Jian-Wen Bao (ESRL/PSD) S. G. Gopalakrishnan (AOML/HRD) Sara A. Michelson (ESRL/PSD) NOAA/OAR
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Transcript of Jian-Wen Bao (ESRL/PSD) S. G. Gopalakrishnan (AOML/HRD) Sara A. Michelson (ESRL/PSD) NOAA/OAR
Jian-Wen Bao (ESRL/PSD)
S. G. Gopalakrishnan (AOML/HRD)
Sara A. Michelson (ESRL/PSD)
NOAA/OAR
in collaboration with Frank Marks of AMOL/HRD,
and Vijay Tallapragada of NCEP/EMC
Sensitivity of the WRF-NMM Model to Physics Parameterizations at Various Vertical and
Horizontal Resolutions
Presented atThe 64th Interdepartmental Hurricane Conference
Savannah, GA, 1-4 March 2010
Outline
1. Motivation and methodology
2. Model initialization and physics options tested so far
3. Highlighted results
4. Summary
Motivation
Methodology
• To explore the flexibility of running HWRF with various physics options in the WRF-NMM modeling framework.
• To benchmark the response of the WRF-NMM dynamic core to various permutations of physics options.
• Idealized case setup to complement real-event investigation
• Evaluation with observation composites and theoretical understanding
Model Initialization
• f plane located at 12.5ºN
• A prescribed axisymmetric vortex:
— maximum sfc tangential wind: 15 m/s
— radius of sfc maximum wind: 90 km
• Quiescent environment thermally corresponding to the Jordan sounding with a constant sea surface temperature of 29ºC
• Initial mass and wind fields derived by solving the nonlinear balance equation for the prescribed vortex (Wang 1995, MWR)
Physics Options Tested So Far
SL/ABL Physics Options
MYJ (NMM Default) GFS (HWRF Default)
Microphysics Options
Option # = 4, WSM 5-class scheme= 5, Ferrier (new Eta) = 6, WSM 6-class graupel scheme
= 8, Thompson scheme
Subgrid Convection Options
SAS (HWRF default)BMJ (Betts-Miller, NMM default)
Radiation Options
Option # = 1, Dudhia SW and RRTM LWOption # = 99, GFDL SW and LW (NMM default)
EXPERIMENT#
Boundary Layer Scheme
Convective parameterization scheme
(D1/D2)
Radiation Scheme
Microphysics scheme
1 MYJ SAS/SAS 1 5
2 GFS SAS/SAS 1 5
3 GFS SAS/SAS 99 5
4 GFS SAS/SAS 99 4
5 GFS SAS/SAS 99 6
6 GFS SAS/SAS 99 8
7 GFS SAS/None 99 5
8 MYJ BMJ/BMJ 1 5
9 GFS BMJ/BMJ 99 5
Physics Permutations
Model grid spacing:dx = 0.06, 0.02 (~9 km, ~ 3 km)dy = 0.06, 0.02 (~9 km, ~ 3 km)kx = 43 (NMM sigma-p levels)
Boundary Layer
Scheme
Convective parameterization
scheme (9km/3km)
Radiation Scheme
Microphysics scheme
Black MYJ SAS/SAS 1 5
Red GFS SAS/SAS 1 5
Gray MYJ BMJ/BMJ 1 5
Yellow GFS BMJ/BMJ 99 5
Sensitivity to SL/ABL and Radiation
Max Surface Wind Speed Min Sea-Level Pressure
36-48 h
Boundary Layer
Scheme
Convective parameterizatio
n scheme (9km/3km)
Radiation Scheme
Microphysics scheme
Green GFS SAS/SAS 99 5
Blue GFS SAS/SAS 99 4
Magenta GFS SAS/SAS 99 6
Orange GFS SAS/SAS 99 8
Purple GFS SAS/None 99 5
Sensitivity to microphysics and Sub-Grid ConvectionMax Surface Wind Speed Min Sea-Level Pressure
36-48 h
Exp. 1 Exp. 2 Exp. 3
Exp. 4 Exp. 5 Exp. 6
Exp. 7 Exp. 8 Exp. 9
36-48 h average Color shades: vertical motion Contours: radial winds Arrows: circ. vectors
MYJ PBL
MYJ PBL
Exp. 1MYJ PBL
Exp. 2GFS PBL
z
wr
v
ru
tdt
dr
Color Shades: Tan. Acc. Averaged over hours 36-48Contours: Tangential windsArrows: Circulation vectors
vDfu
r
vup
rdt
dvr
r
+ 1
UST: 36 - 48 hour averageEXP
#Bound. Layer
Scheme
Convective parameteriz-ation scheme
(D1/D2)
Radia-tion
Scheme
Microphy-sics
scheme
Black (1) MYJ SAS/SAS 1 5
Red (2) GFS SAS/SAS 1 5
Green (3) GFS SAS/SAS 99 5
Blue (4) GFS SAS/SAS 99 4
Magenta (5)
GFS SAS/SAS 99 6
Orange (6)
GFS SAS/SAS 99 8
Purple (7)
GFS SAS/None 99 5
Gray (8) MYJ BM/BM 1 5
Yellow 9) GFS BM/BM 99 5
EXP#
Bound. Layer
Scheme
Convective parameteriza-tion scheme
(D1/D2)
Radia-tion
Scheme
Microphy-sics
scheme
Black (1) MYJ SAS/SAS 1 5
Red (2) GFS SAS/SAS 1 5
Green (3) GFS SAS/SAS 99 5
Blue (4) GFS SAS/SAS 99 4
Magenta (5)
GFS SAS/SAS 99 6
Orange (6)
GFS SAS/SAS 99 8
Purple (7)
GFS SAS/None 99 5
Gray (8) MYJ BM/BM 1 5
Yellow(9) GFS BM/BM 99 5
Sensible Heat Flux: 36-48 hour average
Latent Heat Flux: 36-48 hour averageEXP
#Bound. Layer
Scheme
Convective parameteriza-tion scheme
(D1/D2)
Radia-tion
Scheme
Microphy-sics
scheme
Black (1) MYJ SAS/SAS 1 5
Red (2) GFS SAS/SAS 1 5
Green (3) GFS SAS/SAS 99 5
Blue (4) GFS SAS/SAS 99 4
Magenta (5)
GFS SAS/SAS 99 6
Orange (6)
GFS SAS/SAS 99 8
Purple (7)
GFS SAS/None 99 5
Gray (8) MYJ BM/BM 1 5
Yellow(9) GFS BM/BM 99 5
Summary
(1) It is useful to set up idealized benchmark cases for the evaluation and understanding of ongoing improvements of WRF-NMM/HWRF.
(2) The intensification, as realized by the WRF-NMM model, is sensitive to both the SL/ABL physics options, the cloud physics options and the radiation options.
(3) Different permutations of the SL/ABL and the cloud physics lead to various dynamical properties of the vortex in terms of du/dt and dv/dt .
(4) Future work will be focused on using observational analysis and theoretical understanding to help determine an “improved”, operational physics configuration.