Articles | Volume 9, issue 4
Hydrol. Earth Syst. Sci., 9, 285–299, 2005
https://doi.org/10.5194/hess-9-285-2005

Special issue: Advances in flood forecasting

Hydrol. Earth Syst. Sci., 9, 285–299, 2005
https://doi.org/10.5194/hess-9-285-2005

  07 Oct 2005

07 Oct 2005

Orographic effects on convective precipitation and space-time rainfall variability: preliminary results

P. Bongioannini Cerlini2,1, K. A. Emanuel1, and E. Todini3 P. Bongioannini Cerlini et al.
  • 1Dept. Earth Atmospheric and Planetary Sciences, MIT Cambridge, USA
  • 2Dept.of Physics, University of Perugia, Italy
  • 3Dept. of Earth and Geo-Environmental Sciences, University of Bologna, Italy
  • E-mail for corresponding author: cerlini@fisica.unipg.it

Abstract. In the EFFS Project, an attempt has been made to develop a general framework to study the predictability of severe convective rainfall events in the presence of orography. Convective activity is embedded in orographic rainfall and can be thought as the result of several physical mechanisms. Quantifying its variability on selected area and time scales requires choosing the best physical representation of the rainfall variability on these scales. The main goal was (i) to formulate a meaningful set of experiments to compute the oscillation of variance due to convection inside model forecasts in the presence of orography and (ii) to give a statistical measure of it that might be of value in the operational use of atmospheric data. The study has been limited to atmospheric scales that span the atmosphere from 2 to 200 km and has been focused on extreme events with deep convection. Suitable measures of the changing of convection in the presence of orography have been related to the physical properties of the rainfall environment. Preliminary results for the statistical variability of the convective field are presented.