Relation between ice and liquid water mass in mixed-phase cloud layers measured with Cloudnet
Abstract. An analysis of the Cloudnet dataset collected at Leipzig, Germany, with special focus on mixed-phase layered clouds is presented. We derive liquid and ice water content together with vertical motions of ice particles falling through cloud base. The ice mass flux is calculated by combining measurements of ice water content and particle fall velocity. The efficiency of heterogeneous ice formation and its impact on cloud lifetime is estimated for different cloud-top temperatures by relating the ice mass flux and the liquid water content at cloud top. Cloud radar measurements of polarization and fall velocity yield, that ice crystals formed in cloud layers with a geometrical thickness of less than 350 m are mostly pristine when they fall out of the cloud. It is also found that current and future spaceborne cloud radars might miss a large portion of that primary ice formation, especially for cloud layers with top temperatures warmer than −15 °C.