Enhanced Upper Tropical Tropospheric COS: Impact on the Stratospheric Aerosol Layer
J. Notholt,1*
Z. Kuang,2
C. P. Rinsland,3
G. C. Toon,4
M. Rex,5
N. Jones,6
T. Albrecht,5
H. Deckelmann,5
J. Krieg,5
C. Weinzierl,1
H. Bingemer,7
R. Weller,8
O. Schrems8
Carbonyl sulfide (COS) is considered to be a major
source of the stratospheric sulfate aerosol during periods of volcanic quiescence. We measured COS at the tropical tropopause and find mixing
ratios to be 20 to 50% larger than are assumed in models. The enhanced
COS levels are correlated with high concentrations of biomass-burning
pollutants like carbon monoxide (CO) and hydrogen cyanide (HCN). The
analysis of backward trajectories and global maps of fire statistics
suggest that biomass-burning emissions transported upward by deep
convection are the source of the enhanced COS in the upper tropical
troposphere.
1 University of Bremen, D-28334 Bremen,
Germany.
2 California Institute of Technology,
Pasadena, CA 91125, USA.
3 NASA Langley Research
Center, Hampton, VA 23681-2199, USA.
4 Jet
Propulsion Laboratory, California Institute of Technology, Pasadena, CA
91109, USA.
5 Alfred Wegener Institute for Polar and
Marine Research, D-14473 Potsdam, Germany.
6 University of Wollongong, Wollongong, New South
Wales 2522, Australia.
7 J. W. Goethe-University, D-60325 Frankfurt am Main, Germany.
8 Alfred Wegener Institute for Polar and Marine
Research, D-27568 Bremerhaven, Germany.
*
To whom correspondence should be addressed. E-mail:
jnotholt{at}iup.physik.uni-bremen.de
Present address: University of Washington, Seattle, WA
98195-1640, USA.
