the ensemble prediction system and its application at cma€¦ · its application at cma chen jing,...

The Ensemble Prediction System and The Ensemble Prediction System and Its Application at CMAIts Application at CMA

CHEN Jing, TIAN Hua, DENG Guo, LI Xiaoli, GONG Jiandong,

中国气象局中国气象局中国气象局中国气象局中国气象局中国气象局中国气象局中国气象局 China Meteorological Administration

CHEN Jing, TIAN Hua, DENG Guo, LI Xiaoli, GONG Jiandong,LI Yinglin, WANG Xiaocong and HU Jiangkai

The Center of Numerical Weather Prediction,CMA.

15 November 201215 November 201215 November 201215 November 2012，，，，ToulouseToulouseToulouseToulouse

OUTLINEOUTLINE

��History of EPS at CMAHistory of EPS at CMA��ConfigurationsConfigurations��Verification and Application Verification and Application


��Verification and Application Verification and Application ��Recent researche and development Recent researche and development ��SummarySummary

Operational NWP System at CMAOperational NWP System at CMA

GRAPESGRAPESGRAPESGRAPES----RUCRUCRUCRUC

Dete

rm

inis

tic

GRPESGRPESGRPESGRPES----MESOMESOMESOMESO

+

Specialized Specialized Forecast ModelsForecast Models：：：：� Wave model

�Typhoon Track

model

�Sand storm model

�air pollutant

diffusion model

Global Global Global Global

model,model,model,model,T639T639T639T639

GRAPESGRAPESGRAPESGRAPES----GFSGFSGFSGFS

10 days

60h

1-24h


T213T213T213T213----GEPSGEPSGEPSGEPS

pro

ba

bilis

tic

GRAPESGRAPESGRAPESGRAPES----GFSGFSGFSGFS

WRFWRFWRFWRF----REPSREPSREPSREPS

10 days

60h

+ Typhoon track Typhoon track Typhoon track Typhoon track

EPSEPSEPSEPS

ApplicationApplicationVerificationVerification

2013-1-14

T213 GEPS test

T213 GEPS implem.

Jun.1998

Mar.

2001

Dec.2005

Dec.2006

May.2008

11、、、、、、、、History of EPS at CMAHistory of EPS at CMA

T213 GEPS implement.

T213 Typhoon Track implement.T106L19

GEPS testT106L19 GEPS Implement.


2006May2009

Jun2010

workingon REPS over China

working on REPS based on the WMO BO8RDP project. Real

time running.

T213L31

BGM perturbation method

SSI+ATOVS

configurations configurations configurations configurations T213 GEPS SystemT213 GEPS SystemT213 GEPS SystemT213 GEPS System

modelmodelmodelmodel T213L31 T213L31 T213L31 T213L31

Horizontal Horizontal Horizontal Horizontal

ResolutionResolutionResolutionResolution

0.56250.56250.56250.5625

Vertical ResolutionVertical ResolutionVertical ResolutionVertical Resolution 31313131

2、、、、Configurations-----T213 GEPS

6h Cycle


Cont。。。。Run

IC1+ IC1- IC2+ IC2-

10day Run

for all members.

Product processing

Analysis systemAnalysis systemAnalysis systemAnalysis system 3D SSI+ATOVS3D SSI+ATOVS3D SSI+ATOVS3D SSI+ATOVS

Perturbation methodPerturbation methodPerturbation methodPerturbation method BGMBGMBGMBGM

Perturbation regionPerturbation regionPerturbation regionPerturbation region GlobalGlobalGlobalGlobal

EPS membersEPS membersEPS membersEPS members 15151515

forecastforecastforecastforecast 10 days10 days10 days10 days

TyphoonTyphoonTyphoonTyphoon

relocation and relocation and relocation and relocation and

vortex perturbationvortex perturbationvortex perturbationvortex perturbation

GEPS ProductsGEPS ProductsGEPS ProductsGEPS Products

parameterparameterparameterparameter levellevellevellevel Line intervalLine intervalLine intervalLine interval unitsunitsunitsunits regionregionregionregion

