Shouldn’t snowpacks be sources of monocarboxylic acids?

Authors

Jack E. Dibb, University of New HampshireFollow
Matthew Arsenault, University of New Hampshire - Main Campus

Abstract

We report the first measurements of the mixing ratios of acetic (CH₃COOH) and formic (HCOOH) acids in the air filling the pore spaces of the snowpacks (firn air) at Summit, Greenland and South Pole. Both monocarboxylic acids were present at levels well above 1 ppbv throughout the upper 35 cm of the snowpack at Summit. Maximum mixing ratios in Summit firn air reached nearly 8 ppbv CH₃COOH and 6 ppbv HCOOH. At South Pole the mixing ratios of these acids in the top 35 cm of firn air were also generally >1 ppbv, though their maximums barely exceeded 2.5 ppbv of CH₃COOH and 2.0 ppbv of HCOOH. Mixing ratios of the monocarboxylic acids in firn air did not consistently respond to diel and experimental (fast) variations in light intensity, unlike the case for N oxides in the same experiments. Air-to-snow fluxes of CH₃COOH and HCOOH apparently support high mixing ratios (means of (CH₃COOH/HCOOH) 445/460 and 310/159 pptv at Summit and South Pole, respectively) in air just above the snow during the summer sampling seasons at these sites. We hypothesize that oxidation of carbonyls and alkenes (that are produced by photo- and OH-oxidation of ubiquitous organic compounds) within the snowpack is the source of the monocarboxylic acids.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

5-2002

Journal Title

Atmospheric Environment

Publisher

Elsevier

Digital Object Identifier (DOI)

10.1016/S1352-2310(02)00131-0

Document Type

Article

Recommended Citation

Jack E. Dibb, Matthew Arsenault, Shouldn’t snowpacks be sources of monocarboxylic acids?, Atmospheric Environment, Volume 36, Issues 15–16, May–June 2002, Pages 2513-2522, ISSN 1352-2310, http://dx.doi.org/10.1016/S1352-2310(02)00131-0.