Solar Mesosphere Explorer measurements of polar mesospheric clouds (noctilucent clouds).

The Ultraviolet Spectrometer experiment on board the Solar Mesosphere Explorer satellite has measured scattering of sunlight from the polar mesospheric cloud layer in the 0.2 - 0.3 μm spectral range. The layer is manifested in the limb-scanning measurements as large increases in radiance at heights near 80 km, at latitudes 60 - 90°N and 60 - 90°S and during the summer season. The data reveal the presence of forward scattering behaviour. This permits the estimation of the mean particle sizes through Mie scattering theory. The relationships of the particle radii, optical depths and equivalent water vapor column mass are described. This is followed by a brief description of the potential of the large SME data base for future studies.