Update of NMC/CMA Global Ensemble Prediction
System
Jing Chen, Hua Tian, Gou Deng
National Meteorological Center (NMC), CMA
Contents
• GEPS System Configuration• GEPS Update• Tigge relative research and use
T213L31
BGM perturbation method
Con.l Run
IC1+ IC1- IC2+ IC2-
Run all members.
Product processing
SSI+ATOVSObs
EPS Upgraded T213 GEPS System
model T213L31
Horizontal Resolution
0.5625
Vertical Resolution
31
Analysis system 3D SSI+ATOVS
Perturbation method
BGM
Perturbation region
Global
EPS members 15
forecast 10 days
Typhoonrelocation and vortex perturbation
T213 GEPS Configuration
Integration withModel T213
IC 1IC 2
First Guess 1
12 or 24 hrs
DIFF=FG1-FG2
Filtered DIFFGauss Filter, Remove waves no.>9
MASKRescalingProcess
Perturbation
Analysis
First Guess 2
EP mem1
EP mem2
1~10 days
GetiniconGetinicon.cmdcmd
GetrscalGetrscal..cmdcmd
ModelnModeln..cmdcmd
T213 GEPS Based on-BGM T213 GEPS Based on-BGM System Structure and Flow ChartSystem Structure and Flow Chart
Global EPS Upgrade Data assimilation from Optimal Interpolation 3DVAR +ATO
VS in 2008T213-EPS ACC (NH 500mb Height)
average for 20080801-20080831
00.10.20.30.40.50.60.70.80.9
1
1 2 3 4 5 6 7 8 9 10valid(day)
AC
C S
core
EPS_mean Control Skill line
ACC (NH 500mb Height)average for 20060601-20060831
00.10.20.30.40.50.60.70.80.9
1
1 2 3 4 5 6 7 8 9 10valid(day)
AC
C S
core
EPS_mean Control Skill line
CMA old EPSCMA upgraded EPS
Control run forecast skill improve from 5 to 6.5 day
Anomaly Correlation Coefficient (ACC)
New update in 2009 for Global TC ensemble prediction
Old TC EPS ： Perturbed TC environmentUpgrade TC EPS ： perturbed TC environment ＋ Vortex.
Old TC EPS New TC EPS Difference
The ensemble products update on the NMC’s webhttp://www.nmc.gov.cn/publish/nwp/eps-t213/probability/precipitation/index.htm
Tigge relative research and use
• Relative Research– Global EPS system upgrade;
– Typhoon EPS system development;
– Method for bias correction & combination, cluster;
– Numerical model error analysis and NWP Probability;
– Hydrology prediction drived by TIGGE data;
– Method for severe weather potential forecast;
– TIGGE-LAM researches
• Data operational use – Medium-range forecast with TIGGE data;
– CXML typhoon track EPS product;
Global TC track EPS CXML digital products
CXML ( Cyclone extensible Markup Language):
CMA ECMWF NCEP
JMA KMA UKMO
No.0817, HIGOS (2008)
Hydrology forecast based on downscaling TIGGE precipitation
TIGGE precipitation in watershed
CMA CMA
ECMWF ECMWF
NCEPNCEP
Period and flood runoff forecast based on EPS
data
Super EPS flood runoff probability prediction
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