A field study of the generation of nitrate in a hill cap cloud

• Published in: Environmental pollution (1987) Vol. 75; no. 1; pp. 69 - 73
• Main Authors: Choularton, T.W., Wicks, A.J., Downer, R.M., Gallagher, M.W., Penkett, S.A., Bandy, B.J., Dollard, G.J., Jones, B.M.R., Davies, T.D., Gay, M.J., Tyler, B.J., Fowler, D., Cape, J.N., Hargreaves, K.J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 1992
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/0269-7491(92)90058-I

A field experiment to investigate the formation of nitrate as an airstream passes through a hill cap cloud has been performed at the UMIST field station on Great Dun Fell. It has been shown that the aerosol nitrate concentration increased by about 0·5 μg m −3 as the airstream passed through the cloud during the night. At sunrise the nitrate production disappeared. It is suggested that the most likely mechanism for this nitrate production was due to the solution of N 2O 5 and NO 3 formed from the reaction of NO 2 with O 3. These higher oxides build up overnight in the absence of short wave radiation to photolyse them. Other possible mechanisms of nitrate production are also discussed.