Accumulent Accumulent Accumulent Accumulent

precipitatioprecipitatioprecipitatioprecipitatio

nnnn

surfacesurfacesurfacesurface

1,5,10,25,50,1,5,10,25,50,1,5,10,25,50,1,5,10,25,50,

100,250100,250100,250100,250

mmmmmmmm

10101010°°°°----55555555°°°°NNNN

70707070°°°°----150150150150°°°°EEEE10m10m10m10m wind wind wind wind

speedspeedspeedspeed

10m10m10m10m 4444 m/sm/sm/sm/s

2m 2m 2m 2m temp.temp.temp.temp. 2m2m2m2m 4444 °°°°CCCC

MSLPMSLPMSLPMSLP 4444 hPahPahPahPa

Geop. heightGeop. heightGeop. heightGeop. height

700;700;700;700;

4444 gpmgpmgpmgpm

Ensemble mean、、、、spread and spaghetti probabilityparameter Probability

12h ccumulated

precipitation

>0.1, >10, >25, 50,>100(mm)

24h ccumulated

precipitation

12 ccumulated snow

24h ccumulated snow

2m Temperature >33,>35 >38,>40 （J/kg）

<-30,<-25 <-20,<-10,<0,<5（J/kg）

10m Wind >5.5m/s, >8.0m/s, >10.8 (m/s),

>17.2m/s, >24.5m/s, >32.7 (m/s

Station Whisker-Box diagram


NHNHNHNH

Geop. heightGeop. heightGeop. heightGeop. height

500;200500;200500;200500;200

4444 gpmgpmgpmgpm

temperaturetemperaturetemperaturetemperature 850850850850 4444 °°°°CCCC

Wind fieldWind fieldWind fieldWind field

850;700;850;700;850;700;850;700;

500;200500;200500;200500;200

Vector Vector Vector Vector

divergencedivergencedivergencedivergence

850;700;850;700;850;700;850;700;

200200200200

444410101010

----5555

ssss----1111

5555°°°°----80808080°°°°NNNN

0000°°°°----160160160160°°°°EEEE

vorticityvorticityvorticityvorticity 500500500500 4444

relative relative relative relative

humidityhumidityhumidityhumidity

850;700850;700850;700850;700 10101010 %%%%

vertical vertical vertical vertical

velocityvelocityvelocityvelocity

700;500700;500700;500700;500

2 (|w|<20)2 (|w|<20)2 (|w|<20)2 (|w|<20)

10(|w|10(|w|10(|w|10(|w|≥≥≥≥20)20)20)20)

m/sm/sm/sm/s

Station Whisker-Box diagram

Strike probability

Typhoon track EPS Typhoon track EPS Typhoon track EPS Typhoon track EPS


Ensemble tracks

2013-1-14

Extreme Forecast Index (EFI））））for 2m temperature and precipitation


0 20 40 60 80 1000

0.2

0.4

0.6

0.8

1

� � � � (mm/24h)

��

CDF

72h climateEPS-0719EPS-0715

98.96%

88%

41.76%

(a)

1

0

2 ( )

(1 )AD

p F pEFI dp

p pπ−=

−∫

F.Lalaurette（（（（2003））））

NCARNCEP

CMC

UKMO

ECMWF

MeteoFrance

JMAKMA

CMA

TIGGE Archive Centres and Data Providers（（（（10））））


Archive Centre

Current Data Provider

BoM

CPTEC

Configuration of REPSConfiguration of REPSConfiguration of REPSConfiguration of REPS

� Model(WRF-ARW dynamical core)� 15km grid space, 31 vertical levels� 60h forecast� 15 members � BGM initial perturbation method � multi- physics

Ens. memEns. mem

MicrophysicsMicrophysics

schemescheme

Convective schemeConvective scheme

PBL schemePBL scheme


Ctrl.Ctrl. Lin schemeLin schemeLin schemeLin scheme BettsBettsBettsBetts MYJMYJMYJMYJ

Pair 1Pair 1 Lin schemeLin schemeLin schemeLin scheme KFKFKFKF YSUYSUYSUYSU

Pair 2Pair 2 Lin schemeLin schemeLin schemeLin scheme BettsBettsBettsBetts----MillerMillerMillerMiller YSUYSUYSUYSU

Pair 3Pair 3 Lin schemeLin schemeLin schemeLin scheme BettsBettsBettsBetts----MillerMillerMillerMiller----

