Parameterization of subgrid condensation in cumulus convection for mesoscale forecast models
Abstract
Funds are provided to conduct research to develop a new unified parameterization of microphysical processes in marine clouds for application in mesoscale NWP models. The proposed research aims at developing sub-grid-scale parameterization of the condensation/evaporation process, as well as the corresponding latent heart release in trade wind cumulus convective clouds. It will focus on cases of cumulus convection where the average humidity over the grid box is below saturation and, therefore, is not sufficient to describe SGS cloud formation and growth, as well as cloud distributions inside the grid box. This research will be based on high resolution LES (Large Eddy Simulations) initialized with data from field experiments and will be divided into three tasks:1. The development of the PDF closure schemes as functions of conservative thermodynamic prognostic variables of the NWP model which serve as inputs to condensation process. 2. Evaluation of the moist saturation adjustment scheme and rain evaporation formulation in environments with different Cloud Condensation Nuclei concentrations, and derivation of a revision of these formulations in the case where their accuracy is insufficient.3. Investigation of the physical mechanisms behind the mathematical relationships describing the dependence of the condensed water and released latent heat on thermodynamic variables.In summary, the parameterization of the condensation/evaporation process combined with parameterization of the conversion rates will provide a complete formulation of sub-grid cloud microphysics in cases of fractional cloud cover.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141612487
Entities
People
- Yefim Kogan
Organizations
- Northwest Research Associates
- Office of Naval Research
- United States Navy