1Hans-Ertel Centre for Weather Research, Deutscher Wetterdienst, Hamburg, Germany
2Max Planck Institute for Meteorology, Hamburg, Germany
Received: 12 Dec 2012 – Published in Atmos. Chem. Phys. Discuss.: 17 Jan 2013
Abstract. Trade wind cumulus clouds often organize in along-wind cloud streets and across-wind mesoscale arcs. We present a benchmark large-eddy simulation which resolves the individual clouds as well as the mesoscale organization on scales of O(10 km). Different methods to quantify organization of cloud fields are applied and discussed. Using perturbed physics large-eddy simulation experiments, the processes leading to the formation of cloud clusters and the mesoscale arcs are revealed. We find that both cold pools as well as the sub-cloud layer moisture field are crucial to understand the organization of precipitating shallow convection. Further sensitivity studies show that microphysical assumptions can have a pronounced impact on the onset of cloud organization.
Revised: 25 Apr 2013 – Accepted: 12 May 2013 – Published: 10 Jun 2013
Seifert, A. and Heus, T.: Large-eddy simulation of organized precipitating trade wind cumulus clouds, Atmos. Chem. Phys., 13, 5631-5645, doi:10.5194/acp-13-5631-2013, 2013.