of us will live long enough to see what other periodicities may occur. Though the timeline is short, it pretty clearly puts the lie to CAGW…
Village Idiot says:
March 2, 2014 at 5:11 am
I think the amount of heat stored could be described as “quite a lot”, especially as we’re being lead to believe that the Earth is undergoing a statistically significant and rapid cooling.
—————————————————————————————————————-
I have had a thought in the back of my mind on what the purpose of that heat load might be for. What if it is the release of stored oceanic heat that helps pull the Earth out of a glaciation, or even a deep cold spell such as the LIA?
Speed says:
March 2, 2014 at 4:41 am
“Averages are sometimes useful, sometimes not. My nine year old car has operated at an average speed of 1.14 miles per hour over its lifetime. This reveals almost nothing about the car or how I drive.”
But averages per day, month or year may well provide data that is of interest as to usage.
Thanks Willis, I really like that first graphic. It looks like the Arctic is a dumping ground and escape valve for heat. Like others, it ran a little fast at .1 second per frame, I slowed it to .5 seconds a frame here:
http://oi57.tinypic.com/12519p1.jpg
In Figure 2, the Atlantic, north of the Tropic of Cancer (for this color blind observer) looks very dark. Is it very warm there or does its placement on the map give it the appearance of warmy?
Temps based on settled science are going up by 5c which allows an ‘environmental economist’ to publish these findings
“rising temperatures in the United States will lead to an additional 22,000 murders, 180,000 cases of rape, and 1.3 million burglaries, among other crimes.
These numbers may sound dramatic, but they’re based on existing crime data and broadly accepted projections for temperature change. Ranson also projects future costs, and estimates that a 5-degree rise in global temperatures over the next century—a middle-of-the-road climate change scenario from the Intergovernmental Panel on Climate Change, or IPCC—will end up costing society $38 billion to $115 billion across the country”
for another paper events like Ukraine would be expected with global warming?
“Hsiang and colleagues analyzed studies of modern and historical data from around the world, and found a surprisingly universal relationship between rising temperatures and increasing conflicts or social unrest.”
http://www.bostonglobe.com/ideas/2014/03/02/climate-change-may-mean-more-crime/dZCKg5nx7mUcj513lwAEyO/story.html
so crime, murder, social unrest never mind being fried with heat should keep those addicted to living in a Munch Scream plenty to ‘worry about’?
Cynics might say add the term global warming to any pet hobby [e.g chess and global warming, Hairdressing and climate change, circle of fifths and climate change] and u will get published in the media ?
Tom Moran March 2, 2014 at 5:45 am
It’s the gulf stream,
& the reason I can grow sub-tropical plants outside in the UK when we live on a line with Newfoundland, Prince Rupert & Moscow.
We have 11°C at moment !!
john
Village Idiot:
The amount of heat really isn’t as important as the thermodynamic equilibrium between the two bodies. The fact the ocean has such a higher heat capacity means it is the source of the planet’s thermal stability. It can’t release the heat to make the atmosphere warmer than it. The probabilities against that in a statistical mechanics sense in negligible. It would be like flipping 100 coins a million times and getting all heads one hundred thousand times – it is possible, but so unlikely as to be unobservable. The oceans are our temperature stability. It takes so much heat to move the thermometer on them that they are practically constant temperature. The atmosphere on the other hand has a very low heat capacity and can swing about wildly with slight changes of inputs to the system, but the oceans warm the air over them and tide things over until inputs come back to normal (whatever that is).
Figure 1 is fantastic, Willis. Thank you.
I’m reminded of the view looking into the tub of my top loading washer while it is agitating. There is lot of mechanical swirling and mixing going on.
“Note that although the amounts of the changes are smaller, the trends at the surface are geographically similar to the trends down to 2000 metres.”
And the most positively trending areas are in the mid latitudes.
Does one have to take into account pressure at different depths for temperature measurements at different depths? Or is that done in your calculation of volume weighted?
The only comments I have to make are these:
C/decade, or is it
C/decade or is it
C/decade?
C/decade, which is a number that ought to be reported as “0” no matter how many “joules” one wishes to discover in the deep ocean. Or at the very least, it should be reported with an error bar, and some empirical and statistical justification for the error bar should be provided.
a) 4000 buoys for 70% of the Earth’s surface is an absurdly sparse grid. The ocean covers roughly 400,000,000 square kilometers. 4000 buoys means that each buoy represents on average 100,000 kilometers. That is a square 300 km — around 200 miles — per side. If the distribution of buoys were either random (Monte Carlo selected fixed locations) or regular, this might be adequate to get a decent estimate. However, they are not — many of the buoys are free-floating and follow the currents. But are the currents themselves random samples of oceanic temperatures, or are they likely to be systematically biased? What is the scale of “features” of oceanic temperature (sea surface or otherwise). Would the state of North Carolina (in comparison) be well-represented in the land surface record by no more than three thermometers?
