Application of TRMM/PR data for numerical simulations with mesoscale model MM5

Numerical simulations of two heavy rainfall cases in the Changjiang-Huaihe River basin are performed with TRMM/PR (precipitation radar) data incorporated into the PSU/NCAR meso scale model MM5. The mixing ratio of rainwater q(r) is obtained from the R - q(r) relation (R is the rainfall rate), and the mixing ratio of water vapor q(v) in the model is replaced by q'(v) = q(v) + q(r). Then, TRMM/PR data are used to modify humidity analysis obtained from conventional radiosonde data, and sensitivity experiments (STE) are performed and compared to control experiments (CTL). Results show that both the heavy rainfall distribution and its maximum amounts from STE are improved compared with those from CTL.