Detection of nitrous acid in the atmosphere by differential optical absorption

Abstract

HNO2 was investigated by long path optical absorption at three sites in Western Europe. It vas definitely identified and measured in moderately polluted air at Jülich. Mixing ratios as high as 0.8 ppb were observed before sunrise. After sunrise the HNO2 is photolyzed and considerable amounts of OH are produced. The formation of HNO2 is unclear and possible reactions are discussed. Copyright 1979 by the American Geophysical Union.