Mesoscale and microscale structure of cirrus clouds: three case studies

Abstract

The cloud systems consist of a multilayered orographic cirrus, a 6-km deep cirrostratus, and a group of fibrous cirrus bands at the tropopause. Generating regions appear to be composed of complexes of much smaller convective structures, presumably on the ~1-km scale of cirrus uncinus cells, and so are termed Mesoscale Uncinus Complexes (MUC). Accumulations of ice particles within cirrus, commonly referred to as precipitation trails, are associated with generating regions at or near cloud tops, but are also created by the local production of ice crystals within embedded convective impulses. Supercooled cloud droplets large enough to be detected by aircraft probes (≥5 μm diameter) were sampled in embedded convective cells near cloud base at temperatures ranging from -21° to -36°C. -from Authors