Precipitation Estimates from CloudSat Using a Path-Integrated Attenuation Approach

Initial CloudSat data has provided a wealth of information on the structure of global cloud systems. This information is not limited to cloud particles only; there is also significant information about precipitation, its frequency of occurrence relative to various type of cloud systems in different geographic and dynamical regimes, and the intensity of rainfall within these systems. W-band radars undergo attenuation in precipitating systems. While this is often viewed as an undesirable characteristic of meteorological radar, in this work attenuation is utilized as a measurement rather than noise. It is shown that attenuation of the surface signal by precipitation is directly related to the intensity of rainfall occurring through the precipitating layer, and that the magnitude of this surface signal as viewed from CloudSat is sufficiently large that it is possible to estimate rainfall in both lightly and moderately precipitating systems. The characteristics of rainfall and the cloud systems they occur in, as observed by over four months of CloudSat data, will be examined for both land and ocean.