STRATOSPHERIC THERMAL DAMPING TIMES

Radiative damping of stratospheric temperature waves has wide implicat ions for stratospheric physical processes. Damping is linearly paramet erized as proportional to the local temperature. Thermal damping is ca lculated using the Goddard radiative transfer model and 17 years obser vations. Damping times of stratospheric temperatures are calculated fo r each month at all latitudes. These damping times are consistent with previous stratospheric estimates, but show shorter tropical time scal es. Damping times range from an annual global average of 28 days (100 hPa) to 4 days (1 hPa). A considerable annual cycle is seen over much of the stratosphere, which is directly related to the annual cycle of temperatures, with longer damping times associated with colder tempera tures.