Nova’s Ocean of Doubt

Rather than producing a scientifically supported theory, Joanne Nova raises more “Merchant of Doubt” material based upon a bunch of blogger posts at WUWT and Bob Tisdale (famous for producing Excel graphs supposedly proving everyone wrong, but he won’t/can’t publish because there’s a conspiracy to stop “real science”).

We’ve covered much of what she mentions before, but let’s cover a few new items.

Nova vs Nova

In another case of Nova vs Nova, as the long term trend in ocean warming overwhelms short term fluctuations, Jo switches tactics from being an Argo supporter to become caster of uncertainty.

In 2010, based upon a few years of Argo data only, Jo “Cherry Picker” Nova claimed the oceans were not warming saying …

Argo found that the oceans have been in a slight cooling

Now that the trend in both 0-700m and 0-2,000m depths are both showing warming, Nova now says …

And the ocean is sampled often and closely enough… no, not even 3,000 floats/buoys is enough.

Where was Nova’s “Uncertainty” in 2010?

Uncertainties in ARGO data

Nova’s not known for her aptitude in statistics, and in this case demonstrates her lack of knowledge for all to see. She claims …

A single ARGO buoy … has an uncertainty of about 0.1C. But using 3,000 buoys doesn’t make that uncertainty dramatically smaller … So the measurement uncertainty is closer to the instrument error of 0.1C than the 0.004C as claimed by fans of man-made global crisis

Hmmmm. Let’s think about that. Nova is saying one sample will give a result with error margin of +/-0.1°C, and a billion samples would give a result of the same error margin. Yeah, right! Common sense (and Statistics) tells us otherwise. Even her attempt at calculating the error margin is a fail because she uses 3,000 (the approximate number of floats) rather than the number of samples taken – each float takes many samples each year.

Nova confuses SST with OHC

Nova is all too keen to cast doubt on the data prior to Argo (because it would mean she has to address the long term observed warming) by saying that Buckets were used to capture the data. That is incorrect, buckets were used to capture Sea Surface Temperatures (SST) NOT to capture the heat of the ocean at depth. The data used in Ocean heat Content (OHC) prior to Argo is from expendable bathythermographs (XBT) and mechanical bathythermographs (MBT), but not buckets. That would be stupid.

More Graphic Trickery

Nova plots a trend line representing expected OHC against the Argo data. Strangely she picks the very start of the Argo data as if that point precisely represented the OHC at that point in time (where’s her uncertainty now?). Plotting the expected OHC against all OHC data (including XBT) and using data to all depths (Nova only compares to 700m) results in a more accurate representation as shown below from Balmaseda,  M. A., K. E. Trenberth, and E. Källén (2013).

Experts Disagree with Nova

Global conspiracy theories aside, looking at the peer-review process (which is responsible for all modern science today) it appear scientists that are competent enough to get papers published, disagree with Nova’s self-editing web bloggers. Here’s a few examples …

Retrospective prediction of the global warming slowdown in the past decade

The top-of-atmosphere net energy input remained in the [0.5–1] W m−2 interval during the past decade, which is successfully captured by our predictions. Most of this excess energy was absorbed in the top 700 m of the ocean at the onset of the warming pause, 65% of it in the tropical Pacific and Atlantic oceans. Our results hence point at the key role of the ocean heat uptake in the recent warming slowdown. The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models, but also enhances the socio-economic relevance of operational decadal climate predictions.

Distinctive climate signals in reanalysis of global ocean heat content

The elusive nature of the post-2004 upper ocean warming has exposed uncertainties in the ocean’s role in the Earth’s energy budget and transient climate sensitivity. Here we present the time evolution of the global ocean heat content for 1958 through 2009 from a new observation-based reanalysis of the ocean. Volcanic eruptions and El Niño events are identified as sharp cooling events punctuating a long-term ocean warming trend, while heating continues during the recent upper-ocean-warming hiatus, but the heat is absorbed in the deeper ocean. In the last decade, about 30% of the warming has occurred below 700 m, contributing significantly to an acceleration of the warming trend. The warming below 700 m remains even when the Argo observing system is withdrawn although the trends are reduced. Sensitivity experiments illustrate that surface wind variability is largely responsible for the changing ocean heat vertical distribution.

UPDATE – Breaking News – The Ocean is Big

Nova realises 3,000 floats in a huge ocean means one float is attempting to measure an immense volume to the ocean.

Sound familiar? Here’s what I said a couple of years back in response to Nova’s claim that the ocean was cooling …

Whilst Argo data is much more comprehensive than we used to have, it still works out to one float per 380,000  cubic kilometers. That’s cubic kilometres, not just meters, or litres.

Ironically Nova fails to understand that this is reason to be wary of short term trends that might fool the unwary and I don’t think she realises that uncertainty works both ways. The long term warming trend we see in Argo data could possibly be even greater.

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Tags: Argo, Ocean Heat Content