Current Status and Future Plans for KMA Data Assimilation System

Dec, 2016

Current Status and Future Plans for KMA Data Assimilation System

Dec, 2016

Hyun-Cheol Shin, Eun Joo Lee, Eun Hee Lee, Jung-Rim Lee, Eun-Hee Kim,

Hyeyoung Kim, Heejung Kang, Adam Clayton*, Sangwon Joo

Korea Meteorological Administration, UKMO *

2

Contents

� General introduction of KMA NWP system

� Improvements of Global (17km) and Local (1.5km) model in 2016

� KIAPS (Korea Institute of Atmospheric Prediction Systems) Project

� Issues for Future Strategy

3

KMA NWP Performance

2nd supercomputer

1st supercomputer

3rd supercomputer

4th suppercomputer(’15-’16)

Introduction of UM(2010)

90 times

37 times

8.5 times ( 5.8PFlops )

Introduction of supercomputer(1999~) +

NWP Performance

significantly improved

Big gap reduced

Similar Performance to JMA

• 1 TF (Tera Flops) : 1 trillion (1,000,000,000,000) calculations in a second

corresponds the amount that 800,000 people can calculate in a year

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Recent improvements

[ Global model] (2016.6)� Resolution : 25km � 17km / Version Upgrade

� New satellite species (6) : ATMS, Geocloud, GroundGPS, CrIS, MVIRI, SEVIRI

� Dynamics : New Dynamics (ND) � End Game (EG)

[ Global Ensemble ] (2016.6)� Resolution & Members : 40km � 32 km / 24 � 49 members

� Dynamics : New Dynamics (ND) � End Game (EG)

� Version Upgrade

[Regional model] (2015.6)� DA tuning : Typhoon bogus, Satellite data thinning, Soil moisture update

� Model ancillary : Aerosol

[Local model] (2016.6)

� Domain extended (LDPS � XLDPS) / Version upgrade� Dynamics : New Dynamics (ND) � End Game (EG)

[Local Ensemble] (2016.6)

� Version upgrade

� Dynamics : New Dynamics (ND) � End Game (EG)

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KMA Operational NWP system (2016.6)

E-ASIA (ND)

•UM 12kmL70

(top=80km)

•Target Length

87hrs/72hrs (6 hourly)

• Initialization :

4DVAR

GLOBAL (EG)

• Resolution

N768L70 (UM)

(~17km / top = 80km)

• Target Length

288hrs (00/12UTC)

87hrs (06/18UTC)

• Initialization : Hybrid

Ensemble 4DVAR

Global EPS (EG)(EG)(EG)(EG)

• Resolution

N400L70 (UM)

(~32km/ top =80km)

• Target Length

288hrs

• IC : GDAPS

• # of Members : 49

• Perturbation : ETKF,

RP, SKEB200,12: 288hrs : 25 members [including cntl]

06,18: 9hrs: 49 members [including cntl]

LOCAL (XLDPS) ((((EEEEGGGG))))

• Resolution

1.5kmL70 (UM)(744×928 / top =39km)

• Target Length

36hrs (3 hourly cycle)

• Initialization : 3DVAR

LOCAL Ensemble (EG)• Resolution 3kmL70 (UM)

• Target Length : 72hrs

• # of members : 13 (including CNTL)

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Observation species used in NWP models

[ Global model]� 15 observation species used in global model

- Conventional data (3 species) : Surface, Sonde, Aircraft

- Satellite data (12 species) : Scatwind, Satwind, ATOVS, AIRS, IASI, GPSRO, ATMS, Geocloud, GroundGPS, CrIS, MVIRI, SEVIRI

� ATMS, Geocloud, GroundGPS, CrIS, MVIRI, SEVIRI assimilated from 2016 with

17km global model

[Regional model]

� 9 observation species used in regional model- Conventional data (3 species) : Surface, Sonde, Aircraft

- Satellite data (6 species) : Scatwind, Satwind, ATOVS, AIRS, IASI, GPSRO,

[Local model]

� 4 observation species used in Local model

- Conventional data (3 species) : Surface, Sonde, Aircraft- Satellite data (1 species) : Scatwind (+Ground-GNSS, Himawari-AMV, AMSU-B, IASI)

