P7.19
Low-ozone pockets observed by EOS-MLS
V. Lynn Harvey, Univ. of Colorado, Boulder, CO; and C. E. Randall, G. L. Manney, and E. C. Weatherhead
Earth Observing System (EOS) Microwave Limb Sounder (MLS) observations of ozone are combined with meteorological data from the United Kingdom Met Office to create an automated algorithm for the detection of low-ozone pockets in stratospheric anticyclones. To demonstrate the algorithm, a case study presents the synoptic evolution of a large low-ozone pocket that formed in the Aleutian High in January 2006. The figure shows an example of the pocket on 16 January 2006 with a curtain of MLS ozone (in color) that intersects the Aleutian High (black) and the Arctic vortex (grey) at many vertical levels. Inside the vortex and the anticyclone, ozone is depleted by up to 50% over a 20 km layer.
All pockets that are identified in the MLS data form a 3-year climatology that is shown alongside pockets identified subjectively using solar occultation (SO) data. MLS observes all of the pockets seen by SO instruments, albeit more completely in both space and time. MLS results show deeper (lower ozone) pockets in the Northern hemisphere compared to the Southern hemisphere, decreasing pocket ozone further poleward, and descent of pockets over their lifetime. The total number of ozone molecules lost due to pocket formation is then calculated based on pocket volume and the extent of ozone loss inside the pocket compared to outside. These results are used to provide an estimate of the effect of changing low-ozone pocket occurrence frequency on ozone trend calculations.
Poster Session 7, Stratospheric Chemistry and Ozone Recovery Posters
Thursday, 23 August 2007, 3:30 PM-5:30 PM, Holladay
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