Denitrification through PSC formation - A 1-D model incorporating temperature oscillations
Abstract
A one-dimensional model of polar stratospheric cloud (PSC) formation and evolution during the polar winter, incorporating both HNO3 and H2O condensation, has been developed to investigate the interactions between Type I and Type II PSCs and the effects of these clouds on the stratospheric composition. Model simulations for various meteorological conditions and the results of extensive sensitivity tests are presented. Temperature oscillations, which have been included in the model, are shown to have an important influence on the characteristic and effects of the PSCs. The predicted proportions of the PSCs are consistent with observations of number, size, and optical effects, such as depolarization. Denitrification of stratospheric air by 35-88 percent is shown to occur in the presence of both Type I and Type II PSCs, with comparable nitrate removal in both types of clouds. Dehydration by Type II clouds simultaneously removes similar percentages of water vapor, up to 79 percent at lower altitudes. Although dehydration is insensitive to most of the parameter variations except the minimum temperature, the porocess of denitrification, especially the proportion removed by Type I PSCs, is highly variable.
- Publication:
-
Journal of Atmospheric Chemistry
- Pub Date:
- May 1991
- DOI:
- 10.1007/BF00114773
- Bibcode:
- 1991JAtC...12..319D
- Keywords:
-
- Cloud Physics;
- Stratosphere;
- Temperature Distribution;
- Water Vapor;
- Atmospheric Models;
- Dehydration;
- Nitrates;
- Polar Regions