JanjicJanjicJanjicJanjic

YSUYSUYSUYSU

Pair 4Pair 4 Lin schemeLin schemeLin schemeLin scheme KFKFKFKF MJYMJYMJYMJY

Pair 5Pair 5 WSM6WSM6WSM6WSM6 BettsBettsBettsBetts----MillerMillerMillerMiller MJYMJYMJYMJY

Pair 6Pair 6 WSM3WSM3WSM3WSM3 BettsBettsBettsBetts MJYMJYMJYMJY

Pair 7Pair 7 WSM3WSM3WSM3WSM3 BettsBettsBettsBetts YSUYSUYSUYSU

Forecast data was put into CMA TIGGE archive center every day

6hcycle

TheTheTheThe FlowFlowFlowFlow chartchartchartchart ofofofof REPSREPSREPSREPS

BGM for GEPS and


Downscale for Boundary conditions at 00Z,12Z

GEPS and REPS separately

Name Variables Products Probability

3D variables

HGT Height Layers：200 ,250,500,700,850,925,

1000hPa

Mean,Spread

Forecast hoursForecast hoursForecast hoursForecast hours：：：：

000,003,006,012,018,021,024000,003,006,012,018,021,024000,003,006,012,018,021,024000,003,006,012,018,021,024，，，，

027,030,036027,030,036027,030,036027,030,036，，，，039039039039，，，，42424242，，，，045045045045，，，，048048048048，，，，051051051051，，，，054054054054，，，，

057057057057，，，，060 060 060 060

QVAPOR Specific humidity

RH Relative humidity

UV U and V component Wind

TCTD Temperature and Dew-point temperature

THETASE Pseudo-wet-bulb potential temperature

DBZ Radar reflection Mean, Spread, Probability >10,>30,>50

SOIL 4 level Soil humidity Mean, Spread

2D variables

RAIN_3HR 3h accumulated precipitation Mean, Spread, Probability

RAIN_6HR 6h accumulated precipitation

Products for REPSProducts for REPSProducts for REPSProducts for REPS


>0.25, >5, >15, >25, >50(mm)




RAINC_3HR 3h accumulated convective precipitation

RH2M 2m Relative humidity Mean, Spread, Probability

SAUN Sangla Index

CIN Convective inhibition

SLP Sea Level Pressure

T2M 2m Temperature Mean, Spread, Probability >35,>38（J/kg）

CAPE Convective Available Potential Energy Mean, Spread, Probability >500,>1000， >1500,>2000 （J/kg）

UV10M 10m Wind Mean, Spread, Probability >8m/s, >12m/s, >16 (m/s)

Convective Risk Index

RISK_PRB1 Convective Risk Index Probability

RISK_PRB2 Convective Risk Index Probability

The lists of REPS products distributed local weather service

NamesVariables REPS products Thresholds

RAIN_3HR 3h accum. Precip Ensemble mean;Probabilistic map.

>0.1,>3,>10,>20,>50(mm)

RAIN_6HR 6h accum. Precip >0.1,>4,>13,>25,>60(mm)

RAIN_12HR 12h accum. Precip. >0.1,>5,>15,>30,>70(mm)

RAIN_24HR 24h accum. precip. >0.1,>10,>25,>50,>100(mm)

CIN Convective inhibition Ensemble mean


CIN Convective inhibition Ensemble mean

T2M 2m temp. Ensemble meanProbabilistic map.

>35 ,>38 cesuls degree

CAPE Convective available potential energy

Ensemble meanProbabilistic map.

>500、1000、1500、2000J/kg

UV10M 10m wind speed Ensemble meanProbabilistic map.

>8, 12,16m/s

RISK_PRB Convective risk prob. Prob. Prob.

3333、、、、VerificationVerificationVerificationVerification andandandand applicationapplicationapplicationapplication

4.0 days


Precipitation Probability (>0.1mm,36-60h) in China average for 2010092612-2010102512

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Forecast Probability

Obse

rved

Rel

ativ

e Fre

quen

cy

GEPS REPS

36-60hr

Reliability diagram

36-60hr

Brier Score

Comparison of GEPS and REPS for China Precip.

