Pats&Sox
05-29-2008, 09:40 AM
But one such peak has confused them a hell of a lot. The sharp drop in 1945 by around 0.3 °C - no less than 40% of the century-long upward trend in global mean temperature - seemed inexplicable There was no major eruption at the time, nor is anything known of a massive El Nino that could have caused the abrupt drop in sea surface temperatures. The nuclear explosions over Hiroshima and Nagasaki are estimated to have had little effect on global mean temperature. Besides, the drop is only apparent in ocean data, but not in land measurements.
Now scientists have found – not without relief - that they have been fooled by a mirage.
The mysterious post-war ocean cooling is a glitch, a US-British team reports in a paper in this week’s Nature. What most climate researchers were convinced was real is in fact “the result of uncorrected instrumental biases in the sea surface temperature record,” they write. Here is an editor’s summary.
How come? Almost all sea temperature measurements during the Second World War were from US ships. The US crews measured the temperature of the water before it was used to cool the ships engine. When the war was over, British ships resumed their own measurements, but unlike the Americans they measured the temperature of water collected with ordinary buckets. Wind blowing past the buckets as they were hauled on board slightly cooled the water samples. The 1945 temperature drop is nothing else than the result of the sudden but uncorrected change from warm US measurements to cooler UK measurements, the team found.
http://blogs.nature.com/climatefeedback/2008/05/postworld_war_ii_cooling_a_mir.html
Now scientists have found – not without relief - that they have been fooled by a mirage.
The mysterious post-war ocean cooling is a glitch, a US-British team reports in a paper in this week’s Nature. What most climate researchers were convinced was real is in fact “the result of uncorrected instrumental biases in the sea surface temperature record,” they write. Here is an editor’s summary.
How come? Almost all sea temperature measurements during the Second World War were from US ships. The US crews measured the temperature of the water before it was used to cool the ships engine. When the war was over, British ships resumed their own measurements, but unlike the Americans they measured the temperature of water collected with ordinary buckets. Wind blowing past the buckets as they were hauled on board slightly cooled the water samples. The 1945 temperature drop is nothing else than the result of the sudden but uncorrected change from warm US measurements to cooler UK measurements, the team found.
http://blogs.nature.com/climatefeedback/2008/05/postworld_war_ii_cooling_a_mir.html