NOAA Joint OSSE System’s Applications for WISDOM project

Y. Zhang, Y. Xie, N. Prive, and B. Mock

Jan 18, 2012

GSD/FAB

Outline

• Introduction of WISDOM OSSE;• Necessary elements;

– Selection of launch sites (forward and reverse runs);– Generating synthetic WISDOM balloon data;– GSI data assimilation (WISDOM data treated as

sonde data);• Results;• Conclusions and future works.

What is an OSSE?

An OSSE is a modeling experiment used to evaluate the impact of new observing systems on operational forecasts when actual observational

data is not available.

Nature run (“truth”): A long model run

Synthetic observation: from the nature run

Forecast: A second model

NOAA Joint OSSE System• Nature Run: ECMWF operational model,

– T511/91L resolution– 13 month free integration, 01 May 2005 - 31 May 2006– 13 Atlantic basin tropical cyclones which show sufficiently

realistic track behavior

• Forecast Model: GSI/GFS– early 2007 NCEP operational version and updated to 2010– T384/64L resolution– 120 hour forecasts at 00Z and 12Z

Why a WISDOM OSSE?

• WISDOM data impact on hurricane track?

• Cost benefit evaluation for NOAA WISDOM program;

• Design for WISDOM launch strategy: Such as: balloon launch sites; drift height etc.

WISDOM Experiments• Initial case study focused on track forecasts for

AL01

• Forward experiments:Impact of WISDOM balloon data on

hurricane track forecasts

Forward Experiments• Prepare the Synthetic WISDOM balloon data:

Generate from nature run.

• The forecast: GSI/GFSControl run(without wisdom data)Simulation run(with wisdom data)

• The nature run: ECMWF operational model

Prepare the synthetic WISDOM data

• Used to use the Matlab takes several days to get the data.

• Use the Fortran to get the synthetic data. It only takes several hours to get all the WISDOM synthetic data.

Prepare the synthetic WISDOM data

• Generate the synthetic WISDOM data from the nature run:

-Set up the balloon launch strategy: launch sites; launch time;

the frequency of data output; drift height.-Get the data from the nature run at the each data output time of each balloon-Output the formatted WISDOM data

Read the nature run’s data at ti /ti+dt. Then loop over from ti to ti+dt: Check the balloon status at ti+dmin:

not launched yet/need to be launched/still flying/dead

Get the location of the flying/launched balloonUse the u/v and w to calculate the new longitude/latitude and height

Do the interpolation at the balloon locationUse the nearby grid(12 points) to do the interpolation

Output the data at each output time

Prepare the synthetic WISDOM data

Synthetic WISDOM data• WISDOM balloon launch sites:

The blue points is the WISDOM balloon launch sites. 111 launch sites

Synthetic WISDOM data• WISDOM balloon track:

Twice a day: 1th/Aug ~ 5th/Aug

Get the WISDOM data: Every 30 minutes

Two levelsDrift height:

3650m/8000m

Balloon numbers: 5*2*2*111=2220 Total data : 427,128

The synthetic WISDOM dataThe formatted synthetic WISDOM data:

……………………….. 990 08 05 09 0 335.3394 15.1681 3650.0000 661.8108 280.5027 0.0046 -13.1778 2.2225 991 08 05 09 0 335.3278 15.1780 3650.0000 661.8168 280.5037 0.0046 -13.1868 2.2165 992 08 05 09 0 334.9585 15.4309 3650.0000 661.9054 280.4928 0.0046 -14.0591 1.8207 993 08 05 09 0 346.2748 9.0562 3650.0000 660.6028 278.1284 0.0062 -1.1717 -5.5093 994 08 05 09 0 346.6964 8.0057 3650.0000 660.5472 278.2640 0.0059 -1.4318 -5.4787 995 08 05 09 0 343.8452 28.2141 3650.0000 662.8626 284.2172 0.0051 0.8184 -0.6793 996 08 05 09 0 343.0198 17.2972 3650.0000 662.4750 282.2396 0.0063 -12.2012 -7.1161 997 08 05 09 0 341.7729 14.2278 3650.0000 661.7869 280.2286 0.0063 -11.1233 -5.1319 998 08 05 09 0 342.2312 14.2233 3650.0000 661.7036 280.3158 0.0063 -10.2152 -6.4130 999 08 05 09 0 342.6686 15.3252 3650.0000 661.9710 281.0749 0.0063 -11.2500 -6.7864 1111 08 05 09 0 279.6201 39.7949 8000.0000 370.0029 244.8437 0.0007 23.7174 -9.1831 1112 08 05 09 0 246.9378 14.3139 8000.0000 378.7501 253.7333 0.0008 -4.4780 -0.4843 1113 08 05 09 0 273.8472 45.8047 8000.0000 366.9842 241.9702 0.0002 19.3304 -22.2680 1114 08 05 09 0 314.7721 82.3237 8000.0000 357.3938 237.7147 0.0002 7.4927 -6.5102 1115 08 05 09 0 307.3623 57.7163 8000.0000 361.2642 239.1260 0.0002 2.5476 12.1774 1116 08 05 09 0 294.2139 50.2862 8000.0000 359.8100 238.5330 0.0002 16.0568 11.8093 1117 08 05 09 0 283.7850 42.1108 8000.0000 365.4696 241.0415 0.0007 19.0525 1.3713 1118 08 05 09 0 291.1477 77.4562 8000.0000 362.0339 239.3750 0.0001 8.9179 -6.8950 1119 08 05 09 0 282.7004 79.8352 8000.0000 359.1806 238.9504 0.0001 19.4687 11.0594………………………..

