A study of stratospheric chlorine partitioning based on new satellite measurements and modeling

摘要: [1] Two recent satellite instruments, the Microwave Limb Sounder (MLS) on Aura and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) SCISAT-1, provide an unparalleled opportunity to investigate stratospheric chlorine partitioning. We use measurements of ClO, HCl, ClONO2, other species from MLS ACE-FTS study evolution reactive reservoir throughout lower stratosphere during two Arctic Antarctic winters characterizing both relatively cold warm disturbed conditions in each hemisphere. At middle latitudes, at high latitudes beginning winter, HCl greatly exceeds representing ∼0.7–0.8 estimated total inorganic chlorine. Nearly complete activation is seen inside winter polar vortices. In Arctic, recovery follows different paths winters: 2004/2005, deactivation initially takes place through reformation then reservoirs are produced concurrently but ClONO2 continues significantly exceed finally slow repartitioning between occurs; 2005/2006, rise comparable rates some regions. Antarctic, proceeds a similar manner winters, with rapid accompanying decrease ClO. The compared customized runs SLIMCAT three-dimensional chemical transport model. Measured modeled values typically agree well outside contrast, partly because equilibrium scheme used parameterize clouds, model overestimates magnitude, spatial extent, duration