data assimilation system based on nudging for cosmo- ru7/ru2 · 2016. 12. 20. · das7, das2...

Denis Blinov, Gdaly Rivin, Inna Rozinkina, Anastasia Revokatova

Data assimilation system based on nudging for COSMO-

Ru7/Ru2

1 GM, WG CORSO, 8 September 2014

Outline • Motivation • Data Assimilation System (DAS) based on nudging

– Initial conditions for COSMO-Ru – Observation – Configuration

• Verification for period 1 February – 16 March – PMSL – Wind Speed at 10m – Dew point at 2m – Temperature at 2m

• Standard verification • Clear and clod weather • Problem with temperature in PBL and soil

– Comparison with DAS from DWD • Conclusions • Future plans


Disadvantages of using initial data from global model GME

• Sometimes initial data from GME have significant errors for temperature at surface and T_PBL for domain COSMO-Ru;

• Often this error lead for big errors in all time forecast;

• Low resolution is no good for nowcasting; • Errors in the initial data associated with all 3 types of fields: external parameters, atmospheric

and surface fields;

GM, WG CORSO, 8 September 2014 3

Motivation

Verification T_2m for Sochi coastline stations (Adler-cluster); model COSMO-Ru2; 00, 06, 12, 18 UTC runs; for winter 2011/2012 (left) and 2012/2013 (right)

4

RMSE

ME

Errors of initial conditions

Data assimilation system

Data Assimilation System (DAS) for COSMO-RU prepare initial conditions (IC) from the interpolated data GME (h=20 km) and from nudging scheme assimilation are concluded: atmosphere fields (U, V, P, W, T, QV); soil fields (T_SO, W_SO, T_S); snow analyses (T_SNOW, H_SNOW , T_S); sea surface temperature (T_ICE, H_ICE , T_S).

external parameters.


Data Assimilation System

• The scheme Nudging in Cosmo is correcting atmosphere fields T, PS, H, QV, U, V

• DAS uses observations SYNOP, TEMP, SHIP, BUOY, AIREP, RASS

• On first step DAS is based on 6 hour cycle - Main Run (MR)

• On the next step DAS will included on continuous cycle - Recalculate Run (RR) for Cosmo-Ru2

• Cold start for COSMO-Ru2 run from 16 October 2013 6 GM, WG CORSO, 8 September 2014

Scheme of assimilation system

Parameters DA-M Ru7 DA-R Ru2 DA-M Ru2

data_ini (U, V, P, W, T, QV) GME — 6 h DA-R — 6 h DA-R — 6 h

data_bd GME — 6 h Ru7 — 6 h Ru7 — 6 h data_ini_surf

(T_S, T_SNOW, T_ICE, H_ICE, T_SO, W_SO)

GME — 6 h GME — 6 h GME — 6 h

hstop 6 6 6

number of runs 4 4 4

cut-off time 02:45 06:50 01:10

hnudgend 10 10 10

synop 2600 145 145

temp 119 6 6 7 GM, WG CORSO, 8 September 2014

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11 12 13

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The operational schemes COSMO-Ru7 и COSMO-Ru2

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Without DAS

download GME 00UTC 06UTC 12UTC 18UTC start 02:50 08:50 14:50 20:50 end 03:25 09:10 15:25 21:10

Time work 00:35 00:20 00:35 00:20

00UTC 06UTC 12UTC 18UTC Ru7 00UTC 06UTC 12UTC 18UTC 02:50 08:50 14:50 20:50 start 02:30 02:50 08:30 08:50 14:30 14:50 20:30 20:50 03:30 09:10 15:30 21:10 end 02:50 03:30 08:50 09:10 14:50 15:30 20:50 21:10 00:40 00:20 00:40 00:20 Time work 00:20 00:40 00:20 00:20 00:20 00:40 00:20 00:20

00UTC 06UTC 12UTC 18UTC Ru2 00UTC 06UTC 12UTC 18UTC 03:30 09:10 15:30 21:10 start 02:40 03:00 08:40 09:00 14:40 15:00 20:40 21:00 05:10 10:50 17:10 22:50 end 03:00 05:00 09:00 11:00 15:00 17:00 21:00 23:00 01:40 01:40 01:40 01:40 Time work 00:20 02:00 00:20 02:00 00:20 02:00 00:20 02:00


With DAS

Model grids and used observations

OBSERVATIONS

Domain COSMO

Count horizontal grid points

Temper. (TEMP)

wind, pres., humid. (TEMP + SYNOP)

Ru7 434 000 119 2700 CFO02 197.400 10 190

Ru2 197 400 6 170 VFO02 211.500 9 161 ENA13 500.000 295 4368 SIB14 90.000 78 1006

The number of grid points of the model COSMO-Ru7 more than stations in ~1600 for the temperature and ~32000 for COSMO-Ru2. Not enough of upper-air stations for successfully correcting temperature. You must use t_2m observation from SYNOP.


