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Trace gas concentrations, intertropical convergence, atmospheric fronts, and ocean currents in the tropical Pacific m(Paper 8C1060)

Journal Article · · J. Geophys. Res.; (United States)
Shipboard measurements of atmospheric /sup 222/Rn, CO, and CH/sub 4/ and of dissolved CO in surface waters have been carried out in the equatorial Pacific on a cruise from Ecuador to Hawaii, Tahiti and Panama in March and April of 1974, and during transit from Los Angeles to Antarctica in November and December of 1972. The trace gas results, combined with conventional meteorological data and with satellite images from Nimbus 5 and the defense meteorological satellite project (DMSP), have provided descriptions of the intertropical convergence zones (ITCZ) near 04/sup 0/N, 102/sup 0/W and 03/sup 0/N, 154/sup 0/W in March of 1974, near 04/sup 0/N, 86/sup 0/W in April of 1974, and near 05/sup 0/N, 139/sup 0/W in November of 1972. In all cases the ITCZ seems to be located north of the south equatorial current (SEC) as shown by dissolved CO peaks in surface waters. In April of 1974 a 'second' ITCZ was observed near 01/sup 0/S, 102/sup 0/W just south of the SEC. A stationary front near Hawaii (20/sup 0/N, 147/sup 0/W) in March of 1974 was investigated. The ITCZ was marked by light shifting winds near a zone of heavy cloud cover and precipitation. In the eastern Tropical Pacific atmospheric /sup 222/Rn increases distinctly north of the ITCZ and thus serves as an indicator for the ITCZ. CO and CH/sub 4/ do not always increase coincident with atmospheric /sup 222/Rn. The atmospheric features of the stationary front near Hawaii are in many ways similar to those observed for the ITCZ. The front is marked by cloud cover, precipitation zone and light shifting winds. /sup 222/Rn, CO and CH/sub 4/ increase signifantly behind the front in subsiding air which was traced back to the Asian continent. The variation of atmospheric /sup 222/Rn, CO and CH/sub 4/ with time and geographical area over the equatorial Pacific seems to be a consequence of seasonal variations of the trade wind field and long range transport to the central Pacific from Asia and to the eastern equatorial Pacific from North and Central America.
Research Organization:
National Science Foundation, Washington, D. C.
OSTI ID:
5731594
Journal Information:
J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 84:C11; ISSN JGREA
Country of Publication:
United States
Language:
English