A linearized approach to the radiative budget of the stratosphere: Influence of the ozone distribution

Abstract

The influence of the ozone distribution on stratospheric temperatures is studied using a linearized version of a detailed radiative code. The response of the linear radiation model to ozone change is found to be very consistent with the sensitivity of the ECMWF general circulation model (GCM). In particular, the lower stratospheric temperatures of the linear model and of the GCM respond similarly to changes in the vertical ozone gradient in the upper troposphere-lower stratosphere. It is concluded that the GCM sensitivity to ozone is mostly a linear response via changes in the solar and long wave radiation absorption, combined with the very long radiative damping times that prevail in the lower stratosphere. The present linearized approach to radiative transfer can therefore constitute a valuable means to obtain at low computational cost a first guess of the stratospheric temperature response of coupled GCM-Chemical Transport Models to ozone distribution changes. Copyright 2006 by the American Geophysical Union.