Nitric acid forecast experiments

Results of two three-dimensional forecasts of the time evolution of the distribution of HNO3 in the stratosphere are reported. The first is for the February 1979 stratospheric warming, and the second is for a period in March, 1979 when the relative importance of photochemistry and dynamics is thought to be rapidly changing. The zonal mean results of the model calculations are in general qualitative agreement with the LIMS HNO3 observations. However, the calculated three-dimensional fields show significant differences from the observations. The results provide insight into what must be done to form a successful constituent forecast model and provide information on the modeling technique and the self-consistency of the observed dynamical and constituent fields.