Id m d h m lon lat height pre temp hum u v

Check the WISDOM synthetic data

The temperature of nature run and synthetic WISDOM data at 06 Aug 00ZThe left nature run. The right one is the synthetic WISDOM dataShadow areas are the temperature; Grey points is the balloon location at that timeThe height of 710hPa is 3450 to 3850.

Check the WISDOM synthetic data

The q and wind of nature run and synthetic WISDOM data at 06 Aug 00ZThe left nature run. The right one is the synthetic WISDOM dataShadow areas are the q (mg/kg); black points is the balloon location at that time

Design of the control and simulation runs

• The common of GSI/GFS between the control and simulation runs:-Get the initial field at 1 Aug 00Z-Assimilate the RAOB, AMSU-A, ACAR, AIRS GOES data to get the analysis field.-Use GFS to get the forecast: 120h forecast at every 6h interval from 1 Aug 06Z to 7Aug 12Z

• The difference of GSI/GFS between the control and simulation runs:-Simulation run assimilates the WISDOM data.

Design of the control and simulation runs

initial field time2005080100

GFS background for GSI:

2005080106

GSI analysis field for GFS:

2005080106

120h forecast

GFS background for GSI:

2005080112

analysis field for GFS:

2005080112

120h forecast

GFS background for GSI:

2005080200

GFSGSI2005080712’s120h forecast

wisdom datafrom 080103 to

080109

wisdom datafrom 080109 to

080115

GSI

Prepare the WISDOM data for GSI

• GSI only taken the BUFR format data

-Need to convert the WISDOM format data into WISDOM BUFR format.

Synthetic WISDOM data BUFR format

Validation of WISDOM Data Ingest

The analysis field’s 710hPa/500hPa height at 6 Aug 00Z.( s_run/c_run/n_run)

Balloon location and forecast track

Balloon location and forecast track for the 6 Aug 00ZThe number of balloon data: 21312

Impact of WISDOM on Track

The impact of WISDOM data on hurricane track forecast at different forecast time

Forecast errors (km)Time/Forecast

hours01 Aug

12Z02 Aug

00Z02 Aug

12Z03 Aug

00Z04 Aug

00Z04 Aug

12Z05 Aug

00Z05 Aug

12Z06 Aug

00Z06 Aug

12Z07 Aug

00Z07 Aug

12Z means

Analysis 0.00 -4.95 0.00 9.29 -8.17 -4.45 54.59 26.20 8.46 -5.70 -48.98 -2.60 1.97

24h 20.71 -10.22 -20.93 -20.62 -7.49 -40.75 -35.68 -59.33 -31.30 10.42 0.56 14.27 -15.03

48h -12.14 -9.92 -11.17 -21.19 -42.38 -101.57 -102.22 -83.40 -69.46 28.33 8.97 19.59 -33.05

72h 0.00 -32.78 -42.67 -24.60 -75.71 -148.32 -68.18 -84.61 -62.69 20.37 -81.42 -44.11 -53.73

96h -10.43 -42.51 -20.74 -9.59 -37.95 -60.84 58.84 65.35 -17.39 201.42 -34.60 -95.21 -0.30

120h 6.39 30.34 23.52 -99.97 175.53 311.06 538.89 313.74 321.29 157.98 177.88

Red = improvementBlack = worsening

Discussion

• The large numbers of WISDOM synthetic data do not have a significance impact on trajectory forecast in this experiments:

a. The improvement of trajectory forecast errors are limited

b. The simulation run have a better trajectory pattern.

Future Work

• Use another control run which has a closer hurricane location or uses a relocation method.

• Add observation errors into the synthetic WISDOM data

• Use adaptive method(ETKF) to design WISDOM launch strategy over targeted observation areas.

For ETKF: Need to get some ensemble forecast first.

THANK YOU