92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Thursday, 26 January 2012: 4:15 PM
Sensitivity of the Amundsen-Bellingshausen Seas Low to Changes in Ozone Depletion and Greenhouse Gas Concentrations
Room 354 (New Orleans Convention Center )
Elizabeth A. Zbacnik, Ohio University, Athens, Ohio; and R. L. Fogt

The Amundsen-Bellingshausen Seas Low (ABSL), a semi-permanent low pressure off the coast of West Antarctica, has important monthly and seasonal variations that are not yet fully understood. Since the presence of the ABSL contributes to the marked warming and sea ice loss occurring in the region, it is necessary to further characterize these variations. A recent study suggested some of the ABSL variations are due to stratospheric polar ozone depletion. With this in mind, this study seeks to determine the sensitivity of the ABSL to ozone depletion and changes in greenhouse gas concentrations using chemistry-climate models (CCM), which more accurately depict the stratosphere where ozone-depleting processes occur. Our analysis is done using CCM data from the Stratospheric Processes and their Role in Climate (SPARC) Chemistry-Climate Model Validation project phase 2 (CCMVal2), focusing on the region of the ABSL [45-75S; 180-60W]. Temperature, wind, and geopotential height at various pressure levels are examined for the period of 1979-2001. The models are validated against the NNR, ERA-40 and JRA-25 reanalysis datasets. Reference simulations are compared to two sensitivity runs: one with constant ozone and one with constant greenhouse gas levels, to examine the sensitivity of the ABSL to each forcing. Results from this study can increase our understanding of how the ABSL might respond to changes in ozone and increasing greenhouse gas concentrations, and therefore the future impact it will have on the climate of the region.

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