| Full text | |
| Author(s): |
Fowler, Laura D.
[1]
;
Skamarock, William C.
[1]
;
Grell, Georg A.
[2]
;
Freitas, Saulo R.
[3]
;
Duda, Michael G.
[1]
Total Authors: 5
|
| Affiliation: | [1] Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 - USA
[2] NOAA, Earth Syst Res Lab, Boulder, CO - USA
[3] INPE, Ctr Weather Forecasting & Climate Studies, Sao Paulo - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | MONTHLY WEATHER REVIEW; v. 144, n. 6, p. 2285-2306, JUN 2016. |
| Web of Science Citations: | 12 |
| Abstract | |
The authors implemented the Grell-Freitas (GF) parameterization of convection in which the cloud-base mass flux varies quadratically as a function of the convective updraft fraction in the global nonhydrostatic Model for Prediction Across Scales (MPAS). They evaluated the performance of GF using quasi-uniform meshes and a variable-resolution mesh centered over South America, the resolution of which varied between hydrostatic (50 km) and nonhydrostatic (3 km) scales. Four-day forecasts using a 50-km and a 15-km quasi-uniform mesh, initialized with GFS data for 0000 UTC 10 January 2014, reveal that MPAS overestimates precipitation in the tropics relative to the Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis data. Results of 4-day forecasts using the variable-resolution mesh reveal that over the refined region of the mesh, GF performs as a precipitating shallow convective scheme, whereas over the coarse region of the mesh, GF acts as a conventional deep convective scheme. As horizontal resolution increases and subgrid-scale motions become increasingly resolved, the contribution of convective and grid-scale precipitation to the total precipitation decreases and increases, respectively. Probability density distributions of precipitation highlight a smooth transition in the partitioning between convective and grid-scale precipitation, including at gray-zone scales across the transition region between the coarsest and finest regions of the global mesh. Variable-resolution meshes spanning between hydrostatic and nonhydrostatic scales are shown to be ideal tools to evaluate the horizontal scale dependence of parameterized convective and grid-scale moist processes. (AU) | |
| FAPESP's process: | 14/01563-1 - Assessment of impacts of inclusion of aerosol effects in numerical weather prediction over South America |
| Grantee: | Saulo Ribeiro de Freitas |
| Support Opportunities: | Scholarships abroad - Research |