Wednesday, July 01, 2009

Are the Oceans Warming?

On his blog yesterday Roger Pielke Sr. wrote that "Their has been no statistically significant warming of the upper ocean since 2003."

ClimateDepot picked that up, of course (strangely calling it an "article). In any case, I don't think it's true. Here's the most recent data I was able to find (click to enlarge):

Source: Levitus, S., J. I. Antonov, T. P. Boyer, R. A. Locarnini, H. E. Garcia, and A. V. Mishonov (2009), Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems, Geophys. Res. Lett., 36, L07608, doi:10.1029/2008GL037155.


Dano said...

Yes, RP Sr dissembles about a number of issues. I tried to nail him down on his seeming assertion that alpine glaciers are not in retreat, never got an answer. Can't find it now, but I've seen more than one analysis of SLR that breaks the slope down into decades or so, and there is a clear trend of increase of late.

Plus, La NiƱa cooling and slowing of thermal expansion is noise in the long-term trend.



Dano said...

I just followed your link to RP Sr's site. Sheesh, he's dissembling and misleading all over the place. Is it age-itis?



Dano said...




Dano said...

In any case, I don't think it's true.

Nor does RC, which has an interesting...."article".



Anonymous said...

Since ocean heat content has a large short term variation, one cannot make a statistically significant warming or cooling in just the 6 years since 2003.

Follow the link to Pielke's blog and you will see that he commenting on the another bloggers statement that
"Some aspects of climate change are progressing faster than was expected a few years ago - such as rising sea levels, the increase of heat stored in the ocean and the shrinking Arctic sea ice."

Pielke didn't say that the ocean is no longer warming. His statement is "Their has been no statistically significant warming int he upper ocean since 2003".

Appears to state that ocean heat content rise has accelerated in the last few years. That data does not support that.

Jason S said...

RP is using the same Argo data as the cited graph.

The main difference is that the cited graph splices the Argo data together with older data sources. This results in an enormous increase in heat content around 2002.

Since there is no independent confirmation of this sudden surge, and since it is well known that splicing together data series with limited periods of intersection can result in artifacts like this, the most likely conclusion is that the 2002 spike is a statistical anomaly (that didn't actually happen).

If it did happen, one presumes that empirical data will eventually appear in the literature to support this.

Anonymous said...

There are three issues presented in this post. First, is Pielke’s claim veridical with the evidence? Is the graph David presents definitive? And if not, what do the several data sets say?

First, Pielks’s claim comes from satellite data set from Jason
For the last three years (2006-9), the data do show a flattening trend.
Therefore Pielke’s claim is clear and supported.

Second, is this graph (Levitus, et al)
definitive? Since the graph aggregates at least three different data sets (tidal gauges, and since 1993-2002 one satellite, there after another), the answer is unclear.

The first set of tidal gauges have a consistent long-term slope of about 2mm/year; an acceleration during recent decades is not apparent.
(While not an aggregate tidal gauge graph, this one from San Francisco is not untypical

Meanwhile, the satellite rate of 3.2mm (+-1) records a steeper rate of change. How is this difference to be reconciled? The data set is shorter and blending two different instruments may have calibration errors. The difference remains unexplained.

So, as I said, the significance of the more modern and presumably more comprehensive and precise data is less clear when see against the older and longer data set. Have SLR rates accelerated? I don’t know.

But to take up Peilke’s claim again, do we have independent data to support his claim of SLR flattening?Yes.

First, since satellite LT temperatures have declined during the past decade, since oceans respond to temperature change much more slowly, a later flattening of SLR makes sense. Second, GISS map of sea levels from 2002 and 2008 (SEE ”Surface Temperature Anomaly,” figure 3, here are also consistent with Pielk’s assertion.

Thus, while Pielke’s claim which David rejects is clear, his own surmise is not.

Finally, let me toss out another even more confounding SLR and temperature change graph from from Nir Shaviv, recently published in JGR
Examine fig. 2 here:

This chart of ”Sea level change rate over the 20th century is based on 24 tide gauges,” and shows a dynamically close correlation between solar intensity and SLR change.

In light of this evidence, the IPCCs neglect of solar influence on temperature change looks remarkably unconvincing - and thus what is really happening in satellite measures of SLR since 1992 even more difficult to divine.

-Orson Olson
environmental scientist, Boulder, CO