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.
@Heber Rizzo
Let’s see what the Argo Team says:
“The global Argo dataset is not yet long enough to observe global change signals. Seasonal and interannual variability dominate the present 7-year globally-averaged time series. Sparse global sampling during 2004-2005 can lead to substantial differences in statistical analyses of ocean temperature and trend (or steric sea level and its trend, e.g. Leuliette and Miller, 2009). Analyses of decadal changes presently focus on comparison of Argo to sparse and sometimes inaccurate historical data. Argo’s greatest contributions to observing the global oceans are still in the future, but its global span is clearly transforming the capability to observe climate-related changes.”
They also have a lower number for the temp rise:
“This is consistent with the comparison by Roemmich and Gilson (2009) of Argo data with the global temperature time-series of Levitus et al (2005), finding a warming of the 0 – 2000 m ocean by 0.06°C since the (pre-XBT) early 1960’s.”
http://www.argo.ucsd.edu/global_change_analysis.html
When I posted these facts on a Dana rant on The Groan it was not appreciated. 🙂
Good work Willis. Lovely diagrams.
Thanks Willis. Impressive.
Average temperature 6C or 273+6 = 279K
Trend 0.03C (K) /decade or 0.03/279 = 0.01%
Negligible change.
OK. It’s 2 AM and I might be missing something simple, but set me straight if you would. Gently, please. Right at the top you say:
“There are about 4,000 Argo floats in the ocean. Most of the time they are asleep, a thousand metres below the surface.”
Then you continue with 2000 meter depths. How come?
And please don’t answer with, “Argo bleep yourself!” or something saltier. Remember, it’s 2 AM and I’m feeling delicate.
Thanks
In agreement with tty at 1:38.
The margins of error might not be considerable, but are uncomfortably close in size to the signal.
The trend in this data (6.9 ± 0.6 e+22 joules per decade)
That indeed looks very precise. 69 ± 6 ZJ. or 0.022 ± 0.002 deg C / decade
(at 27.5 ZJ per 0.01 deg C for 0-2000 meters)
Can we believe we have that much precision to 0.002 deg C / decade? And we have not yet measured a full decade. With 4,000 Argo floats, 130,000 sounding per year, with one Argo float for every 200,000 km^3 of ocean.
That is remarkable precision, especially when the average temperature of the entire 0-2000 column runs from 0.000 – 10.000 deg C and the surface runs from 0.000 to 30.000+ deg C (extra decimal points added to make a point)
Willis’ Decimals of Precision post is excellent and deserves to be referenced here.
If we can believe this precision above, they we should also believe that we could measure a trend to ± 0.02 deg C / decade with just 1/100 of the Argo buoys, just 40 of them. That seems like a stretch to me.
The Argo bouys have that level of granulaity?
One of the responders to my Groan comments quoted Levitus at me:
“Levitus (2012) thankfully puts it in context for the measurement-challenged:
If this heat were instantly transferred to the lower 10 km of the global atmosphere it would result in a volume mean warming of this atmospheric layer by approximately 36°C”
It seemed to me to be an spectacularly unscientific piece of alarmism. It seems climate scientists do not need to learn how to communicate their findings better, as some say. Instead they need to call out their fellow ‘scientists’ when they publish nonsense like this.
ALL of the progress in climate science has been driven by sceptics, like this site. Climate scientists will deny the plateau is real (as Dana is still trying to do), will link any weather to CC, will forecast ‘no ice at the poles’ etc. etc. and their fellow grant-aided ‘experts’ will never contradict them.
Thank sanity for sceptics.
OK…Perhaps a stupid question: if the Argoes are free-floating, how do they maintain station and not all end up in an Argo gyre?
Dear Mr Eschenbach, I think you are too ready to take ocean heat content at face value. I’ve attempted to work back from OHC in joules to actual temperatures, and here are the results,
OCEAN TEMPERATURES TO A DEPTH OF 2000 METERS.
(1) The “heat content” of the world’s oceans, to a depth of 2000 meters, increased by 30 times (10 to the power of 22)(joules) = (30)(10^22)(joules) between 1950 and 2013.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
(2) Mass of the world’s oceans = 1.4 times (10 to the power of 24)(grams) = (1.4)(10^24)(g)
http://hypertextbook.com/facts/1998/AvijeetDut.shtml
(3) Average depth of the world’s oceans = 3688 meters.
http://www.ngdc.noaa.gov/mgg/global/etopo1_ocean_volumes.html
(4) 2000/3688 = 0.54
(5) Mass of the the world’s oceans to a depth of 2000 meters = (1.4)(10^24)(0.54)(g) = (0.76)(10^24)(g)
(6) It takes 4.186 joules to raise the temperature of 1 g of water by 1 °C.
