1. 2002 MM5 Model Evaluation 12 & 36 km Sensitivity Tests
Chris Emery, Yiqin Jia, and Ralph Morris
ENVIRON International Corporation
Zion Wang
UCR CE-CERT
Western Regional Air Partnership (WRAP)
Regional Modeling Center (RMC)
National RPO Meeting
May 25, 2004

2. Addition of 12-km WRAP Grid
IC/BC’s extracted from 36-km MM5 fields
3-D FDDA fields extracted from 36-km MM5 fields
Preliminary 5-day run starting 12Z July 1

3. Subdomains for 12-km Model Evaluation
1 = Pacific NW
2 = SW
3 = North
4 = Desert SW
5 = CenrapN
6 = CenrapS
7 = Great Lakes
8 = Ohio Valley
9 = SE
10 = NE
11 = MidAtlantic

4. 2002 MM5 12 km Sensitivity Tests
Tests with 12-km grid:
Run 1 (initial simulation):
Soil moisture nudging on
Initial soil moisture from 36-km output
3-D FDDA from 36-km output (no 2-D surface FDDA)
No Obs FDDA
Run 2:
Soil moisture nudging off
Initial soil moisture from LANDUSE.TBL
3-D FDDA from 36-km output
Observational FDDA from NCAR DS.472

5. 2002 MM5 12 km Sensitivity Tests
Run 3:
Soil moisture nudging off
Initial soil moisture from 36-km output
3-D FDDA from 36-km output
Obs FDDA from NCAR DS.472
Run 4:
Initial soil moisture from 36-km EDAS fields
3-D FDDA from 36-km EDAS fields

6. 2002 MM5 12 km Sensitivity Tests
Overall:
No significant impact on wind speed/direction performance in any run
Focus on temperature & humidity performance
Run 2 (soil nudging off, default moisture, Obs FDDA):
Best performance in Desert SW, but worst in other regions
Run 3 (soil nudging off, Obs FDDA):
Performance slightly improved in all 3 regions

7. 2002 MM5 12 km Sensitivity Tests
Run 4 (soil nudging off, EDAS moisture,
EDAS + Obs FDDA):
Similar to Run 3, but even better performance in Desert SW
Removing soil moisture nudging has a positive impact on performance
Using EDAS to provide initial soil moisture and analysis FDDA (instead of 36-km MM5 results) has a positive impact on performance
Obs FDDA has negligible impact on performance

8. 2002 MM5 36 km Sensitivity Tests
Tests with 36-km grid:
Run 0 (initial simulation):
Soil moisture nudging on
3-D & 2-D nudging to EDAS enhanced with NWS observations
Cumulus parameterization is KF
LSM/PBL is P-X
Run 1:
Soil moisture nudging off

9. 2002 MM5 36 km Sensitivity Tests
Run 2:
Soil moisture nudging off
Cumulus parameterization changed to KF II (based on comparison to VISTAS results)
Run 3:
LSM/PBL changed to NOAH and modified-MRF (removal of “scaled virtual temperature excess” and “convective velocity” contribution in U* calculation)

10. 2002 MM5 36 km Sensitivity Tests
Overall:
No significant impact on wind performance, generally sensitivity cases slightly reduce speed
Focus on temperature & humidity performance
Run 1 (soil nudging off):
No significant impact in Desert SW
Improved performance in SW
Mixed performance in Pacific NW
Run 2 (KF II):
Similar results to Run 1 in SW and Pacific NW
Good improvement in Desert SW

11. 2002 MM5 36 km Sensitivity Tests
Run 3 (NOAH + modified MRF):
Best overall performance in Desert SW
Worst performance in SW and Pacific NW
Summary:
Soil moisture nudging is generally a negative attribute
KF II helps performance where most convection occurs
Moving to a different LSM/PBL combo is not a universally good idea

12. New 36/12 Nested Sensitivity Test
Run 5:
2-way nesting
No soil moisture nudging
KF II
P-X LSM/PBL
Wind performance similar to all other runs in all regions
Similar temperature & humidity performance to other tests in SW and Pacific NW
Best temperature & humidity performance of all runs in Desert SW

16. New 36/12 Nested Sensitivity Test
Run 5 forms basis for revised /12 WRAP simulations
Identical physical configuration
1-way grid nesting (2-way set up but no feedback)
Adds 2-D surface nudging on 12-km grid to EDAS enhanced with NWS observations