1. Analysis of the MM5-Simulated Surface Fields with Three PBL schemes over the Eastern U.S. during 6-16 August 2002
Winston, Mike Ku, and Gopal Sistla
NYSEC-DAR
and
Da-Lin Zhang
University of Maryland

2. 1. Background
Zhang, D.-L. and W.-Z. Zheng, 2004: Diurnal Cycles of Surface Winds and Temperatures as Simulated by Five Boundary-Layer Parameterizations. Journal of Applied Meteorology, 43,

3. Observed diurnal cycles of Tsfc and Vsfc over 105 surface stations taken over an area of 800 km x 800 km during 12 – 15 July 1997

4. Model description – MM5
Two-way nested, x = 36/12 km;
Kain-Fritsch cumulus parameterization
Simple cloud/ice parameterization
PBL schemes being tested:
a) Blackadar; b) Gayno-Seaman; c) MRF;
d) Miller-Yamada-Jajic; e) Burke-Thompson.
Surface layer (half-) at 10 m
Integration: 1200 UTC June 1997

5. Comparison of diurnal cycles of Tsfc between the observed and the simulated with the Blackadar, Gayno-Seaman, MRF, Miller-Yamada-Jajic and Burke-Thompson schemes

6. Comparison of diurnal cycles of Vsfc between the observed and the simulated with the (new) Blackadar, Gayno-Seaman, MRF, Miller-Yamada-Jajic and Burke-Thompson schemes

7. Diurnal cycle of the low-level winds generated by the Gayno-Seaman and (b) Blackadar schemes

8. 2. Summer Season of 2002 - MANE-VU
• A two-way nested (36/12 km) grid.
• Three PBL schemes:
1) the Plen-Xiu scheme including the land- surface processes;
2) the Blackadar scheme;
3) the Blackadar plus a land-surface scheme.
• Dynamic nudging:
upper-air plus surface winds observations
• Integration time:
1200 UTC UTC 16 August 2002

9. Nested Domains

10. Vsfc from the Plen-Xiu scheme

11. Vsfc from the Blackadar scheme

12. Vsfc from the Blackadar + a land-surface scheme

13. Tsfc from the Plen-Xiu scheme

14. Tsfc from the Blackadar scheme

15. Tsfc from the Blackadar+ a land-surface scheme

16. Qsfc from the Plen-Xiu scheme

17. Qsfc from the Blackada scheme

18. Qsfc from the Blackadar + a land-surface scheme

19. 3. Summary and Conclusions:
It appears that the Blackadar scheme exhibits a better correspondence to the observed than the other two schemes, but does not capture well the observed diurnal pattern of humidity.
While the Plen-Xiu scheme shows a better correspondence to the observed humidity, it fails to perform well for wind speed and temperature.