DIRECT MEASUREMENT OF TROPOSPHERIC OZONE DISTRIBUTIONS FROM SPACE

The role of ozone in absorbing ultraviolet solar radiation is well kno wn, Ozone also makes a significant contribution to the radiative balan ce of the upper troposphere and lower stratosphere, such that changes in the distribution of ozone in these atmospheric regions will affect the radiative forcing of climate(1,2). Furthermore, tropospheric ozone is the source of the hydroxyl radical which controls the abundance an d distribution of many atmospheric constituents, including greenhouse gases such as methane and hydrochlorofluorocarbons, Tropospheric ozone is produced photochemically in situ and is also transported down from the stratosphere, but the relative importance of these two sources to its global budget is poorly understood, High-quality tropospheric and lower-stratospheric ozone profile measurements are available from son des and lidar techniques, but their geographical sampling is very limi ted. Complementary satellite measurements of the global ozone distribu tion in this height region are therefore required to quantify ozone's tropospheric budget and its participation in climate-forcing and tropo spheric chemistry. Here we present direct measurements of tropospheric ozone concentrations from space, made by the European Space Agency's Global Ozone Monitoring Experiment. These results demonstrate the pote ntial of satellite measurements to provide self-consistent tropospheri c and stratospheric ozone distributions on a global scale.