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Received Data / Used Data

� Ratio of used data against received data

� Global Model : GPSRO (largest ratio) > Surface > Sonde > ATMS

� Less than 10 % : Satellite data (Scatwind, Satwind, ATOVS, GroundGPS,

SEVIRIClear, MVIRIClear, GOESClear), Removed Mainly By Thinning

� Total ratio : Local model (16.6%) > Global model (8.1%) > Regional model (3.2%)

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N768 2016041700N768 2016041700N768 2016041700N768 2016041700

Used Data (Global - UKMO / KMA)

� 83 % used compared with UKMO

� 2.5 % increased ratio than N512(25km) after N768(17km) was installed

� GOES Clear, ATMS, CrIS, MVIRIClear, Ground GPS added compared with N512(25km)

� But SSMIS, SEVIRIClear, AMSR, MWSFY3C, MTSAPHIR not used

Less OBS used than UKMO : Mainly due to …

- Different cut off time (+6:25 : +6:40) - Longer route to get obs

- Different QC (OPS) version

~

Improvements of Global NWP System (2016)Improvements of Global NWP System (2016)

� Resolution : 25km � 17km / Version Upgrade� New satellite species : ATMS, Geocloud, GroundGPS, CrIS, MVIRI, SEVIRI

� Dynamics : New Dynamics (ND) � End Game (EG)

Verification (RMSE)

25km(old)

17km(new)

25km(old)

17km(new)

2015.7 (summer) 2016.1 (winter)

500hPa Z 00 UTC 12UTC

Analysisverification

6.6% 6.8%

Observationverification

6.2% 9.7%

500hPa Z 00 UTC 12UTC

Analysisverification

1.9% 4.8%

Observationverification

1.0% 7%

Average improvements (all levels and lead times, 4 variables) summer winter

Analysis verification 14.2 % 4.1 %

Observation verification 7.3 % 4.3 %

Improvements

Greatly improved for most cases. Maximum improvement 14 %

500 hPa Z RMSE reduced for all forecast times

Verification Period : 2015. 7.

Target Typhoons : 9th - 12th Typhoon in 2015 (4 typhoons)

Typhoon Track Error (1509, 1510, 1511,1512)

Initial Central Pressure of Typhoon

Typhoon Track Error (Average forecast Error for 120 hour forecast, km)

• Typhoon track and intensity forecast improved

25km(old)

17km(new)

25km(old)

17km(new)

25km(old)

17km(new)

25km(old)

17km(new)

1509 1510 1511 1512

25km(old)

17km(new)

best

25km(old)

17km(new)

best

25km(old)

17km(new)

best

25km(old)

17km(new)

best

Typhoon Forecast Verification

Significantly reduced track error

More realistic intensity

Improvements of Local NWP System (2016)Improvements of Local NWP System (2016)

� Domain extended (LDPS � XLDPS) / Version upgrade� Dynamics : New Dynamics (ND) � End Game (EG)

국립기상과학원

국립기상과학원국립기상과학원

국립기상과학원 | National Institute of Meteorological Research

XLDAPSXLDAPSXLDAPSXLDAPS

• Extended reduced resolution zones

- to reduce strong impact from the boundary fields

4x4km

4x4km 4x4km

4x4km1.5x4km

1.5x4km

4x1.5km 4x1.5km

1.5x1.5km

Extended LDAPS domain(XLDAPS)

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LDPS domain vs. XLDPS domain

LDPS ( ) XLDAPS ( )

622X810

622X810622X810

622X810

1.5km X 1.5km

1.5km X 1.5km1.5km X 1.5km

1.5km X 1.5km

2

4km X 4km

4km X 4km4km X 4km

4km X 4km 1.5km X 4km

1.5km X 4km1.5km X 4km

1.5km X 4km 4km X 4km

4km X 4km4km X 4km

4km X 4km

4km X 1.5km

4km X 1.5km4km X 1.5km

4km X 1.5km 4km X 1.5km

4km X 1.5km4km X 1.5km

4km X 1.5km

1.5km X 4km

1.5km X 4km1.5km X 4km

1.5km X 4km4km X 4km

4km X 4km4km X 4km

4km X 4km 4km X 4km

4km X 4km4km X 4km

4km X 4km

622X810

622X810622X810

622X810

1.5km X 1.5km

1.5km X 1.5km1.5km X 1.5km

1.5km X 1.5km

744X928744X928744X928744X928 1188X11481188X11481188X11481188X1148

Same fixed grid area / Variable grid area extendedNew Dynamics (Vn 8.2) � End Game(Vn 10.1 )

