Arctic snowpack bromine release: Shepson Atmospheric Chemistry Group: Purdue University

Arctic snowpack bromine release

04-14-2013

Jon Abbatt 

Sea ice and snow help to shape climate at the poles. These surfaces reflect incoming solar radiation, diminishing its ability to warm the planet. Icy surfaces also mediate chemical reactions that affect the composition of the atmosphere1,2. The formation and proliferation of gaseous halogens in polar, snowy environments in spring is one example of such ice-mediated interactions, whereby chemical reactions in the ice facilitate the conversion of halogen-containing compounds to more volatile, reactive species2,3. These halogens — particularly bromine — chew up pollutants such as ozone and mercury, leading to the rapid depletion of tropospheric ozone during polar spring, and the deposition of biologically sensitive mercury to the surface. However, the exact source of these chemically reactive halogens has remained uncertain. Writing in Nature Geoscience, Pratt and colleagues4 show that surface snow can serve as a source of bromine to the Arctic atmosphere.

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