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Aerosol particles in the upper troposphere and lower stratosphere: Elemental composition and morphology of individual particles in northern midlatitudes
Author(s) -
Sheridan Patrick J.,
Brock Charles A.,
Wilson James C.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl01387
Subject(s) - stratosphere , troposphere , aerosol , middle latitudes , sulfate , particle (ecology) , soot , tropopause , mineralogy , particle size , sulfur , environmental chemistry , chemistry , atmospheric sciences , geology , combustion , oceanography , organic chemistry
Atmospheric particles were collected in the midlatitude upper troposphere (UT) and lower stratosphere (LS) by inertial impaction for subsequent electron microscopy and individual particle elemental analysis. More than 97% of particles analyzed on impactor substrates exposed in the LS contained only O and S in detectable quantites; these particles are believed to be acidic sulfate. Nonsulfate materials seen in the remaining particles included soot, other c‐rich substances and crustal materials. Although not predominantly sulfate, usually carried a sulfur‐rich coating in the LS. Samples collected very near and just below the tropopause were also dominated by sulfates. The fraction of sulfate particles analyzed on impactor substrates exposed in the UT was 91–94% of the total particle concentration. Nonsulfate substances observed in the UT samples included crustal‐type materials, hydrated marine salts, carbon‐rich materials of several types, and metal‐containing substances of uncertain origin. Most of these UT particles were not coated with detectable quantities of sulfate.