HR: 10:50h
AN: A32C-03    [Abstracts]
TI: Trend Analysis of Tropical Ozone From the Southern Hemisphere Additional Ozonesondes (SHADOZ) Data
AU: * Morioka, H
EM: e023259k@ees.hokudai.ac.jp
AF: Hokkaido University, N10 W5, Sapporo, 060-0810, Japan
AU: Fujiwara, M
EM: fuji@ees.hokudai.ac.jp
AF: Hokkaido University, N10 W5, Sapporo, 060-0810, Japan
AU: Shiotani, M
EM: shiotani@rish.kyoto-u.ac.jp
AF: Kyoto University, Gokasho, Uji, 611-0011, Japan
AU: Thompson, A M
EM: anne@met.psu.edu
AF: The Pennsylvania State University, 510 Walker Building, University Park, PA 16802, United States
AU: Witte, J C
EM: witte@gavial.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Mail Code 613.3, Greenbelt, MD 20771, United States
AU: Oltmans, S J
EM: Samuel.J.Oltmans@noaa.gov
AF: NOAA-Boulder, 325 Broadway, Boulder, CO 80305, United States
AB: Linear trends of ozone for 1998-2007 are estimated for the troposphere through the lower stratosphere at ten tropical ozonesonde stations participating in the Southern Hemisphere Additional Ozonesondes (SHADOZ) project. Most stations cover the period from early 1998 to the end of 2006, but some stations have a shorter or longer record. Soundings are made once to four times per month, varying for station and year, but cover basically all seasons. The total sounding number ranges from 102 for Malindi to 429 for Ascension Island. Trends are calculated for vertically averaged values in each 1-km bin from 0-1 km to 30-31 km, and expressed as percent per year. Statistical test is also made. Around the tropopause, between 15 and 20 km, negative trends are seen for most stations. At San Cristobal (in the eastern Pacific) at 16-17 km, the trend is -4.3 ± 3.0 percent per year, and at Watukosek (in Indonesia) at 17-18 km, it is -4.8 ± 3.9 percent per year, both statistically significant. However, at Ascension (in the Atlantic) and at Natal (in South America), the tropopause trend is near zero and not statistically significant. At Natal at 12-13 km, the trend is +3.7 ± 3.0 percent per year, and at Malindi (in Africa) at 11-12 km, it is +5.0 ± 4.6 percent per year, both statistically significant. Generally in the free troposphere, positive trends are seen, but are statistically not significant for most regions. In the planetary boundary layer, statistically significant positive trends are seen at Kuala Lumpur (in Southeast Asia) and at Fiji (in the southwestern Pacific), and a statistically significant negative trend is seen at Paramaribo (in South America). The trend analysis is also made for four different seasons. Around the tropopause, seasonality in trend is small for all stations. In the upper troposphere, at Fiji and at Samoa, negative trends are seen in SON, but positive trends are seen in DJF.
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting