A SIMPLE PARAMETERIZATION OF OZONE INFRARED-ABSORPTION FOR ATMOSPHERIC HEATING RATE CALCULATIONS

A simple parameterization of ozone absorption in the 9.6-mu-m region which is suitable for two- and three-dimensional stratospheric and tropospheric models is presented. The band is divided into two parts, a band center region and a band wing region, grouping together regions for which the temperature dependence of absorption is similar. Each of the two regions is modeled with a function having the form of the Goody random model, with pressure and temperature dependent band parameters chosen by empirically fitting line-by-line equivalent widths for pressures between 0.25 and 1000 mbar and ozone absorber amounts between 1.0 x 10(-7) and 1.0 cm atm. The model has been applied to calculations of atmospheric heating rates using an absorber amount weighted mean pressure and temperature along the inhomogeneous paths necessary for flux computations. In the stratosphere, maximum errors in the heating rates relative to line-by-line calculations are 0.1 K/d, or 5% of the peak cooling at the stratopause. In the troposphere the errors are at most 0.005 K/d.