Enhanced upper tropical tropospheric COS: impact on the stratospheric aerosol layer.
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.
Notholt
J
J
University of Bremen, D-28334 Bremen, Germany. jnotholt@iup.physik.uni-bremen.de
Kuang
Z
Z
Rinsland
C P
CP
Toon
G C
GC
Rex
M
M
Jones
N
N
Albrecht
T
T
Deckelmann
H
H
Krieg
J
J
Weinzierl
C
C
Bingemer
H
H
Weller
R
R
Schrems
O
O