High Altitude Lidar Observations of Marine Stratocumulus Clouds

The present study describes the cloud top structure of an East Pacific marine stratocumulus cloud layer as observed from a downward-pointing lidar system aboard the NASA ER-2 aircraft. The lidar observations were coordinated with in situ observations of cloud parameters. These data are applied to study important statistical properties of the stratus clouds. The study of cloud top structures is highly relevant for detailed radiation budget calculations. Because large gradients in temperature and humidity exist near the cloud top, cloud top emmitted radiation varies significantly in the vertical. Precise knowledge of cloud top location allows for a precise determination of cloud top cooling and thus determines an important loss/gain in the atmospheric thermodynamic energy budget. Cloud top topography and periodic structures influence the solar reflectance and therefore the albedo of the clouds.