HR: 16:15h
AN: A54A-04    [Abstracts]
TI: The Solar Cycle Variation of Stratospheric Ozone: A Comparative Analysis of Version 8 SBUV(/2) and UARS HALOE Data
AU: * Hood, L L
EM: lon@lpl.arizona.edu
AF: Lunar and Planetary Laboratory University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 United States
AU: Soukharev, B E
EM: boris_soukharev@hotmail.com
AF: Lunar and Planetary Laboratory University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 United States
AU: Remsberg, E
EM: Ellis.E.Remsberg@nasa.gov
AF: NASA, Langley Research Center, Hampton, VA 23681 United States
AB: The observed solar cycle variation of ozone is a key constraint on climate models that include solar UV / ozone / dynamical coupling as a sun-climate forcing mechanism. Here, we report a comparative analysis of the solar cycle component of ozone interannual variability based on (1) the recently released Version 8 SBUV(/2) ozone profile data set extending from 1979 to 2003 (NASA Ozone Processing Team, http://code916.gsfc.nasa.gov/Data_services/); and (2) the UARS HALOE ozone profile data set extending from late 1991 to the present (NASA Langley Research Center, http://haloedata.larc.nasa.gov/). The two data sets are complementary. On the one hand, because HALOE is an occultation instrument, the vertical resolution of this data set is much higher than that of SBUV. On the other hand, the sampling frequency of the SBUV, which is a vertical sounder, is much greater than that of HALOE and the combined Version 8 data set covers a period of more than 25 years. The HALOE profile data (both sunset and sunrise) are first interpolated to pressure levels comparable to those for which Version 8 SBUV ozone data are available (1, 1.5, 2, 3, 5, 7, 10 hPa). Daily zonal averages are then calculated within 5-degree latitude zones if at least 10 profiles are available for a given latitude band and a given day. These daily zonal averages (typically several per month) are then averaged within 10 degree latitude zones and within 3-month intervals to construct seasonal zonal average time series. A similar procedure is applied to the Version 8 daily zonal mean SBUV data to calculate monthly and seasonal averages. Both data sets are then analyzed using a standard multiple regression statistical model including seasonal, QBO, solar cycle, and linear trend predictor terms. Results show that the solar cycle component is largest in the SBUV data over a broad range of latitudes near 1 hPa with an amplitude (solar max minus min) of 4 to 6 per cent while it is largest in the HALOE data near 2 hPa with an amplitude of about 4 per cent. A secondary maximum in the solar cycle component is also found in both data sets at middle latitudes near the 7 hPa level. In the lower stratosphere, a significant solar cycle variation is found in the HALOE data near the ozone concentration maximum. This lower stratospheric decadal variation appears to be mainly responsible for the solar cycle variation of total ozone that has been found in the merged TOMS / SBUV data set.
DE: 0340 Middle atmosphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly