Impacts from urban & rural surface modifications on meteorology and air quality in Houston:

1. Impacts from urban & rural surface modifications on meteorology and air quality in Houston: preliminary results Haider Taha haider@altostratus.com Altostratus Inc. 940 Toulouse Way, Martinez, CA 94553 (925) 228-1573 Robert Bornstein San Jose State University pblmodel@hotmail.com Rochelle Balmori San Jose State University balmori@met.sjsu.edu For GUM Workshop, JULY 2004

2. OUTLINE • uMM5 CONFIGURATION • SYNOPTIC SUMMARY: 700 MB & SFC • DOMAIN 1: MM5 SYNOPTIC WINDS VS NWS • MM5 WINDS (MESO CONVENTION) • FULL BARB = 1 M/S • FLAG = 5 M/S • DOMAINS 2-4: MM5 WINDs • DOMAIN 5: uMM5 TEMPs • CONCLUSION

3. Work in progress: • Model: EPA uMM5 (Dupont, Burian, et al.) • Study: Aug-Sept Houston (Texas ’00) 03 episode • Improve uMM5 input and physics • Evaluate: uMM5 vs. MM5 performance • Evaluate uMM5 sensitivity to LU/LC changes

5. Urbanization Techniques • Urbanize surface, SBL, & PBL momentum, thermo, & TKE Eqs • Allows prediction within UCL • From vegetation canopy-model of Yamada (1982) • Veg parameters replaced with urban (GIS/RS) terms • Brown and Williams 1998 • Masson 2000 • Sievers 2001 • Martilli et al. 2001 (in TVM) • Dupont et al. 2003 (in MM5) • LLNL 2004

6. From Masson (2000)

7. From Masson (2000)

11. 5-domain configuration, D0-5 is “urbanized” Resolution: 108, 36, 12, 4, 1 km Grid dimensions (excluding surface): 43×53×28, 55×55×28, 100×100×28, 136×151×28, 133×141×48.

12. MM5 input + as f (x, y) in D-05: • land use (38 categories) • roughness elements • anthropogenic heat as f (t) • vegetation and building heights • paved surface fractions • drag-force coefficients for buildings & vegy • building height-to-width, wall-to-plan, & impervious-area ratios • building frontal, building plan, & and rooftop area-densities • vegetation top- and area-densities • root zone and sub-soil layers characterization • vegetation-canopy characterization, stomatal resistance • ε, cρ, α, etc. of walls and roofs

14. Base-case vegetation cover (urban min)

15. Modeled increases in vegetation cover (urban max)

16. NWS SYNOPTICS

17. 1200 UTC (0700 DST) 24 AUG ‘00 • 700 mb • Pre-episode AM • SE flow NE of Houston

18. 1200 UTC (0500 DST) 25 AUG ‘00 • 700 mb • Episode AM • Opposing NE flow NE of Houston • Will cause con with sfc SB V

19. 1200 UTC (0700 DST) 25 AUG • Sfc chart • Episode AM • Not much detail • Similar to day b/f & after

20. D-01 MM5 WINDS

21. 1200 UTC (0700 DST) 24 AUG • 700 mb • Pre-episode • Weak off- shore L (not in NWS) • Weak NE flow NE of city

22. 1200 UTC (0700 DST) 25 AUG • 700 mb • Episode AM • Stronger off-shore L • Stronger NE ff NE of city • Will cause con with SB ff

23. 1800 DST 23 AUG • Sfc chart • Pre-episode • On-shore SB • Not much difference at same time on next 2 days • Need to see inner domains

24. D-02 to -04 MM5 Output

28. D-05 uMM5 Output

30. Daytime (end): 2100 DST 21 AUG • Upper L: MM5 • Upper R: uMM5 • Lower L: MM5-uMM5 • uMM5 1 K warmer • Blob is LU/LC error

31. Nighttime (end): 0900 DST 22 AUG • Upper L: MM5 • Lower L: uMM5 • Upper R: MM5-uMM5 • uMM5 2 K cooler

32. Explanation of uMM5 UHI & UCI • Wet soil TI > urban TI > dry soil TI • Urban an area surrounded by wet soil thus has • Daytime UHI (as urban area warms faster than soil) • Nighttime UCI (as urban area cools faster than soil) • Reverse true with dry rural soil • Current results thus consistent with wet rural soil (as expected) around Houston, as uMM5 produced daytime warming & nighttime cooling over urban Houston

33. Ongoing efforts • Additional analysis of current simulation results • Additional simulations on new 106 CPU cluster • Use planned 2005-6 Houston field-study data to determine atm and (GIS/RS) urban parameters • Develop parameterizations to replace current M-O SBL formulations • Link urban CFD & meso-models for Emergency-Response applications