Download - WRF Model: Physics Implementation
![Page 1: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/1.jpg)
WRF Model:
Physics Implementation
OUTLINE
Physics schemesThree_level StructureRules for WRF physicsWRF Physics FeaturesWRF LanguageWhat you might need to do
Shu-hua Chen
![Page 2: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/2.jpg)
Physics Schemes
Physical Process Available
Microphysics Kessler, Lin et al. , Ncloud3, Nloud5
Cumulus KF, BMJ
Subgrid scale turbulence TKE, Smagrinsky,
Constant K
Radiation RRTM(L), Dudhia(S),
Goddard(S)
PBL MRF
Surface layer Similarity theory
Land-surface layer 5-layer soil temperature
![Page 3: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/3.jpg)
Physics Interface Design
User friendly •• Simple
Different dynamics cores •Three-level structure =>
![Page 4: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/4.jpg)
Solver
Physics_driverSELECT CASE (CHOICE) CASE ( NOPHY ) CASE ( SCHEME1 ) CALL XXX CASE ( SCHEME2 ) CALL YYY CASE DEFAULTEND SELECT
Individual physics scheme ( XXX )
Three-level Structure
![Page 5: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/5.jpg)
WRF … solve_rk ADV TENDENCIES
phy_init
ADVANCE VARS
…
INIT
.
.
.
microphysics_driver
Radiation_driver
Cumulus_driver
pbl_driver
phy_prep
moist_physics_prep
![Page 6: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/6.jpg)
phy_prep & moist_physics_prep
• Decouple variables
• Convert variables from C grid
to A grid
![Page 7: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/7.jpg)
Domain size: ids, ide, jds, jde, kds, kde
Memory size: ims, ime, jms, jme, kms, kme
Tile size: its, ite, jts, jte, kts, kte
Three Sets of Dimensions
![Page 8: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/8.jpg)
Tile size (its,kts,jds)
halo
halo
haloh
alo
(ims,ime)
tile
tile
tile
tile
tile
tile
(its,ite)
![Page 9: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/9.jpg)
Coding rules
Vectorized code preferred
( might depend on which physics component )
Rules for WRF Physics
Naming rules
One scheme one module
![Page 10: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/10.jpg)
a) Replace continuation characters in the 6th column with f90 continuation `&‘ at end of previous line
1. F90
b)Replace the 1st column `C` for comment with `!`
2. No common block
3. Use “ implicit none ”
5. Variable dimensions and do loops
Coding Rules
4. Use “ intent ”
![Page 11: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/11.jpg)
xxx = individual scheme
ex, module_cu_kf.F
Naming Rules
module_yy_xxx.F (module)
yy = ra is for radiation bl is for PBL cu is for cumulus mp is for microphysics.
![Page 12: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/12.jpg)
YY = ra is for radiation bl is for PBL cu is for cumulus
Naming Rules
RXXYYTEN (tendencies)
XX = variable (th, u, v, qv, qc, … )
ex, RTHBLTEN
![Page 13: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/13.jpg)
• Unified global constatnts
(module_model_constants.F)
WRF Physics Features
• Unified some calculations
(saturation mixing ratio)
• Vertical index (kms is at bottom)
• kme = kte + 1 (physics)
kme = kte (dynamics)
![Page 14: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/14.jpg)
WRF Language
• Patch, tile, ….
• Moisture field, moist(i,k,j,?), is 4D
• P_QV, P_QC, P_QR, P_QI,P_QS,
P_QG (module_state_description.F)
• PARAM_FIRST_SCALAR
IF ( P_QI .ge. PARAM_FIRST_SCALAR )
. . .
![Page 15: WRF Model: Physics Implementation](https://reader036.vdocuments.us/reader036/viewer/2022072111/56812ef2550346895d9493e6/html5/thumbnails/15.jpg)
namelist.input
mp_physics = 2, ra_lw_physics = 1, ra_sw_physics = 1, bl_sfclay_physics = 1, bl_surface_physics = 1, bl_pbl_physics = 1, cu_physics = 1,