AMPS Update – July 2010

Kevin W. ManningJordan G. Powers

Mesoscale and Microscale Meteorology DivisionNCAR Earth System Laboratory

National Center for Atmospheric Research, Boulder, CO

NCAR is sponsored by the National Science FoundationAMPS is sponsored by the National Science Foundation – Office of Polar Programs

5th AMOMFW – Columbus, OH – 12-14 July 2010

Antarctic Mesoscale Prediction Systemhttp://www.mmm.ucar.edu/rt/amps

Funded by the NSF-OPP Experimental NWP system for Antarctica

Using Weather Research and Forecasting Model (WRF) Advanced Research WRF (WRF-ARW)

Formal collaboration among National Center for Atmospheric Research Ohio State University – Byrd Polar Research Center University of Colorado

Informal interaction with many groups Officially in support of USAP forecasters

We try to be useful to other groups doing Antarctic research and forecasting

5th AMOMFW – Columbus, OH – 12-14 July 2010

What’s new this year

• AMSU-A radiance assimilation• Correction to radiation scheme at model top

(Powers presentation)• CAM radiation physics (tried but then removed)• Observations statistics (Wilson presentation)• Real-time SOM product (CU)

5th AMOMFW – Columbus, OH – 12-14 July 2010

AMSU-A Radiance Assimilation

Advanced Microwave Sounding Unit Passes from several polar-orbiting satellites within

a few hours of model initialization time Channels 5, 6, 7, 8, 9 – tropospheric temperatures

Variational data assimilation in the WRF-VAR package with adaptive bias correction (Auligne et al., 2007) Attempts to distinguish between model bias and

observations bias by taking into consideration other observation sources

5th AMOMFW – Columbus, OH – 12-14 July 2010

AMSU-A Radiance Assimilation

AMSU-A Data within 3 hours of 12 UTC, 01 Jul 2010

Before WRFVAR screening After WRFVAR screening

5th AMOMFW – Columbus, OH – 12-14 July 2010

NOAA-18

NOAA-15

NOAA-16

METOP-2

AMSU-A Radiance Assimilation

5th AMOMFW – Columbus, OH – 12-14 July 2010

BIASRMSE BIASRMSE

Test Period – 20 December 2009 through 25 January 2010

Forecast hour 0 (i.e., analysis time) Forecast hour 24

200

300

400

500

100

600

700

800

9001000

Temperature statistics – verification against all Antarctic radiosonde reports

With AMSU

Without AMSU

200

300

400

500

100

600

700

800

9001000

AMSU-A Radiance Assimilation

5th AMOMFW – Columbus, OH – 12-14 July 2010

BIASRMSE BIASRMSE

200

300

400

500

100

600

700

800

9001000

Forecast hour 0 (i.e., analysis time) Forecast hour 48

With AMSU

Without AMSU

Test Period – 20 December 2009 through 25 January 2010

Temperature statistics – verification against South Pole radiosonde reports

200

300

400

500

100

600

700

800

9001000

CAM Radiation Schemes LW and SW Radiation physics packages from the NCAR

Community Atmospheric Model are options in WRF-ARW CAM is the atmospheric component of NCAR’s

Community Climate System Model (CCSM) Tested in Antarctica with good results

Prompted by Arctic results of Mark Seefeldt and John Cassano, reported at last year's workshop

Implemented in the AMPS real-time forecasts in October 2009 Problems arose in the real-time configuration Mysterious model / computer failures

Changes reverted in December 2009 (RRTM LW, Goddard SW)

5th AMOMFW – Columbus, OH – 12-14 July 2010

CAM Radiation Tests

Consistency from forecast to forecast, but significant near-surface warm bias in summer, especially at elevated sites.

Ad hoc adjustment of the snow albedo improved matters Varied albedo from 75 % near sea level to 80 % at

2500 m and above.

5th AMOMFW – Columbus, OH – 12-14 July 2010

CAM Radiation Tests

5th AMOMFW – Columbus, OH – 12-14 July 2010

RRTM LW GODDARD SW CAM LW CAM SW

Temperature at AWS site Henry; January 2010

CAM Radiation Tests

5th AMOMFW – Columbus, OH – 12-14 July 2010

Temperature at Byrd camp; January 2010

RRTM LW GODDARD SW CAM LW CAM SW

New real-time productThe Self-Organizing Map (SOM)

• Self-Organizing Map of sea-level pressure in the Ross Sea region, from John Cassano et al.

• Offers forecasters a view of how well the model has performed in similar situations in the past

5th AMOMFW – Columbus, OH – 12-14 July 2010

LARISSA one-way nest

In support of forecasting for the LARISSA (Larsen Ice Shelf System, Antarctica) field campaign

2.5-km grid, initial and boundary conditions from the AMPS 5-km Antarctic Peninsula nest

Grid active from 04 Jan through 08 Mar 2010

5th AMOMFW – Columbus, OH – 12-14 July 2010

5th AMOMFW – Columbus, OH – 12-14 July 2010

NCAR is sponsored by the National Science Foundation

Future?

Transition to WRF Version 3.2Some polar modifications ported into the supported

WRF codeRe-test CAM radiation schemes