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Distributions of Beryllium 7 and Lead 210, and Soluble Aerosol-Associated Ionic Species Over the Western Pacific: PEM West BAerosol sampling for the determination of the concentrations of soluble ionic species and the natural radionuclides Be-7 and Pb-210 was conducted from the NASA DC-8 over the western Pacific as part of GTE/PEM-West B during February - March 1994. Concentrations of most soluble ionic species in the free troposphere were higher in samples collected on flights originating from Hong Kong and Japan than those collected further east over the open ocean. In both regions the measured concentrations were higher than those found during PEM-West A (fall 1991). Activities of Pb-210 tracer of air masses influenced by sources on the Asian continent, showed the same patterns. These data indicate the effect of stronger continental outflow from Asia over the western Pacific during the spring compared to fall season. For readily scavenged aerosol-associated species and soluble acidic gases the strongest indications of Asian outflow were restricted to altitudes below 6 km. The distribution of the continental tracer Pb-210 was also compared to those of a large number of gas phase species measured on the DC-8. Relatively strong correlations were found with O3 and peroxyacetylnitrate (PAN), but only during the flights over the remote Pacific. During PEM-West A, similar correlations were seen, but they were stronger near Asia. We believe that these correlations are a signature of continental air that has been processed by deep wet convection over land before being advected over the ocean. One flight over the Sea of Japan provided the opportunity to sample upper troposphere/lower stratosphere air in and around a tropopause fold. Concentrations of Be-7 reached 7 pCi/cu m STP, and peak O3, mixing ratios of 480 ppb were encountered at 10.7 km. The Be-7 data are used to estimate the fraction of stratospheric air mixed down into the troposphere by circulation in the fold.
Document ID
19990019292
Acquisition Source
Langley Research Center
Document Type
Reprint (Version printed in journal)
Authors
Didd, J. E.
(Institute for the Study of Earth, Oceans and Space Durham, NH United States)
Talbot, R. W.
(Institute for the Study of Earth, Oceans and Space Durham, NH United States)
Lefer, B. L.
(Institute for the Study of Earth, Oceans and Space Durham, NH United States)
Scheuer, E.
(Institute for the Study of Earth, Oceans and Space Durham, NH United States)
Gregory, G. L.
(NASA Langley Research Center Hampton, VA United States)
Browell, E. V.
(NASA Langley Research Center Hampton, VA United States)
Sandholm, S. T.
(Georgia Inst. of Tech. Atlanta, GA United States)
Singh, H. B.
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 19, 2013
Publication Date
December 20, 1997
Publication Information
Publication: Journal of Geophysical Research
Publisher: American Geophysical Union
Volume: 102
Issue: D23
ISSN: 0148-0227
Subject Category
Environment Pollution
Report/Patent Number
Paper-96JD02981
Distribution Limits
Public
Copyright
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