Scheme of assimilation system

Verification Names of experiments for COSMO-Ru:

das7, das2 (forecast with IC from DAS) ref7, ref2 (forecast with IC from GME)

Period testing: 1 February 2014 – 16 March 2014 also February 2012, July 2012, December 2012


Name Number of stations Area EU1845 1845 domain COSMO-Ru7 SFO02 145 domain COSMO-Ru2 SFO01 65 domain COSMO-Ru1

(coastline and mountain near Olympic object)

Selected stations for verification

Model overview

COSMO GM2014 Eretria, Greece, 8-11.09.2014 12

COSMO-Ru7 Domain: 4900 km x 4340 km Grid: 700 x 620 x 40 Space step: 7 km Time step: 40 s Forecast: 78 h

COSMO-Ru2 Domain: 900 km x 1000 km Grid: 420 x 470 x 50 Space step: 2.2 km Time step: 20 s Forecast: 48 h

COSMO-Ru1 Domain: 495 km x 495 km Grid: 450 x 450 x 50 Space step: 1.1 km Time step: 5 s Forecast: 36 h

Model domain


Verification

-1

-0.5

0

0.5

1

1.5

2

2.5

0 6 12 18 24 30 36 42

ME

and

RM

SE P

MSL

[gP

a]

Time forecast from 00UTC (1 Febuary 2014 - 16 March 2014)

Mean Error and RMSE of the PMSL for 145 stations of domain COSMO-Ru2

das2 ME

ref2 ME

das2RMSE

ref2 RMSE


Verification

0

0.5

1

1.5

2

2.5

3

0 6 12 18 24 30 36 42

ME

and

RM

SE w

ind

spee

d [m

/s]

Forecasts from 00UTC (1 February 2014 - 16 March 2014)

Mean Error and RMSE of the wind speed at 10m for 145 stations of domain COSMO-Ru2

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE


-0.5

0

0.5

1

1.5

2

2.5

3

3.5

0 6 12 18 24 30 36 42

ME

and

RM

SE T

d_2m

[de

gree

]

Forecasts from 00UTC (1 February 2014 - 16 March 2014)

Mean Error and RMSE of the dew point at 2m for stations of domain COSMO-Ru2

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE

Verification


Verification

-2

-1

0

1

2

3

4

0 6 12 18 24 30 36 42

ME

and

RM

SE T

_2m

[de

gree

]


Mean Error and RMSE of the temperature at 2m For 145 stations of domain COSMO-Ru2

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE


Verification

-2

-1

0

1

2

3

4

0 6 12 18 24 30 36 42

ME

and

RM

SE T

_2m

[de

gree

]

Time forecasts from 00UTC (1 February 2014 - 16 March 2014)

Mean Error and RMSE of the temperature at 2m for 145 stations of domain COSMO-Ru1

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE


-2

-1

0

1

2

3

4

0 6 12 18 24 30 36 42 48 54 60 66 72 78

ME

and

RM

SE T

_2m

[de

gree

]


Mean Error and RMSE of the temperature at 2m for 1845 stations of domain COSMO-Ru7

das7 ME

ref7 ME

das7 RMSE

ref7 RMSE

Verification

Summary conclusion: ME and RMSE better for experiments DAS for all selected stations and for all models (Ru7 and Ru2)

-1

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

0 6 12 18 24 30 36 42

ME

and

RM

SE T

_2m

[d

egre

e]


cloud weather

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE

Mean Error and RMSE of the temperature at 2m for clear sky (top) and cloud weather (bottom)

for 145 stations of domain COSMO-Ru2


-6

-4

-2

0

2

4

6

0 6 12 18 24 30 36 42

ME

and

RM

SE T

_2m

[d

egre

e]


clear weather

das2 ME

ref2 ME

das2 RMSE

ref2 RMSE

-2

-1.5

-1

-0.5

0

0.5

1

0 6 12 18 24 30 36 42 48 54 60 66 72 78

TIME Forecast from 00UTC (February 2012)

