Seven years of stratospheric BrO observations from SCIAMACHY
Alexei Rozanov(1), Bjoern-Martin Sinnhuber(1), Heinrich Bovensmann(1) and John Burrows(1)
(1) University of Bremen, P.O. Box 33 04 40, D-28334 Bremen, Germany
Bromine plays an important role in stratospheric ozone depletion. One
important question is whether the stratospheric bromine loading is
consistent with known sources of bromine, with the ultimate goal to be
able to predict how the stratospheric bromine loading will change as a
result of changes in emissions and under a changing climate.
The SCIAMACHY instruments launched on board ENVISAT in March 2002
provides now almost seven years of global stratospheric bromine monoxide
(BrO) measurements. The vertically resolved stratospheric
concentrations of BrO are obtained from the measurements of the scattered
and reflected solar radiation performed by the SCIAMACHY instrument in the
limb viewing geometry. The global coverage is achieved in 6 days.
Here we will present the seven year SCIAMACHY BrO data set in comparison
to multi-year calculations from our stratospheric chemical transport
model (CTM). In particular we will discuss the observations of BrO
in the tropical lowermost stratosphere. SCIAMACHY BrO observations in the
tropical tropopause region show clear signatures of deep convection with
lowest BrO in actively convective regions. These observations will be
compared with calculations from our chemical transport model and implications
for the transport of very short-lived source gases into the stratosphere
will be discussed.