Large-eddy simulation of organized precipitating trade wind cumulus clouds 1Hans-Ertel Centre for Weather Research, Deutscher Wetterdienst, Hamburg, Germany
10 Jun 2013
2Max Planck Institute for Meteorology, Hamburg, Germany
Received: 12 December 2012 – Published in Atmos. Chem. Phys. Discuss.: 17 January 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 April 2013 – Accepted: 12 May 2013 – Published: 10 June 2013
Citation: 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.