Controls on atmospheric chloroiodomethane (CH2ClI) in marine environments

Authors

Ruth K. Varner, University of New Hampshire, DurhamFollow
Yong Zhou, University of New Hampshire, Durham
Rachel S. Russo, University of New Hampshire, Durham
Oliver W. Wingenter, New Mexico Institute of Mining and Technology
Elliot Atlas, University of MiamiFollow
Craig Stroud, Meteorological Service of Canada
Huiting Mao, University of New Hampshire, Durham
Robert W. Talbot, University of New Hampshire, Durham
Barkley C. Sive, University of New Hampshire, Durham

Abstract

Mixing ratios of chloroiodomethane (CH2ClI) in ambient air were quantified in the coastal North Atlantic region (Thompson Farm, Durham, New Hampshire, and Appledore Island, Maine) and two remote Pacific areas (Christmas Island, Kiribati, and Oahu, Hawaii). Average mixing ratios were 0.15 ± 0.18 and 0.68 ± 0.66 parts per trillion by volume (pptv) at Thompson Farm and Appledore Island, respectively, compared to 0.10 ± 0.05 pptv at Christmas Island and 0.04 ± 0.02 pptv in Hawaii. Photolysis constrained the daytime mixing ratios of CH2ClI at all locations with the minimum occurring at 1600 local time. Daily average fluxes to the atmosphere were estimated from mixing ratios and loss due to photolysis at Appledore Island, Christmas Island and Hawaii, and were 58 ± 9, 19 ± 3, and 5.8 ± 1.0 nmol CH2ClI m−2 d−1, respectively. The measured sea‐to‐air flux from seawater equilibrator samples obtained near Appledore Island was 6.4 ± 2.9 nmol CH2ClI m−2 d−1. Mixing ratios of CH2ClI at Appledore Island increased with increasing wind speed. The maximum mixing ratios observed at Thompson Farm (1.6 pptv) and Appledore Island (3.4 pptv) are the highest reported values to date, and coincided with high winds associated with the passage of Tropical Storm Bonnie. We estimate that high winds during the 2004 hurricane season increased the flux of CH2ClI from the North Atlantic Ocean by 8 ± 2%.

Department

Earth Systems Research Center

Publication Date

5-20-2008

Journal Title

Journal of Geophysical Research: Atmospheres

Publisher

American Geophysical Union (AGU)

Digital Object Identifier (DOI)

https://dx.doi.org/10.1029/2007JD008889

Document Type

Article

Recommended Citation

Varner, R.K., °Y. Zhou, °R.S. Russo, O. W. Wingenter, E. Atlas, C. Stroud, H. Mao, R. Talbot, and B. C. Sive (2008), Controls on atmospheric chloroiodomethane (CH2ClI) in marine environments, J. Geophys. Res., 113, D10303, doi:10.1029/2007JD008889.

Rights

©2008. American Geophysical Union. All Rights Reserved.

Comments

This is an article published by AGU in Journal of Geophysical Research: Atmospheres in 2008, available online: https://dx.doi.org/10.1029/2007JD008889