A mixed-phase bulk orographic precipitation model with embedded convection

Cannon, D., Kirshbaum, D. J. and Gray, S. L. ORCID: https://orcid.org/0000-0001-8658-362X (2013) A mixed-phase bulk orographic precipitation model with embedded convection. Quarterly Journal of the Royal Meteorological Society, 140 (683). pp. 1997-2012. ISSN 0035-9009 doi: 10.1002/qj.2269

Abstract/Summary

A novel analytical model for mixed-phase, unblocked and unseeded orographic precipitation with embedded convection is developed and evaluated. The model takes an idealised background flow and terrain geometry, and calculates the area-averaged precipitation rate and other microphysical quantities. The results provide insight into key physical processes, including cloud condensation, vapour deposition, evaporation, sublimation, as well as precipitation formation and sedimentation (fallout). To account for embedded convection in nominally stratiform clouds, diagnostics for purely convective and purely stratiform clouds are calculated independently and combined using weighting functions based on relevant dynamical and microphysical time scales. An in-depth description of the model is presented, as well as a quantitative assessment of its performance against idealised, convection-permitting numerical simulations with a sophisticated microphysics parameterisation. The model is found to accurately reproduce the simulation diagnostics over most of the parameter space considered.