By JR on Tuesday, October 28, 2014
Revising Southern hemisphere ocean heat
The article below has excited some Warmists (e.g. "Scientists Say Global Warming Has Been "Hugely Underestimated"), offering, as it does, another explanation for the "missing" heat that Warmists believe to be "hiding" somewhere that normal thermometers cannot reach. The starting point of the article is that measured Southern hemisphere temperatures are even more at variance with Warmist models than are Northern hemisphere temperatures. Hemispheric differences are not inherently surprising considering that there is less land in the South and that it is differently distributed (with a major continent straddling the pole, unlike in the North). But the writers below think it is suspicious and say that the measured temperatures must be wrong. From that point they offer some speculative "adjustments" to the observed temperatures that make them fit the Warmist models better. If you don't like real data, invent nicer data! So the article proves nothing
Quantifying underestimates of long-term upper-ocean warming
Paul J. Durack et al.
The global ocean stores more than 90% of the heat associated with observed greenhouse-gas-attributed global warming1, 2, 3, 4. Using satellite altimetry observations and a large suite of climate models, we conclude that observed estimates of 0–700 dbar global ocean warming since 1970 are likely biased low. This underestimation is attributed to poor sampling of the Southern Hemisphere, and limitations of the analysis methods that conservatively estimate temperature changes in data-sparse regions5, 6, 7. We find that the partitioning of northern and southern hemispheric simulated sea surface height changes are consistent with precise altimeter observations, whereas the hemispheric partitioning of simulated upper-ocean warming is inconsistent with observed in-situ-based ocean heat content estimates. Relying on the close correspondence between hemispheric-scale ocean heat content and steric changes, we adjust the poorly constrained Southern Hemisphere observed warming estimates so that hemispheric ratios are consistent with the broad range of modelled results. These adjustments yield large increases (2.2–7.1 × 1022 J 35 yr−1) to current global upper-ocean heat content change estimates, and have important implications for sea level, the planetary energy budget and climate sensitivity assessments.