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Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division, National Institute of Meteorological Research, KMA The Experiments of Sensitivity test with 2012 winter special observation data using WRF model 2012 THORPEX-Asia Workshop
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Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Jan 19, 2016

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The Experiments of Sensitivity test with 2012 winter special observation data using WRF model. Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division, National Institute of Meteorological Research, KMA. 2012 THORPEX-Asia Workshop. Background. - PowerPoint PPT Presentation
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Page 1: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung

Forecast Research Division,

National Institute of Meteorological Research, KMA

The Experiments of Sensitivity test with 2012 winter special observation data using WRF

model

2012 THORPEX-Asia Workshop

Page 2: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 2

Background

West SeaObservation points

of Central area

Observation points

of east coast line

Observation targets

• Observe the weather elements using KMA ground-

based

observation network

• Observe the weather elements over the sea using

Gisang1

• Observe the precipitation and cloud vertical structure

using Radio-sonde and wind-profiler, Radiometeor

The special observation has performed for two years

around

middle area in south Korea

Expectation of bservation effects − initial condition Improve the initial field by assimilation scheme using obs data − cycle run Reduce the forecast error (first guess) by adding observation data continuously − location Verify the optimal locations of Observation that are sensitive to the predictibility

Page 3: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 3

INC BOS BOSINCCNTL

Looks like Similar initial conditions for each observation It can make differences in 48-h forecasts!

Background

00 fcst

48fcst

Page 4: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 4

Objective

Sensitivity Analysis − Evaluating how observation data affects a forecast − Location for which additional observations may reduce errors or improve the forecast

evaluate the initial increments translated downstream

investigation of observation location are sensitive to the forecast

the precipitation forecast is investigated.

Page 5: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 5

Cases

The selected case is the developing cyclone while passing the West sea and Korean peninsula

the cold front was formed over the south korea on 31 January 2012. The relatively plenty of snow fall is recorded along cold front.

The stream line and moisture flux flowed in Korean peninsula between the Siberia high and north Pacific high at least for 24 hours.

1200UTC 31 JAN 20121200UTC 31 JAN 2012

Page 6: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 6

Experiment design(I)

Forecast

model

WRF/ARW 3.1

Resolution 12 km (141 x 161)

Forecast time 72hours

Initial & boundary condition UM forecast field

Physical Process

Microphysics scheme WSM6

Radiation scheme Dudhia/RRTM

Cumulus

parameterizationKain-Fritsch

Land-surface model Noah LSM

PBL scheme YSU Scheme

Data Assimilation

system

WRFDA v3.1.1

Method 3DVAR

Resolution 12 km ( 141x161)

Assimilation window 4 hours (±2)

cases Remarks

19 JAN 2012snow

east-south coast

31 JAN 2012Snow

Over the Korean peninsula

25 FEB 2012Snow

East coast and southwest land

3 march 2012rain

Over the Korean peninsula

Experiments period

2012.1.26~2.1

Page 7: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 7

3DVAR data assimilation3DVAR data assimilation

0000 0606 1212 1818 2424UTCUTC

CYCLE run

72-h forecast

72-h forecast

3030 3636

72-h forecast

Experiments Remarks

CNTL Operational observation data (GTS)

INC CNTL + Incheon OBS

BOS CNTL + Boseong OBS

BOSINC CNTL + Incheon + Boseong

Experiment design (II)

Page 8: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 8

Increments (A-B) on 0600UTC 26 JAN 2012Increments (A-B) on 0600UTC 26 JAN 2012INC BOS BOSINCCNTL

Increments (A-B) on 1200UTC 26 JAN 2012Increments (A-B) on 1200UTC 26 JAN 2012

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Page 9: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 9

Increments (A-B) on 1200UTC 30 JAN 2012Increments (A-B) on 1200UTC 30 JAN 2012

Increments (A-B) on 1200UTC 31 JAN 2012Increments (A-B) on 1200UTC 31 JAN 2012

INC BOS BOSINCCNTL

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Page 10: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 10

CNTCNTLL

AWSAWS Difference (experiments-Difference (experiments-CNTL)CNTL)

12 hr accumulated precipitation and difference (1200UTC 31 12 hr accumulated precipitation and difference (1200UTC 31 JAN 2012)JAN 2012)

BOSBOSINCINC BOSINBOSINCC

TMPTMPAA

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Page 11: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 11

Difference of 850 hPa Mixing ratio (exp-ctl) on 0600 UTC 31 JAN 2012 at 12hr fcst

Difference of 850 hPa Mixing ratio (exp-ctl) on 0600 UTC 31 JAN 2012 at initial

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Exps - CTN

Page 12: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 12

F00

F12

F24

BOSINC BOSINC

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Increments of 850 relative humidity

850 wind vectors

Page 13: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 13

Increments of 500 height from -6 to 6

850 equivalent potentialTemperature

BOSINC BOSINC

Sensitivity Experiment : ResultsSensitivity Experiment : Results

F00

F12

F24

Page 14: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 14

Exp. BOS INC BOS+INC

rate (2.5 mm)

34% 1% 27%

2.5mm/12hr ETS (2012012600~2012020118)

12hr ETS (2012013112)

Sensitivity Experiment : ResultsSensitivity Experiment : Results

ETS for 12 hours accumulated prec. On 31 ETS for 12 hours accumulated prec. On 31 January 2012January 2012

Page 15: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

Page 15

Geopotential height Temperature

At low altitude, RMSE of height of all experiments show small difference. Otherwise, CNTL and INC have the largest RMSE than BOS and BOSINC

at upper altitude. RMSE of temperature is similar with RMSE of height except for low levels. The observation data of Boseong reduced the RMSE in this case.

RMSE of height and Temperature

Sensitivity Experiment : ResultsSensitivity Experiment : Results

Page 16: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,

observation data is used to identify sensitivity regions of winter 2012 over south Korea. Sensitivity test is conducted using two points of observation data

initial increments in experiments were introduced near the observing points.

These increments damped as they translated downstream.

Predictability of BOS and BOSINC are better than INC and CNTL(noDA).

The moisture adjustment contribute the improvement of predictability

To improve predictability of south Korea, observation of the south is important in land. If supplementary observation is needed, it must be conducted over the south of the Korean Peninsula.

Summary and Conclusion

Page 17: Jaekwan Shim, Yoon-Jeong Hwang, Yeon-Hee Kim, Kwan-Young Chung Forecast Research Division,