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Urbanized-MM5 urban-climate simulations of Houston-Galveston

Bob Bornstein * R. Balmori and H. Taha Dept. of Meteor., San Jose State Univ. San Jose, CA USA for copy of ppt: * pblmodel@hotmail.com presented at 6 th ICUC Göteborg, Sweden 12-16 June 2006. Urbanized-MM5 urban-climate simulations of Houston-Galveston. OVERVIEW. Introduction MM5

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Urbanized-MM5 urban-climate simulations of Houston-Galveston

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  1. Bob Bornstein* R. Balmori and H. Taha Dept. of Meteor., San Jose State Univ. San Jose, CA USA for copy of ppt: *pblmodel@hotmail.com presented at 6th ICUC Göteborg, Sweden 12-16 June 2006 Urbanized-MM5 urban-climate simulations of Houston-Galveston

  2. OVERVIEW • Introduction • MM5 • Urbanized uMM5 • Houston uMM5 Urban Ozone-Study • GC/Synoptic influences • Gulf & Bay breezes • Urban-climate effects • Current • After tree-planting • Ozone-transport patterns • Future Work

  3. Urbanization Techniques • Urbanize subsurface, surface, UCL, SBL, & PBL: momentum, thermo, & TKE Eqs • From forest-canopy model (Yamada 1982) • Veg param replaced with urban (GIS/RS) terms • Brown and Williams (1998) • Masson (2000): urban-canyon energy-budget • Martilli et al. (2001): urban+PBL in TVM • Dupont et al. (2003): Martilli + EPA/MM5 (for Ching) UPC • Taha et al. (2005): LU/LC + UPC uMM5

  4. From EPA uMM5: Mason + Martilli (by Dupont) Within Gayno-Seaman PBL/TKE scheme

  5. Martilli et al. 3 new-terms in each prog. PBL eq. e.g., Momentum ↓ Building: vol & sfc area  Advanced urbanization scheme from Masson

  6. uMM5 inputs as f (x, y) • land use (38 categories) • roughness elements • anthropogenic heat as f (z, t) • building heights • paved surface-fractions • building drag-force coefficients • building height-to-width, wall-to-plan, & impervious-area ratios • building frontal, building plan, & rooftop area-densities • ε, cρ, α, etc. of walls and roofs

  7. UCP-inputs (1 km grid) Houston: Ching & Burian (2006) Wall-to-Plan area ratio Building plan area fraction Building frontal area index Height-to-Width ratio

  8. Brown & Williams: urbanized meso-met model TKE(z) hc =building top max urban effect

  9. uMM5 Houston Runs: 22-26 August 2000 • Model configuration • 5 Domains: 108, 36, 12, 4, 1 km • (x,y) grids: 43x53, 55x55, 100x100, 136x151, 133x141 • s-levels: 29 in Ds1-4; 49 in D5; lowest ½ s = 7 m • 2-way feedback in D1-4 • 96 CPU 4.5 hr for a 24 hr simulation • Physics options > Grell Cu in D1-2 > ETA or MRF PBL in Ds 1-4 > Gayno-Seaman TKE PBL in D5 > Simple ice > Urbanization in D-5 > NOAH LSM > RRTM radiation • Inputs > NNRP Reanalysis + ADP obs > Burian LIDAR building-data in D5 > Byun LU/LC modifications

  10. Houston Galveston emissions: 2nd most O3-polluted US city SHIP CHANNEL AREA Houston-Galveston refineries & chemical plants: along Galveston Bay ship-channel (Source: Byun 2003)

  11. H H Episode-day Synoptics: 8/25, 12 UTC (08 DST) Surface Dp = 4 hPa 700 hPa Dz = 30 m 700 hPa & sfc GC H’s: at weakest (no gradient) over Texas  meso-scale forcings (sea-breeze & UHI-convergence) dominate

  12. H H Dp= 2 hPa Concurrent NNRP fields at 700 hPa & sfc Dz = 30 m NNRP-inputs to MM5(as IC/BC) captured GC/synoptic location & strength of NWS-H (on previous slide) MM5 can thus do well (Bornstein 2006)

  13. D-1 D-2 L D-3 MM5: episode day, 3 PM> D–1: reproduced weak GC p-grad & V> D-2: new weak coastal-L > D-3: (well formed) L along-shore V L

  14. Domain 4 (3 PM) : L off of Houston on high O3 day (25th)  Episode day L L

  15. uMM5 Domain 5sfc-winds at 3 PM: 4 successive days H • Episode day: off-shore L  along-coast V  warm-inland  high O3 C

  16. HGA (gridded) Tx2000 HGA 25 Aug (episode day) 1500 UTC (same as last slide) Observed winds at different-scales: alongshore flow

  17. O3 Interval: 5 ppb (00-16 UTC) & 10 ppb (>16 UTC) H 17 UTC: Bay Breeze + Ship Channel max L C H H L H 23 UTC Gulf Breeze & trajec-tory of O3 max 18 UTC: urban L (titration) 23 H L 21 16 18 19 14 UTC 15 17 > 02 UTC: UHI Con > O3: urban-L + weak left-over H + Houston Heat-pump Note: early stagnation

  18. + - + + - + V + Urban-effects on night-(non UHI, as wet rural soil) speeds (D-5): z0 speed-decreases (m/s) over urban-centers uMM5 + + - + + Obs

  19. 08/24/00 C C Daytime UHI (wet rural soil) urban-induced convergence & acceleration C uMM5 Gridded Obs

  20. H C Along–shore V came from Cold-Core L:D-3 MM5 vs Obs Temps MM5: produces coastal cold-core low H 18 UTC,Cold-core L (only 1-ob) & Urban area (blue-dot clump) seems to retards cold-air penetration!

