Tibetan dust could lower Himalayan glacier albedo

Changing wind patterns due to current climate changes sweep up more dust from the Tibetan Plateau, lake sediment measurements show. Jessica Conroy, a graduate student in paleoclimatology at the University of Arizona in Tucson, presented a dust record dating back to 1050 C.E. at the December meeting of the American Geophysical Union.

The data shows dusty episodes coincide with summers that have a positive phase in the Arctic Oscillation – with prevalent low pressure systems over the Arctic Ocean and relatively high pressure over the Eurasian continent. The current warming trend encourages this positive phase, Conroy states.

When summer droughts increase over the plateau and wind picks up the dust, much of this could land in the Himalayan Mountains, where summer glacier albedo would be lowered. This could in turn speed up the melting process, as darker ice absorbs more of the summer sun’s energy. In winter time fresh, white snow would periodically mask this albedo effect.

© Rolf Schuttenhelm | www.bitsofscience.org

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