15.0 mm


Forecast Probability

Area of ROC, Total Precipitation >(13.0mm) in Chinaaverage for 2010092612-2010102512

0.5

0.6

0.7

0.8

0.9

6 12 18 24 30 36 42 48 54 60Forecast range [hours]

Are

a of R

OC

GEPS REPS

Area of ROC for heavy rainfall

Locations of 2510 rain gauge stations

2013-1-14

The heaviest rainfall in 61 years fell on Beijing on July 21, 2012.

�77 people had been killed by floods.

�Deaths resulted from drownings, collapsed buildings, lightning, and electrocutions from downed power lines

Rainfall over Beijing averaged 190.3 millimeters

reached 460mm in


460mm in Fangshan District

CMA T213 24h accumulated precipitation Stamps CMA T213 24h accumulated precipitation Stamps CMA T213 24h accumulated precipitation Stamps CMA T213 24h accumulated precipitation Stamps

initial: 2012initial: 2012initial: 2012initial: 2012----7777----20202020----12:00UTC, valid 201212:00UTC, valid 201212:00UTC, valid 201212:00UTC, valid 2012----7777----22222222----00:00UTC00:00UTC00:00UTC00:00UTC


Maximum precipitation

value among EPS

members: ：：：：170mm，，，，

Nearby Beijing

ECMWF T639 24h accumulated precipitation Stamps .ECMWF T639 24h accumulated precipitation Stamps .ECMWF T639 24h accumulated precipitation Stamps .ECMWF T639 24h accumulated precipitation Stamps .

Initial time: 2012Initial time: 2012Initial time: 2012Initial time: 2012----7777----20202020----12:00UTC , Valid: 201212:00UTC , Valid: 201212:00UTC , Valid: 201212:00UTC , Valid: 2012----7777----22222222----00:00UTC00:00UTC00:00UTC00:00UTC


Maximum precipitation value among members: 165.52 mm,located in Beijing

+1 DAY probability of heavy rainfall for ECMWF and CMA EPS

EC-T1279 forecast

EC-T639 EPS >50mm prob. EC-T639 EPS >100mm prob.

Obs.


CMA-T639 forecast

CMA-T213 EPS >50mm prob. CMA-T213 EPS >100mm prob.

� EPS can provide good probability for EPS can provide good probability for EPS can provide good probability for EPS can provide good probability for

heavy rainfall events, but is heavy rainfall events, but is heavy rainfall events, but is heavy rainfall events, but is

difficult to forecast extreme difficult to forecast extreme difficult to forecast extreme difficult to forecast extreme

precipitation value in monsoon precipitation value in monsoon precipitation value in monsoon precipitation value in monsoon


precipitation value in monsoon precipitation value in monsoon precipitation value in monsoon precipitation value in monsoon

season. season. season. season.

+8 day +7day


+6 day +5 day

+4 day+4 day+4 day+4 day +3ay+3ay+3ay+3ay


+2 day+2 day+2 day+2 day +1day+1day+1day+1day

� It is still a great challenge to It is still a great challenge to It is still a great challenge to It is still a great challenge to

apply EPS products to extreme weather apply EPS products to extreme weather apply EPS products to extreme weather apply EPS products to extreme weather

event forecast in monsoon season.event forecast in monsoon season.event forecast in monsoon season.event forecast in monsoon season.


� Recent research and developmentRecent research and developmentRecent research and developmentRecent research and development


GEPS operational systemreal time running EPS in Shenwei computer

Upgrade plan

Model T213L31 T213L31 T639L61

Horizontal resulation

0.5625Reduced Grid

0.5625Reduced Grid

0.28125Reduced Grid

Vertical resolution 31 31 61

Analysis Scheme SSI 3DVAR SSI 3DVAR GSI 3DVAR

Upgrade plan for operational GEPS in 2013Upgrade plan for operational GEPS in 2013--2014 year2014 year


Analysis Scheme SSI 3DVAR SSI 3DVAR GSI 3DVAR

Perturbation BGM ET BGM

Stochastic perturbation no no Yes

SST perturbation no noUnderdeveloping

Target area Global Global Global

Members 15 24 15

Lead time 10 15 10-15

AAAA：：：：tendency of grid scale tendency of grid scale tendency of grid scale tendency of grid scale

process process process process

PPPP：：：：tendency of subtendency of subtendency of subtendency of sub----grid grid grid grid

physics physics physics physics

scale processscale processscale processscale process

（（（（Buizza,1999)Buizza,1999)Buizza,1999)Buizza,1999)

