Sea ice Cracks Causing Toxic Mercury Buildup in Arctic Air
Tiny tempests above Cracks in Arctic Sea ice help pull down toxic mercury and ozone
From the Sky - an unexpected new source of mercury pollution in the polar
environment, according to research published Wednesday in the journal Nature.
Low concentrations of mercury vapor, from sources such as coal-fired power plants and gold mining, pollute
the atmosphere everywhere on Earth. The gas can
Travel thousands of miles from its source, even reaching the North and South poles.
Mercury leaves the atmosphere above the Arctic every spring. About 20 years ago,
scientists discovered how it escapes: a strange chemistry triggered by the sun that
takes place mainly along coastal areas. When the sun peeks above the horizon after
a long, dark winter, the solar rays jump - start chemical reactions that quickly remove
mercury and ozone from the lowest layers of the atmosphere. ( the ozone destroyed
during this process is a pollutant, not the protective ozone in Earth's stratosphere,
a layer of the atmosphere above the one humans live in, called the troposphere.)