Abstract

NOx and NOy were determined in the interstitial air of surface snow and in ambient air at Summit, Greenland. NOx levels in interstitial air were 3 to >10 times those in ambient air, and were generally greater than ambient NOy levels. [NOy] in interstitial air varied diurnally in a manner consistent with photochemical generation within the snowpack. These observations imply that photochemical reactions occurring within or upon the ice crystals of surface snow produced NOx from a N-reservoir compound within the snow. Average [NOX]:[HNO3] and [NOx]:[NOy] ratios in ambient air above the snow were elevated relative to other remote sites, indicating that NOx release within the snowpack may have altered NOX levels in the overlying atmospheric boundary layer. We suggest that the observed release of NOx may have been initiated by photolysis of nitrate, present in relative abundance in surface snow at Summit. Such a process may affect levels of nitrate and other compounds in surface snow, the overlying atmosphere, and glacial ice, and its potential role in cirrus cloud chemistry should be investigated.

Publication Date

3-15-1999

Journal Title

Geophysical Research Letters

Publisher

Wiley

Digital Object Identifier (DOI)

10.1029/1999GL900077

Document Type

Article

Rights

© 1999 by the Chinese Geophysical Society

Share

COinS