Practical Implications of CLIMCAPS Cloud Clearing and Derived Quality Metrics

Abstract

AbstractClouds present one of the largest sources of uncertainty in infrared (IR) measurements of the vertical atmospheric state. Hyperspectral instruments onboard Earth orbiting satellites, such as the Atmospheric Infrared Sounder (AIRS) on Aqua (2002–present), measure the top of atmosphere (TOA) radiances emitted by Earth surface and atmosphere. IR measurements are limited in their ability to distinguish different cloud structures. Lack of prior knowledge about clouds at the time of measurement can therefore significantly reduce the quality of retrieved soundings. The Community Long‐term Infrared Microwave Atmospheric Product System (CLIMCAPS) uses the AIRS Science Team (AST) cloud clearing methodology to remove the radiative effect of clouds from TOA IR measurements to improve the quality of its sounding retrievals and enable vertical observations in clear and partly cloudy conditions. In this paper we discuss how AST cloud clearing affects CLIMCAPS soundings and enable a global product for long‐term analysis of the atmospheric state.