Considerations for spaceborne 94 GHz radar observations of precipitation

Spaceborne 94 GHz radars offer sufficient sensitivity to observe all types of precipitation and their associated clouds without stretching the instrument requirements. In this study, considerations for precipitation classification and detection from space using 94 GHz radars are presented. First, a technique that uses the path-integrated attenuation normalized to the depth of the rain layer, the snow-integrated reflectivity and the reflectivity difference from snow to rain to discriminate convective and stratiform profiles is proposed. Second, we present a critical view of sampling issues for precipitation and Doppler measurements from space at 94 GHz. A new sampling strategy for spaceborne 94 GHz radars with alternating cloud and precipitation modes is discussed that can improve our ability to detect and measure precipitation without losing sight of the main objective of deploying such high frequency radars in space, to map the global distribution of clouds.