Numerical Simulations of Catastrophic Floods in China with Regional Climate Model Yiming Liu, Yihui Ding et al. (National Climate Center)

Content §Frame of RegCM/NCC §Simulative Experiments §Conclusions and Discussion

Frame of RegCM/NCC

RegCM/NCC Domain center point:115E,30N resolution:60km×60km × 16σ

Vertical grid structure in RegCM/NCC

Modification of NCAR RegCM2 Physical Process NCAR RegCM2 RegCM/NCC Land-surface LPM1 process BATS LPM2 Cumulus Kuo － Anthes Mass Flux Scheme convection Grell Betts － Miller Radiation transfer CCM2 CCM3 PBL Holtslag TKE the Tibetan Plateau the Three-Dimensional nesting method

Initial data lateral boundary data RegCM/NCC E, 10-60N center point: 115E, 30N 60km × 60km × 16 σRegCM/NCCRegCM/NCC Land-use data surface data LPM1LPM2 Mass Flux Scheme Betts-Miller CCM3 radiation scheme Mass Flux Scheme Betts-Miller CCM3 radiation scheme Terrain TKE scheme Three dimensional nesting Out data T,Pr,q,u,v,H,T soil,q soil ……

Simulative Experiments

Land- surface Process OBS LPM-I BATS §Ts §June 1991

LPM-2 OBS BATS Precipitation June 1994

Convection §Precipitation §June 1991 OBS KUO MFS

Daily precipitation averaged over region ( E,28-34N) In May-July 1991 （ mm/d ） Black: OBS ； Green: Kuo ； Blue: Grell ； Red: MFS

Convection §Precipitation §May-July 1994 OBS Kuo MFS

Convection Betts-Miller scheme Precipitation 1st May - 15th July 1991

OBS Kuo Betts-Miller Precipitation June-July 1998

§CCM2 §CCM3 §precipitation §May-July 1998 Radiation OBS

PBL PBL Hotslag TKE (grassland plateau crop desert ocean)

June July August 1-10 NCEP Hotslag TKE Daily precipitation (mm/d)

Observation Observation Height 700hPa May

2-D nesting method Height 700Hpa May

3-D nesting method Height 700hPa May

Height 700hPa July Height 700hPa July observation 2-D nesting method 3-D nesting method July May 1- July

6/ South China 7/ Changjiang River 5/ North China average Compare of rain belt between OBS and simulation ( RegCM/NCC )

Rainfall June 1994 OBS RegCM2 TKE, TKE, MFS, BM Rad ccm3, Rad CCM3

TKE,MFS,RAD ccm3 TKE,BM,RAD ccm3 OBS RegCM2 Rainfall July 1994

Conclusions and Discussion §RegCM/NCC is feasible and steady. §Simulative results show that the new schemes can improve the simulation in some degree. §In next 1-2 years we will make more simulations and predictive experiments to verify the performance of RegCM/NCC.

Thank you.