Onset, extent, and duration of dehydration in the southern hemisphere polar vortex

摘要: Satellite observations of water vapor and aerosol extinction along with temperature trajectory calculations are analyzed for the Southern Hemisphere winter 1992 in order to determine onset, extent, duration dehydration within polar vortex. Our investigation uses measurements from Microwave Limb Sounder (MLS) Cryogenic Array Etalon Spectrometer (CLAES), both on board Upper Atmosphere Research (UARS). Evidence persistent ice cloud formation, supported by statistics obtained air parcel trajectories, suggests that onset process occurs between late June early July. By August-early September depleted areas vortex no longer coincide high extinctions, indicating severe has occurred irreversible removal over vast areas. Areas levels vapor, below prewinter values, persist well into November. is found potential surfaces 420 K (the lower limit MLS measurements) 520 (approximately 16 22 km). The horizontal extent dehydrated area at 465 encompasses up 35% total equatorward 80°S. A comparison CLAES model an average particle number concentration size 10−2–10−3 cm−3 10–30 μm, respectively. We show difference timing here a recent analysis Polar Ozone Aerosol Measurement III (POAM) can be explained latitudinal sampling pattern POAM instrument.