Environmental Research Web addresses this evaporation paradox in an audio interview with Michael Roderick of the Australian National University, winner of the European Geosciences Union’s Dalton medal in 2013.
Dr. Dalton points out that the common assumption that evaporation is controlled by temperature is incorrect, as well as all climate models which also make this false assumption. The real-world situation is far more complex and unrelated to temperature. He notes pan evaporation research worldwide demonstrates evaporation is actually controlled by solar radiation and wind speeds, causing gradients of temperature, but not absolute temperatures. He notes there has been no global change in relative humidity, but wind speeds have declined globally over recent decades for unknown reasons, in addition some areas have experienced "global brightening" of surface solar radiation and others such as China "dimming" from air pollution.
Dr. Dalton says the implications of this research are that there will overall be little change in drought worldwide as a result of climate change, and that this has been borne out by observations over recent decades.
Feb 7, 2014
Although you might assume that evaporation will increase as temperatures rise, in reality measurements reveal that evaporation has been dropping off worldwide since the 1950s. So what exactly is going on? Michael Roderick of the Australian National University, winner of the European Geosciences Union’s Dalton medal in 2013, revealed his findings, what these could mean for drought, the role of windspeed and the puzzles that remain to environmentalresearchweb.
Changing times for evaporation
Michael Roderick of the Australian National University details his prize-winning findings on evaporation to environmentalresearchweb.
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