b) Twelve years is an absurdly short interval in climate science. Here we know some of the time constants. Thermohaline circulation — which surely is a major if not dominant factor in the time variation — has a cycle time on the order of 1000 years. That means that a significant fraction of any observed variation has nothing to do with what is going on now — the mid-ocean heat at depth visible in the Atlantic, for example, has to be decades to centuries old, for example. We know that there is no reasonable physical mechanism for transporting heat from the surface straight down to 2000 meters in a decade, or even two or three decades. The ocean is thermally stratified and (past a few tens of meters from the top) effectively opaque to solar energy, and the salinity variation that causes thermohaline turnover and mixing due to surface winds does not generally cause deep mixing, although there are specific sites where the thermohaline circulations turns over and warm surface currents descend into the depths for return. The movies above are indeed nifty, but they are like looking at gust of wind on a windy day and trying to conclude that the wind is rising as a climate feature. Are we looking at noise? Signal? Detrending on a decade’s worth of data doesn’t even catch one of the decadal oscillations that surely have a “trend” of their own.
c) As always in climate science, no error bars. Everything is smoothed. We cannot see which parts of the globe are oversampled (because ocean currents create an eddy that collects more than its share of buoys) and undersampled (because prevailing currents push buoys away, or because currents are depleted by buoys trapped in eddies). We do not get any feel for the granularity of the actual measurements. It might be more interesting to recreate the same map with each buoy’s results represented by a small patch of pixels along its actual trajectory in color — that, I suspect, would eliminate the smooth contours and impression of homogeneity produced by the maps above, and would give the viewer a much better idea of the probable error in the contours.
The point being, 0.02C/decade — is that
The answer to that one is simple. HADCRUT4 represents what, tens of thousands of reporting stations, including all of ARGO to represent the sea surface, and claims (probably egregiously, given the lack of UHI correction) 0.15C accuracy.
That’s the fundamental problem. I rather suspect that the reported warming is
rgb
There has of course been many more months of La Nina than El Nino from 2005 to 2012.
Remember now, supposedly the “warming” is hiding in the “deep oceans”.
According to Wikipedia (sorry) using “Deep Ocean” article):
“The deep sea, or deep layer,[1] is the lowest layer in the ocean, existing below the thermocline and above the seabed, at a depth of 1000 fathoms (1800 m) or more.”
The ARGO bouys only sample the top 200 meters (1800 to 2000) of the deep ocean and only the top 2000 meters of the oceans.
Moreover, again using Wikipedia “Ocean” article:
“The ocean contains 97% of the Earth’s water, and oceanographers have stated that only 5% of the ocean as a whole on Earth has been explored.[6] The total volume is approximately 1.3 billion cubic kilometres (310 million cu mi)[7] with an average depth of 3,682 metres (12,080 ft).
(bold mine)
Maybe one should say “the warming is conveniently hiding in the deep oceans”, since the deep ocean is an area well beneath what we are measuring with a wide sampling.
Re: the comment upstream that the rise is “quite a lot”. This trivial rise may be well within the margin of sampling error (due to Argo precision as well as Argo placement, not to mention short span of time). Meaning that the anomalous rise may be spurious and a result of this particular short string of averaged data. Trivially small trends will be seen in random data strings so no cause for panic, worry, upset tummy, or interrupted sleep. Your own normal body temperature could change WAY more than that.
Is that hot plume in the Atlantic (0-2,000 m), spilling out of the Mediterranean? I imagine the Med does get a bit warmer than the Atlantic.
SR
Neat. Interesting how the pumping to the north is in contrast to what you see at the south…..hehe
From what I remember reading, argo floats have a resolution of 0.005C, which is by far the most accurate system for ocean temp measurement ever. There’s a Wiki page here:
http://en.wikipedia.org/wiki/Argo_%28oceanography%29
and the argo project home page here:
http://www.argo.net/
Well worth spending some time at and a very ambitious project…
Pamela Gray says:
March 2, 2014 at 7:17 am
Re: the comment upstream that the rise is “quite a lot”.
Well, it wouldn’t be much to talk about if one said that during the short term of the ARGO bouys a change of temperature in the first 2000 meters of the ocean is not currently discernable, would it?
🙂
Is it possible rgbatduke has a point about the relevant ocean layer being very near the surface? Not sure at what depth increments Argo measures, but could the joules/decade calculation be made from say, 0 to 50 meters?
Also, is it possible to make a reasonable estimate of how many joules/decade would represent a 0.2, 0.4, and 0.6 C/decade surface warming. Would then comparing those numbers provide an indication of the validity of the theory that significant surface warming would be occurring, but for being masked by oceanic heat absorption?
Re: March 2, 2014 at 12:42 am | manacker says:
“BTW, the guy speaking Swiss German to Delaney(?) explained that it never snows in summer in Switzerland.”
I was married in Davos on July 4th 1970 and it snowed on Weissfluhgipfel that day with rain mixed with snow down in the valley.
rgbatduke-
Every time I read one of your comments it increases my knowledge and forces me to gain some different perspectives on the issue at hand. They have been invaluable in trying to sort through all the discussions about the climate. Thanks
Great stuff, Willis! (as always)
I think I know what “NaN” means (in the captions), but you might want to define it somewhere.
One important thing is not to confuse resolution(0.005 c) with accuracy or uncertainty.
I do not believe that the changes measured are more than the uncertainty.