Nitric acid forecast experiments

Three-dimensional forecasts of the time evolution of the distribution of HNO 3 in the stratosphere during two time periods (17-24 February 1979, 13-23 March 1979) are reported. The February time period was during a major wave number 2 stratospheric warming, and dynamics dominate the HNO 3 evolution. Dynamics and photochemistry are both important in the March experiment. The zonal mean results of the model calculations are in general qualitative agreement with the LIMS HNO 3 observations. However, the calculated 3-dimensional fields show significant differences from the observations. The analysis of the differences between the model results and the data gives insight into the problems of the modeling technique and to the consistency of the dynamical and constituent data.