A global stratospheric bromine monoxide climatology based on the BASCOE chemical transport model

摘要

A new climatology of stratospheric BrO profiles based on a parameterizationusing dynamical and chemical indicators has been developed, with the aim toapply it to the retrieval of tropospheric BrO columns from space nadirmeasurements. The adopted parameterization is based on three years of outputdata from the 3-D chemistry transport model BASCOE. The impact of theatmospheric dynamics on the stratospheric BrO distribution is treated bymeans of Br_y/ozone correlations built from 3-D-CTM model results, whilephotochemical effects are taken into account using stratospheric NO₂columns as an indicator of the BrO/Br_y ratio. The model simulationshave been optimized for bromine chemistry and budget, and validated throughcomparisons using an extensive data set of ground-based, balloon-borne andsatellite limb (SCIAMACHY) stratospheric BrO observations.