Length Scales and Spectra in Shallow Precipitating Cumulus Convection

Abstract:

The effects of shallow clouds are one of the largest sources of uncertainty in climate projections. The development of precipitation in trade-wind shallow cumulus boundary layers is an important process both from the energy balance perspective but also because of the potential to modulate the convective environment. The development of precipitation is correlated to the large-scale organization of convection, such as the formation of cold pools. Using large-eddy simulation of the boundary layer observed during the RICO campaign with a very extensive horizontal domain, about 160 x 160 km, and fine resolution (40 m) the integral length scales, spectra and cospectra are studied. The analysis focuses on the rate of energy transfer to the large-scale and quantifies the time scale of convection organization.