HR: 08:30h
AN: A21G-03 INVITED     [Abstracts]
TI: Vertical distribution and attribution of ozone recovery
AU: * Newchurch, M
EM: mike@nsstc.uah.edu
AF: U Alabama in Huntsville, Atmospheric Science Dept., Huntsville, AL 35805 United States
AU: Cunnold, D
EM: cunnold@eas.gatech.edu
AF: Ga Tech, Earth and Atmospheric Sciences, Atlanta, GA 30332 United States
AU: Salawitch, R
EM: rjs@caesar.jpl.nasa.gov
AF: JPL/Cal Tech, 4800 Oak Grove Dr., Pasadena, CA 92209 United States
AU: McCormick, M P
EM: pat.mccormick@hamptonu.edu
AF: Hampton U, Center for Atm Sci, Hampton, VA 23668 United States
AU: Russell, J
EM: james.russell@hamptonu.edu
AF: Hampton U, Center for Atm Sci, Hampton, VA 23668 United States
AU: Zawodny, J
EM: m.j.zawody@larc.nasa.gov
AF: LaRC, Aerosol Research Branch, Hampton, VA 23681 United States
AU: Oltmans, S
EM: samuel.j.oltmans@noaa.gov
AF: CMDL, 325 Broadway, Boulder, CO 80304 United States
AU: Yang, E
EM: yes@eas.gatech.edu
AF: Ga Tech, Earth and Atmospheric Sciences, Atlanta, GA 30332 United States
AU: Yang, E
EM: yes@eas.gatech.edu
AF: U Alabama in Huntsville, Atmospheric Science Dept., Huntsville, AL 35805 United States
AB: Several studies using multiple data sources and analysis techniques show changes in stratospheric-ozone trends since the mid 1990s. These trend changes exhibit strong altitude signatures that differ between the declining and recovery periods. A range of attribution factors could account for these changes, including halogen abundances, solar fluctuations, and dynamical processes. The dynamical forcings (e.g., AO, AAO, tropopause height, EP flux, laminae occurrences) and future evolution of those effects on ozone in a changing atmosphere are least well understood; especially when considering the spatial distribution of the ozone trend changes. We focus on SAGE, HALOE, ozonesonde, and Merged Ozone Data analyzed with the Cumulative Sum of Residuals (CUSUM) technique accounting for the autoregressive AR(1) character of these monthly time series and the inflation of the error envelope due to significant AR(1) coefficients. We report the attribution of changes altitude-resolved from the tropopause to 40 km from both regression analyses and photochemical calculations. We find that the region from 18 km to the top of the atmosphere experienced 80% of the decline in ozone from 1979 to 1997, but only 50% of the improvement since 1997. Most of this improvement was due to diminishing halogen levels. The region between the tropopause and 18 km experienced only 20% of the decline, but 50% of the improvement. Most of the improvement in this lower-stratosphere region was due to dynamical, not chemical, factors.
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005