Asian pollution fuels rain in Australia
Asian pollution fuels rain in Australia
mongabay.com
December 12, 2006
A new study says that the haze produced by fires in southeast Asia causes increased rainfall in Australia by lowering regional ocean temperatures. Particulate matter in the upper atmosphere has been shown to reflect sunlight, hence lowering temperatures.
“Until now, there has been ample evidence that these particles have important effects on climate in the Northern Hemisphere but little such evidence in the Southern Hemisphere,” said CSIRO Marine and Atmospheric Research scientist, Dr Leon Rotstayn.
“What we have seen in our latest climate simulations is that the Asian haze’ is having an effect on the Australian hydrological cycle and generated increasing rainfall and cloudiness since 1950, especially over northwest and central Australia. The effect occurs because the haze cools the Asian continent and nearby oceans, and thereby alters the delicate balance of temperature and winds between Asia and Australia. It has nothing to do with Asian pollution being transported directly over Australia.”
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Rotstayn said that reductions in Asian pollution levels could produce a drier Australia.
“We are really at the beginning of understanding the trends but sooner or later these emissions will be cleaned up and then a trend of increasing rainfall in the northwest and centre could be reversed. This is potentially serious, because the northwest and centre are the only parts of Australia where rainfall has been increasing in recent decades.”
Rotstayn’s paper, which he co-authored with an international team of scientists, will be published early in 2007 in the Journal of Geophysical Research.
This article uses quotes and information from a CSIRO news release.