Atmospheric aerosols play an important role in
radiative transfer and atmospheric chemical processes, thus having a strong
influence on the Earth’s climate. The
direct effect of aerosol is to cool the Earth’s surface by reflecting the Sun’s
light back into space. The indirect
effect, however, results in warming of the Earth’s surface as they act as Cloud
Condensation Nuclei (CCN) and contribute to cloud formation. There is still much to learn about how
aerosols affect regional and global climate. The impacts of natural and
anthropogenic aerosols on climate need to be accurately quantified.
The study presented here attempts to describe
the distribution of Aerosol Optical Depth (AOD) over the Atlantic and Polar
Oceans. For that purpose AOD
measurements with a sunphotometer aboard the German research vessel Polarstern
were conducted between October 2002 and April 2003, covering a meridional
region from 85° North to 62° South.
Results from AOD measurements obtained from the Atlantic Ocean and both
Polar regions will be presented. In
addition, events where extreme high AOD were observed near the West African
coast will also be discussed.