Experiments with DWD assimilation and without for COSMO-Ru7, February 2012,

for 145 station of domain COSMO-Ru2 (SFO)


00.5

11.5

22.5

33.5

44.5

0 6 12 18 24 30 36 42 48 54 60 66 72 780

0.51

1.52

2.53

3.54

4.5

0 6 12 18 24 30 36 42 48 54 60 66 72 78

-2

-1.5

-1

-0.5

0

0.5

1

0 6 12 18 24 30 36 42 48 54 60 66 72 78

TIME Forecast from 12UTC (February 2012)

ME

RMSE

Verification T_2m M

E T

_2m

[de

gree

]

ME

T_2

m [

degr

ee]

RM

SE

T_2

m [

degr

ee]

RM

SE

T_2

m [

degr

ee]

Forecast T_2M for Krasnaya Polyana from 12:00 15 February 2014


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15.0

2.20

14 1

2:00

15.0

2.20

14 1

8:00

16.0

2.20

14 0

:00

16.0

2.20

14 6

:00

16.0

2.20

14 1

2:00

16.0

2.20

14 1

8:00

17.0

2.20

14 0

:00

17.0

2.20

14 6

:00Te

mpe

ratu

re 2

m, C

das02

ref02

obs_37107

sap2Correct module

Verification T_2m

Temperature profile for KrPolyana(left) and Sochi(right)

0200400600800

100012001400160018002000

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temp37099 15.02.2014 12:00:00

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12:

00

16:

48

21:

36

02:

24

07:

12

12:

00

16:

48

21:

36

02:

24Тем

пера

тура

2м

, С

das02ref02

0200400600800

100012001400160018002000

0 5 10 15 20

ref02_KrPol das02_KrPol t2m_37107


Verification T_2m

Errors in field temperature • The daytime temperature is underestimated for all terms and

for all seasons; • Such behavior is often observed in clear weather and strongly

stable stratification. Probably this is the model errors connected with physical parametrizations;

• In result T_S and T_PBL colder than initial data from GME. Because of this temperature at 2m sometimes better from IC of GME than DAS.

• On a 12-h forecast error temperature is minimal in GME, because for initial data of GME exist surface analyze.


Verification T_2m

Conclusions • Mainly large errors for the beginning of the forecast

disappear; • Fields T_2m, Td_2m, PSML, Wind Speed 10m is

better with DAS in 0-3 hours forecast time; • For any cases initial conditions for T_PBL , T_S in

DAS is not so good in clear weather. It is necessary to correct/change the temperature of the soil (T_SO) and Planetary boundary layer (T_PBL), because not enough upper-air stations, especially for the mountain regions;

• It is necessary to use more observations and analyzed scheme.


Future Plans

• Use more observation (RASS, Wind profilers) for nudging

• Use radar data for Latent Heat Nudging • Use Flake in DAS • Use «Module of Correction» (RHM) for

correction T_SO and T_ PBL using T_2M observations


Future Plans


For European part of Russia exist more 10 DMRL and will be even more. Soon we will have operative digital radar data. But we need interpolation software.

Map Russian DMRL from 2014-09-02 (http://orm.mipt.ru/RAD/dmrl.html)

Future Plans

«Module of Correction» • Observations T_2m and model T_PBL are used for

preparing analyze field T_2m for grid COSMO-Ru • Method Cressman is used for horizontal spreading

increment observation • Corrected fields of soil temperature and temperature in

PBL • Correction helped to get better result for Moscow

region in February 2012 • Now the module is tested. Results of experiment are

evaluated. • Need coupling with DAS


Acknowledgement

Christoph Schraff (DWD) for help and consultation about nudging scheme; Jochen Foerstner (DWD) for help, advice about DAS and data of experiments with DAS for COSMO-Ru7; Alexandr Kisanov (HMC), Anastasia Bundel (HMC), Mihail Nikitin (HMC) for help in verification of results experiments.


Thank you for attention!

data assimilation system based on nudging for cosmo- ru7/ru2 · 2016. 12. 20. · das7, das2...

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