  21. D-5 uMM5-MM5 UHI at 8 PM on 21 Aug H H C • Upper L: MM5 UHI = 2.0 K • Upper R: uMM5 UHI = 3.5 K • Lower L: uMM5-MM5 = 1.5 K stronger UHI • Blob is LU/LC error +

  22. UHI UHI Cold Obs: 1 PM uMM5: 3 PM 8/23 Day UHI: obs vs uMM5 (D-5): 2-m Temps H C

  23. Base-case veg (0.1s): urban-min of current tree -cover • Modeled increase • tree-cover ( 0.01s): • urban reforestation • rural deforestation

  24. W’er C’er Run 14(urban-reforestation) minus Run 13 (base case):4 PM 2-m ∆T (K)> reforested urban-areas are cooler > surrounding deforested rural-areas are warmer W’er

  25. RURAL URBAN Max-impact of –0.9 K of a 3.5 K Noon-UHI, of which 1.5 K was from uMM5 DUHI(t): Base-case minus Runs 15-18 • UHI = Temp inUrban-Boxminus Temp inRural-Box • Runs 15-18: urbanre-forestationscenarios • DUHI = Run-17 UHI minus Run-13 UHI  • max effect, green line • Reduced UHI  lower max-O3 (not shown)  • EPA emission-reduction credits  $ saved

  26. Houston Summary • NNRP captured GC forcing for MM5: weak High • uMM5 captured the thus strong observed meso effects • Weak offshore Low • Ship-Channel (large source area) stagnation • Sequential Bay and Gulf breezes • Urbanization LU/LC characteristics • Houston: UHI & heat-pump • Urban-V patterns • UHI convergence/acceleration • Roughness deceleration • Ozone transport-processes • Urban reforestation • Decreased max-daytime UHI-values • Should thus also decrease max-O3 values

  27. FUTURE WORK (1) • Current uMM5  reduced Houston-UHI  reduced: energy use, biogenics, photolosis  reduced (?) CAMx/CMAQ O3 EPA emission-reduction credits • Update uMM5 inputs • Deep-soil BC-temp to eliminate min-T bias • IC soil-moisture (post rain-storm) to eliminate max-T bias • Satellite SST as f(x,y,t) • Better sea-surface z0eq. • Dave Sailor Qa via NSF project

  28. FUTURE WORK (2) • SJSU/NCAR (Fei Chen) uWRF DTRA proposal • uMM5 scheme • Zilitinkevich: diag SBL-eqs for very stable & unstable conditions • Freedman: prog k-ε PBL eqs • 1-way link to: ER canyon-dispersion models • Downscaled climate-change model-output  increased NYC (with Columbia/GISS) > thermal-stress deaths (to NSF) > thunderstorms  urban floods (to NSF) > air pollution (to EPA)

  29. ACKNOWLEDGEMENTS • D. Hitchock & P. Smith, State of TX • D. Byun, U. of Houston • J. Nielsen-Gammon, T&M U. • J. Ching & S. Dupont, US EPA • S. Stetson, SWS Inc • S. Burian, U. of Utah • D. Nowak, US Forest Service • Funding from:USAID, NSF, DHS, HARC

  30. Houston and uMM5 References • Balmori, R., 2006: Urbanized MM5 study of urban impacts on an August 2000 Houston O3 episode. MS Thesis, Dept. of Met., SJSU. • Banta, R. M., et al., 2005: A bad air day in Houston. Bull. Amer. Meteor. Soc., 86, 657-669. • Byun, D., et al., 2004:Modeling effects of land use/land cover modifications on the UHI and air quality in Houston, Texas. Tech. Note, University of Houston, 55 pp. • Dupont, S., et al., 2003:Simulation of meteorological fields within and above urban and rural canopies with MM5. Tech. Rep., US EPA NOAA, ARL, NC, 67 pp. • Martilli, A., et al., 2002: An urban surface exchange parameterization for mesoscale models. Boundary-Layer Meterol., 104, 261-304. • Nielsen-Gammon, J. W., 2004: The surprising dynamics of the Houston urban sea breeze. Preprints, 84th AMS Conf, Seattle, WA. • Taha, H., et al., 2005: UHI alterations from urban-forest changes in Houston: uMM5 model of Aug 2000 O3 episode. SJSU Report to HARC.

  31. The End Any Questions?

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