Radiative forcing due to changes in tropospheric ozone in the period 1980 to 1996

Radiative forcing calculations of changes in tropospheric ozone in the peri od 1980 to 1996 are performed. The tropospheric ozone changes used in this study are from a chemistry transport model [Karlsdottir et al., this issue] . For the radiative transfer calculations, schemes for thermal infrared rad iation and shortwave radiation are used. Effects of reduced stratospheric o zone and emissions of tropospheric ozone precursors on the changes in tropo spheric ozone are taken into account. Large positive radiative forcing is e stimated over Southeast Asia, due to emissions of ozone precursors. Effects of decreased stratospheric ozone have reduced the radiative forcing due to change in tropospheric ozone from 1980 to 1996, particularly at high latit udes where the radiative forcing is negative.