Passive microwave remote sensing from satellites, airborne platforms and ground-based stations has contributed uniquely and substantially to the study of atmospheric chemistry, meteorology, and climate change. The purpose of this session is to present atmospheric research results in the field of passive microwave remote sensing. The session will cover wide radiometry applications such as determination of humidity and temperature structure, retrieval of cloud and precipitation properties and observations of relevant trace gases. The session also covers activities that are used to validate products that are retrieved using these observations. Contributions on fundamental aspects of microwave radiometry and atmospheric-application-driven innovation such as hardware development, radiometer calibration and measurement configuration are welcome, as well as on inversion techniques and their uncertainty specification. We specifically encourage submitting papers that show the potential of combining microwave radiometer observations with other active or passive remote sensing observations, either from the ground or from space. The session also aims to address the use of microwave remote sensing data for now-casting and/or assimilation into NWP models for improving short-term weather forecasts.