Soundings of Ozone and Water in the Equatorial Region/Pacific Mission (SOWER/Pacific) is initiated to improve our understanding on the distribution and variations of the ozone and water vapor in the stratosphere and troposphere of the equatorial Pacific. The mechanism of mass exchange across the tropical tropopause, the chemical ozone depletion due to biogenic halogen compounds in the tropical eastern Pacific, the climatology of the ozone profile in the tropics are some of those subjects included in the scope of SOWER/Pacific.

What is specific is that SOWER/Pacific is trying to have coordinated, year-round ozone and water vapor soundings on a scale across the Pacific paying special attention to the east-west contrast along the equator. The base stations are San Cristobal, Gal㎝agos in Ecuador (0.90S, 89.62W), Christmas Island of Republic of Kiribati (2.00N, 157.38W), and Watukosek in Indonesia (7.57S, 112.63E). The spatial gaps between these stations will be filled by sondes launched from research vessels cruising the central to the eastern Pacific.

Due to the limited fund available, the initial effort has been to undertake spontaneous campaign observations under two extreme atmospheric conditions; the boreal winter (summer) when tropical tropopause is cold (warm) and high (low) reflecting the extratropical pumping activity in the Northern middle and high latitudes. The two periods also correspond to the local rainy season and dry season, respectively. What was unexpected, the record strong El Nino took place in 1997-1998 switching quickly to La Ni紡 in the latter half of 1998. This paper presents some of the important findings on the tropospheric ozone distributions and the water vapor budget in the lower stratosphere obtained from the campaign observations in Gal㎝agos and Christmas Island from 1998 to 2000.


1. Introduction || 2. Characteristic Ozone Profiles || 3. Contribution of Waves || 4. Summary || Acknowledgments || References