Tuesday 14 October 2014 9:39am
Professor Craig Rodger
An international research team that includes an Otago space physicist has discovered a formerly undetected impact of space weather on the polar atmosphere, which may explain some previously puzzling variations in winter weather patterns.
The team from the Finnish Meteorological Institute, Otago University and British Antarctic Survey found that energetic electrons from the outer radiation belt hitting the Earth's atmosphere cause ozone loss at high altitudes (70-80 km above Earth).
Their results will be published today in the leading journal Nature Communications.
The temporary, but frequent, ozone loss occurring after disturbed radiation belt periods may explain the changes in wind patterns which have previously been shown to affect regional winter temperatures in the Northern Hemisphere by a maximum of plus or minus 5 degrees centigrade.
The variation in temperature is only seen during winter because of the complex linkages from space through to the Earth's surface.
The scientists found frequent and large ozone depletions after radiation belt storms after studying data from three different satellites gathered between 2002 and 2012. The measurements suggest increased electron precipitation during storms lasting a few days may temporarily reduce ozone in the upper atmosphere as much as 90 per cent.
University of Otago co-author Professor Craig Rodger says the findings are exciting because they reveal a key part of the chain-reaction of how incoming electrons from space affect ozone, which can then affect polar weather systems.
“This link between space weather, ozone loss and our own weather was not truly understood before. While the dominant effect is around the poles, those changes in turn can influence weather as far away as the sub-tropics. Others have already shown how variations in Antarctic weather systems help drive New Zealand weather and climate, for example influencing winds, rainfall and drought.”
The findings about the mechanism could allow forecasters to incorporate data about radiation belt electron precipitation into their seasonal predictions, potentially in both the Northern and Southern hemispheres, Professor Rodger says.
Professor Rodger’s contribution to this research was supported through the Royal Society of New Zealand-administered Marsden Fund.
For more information, contact:
Professor Craig Rodger
Department of Physics
University of Otago
Email craig.rodger@otago.ac.nz
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