Observations of iodine monoxide columns from satellite

[摘要] Iodine species in the troposphere are linked to ozone depletion and newparticle formation. In this study, a full year of iodine monoxide (IO)columns retrieved from measurements of the SCIAMACHY satellite instrument ispresented, coupled with a discussion of their uncertainties and the detectionlimits. The largest amounts of IO are found near springtime in the Antarctic.A seasonal variation of iodine monoxide in Antarctica is revealed with highvalues in springtime, slightly less IO in the summer period and again largeramounts in autumn. In winter, no elevated IO levels are found in the areasaccessible to satellite measurements. This seasonal cycle is in goodagreement with recent ground-based measurements in Antarctica. In the Arcticregion, no elevated IO levels were found in the period analysed. This impliesthat different conditions with respect to iodine release exist in the twoPolar Regions. To investigate possible release mechanisms, comparisons of IOcolumns with those of tropospheric BrO, and ice coverage are described anddiscussed. Some parallels and interesting differences between IO and BrOtemporal and spatial distributions are identified. Overall, the large spatialcoverage of satellite retrieved IO data and the availability of a long-termdataset provide new insight about the abundances and distributions of iodinecompounds in the troposphere.

[学科分类] 大气科学