Research on stochastic perturbation of Research on stochastic perturbation of Research on stochastic perturbation of Research on stochastic perturbation of

physics processphysics processphysics processphysics process


{ }0

( ) ( ; ) ( ; )t

j j jt j jr re t Ae t Pe t dt=

= +∫

{ }0

( ) ( ; ) ( ; )j

t

j j jte t Ae t Pe t dtr

== +∫

Stochastic total tendency scheme (STPSStochastic total tendency scheme (STPSStochastic total tendency scheme (STPSStochastic total tendency scheme (STPS））））

Stochastic physics perturbation scheme (SPPSStochastic physics perturbation scheme (SPPSStochastic physics perturbation scheme (SPPSStochastic physics perturbation scheme (SPPS））））

stochastic perturbation of physics process experiment：：：：Jul 17 2008 -- Jul 26 2008, totally 10 days


Research plan for developing GRAPES Ensemble Prediction system (EPS)

� Global EPSGlobal EPSGlobal EPSGlobal EPS

� The SV-based perturbations as initial perturbations (starting from 2011)

� The stochastic perturbation for model uncertainties (starting from 2011)

� The application of SV perturbation for typhoon ensemble forecasting

� Based on SV initial perturbation and stochastic model perturbation, theglobal EPS with 31 members at 50 Km horizontal resolution is planed to in


global EPS with 31 members at 50 Km horizontal resolution is planed to inthe future

• Regional EPS Regional EPS Regional EPS Regional EPS

– ItItItIt isisisis plannedplannedplannedplanned totototo developdevelopdevelopdevelop thethethethe supersupersupersuper regionalregionalregionalregional EPSEPSEPSEPS (REPS)(REPS)(REPS)(REPS) basedbasedbasedbased onononon

currentcurrentcurrentcurrent operationaloperationaloperationaloperational WRFWRFWRFWRF----basedbasedbasedbased REPSREPSREPSREPS ,,,, andandandand GRAPESGRAPESGRAPESGRAPES----MESOMESOMESOMESO regionalregionalregionalregional EPSEPSEPSEPS

(REPS)(REPS)(REPS)(REPS)....

– TheTheTheThe mixturemixturemixturemixture initialinitialinitialinitial perturbation(perturbation(perturbation(perturbation( ETKFETKFETKFETKF andandandand DPMM)DPMM)DPMM)DPMM) forforforfor thethethethe GRAPESGRAPESGRAPESGRAPES----MESOMESOMESOMESO

REPSREPSREPSREPS

– TheTheTheThe stochasticstochasticstochasticstochastic perturbationperturbationperturbationperturbation forforforfor modelmodelmodelmodel uncertaintiesuncertaintiesuncertaintiesuncertainties

– TheTheTheThe combinationcombinationcombinationcombination techniquetechniquetechniquetechnique forforforfor twotwotwotwo----modelmodelmodelmodel basedbasedbasedbased supersupersupersuper REPSREPSREPSREPS

NH T850 NH Z500

GRAPES--SVs GEPS experiment：：：：Jan 1 , 2010 to Jan 10 2010, 10days


GRAPES-ETKF REPS experiment：：：：Jul 17 2008 to Jul 26 2008, 10days

� SummarySummarySummarySummary

� GEPS and REPS was established in past 10 years and have been used by forecasters at CMA.

� Current verifications show higher skill of T213 ensemble mean than T639 model for medium-range forecast.

� GEPS and REPS was proved more valuable for heavy rainfall forecast in summer monsoon season .

5555、、、、SummarySummarySummarySummary


forecast in summer monsoon season .

� Further work will do on T213 GEPS in next 2Further work will do on T213 GEPS in next 2Further work will do on T213 GEPS in next 2Further work will do on T213 GEPS in next 2----3 3 3 3

yearsyearsyearsyears

� Upgrade from T213 GEPS to T639 GEPS after the new IBM computer installed in 2013-2014

� Adding Stochastic physics perturbation in T639 � Adding SST perturbation in T639� Extending forecasting days from 10 to 15 days

QUESTIONS ?


the ensemble prediction system and its application at cma€¦ · its application at cma chen jing,...

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