ARCUS | Arctic Research Consortium of the United States

6th Annual ARCUS Award for Arctic Research Excellence


Submitted by   Terra Dassau
Authors   Terra M. Dassau, A.L. Sumner, S.L. Koeniger, P.B. Shepson, J. Yang, R.E. Honrath, N.J. Cullen, K Steffen H.W. Jacobi, M. Frey, M.A. Hutterli, and R.C. Bales
Category   Physical Science
Title   Investigation of the Role of the Snowpack on Formaldehyde Chemistry at Summit, Greenland
Affiliation   Chemistry, Purdue University, West Lafayette, IN, USA

Abstract

Ambient gas-phase and snow-phase measurements of formaldehyde (HCHO) were conducted at Summit, Greenland, during several summers, in order to understand the role of airsnow exchange on remote tropospheric HCHO and factors that determine snowpack HCHO. A gas-phase model was developed that includes known chemistry relevant at Summit and uses data from the 1999 and 2000 field campaigns. The model does not account for the high ambient levels of HCHO at Summit in 1999 (~ 600 ppt), predicting approximately 150 ppt from predominantly CH4 chemistry. Based on the data from these studies, we show that emission from the snowpack has only a small impact on the gas-phase HCHO concentrations, due to the short atmospheric lifetime of HCHO. Thus, we conclude that there are likely missing gas-phase HCHO precursors. Temperature-dependent release of formaldehyde from the snowpack and photochemical production within the snowpack were both found to be important processes. Further investigation should be conducted to determine the nature of organic material in both the snowpack and the gas-phase, the oxidation of which produces HCHO and other volatile products.