Phys.org July 25, 2024 A team of researchers in the US (NSF National Center for Atmospheric Research, industry) provided substantial evidence for significant impacts of turbulence on the evolution of cloud droplet size distributions and rain formation by comparing high-resolution observations of cumulus congestus clouds with state-of-the-art large-eddy simulations coupled with a Lagrangian particle-based microphysics scheme. Turbulence causes earlier rain formation and greater rain accumulation compared to simulations with gravitational coalescence only. The observed rain size distribution tail just above cloud base follows a power law scaling that deviates from theoretical scalings considering either a purely gravitation collision kernel or […]
Tag Archives: Clouds
Aerosols shown to increase size of cloud cells, causing greater radiative cooling under polluted conditions
Phys.org July 9, 2024 Researchers at Pacific Northwest National Laboratory reconfigured the Weather Research Forecasting (WRF) version 4.3 model to quantify the impact of aerosols on evolving cloud fields. Simulations utilizing meteorological boundary conditions were based on 10 case study days offering diverse meteorology during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA). Measurements demonstrated good agreement with the WRF-simulated cloud and aerosol properties. Higher aerosol concentration led to suppressed drizzle and increased cloud water content; that in turn les to larger radiative cooling rates at cloud top, enhanced vertical velocity variance, and increased vertical and horizontal […]
New insights into the formation of tiny cloud particles in the Arctic
Phys.org June 21, 2024 Vertical particle distributions are required to study aerosol–cloud interaction over sea ice comprehensively. An international team of researchers (Germany, USA – University of Colorado) presented vertically resolved measurements of aerosol particle number concentrations and sizes using tethered balloons with the data collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition in the summer of 2020. Radiosoundings, cloud remote sensing data, and 5-day back trajectories supplemented the analysis of thirty-four profiles of aerosol particle number concentration observed in 2 particle size ranges above 150 nm (N>150). The majority of aerosol profiles showed more […]