Precipitation Measuring Mission

A Robust Multi-scale Modeling System for the Study of Cloud and Precipitation Processes for PMM


Scientists Involved: Wei-Kuo Tao (PI), Xiaowen Li (Co-PI), Toshi Matsui (Co-PI), Stephen Lang (Co-PI), Di Wu (Co-I)


Objective. The proposed modeling effort will further study cloud and precipitation processes over many scales of motion, ranging from cloud microphysical processes up to the large-scale circulations that organize the growth and decay of precipitation systems. This proposal will use satellite products (i.e., TRMM, CloudSat, Aqua and GPM core and constellation satellites) as well as data from major field campaigns (i.e., CV3P, MC3E and GCPEx) to validate and improve the microphysical processes in numerical models for the NASA Precipitation Missions.


• Utilize satellite/GV products to identify any weaknesses and/or strengths within the microphysical processes used in the cloud-resolving and regional-scale models and to improve their performance by resolving any deficiencies.
• Conduct high-resolution (both horizontal and vertical) model simulations with improved microphysics and land surface model for a variety of different cloud and precipitation systems from different geographic locations [i.e., the Midlatitude Continental Convective Clouds Experiment (MC3E), Canadian CloudSA T/CALIPSO V alidation Project (C3VP), GPM Cold-season Precipitation Experiment (GCPEx) and two tropical oceanic sites (Tropical Warm Pool - International Cloud Experiment or TWP-ICE and ARM MJO Investigation Experiment/DYNAmics of the MJO or AMIE/DYNAMO)] using the improved microphysics with an emphasis on ice-phase and mixed-phase precipitation systems in high-latitudes.
• Couple the high-resolution model results with a satellite simulator to produce the cloud data (including hydrometeors and their size distributions) and cloud properties (including latent heating, eddy transport and radiation) needed to advance GPM algorithm development and validation.


Figure. (a) Time series of MC3E hourly precipitation from 00 UTC 20 May to 00 UTC 22 May for NLDAS (black) and two NU- WRF simulations (purple: coupled with LIS, red: without LIS). (b) Observed (black background) and simulated (white background) composite radar reflectivity for MC3E at 12 UTC on 20 May 2011. (c) Composite radar reflectivity from NEXRAD (black background) and a NU-WRF simulation (white background) for a synoptic snow event during GCPEx at 20 UTC 10 February 2012.


Figure. LH products (top row) from the version 2 CSH algorithm based on rainfall data from the TRMM Combined Algorithm: (left) instantaneous pixel scale LH off the southeast coast of Africa 1 January 2001 at a height near 2.5 km from the orbital product, (center) same but for the 3G31 gridded (0.5 x 0.5 deg) orbital product, and (right) same but for monthly mean LH from the 3H31 gridded monthly product. The new CSH algorithm uses conditional rain rates and look-up-tables based on GCE results divided into fine intensity and stratiform bins (Tao et al. 2010). The corresponding surface rainfall is shown below each of the LH products.