Seminar: Clouds and climate

Dates: 
30 September, 2009 - 17:00
Speaker(s): 
Dr Georgios Matheou, Post-Doctoral Fellow at NASA's Jet Propulsion Laboratory (JPL) in California, USA
Venue: 
The Cyprus Institute, Guy Ourisson Building, Athalassa Campus (Higher Technical Institute - HTI, grounds)
Abstract

Clouds strongly modulate Earth's radiation budget and currently remain the largest source of uncertainty in climate predictions. In particular, accurate representation of low clouds, and the prediction of the adjustment of their dynamics in a changing climate, presents many challenges in climate models.

In studies of the atmospheric boundary layer, the lowermost layer of the troposphere that is in contact with the surface, large-eddy simulation (LES) models have been used extensively to study the boundary-layer dynamics and in development of parameterizations for weather and climate models.

LES corresponding to the precipitating shallow cumulus composite case of the RICO campaign are presented. The simulations elucidate aspects of individual-cloud dynamics but also of the cloudy boundary layer ensemble.
The observed mechanisms of vertical transport of momentum and species suggest that vertical transport is not diffusive but dominated by vertical motions at cloud cores and cloud edges. The choice of numerical discretization and its impact on the LES statistics is also discussed.

For more information, contact Eroulla Cadd tel. +357 22208600 or email e [dot] cadd [at] cyi [dot] ac [dot] cy