Citation:

Mahlman, J., J. Pinto, AND L. Umscheid. TRANSPORT, RADIATIVE, AND DYNAMICAL EFFECTS OF THE ANTARCTIC OZONE HOLE: A GFDL "SKYHI" MODEL EXPERIMENT. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/308 (NTIS PB94192754), 1994.

Description:

The GFDL 'SKYHI' general circulation model has been used to simulate the effect of the Antarctic "ozone hole" phenomenon on the radiative and dynamical environment of the lower stratosphere. oth the polar ozone destruction and photochemical restoration chemistries are calculated by parametrized simplifications of the still uncertain, more complete chemical processes. he modeled total column ozone depletions are near 25% in spring over Antarctica, with 1 % depletion reaching equatorial latitudes by the end of the 4 1/2 year model experiment. n the lower stratosphere, ozone reductions of 5% reach to the equator. arge coolings of about 8 degrees C are simulated in the lower stratosphere over Antarctica in late spring, while a general cooling of about 1-1.5 degrees is present throughout the Southern Hemisphere lower stratosphere. he model atmosphere experiences a long-term positive temperature-chemical feedback because significant ozone reductions carry over into the next winter. he overall temperature response to the reduced ozone is essentially radiative in character. owever, substantial dynamical changes are induced by the ozone hole effect. he Antarctic middle stratosphere in late spring warms by about 60 over Antarctica and the lower mid-latitude stratosphere warms by approximately one degree. hese warming spots are produced mainly by an increased residual circulation intensity. lso, the Antarctic vortex becomes tighter and more confined as a result of the reduced ozone. hese two dynamical effects combine to steepen the meridional slope of quasi-conservative trace constituent isolines. hus, the entire transport, radiative, and dynamical climatology of the springtime stratosphere is affected to an important degree by the ozone hole phenomenon. ver the entire year, however, these dynamical effects are considerably smaller.

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