TEMPERATURE AVERAGES AND RATES OF STRATOSPHERIC REACTIONS

Use of zonal average temperatures is common in numerical modeling of s tratospheric chemistry. In most cases, this approach is accurate. The exceptions are when a heterogeneous reaction or a thermal process whic h is highly non-linear in temperature is involved. The differences bet ween use of an average temperature and more realistic temperature are presented for cases where temperature fluctuations are of importance i n the stratosphere. In particular, the rates of reactions of HC1 in su lfate aerosols are significantly underestimated by the use of zonal av erage temperatures. Errors associated with using monodispersed aerosol s in place of a size distribution are also addressed.