![]() |
||
![]() |
![]() |
|
![]() |
![]() |
![]()
July
26, 2007 LARGE quantities
of ozone-depleting chemicals
have been discovered in the Antarctic atmosphere by researchers from
the The team of
atmospheric chemists carried out
an 18-month study of the make-up of the lowest part of the earth's
atmosphere
on the Brunt Ice Shelf, about 20 km from the The source of the
halogens is natural –
sea-salt in the case of bromine, and in the case of iodine, almost
certainly bright
orange algae that coat the underside of the sea ice around the
continent. These halogens
cause a substantial depletion
in ozone above the ice surface. This affects the so-called oxidising
capacity
of the atmosphere - its ability to "clean itself" by removing certain
- often man-made - chemical compounds. The iodine oxides also form tiny
particles (a few nanometres in size), which can grow to form ice
clouds, with a
consequent impact on the local climate. Scientists now
plan to carry out further research
to assess what impact this may be having on the local environment. Very
recent
satellite observations by one of the team, Dr Alfonso Saiz-Lopez, have
confirmed that iodine oxides are widespread throughout coastal John Plane,
professor of atmospheric
chemistry at the Using high-tech
measuring equipment, a beam
of light was projected across the ice shelf and the spectrum of the
reflected
light analysed and chemical levels measured. The work was carried out
in a new
atmospheric observatory at Halley Station, operated by the British
Antarctic
Survey, and was supported by funding from the U.K.’s Natural
Environment
Research Council. ##
Recommend this Article to a Friend Back to: News |
Subscribe to the Earth Observatory About the Earth Observatory Contact Us Privacy Policy and Important Notices Responsible NASA Official: Lorraine A. Remer Webmaster: Goran Halusa We're a part of the Science Mission Directorate |