Transcript Development and Evaluation of Polar WRF

ASM Project Update:
Atmospheric Modeling
John J. Cassano and Mark W. Seefeldt
University of Colorado
Cooperative Institute for Research in Environmental Sciences
Department of Atmospheric and Oceanic Sciences
Goals for Year 1 of DOE Project
• Develop and evaluate Polar WRF
– Univ. of Colorado
– Sub-contract to Bromwich / Hines - OSU
• Coupling of WRF to CCSM cpl7
– Lead by Juanxiong He, UAF
Strategy for Polar WRF Development
• Use lessons from development of Polar MM5
• Identify parameterizations that are well-suited for
polar use
• Preference for parameterizations that are most
physically realistic
• Add “missing” physics
• Collaboration with several research groups
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OSU / BPRC
NOAA ESRL
NCAR
University of Colorado
Polar WRF Evaluation
• Evaluate over a variety of polar surface types
– Ice sheet (Hines / Bromwich - Greenland)
– Sea ice / ocean (Hines / Bromwich and CU - SHEBA)
• Implementation of fractional sea ice treatment (OSU)
– Non-ice covered land
• Evaluate atmospheric state
• Evaluate atmospheric processes
– Are we getting the right answer for the right reasons?
• Initial work at University of Colorado
– Identify parameterizations that are inappropriate for
polar use
– Identify “ideal” suite of model parameterizations
– Identify aspects of model in need of improvement
SHEBA Simulations
• Simulations during SHEBA year
– January and June 1998 (CU) - climate mode
– January, June, and August 1998 (OSU) - forecast mode
• Model forcing (CU)
– ECMWF TOGA
atmospheric data and SST
– ERA40 sea ice and
soil state
• Model grid (CU)
– 50 km horizontal
– 31 vertical levels
– Model top: 50 mb
WRF Physics
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Land surface: Noah (Thermal diffusion)
Longwave radiation: RRTM
Shortwave radiation: Goddard (Dudhia)
Boundary layer: YSU (MYJ)
Microphysics: Morrison (WSM5)
Cumulus: Kain-Fritsch (Grell-Devenyi)
• Bromwich / Hines have used a slightly different
selection of model physics for their Greenland and
SHEBA simulations
Shortwave Radiation: Goddard and Dudhia
Goddard SW
June 1998
RRTM LW
WSM5 MP
KF CU
YSU PBL
Noah LSM
Dudhia SW
Land surface: Noah LSM and thermal diffusion
Noah LSM
January 1998
Dudhia SW
RRTM LW
WSM5 MP
KF CU
YSU PBL
Thermal diffusion model
Cumulus: Kain-Fritsch and Grell-Devenyi
Kain-Fritsch
June 1998
Goddard
RRTM LW
Morrison MP
MYJ PBL
Noah LSM
Grell-Devenyi
Cumulus: Kain-Fritsch and Grell-Devenyi
Kain-Fritsch
June 1998
Goddard
RRTM LW
Morrison MP
MYJ PBL
Noah LSM
Grell-Devenyi
Cumulus: Kain-Fritsch and Grell-Devenyi
Kain-Fritsch
June 1998
Goddard
RRTM LW
Morrison MP
MYJ PBL
Noah LSM
Grell-Devenyi
Boundary Layer: YSU and MYJ
YSU
January 1998
Goddard
RRTM LW
Morrison MP
KF CU
Noah LSM
MYJ
Cloud Microphysics: Morrison and WSM5
Morrison
January 1998
Goddard
RRTM LW
KF CU
YSU PBL
Noah LSM
WSM5
Cloud Microphysics: Morrison and WSM5
Morrison
June 1998
Goddard
RRTM LW
KF CU
YSU PBL
Noah LSM
WSM5
Polar WRF and Polar MM5
Polar WRF
January 1998
Goddard
RRTM LW
Morrison MP
KF CU
YSU PBL
Noah LSM
Polar MM5
Polar WRF and Polar MM5
Polar WRF
January 1998
Goddard
RRTM LW
Morrison MP
KF CU
YSU PBL
Noah LSM
Polar MM5
Polar WRF and Polar MM5
Polar WRF
June 1998
Goddard
RRTM LW
Morrison MP
KF CU
YSU PBL
Noah LSM
Polar MM5
Polar WRF and Polar MM5
Polar WRF
June 1998
Goddard
RRTM LW
Morrison MP
KF CU
YSU PBL
Noah LSM
Polar MM5
Polar WRF and Polar MM5
Polar WRF
June 1998
Goddard
RRTM LW
Morrison MP
KF CU
YSU PBL
Noah LSM
Polar MM5
Conclusions: Polar WRF Development
• Some WRF physics options are clearly
inappropriate for polar applications
– Dudhia SW: large negative bias in SWD
– Thermal diffusion soil model: large warm bias
• There appear to be issues with other physics
options, which need more analysis
– Grell-Devenyi cumulus: excessive cloud cover
– MYJ PBL: wintertime cold bias
• Polar WRF has better skill than PMM5 for Jan
• Polar WRF has similar skill as PMM5 for June
• Processes in Polar WRF appear more
realistic than in Polar MM5
Meetings, Presentations,
and Publications
• Conferences
– DOE CCPP Science Team Meeting (Sept 07)
• Poster overview of RACM project
– SEARCH for DAMOCLES (Oct 07)
• Atmospheric Modeling in an Arctic System Model
• Polar Optimized WRF
– Little Alaska Weather Symposium (May 08)
• Development and evaluation of Polar WRF
• Publications
• Bromwich, D.H., K.M. Hines, and L.-S. Bai, 2008:
Development and testing of Polar WRF. Part II. The
Arctic Ocean, submitted to J. Geophys. Res.