A summer time series of particulate carbon in the air and snow at Summit, Greenland

Authors

Gayle S.W. Hagler, Georgia Institute of Technology - Main Campus
M Bergin, Georgia Institute of Technology - Main CampusFollow
Eugene A. Smith, Georgia Institute of Technology - Main Campus
Jack E. Dibb, University of New HampshireFollow

Abstract

Carbonaceous particulate matter is ubiquitous in the lower atmosphere, produced by natural and anthropogenic sources and transported to distant regions, including the pristine and climate-sensitive Greenland Ice Sheet. During the summer of 2006, ambient particulate carbonaceous compounds were characterized on the Greenland Ice Sheet, including the measurement of particulate organic (OC) and elemental (EC) carbon, particulate water-soluble organic carbon (WSOC), particulate absorption coefficient (σ_ap), and particle size-resolved number concentration (PM_0.1–1.0). Additionally, parallel ∼50-day time series of water-soluble organic carbon (WSOC), water-insoluble organic carbon (WIOC), and elemental carbon (EC) were quantified at time increments of 4–24 h in the surface snow. Measurement of atmospheric particulate carbon found WSOC (average of 52 ng m⁻³) to constitute a major fraction of particulate OC (average of 56 ng m⁻³), suggesting that atmospheric organic compounds reaching the Greenland Ice Sheet in summer are highly oxidized. Atmospheric EC (average of 7 ng m⁻³) was well-correlated with σ_ap (r = 0.95) and the calculated mass-absorption cross-section (average of 24 m² g⁻¹) appears to be similar to that measured using identical techniques in an urban environment in the United States. Comparing surface snow to atmospheric particulate matter concentrations, it appears the snow has a much higher OC (WSOC+WIOC) to EC ratio (205:1) than air (10:1), suggesting that snow is additionally influenced by water-soluble gas-phase compounds. Finally, the higher-frequency (every 4–6 h) sampling of snow-phase WSOC revealed significant loss (40–54%) of related organic compounds in surface snow within 8 h of wet deposition.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

11-16-2007

Journal Title

Journal of Geophysical Research

Publisher

Wiley

Digital Object Identifier (DOI)

10.1029/2007JD008993

Document Type

Article

Recommended Citation

Hagler, G. S. W., M. H. Bergin, E. A. Smith, and J. E. Dibb (2007), A summer time series of particulate carbon in the air and snow at Summit, Greenland, J. Geophys. Res., 112, D21309, doi:10.1029/2007JD008993.

Rights

Copyright 2007 by the American Geophysical Union.