Number of used observations

Surface : 2696 � 5160 : 1.9 times increase Sonde : 50 � 101 : 2 times increaseAircraft : 238 � 2407 : 10 times increase Scatwind : 155 � 580 : 3.8 times increase

LDPS XLDPS LDPS XLDPS

Analysis Verification (RMSE, 2015.7)

MSLP – 925 hPa height : LDPS better than XLDPS 500 hPa Z improved 850hPa – 100 hPa height : XLDPS better than LDPS

Temperature & Wind : improved for all cases

Precipitation verification

3 hourly accumulated precipitation

Generally improved

Observation verification

Analysis verification, precipitation verification : XLDPS better than LDPSObservation verification : LDPS better than XLDPS (except RH)Summer case showed better performance than winter case

VLDPS XLDPS

Resolution 1.5km 1.5km

Levels 70 layers 70 layers

Cycle Interval 1 hourly 3 hourly

DA 3DVAR 3DVAR

Visibilityassimilation

Yes No

4DVAR Plan 2017 2018

Operational use 2016.12 2016.6

Forecast hours 12 hours 36 hours

Others ICE-POP -

Future plan VLDPS

VLDPS : Very Short Range forecast model

4km Regional Model4km Regional Model

� Resolution : 12km � 4km� UM version : New Dynamics � EndGame

� DA Versions improved

Future plan 4km Model

0

2

4

6

8

10

12

14

6 12 18 24 30 36

RM

SE

Forecast time(hour)

GPH_500hPa

RDPS12

RDPS4_DA

0

1

2

3

4

5

6

7

8

6 12 18 24 30 36

RM

SE

Forecast time(hour)

WIND_250hPa

RDPS12

RDPS4_DA

Initial version of 4km regional model gave improved resultsStrategic decision among 4km regional model, XLDPS and VLDPS

KIAPS Project(Korea Institute of Atmospheric Prediction Systems)KIAPS Project(Korea Institute of Atmospheric Prediction Systems)

Courtesy of I-H.Kwon (KIAPS)

KIM-SH(High Order Method Modeling

Environment model; NCAR’s CAM-SE)

KIM-SW(Kiaps Integrated Model – Spectral

element method, WRF-Type)

Numerical method

Spectral Element method (Eulerian)

Spherical grid Cubed-sphere (Equi-angular gnomonic projection)

Spatial approximation

piecewise polynomials of degree 3

EquationHydrostatic

(Full variables)Non-hydrostatic

(Perturbation variables)

Temporalapproximation

Fully ExplicitLeapfrog, first-order due to

Robert-Asselin filter

Split-explicit RK3, second-order for nonlinear equation

Explicit spatialdiffusion

4th order linear horizontal diffusion

6th order horizontal diffusion + divergence damping

Cubed sphere grid structure global modeCubed sphere grid structure global modeCubed sphere grid structure global modeCubed sphere grid structure global mode

Horizontal resolution: NE120NP4 ~ 25km Vertical resolution: 50 levels with 0.3 hPa top

KIAPS Integrated Model (KIM) model

Global model25 km � 12km or 6km

Ensemble model50km � 25km(?)50 members

DALETKF, 3DVAR� 4DEnVAR

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� Global NWP system

- Follow up the trace of UKMO ; Almost real time update

- 17km L70 (‘16) � 10km L70 (‘18)

� Limited area model

- Optimization for East Asia : Best performance in our area !

- 4km Regional model ? 1.5 km local model ?

� KIM (KIAPS Integrated Model)

- (25km � 12km) / 4DEnVAR (‘19)

- Start of parallel cycle with UM (‘17-’18)

- How to use UM and KIMS efficiently

- Stable transition to KIM

Issues for Future Strategy

� Daily verification by forecastersECMWF : UM : KIM

ECMWF UM KIM