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html
(7) It takes (4.186 joules)(0.76)(10^24) to raise the temperature of (1 g)(0.76)(10^24) of water by 1°C.
(8) (30)(10^22)(joules) divided by (4.186 joules)(0.76)(10^24) = 0.09
(9) Therefore, the temperature of the world’s oceans, to a depth of 2000 meters, increased by 0.09°C, from 1950 to 2013.
Whenever NOAA etc give us ocean temperature data in terms of joules rather than actual temperatures, they perform calculations somewhat like those above, but in a different order. In my opinion, premises (2) and (3) are only approximations, and must come with a very large margin of error.
Willis, in your Figure 5, you go from an OHC (Range of -70 ZJ to +80 ZJ)
then subtract out a seasonal (-40 ZJ to +40 ZJ)
To get a residual of ( -55 to +40 ZJ)
The Seasonal component isn’t really subtracted. It’s negative is added. The seasonal component is an uncertain value, so it must have a variance. The Variance of the seasonal component must also be added, so the variance in the residual should include the Variance from the seasonal estimate. With this added variance, the error bars on the residual should increase the uncertainty in the slope.
If you do a trend on the upper OHC from the time of seasonal peak in 2006 to the seasonal peak in 2012, what uncertainty in slope do you get then?
Further to my comment about float drift, I should add that Wiki is not clear on this, merely saying they drift and last about four years…
Willis,
I’ve had a theory for many years that the sun & seasons had something to do with the climate ( not in line with ‘The consensus’ & a bit off the wall, I know, always been a maverick !! ) .
Your brilliant article & good animated graphics shows there may be a small possibility of seasonal sun variability, can we get a research grant together??
(I’ll get a few PhDs off Nigerian E-bay & I’ve got some coloured felt pens, so I can make us some Nobel peace prize certs, :-))
Let’s make money !!!
BTW, the guy speaking Swiss German to Delaney(?) explained that it never snows in summer in Switzerland.
Don’t think that can be correct, if it can snow in Zermatt at 1600m early Oct I’m pretty sure it will be snowing on the Matterhorn at 4000m earlier than Oct!
In fact I found a comment on Trip Advisor from 2012 that claims it was snowing early September:
http://www.tripadvisor.com/ShowUserReviews-g188098-d546182-r142272302-The_Matterhorn-Zermatt_Valais_Swiss_Alps.html
Willis, you gotta change your colors. Yellow is a warm color.
Given that the oceans contain about 1000 x as much energy as the atmosphere, and that 0.02 degrees per decade translates into something like a degree every 500 years, isn’t that the true rate of global warming ?? …… whatever the reason is.
so in 10,000 years time crocodiles will be back swimming in the arctic region again.
They also measure salinity.
The top 2000m is OK but the average ocean depth is 4500-5000m. So we know nothing about temperatures below 2000m. The temperature on the ocean floor is 0-2C.
Hockey Schtick said at 12:30 am
Never ever express the ocean data in degrees … the maximum additional that 0.09C ocean warming can warm the atmosphere is 0.09C.
Exactly, it’s much scarier to express it as 10^22 joules. I’m surprised they don’t spell out the 22 zeros.
But all that aside, the data stream from the ARGO floats is a manipulation created by Dr. Josh Willis at NASA’s Jet Propulsion Laboratory. Like everything else, it’s been adjusted to fall into line with Global Warming theory.
Willis: Cool (pun).
Do you have the data sources and the code used to produce that above to hand?
I noted consistent hotter areas off japan and over near the pointy bit od usa near the eu side
at a guess they are undersea volcanic vents?
funny they get NO mention by the agw crew either re deep temps.
Richards in Vancouver asked, “How come?” with reference to the 1,000 vs. 2,000 meter numbers.
The Argo Floats are “parked” at 1,000 meters (drifting depth) and when activated descend to 2,000 meters before rising to the surface while collecting data.
http://www.argo.net/
For others, there is a wealth of operational and experimental data here …
http://www.argo.ucsd.edu/index.html
It’s interesting that many of the warmer areas are near recent seismic activity.
Perhaps that line, that Global Warming causes earthquakes, is simply backwards.
Willis, are you using raw data or “adjusted data”. I get confused by graphs from Bob Tisdale that show most of the ocean basins cooling. so how do we suddenly get ocean warming when the data used by Bob shows cooling ?
I’ve never seen the seasonal cycle before, Willis. Can you compute what the W/m2 imbalances are for the seasonal cycle, and compare them to the CERES-measured changes in Earth’s radiative budget over the seasonal cycle? Just curious how they compare…seems like they should reasonably match.
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.
That first image is amazing, as has been said the Earth breathing, is it my imagination or does the heat rise up the Earth towards the NH during the winter?
It is hard to watch the image and the date at the same time.