2021/02/18 by Kaitlyn Loftus, Robin Wordsworth, Robin D. Wordsworth
Earth and Planetary Sciences · Environmental Science · Physics and Astronomy · #Atmospheric aerosols and clouds #Cloud physics #Convection #Dimensionless quantity #Evaporation #Falling (accident) #Precipitation #Precipitation Measurement and Analysis #Radiative transfer #Range (aeronautics) #Science and Climate Studies #astro-ph.EP #physics.ao-ph
paper · pdf · doi:10.1029/2020je006653
submitted to JGR: Planets; 40 pages, 8 figures, 3 tables, 4 appendices; supporting information with 9 pages, 8 figures, 1 table; associated code at https://github.com/kaitlyn-loftus/rainprops
arxiv created 2021/02/18 · openalex created_date 2021/03/01 · openalex publication_date 2021/03/15 · arxiv updated 2021/05/05 · openalex updated_date 2026/08/06
Abstract The evolution of a single raindrop falling below a cloud is governed by fluid dynamics and thermodynamics fundamentally transferable to planetary atmospheres beyond modern Earth's. Here, we show how three properties that characterize falling raindrops—raindrop shape, terminal velocity, and evaporation rate—can be calculated as a function of raindrop size in any planetary atmosphere. We demonstrate that these simple, interrelated characteristics tightly bound the possible size range of raindrops in a given atmosphere, independently of poorly understood growth mechanisms. Starting from the equations governing raindrop falling and evaporation, we demonstrate that raindrop ability to vertically transport latent heat and condensible mass can be well captured by a new dimensionless number. Our results have implications for precipitation efficiency, convective storm dynamics, and rainfall rates, which are properties of interest for understanding planetary radiative balance and (in the case of terrestrial planets) rainfall‐driven surface erosion.