11.3 Southern polar ozone variability as observed by Aura MLS

Thursday, 11 June 2009: 2:30 PM
Pinnacle A (Stoweflake Resort and Confernce Center)
Shuntai Zhou, NOAA/NWS/NCEP/CPC, Camp Springs, MD; and C. S. Long

The Antarctic ozone hole has shown large inter-annual variability in its size, depth, onset and vanishing times. Even if the ozone depleting gases have been leveled in the stratosphere since mid 1990's, there is still no apparent sign of “ozone recovery” in the southern polar region, as well as in the whole southern hemisphere. It is essential to understand complete life cycles of the ozone hole from its formation to vanishing, in particular how the ozone hole is affected by dynamical processes in different stages, and how stratospheric dynamics are affected by ozone depletions feedback. Previous studies have shown little on the early stage and pre-conditions of ozone holes due to lack of polar ozone data in the polar night, because most satellite ozone instruments (e.g., TOMS, SBUV) require sunlight, and ground-based ozone sonde data were scarce. Now, Aura MLS provides an opportunity with more than four years of ozone (and chlorine) measurements covering major polar night area beyond 80S, allowing a full investigation of polar ozone depletion process. We will use these datasets and other meteorological datasets to study the inter-annual variability of south polar ozone. Our focus is on the southern winter time before ozone holes reach their peaks. We will compare ozone depletion rate and ozone hole onset time among the recent years, and determine how the year-to-year differences are related to dynamical and chemical conditions before and during ozone hole formation.
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