1. Urbanized MM5 simulations of Houston: land-use, UHIs, and August 2000 ozone transport patterns Presented at 86 th AMS Annual Meeting, Atlanta, GA 30 January 2006 R.T.F. Balmori*, R. Bornstein*, M. Voss*, and H. Taha #* *San Jose State University, San Jose, CA, USA # Altostratus Inc., Martinez, CA, USA balmori@met.sjsu.edu

2. Outline INTRODUCTION INTRODUCTION Previous efforts on this case Previous efforts on this case Objective of current study Objective of current study METHODOLOGY METHODOLOGY uMM5 uMM5 Current application Current application RESULTS RESULTS GC/Synoptic forcing GC/Synoptic forcing Analysis of meso-obs for ozone transport Analysis of meso-obs for ozone transport Model results: temp and wind Model results: temp and wind CONCLUSIONS/FUTURE WORK CONCLUSIONS/FUTURE WORK

3. Previous Study of Aug 2000 (Nielsen-Gammon 2002) Houston High-O 3 days typically occur with coastal sfc-winds rotate as inertial circle coastal sfc-winds rotate as inertial circle *morning northerly/offshore flow (+ inland precursors) *morning northerly/offshore flow (+ inland precursors) stagnation for several hours over Galveston Bay stagnation for several hours over Galveston Bay *afternoon SE Bay Breeze flow transports polluted *afternoon SE Bay Breeze flow transports polluted air from Ship Channel to Houston air from Ship Channel to Houston SW Gulf Breeze flow (from rotation) from Houston transports air over Channel again (new emissions) SW Gulf Breeze flow (from rotation) from Houston transports air over Channel again (new emissions)or *Houston Heat Pump: (UHI) convergence into Houston

4. OBJECTIVE: “non-emitting” tree-planting (shading)  OBJECTIVE: “non-emitting” tree-planting (shading)  reduced daytime MM5 UHIs (reduced air conditioning, isoprene emissions, & photolysis rates)  reduced daytime MM5 UHIs (reduced air conditioning, isoprene emissions, & photolysis rates)  reduced CMAQ daytime O 3  reduced CMAQ daytime O 3  EPA emission-reduction credits  save $ EPA emission-reduction credits  save $ STUDY DID NOT INCLUDE: STUDY DID NOT INCLUDE: uMM5 uMM5 urban morphology data urban morphology data Previous study of Aug 2000 case (Byun et al. 2004)

5. Current Objective More accurate urban/rural temp & wind patterns for Aug 2000 O 3 episode by use of urbanized MM5 (i.e., uMM5) plus: TexAQS2000 field-study data TexAQS2000 field-study data New EPA/UofU urban morphological data New EPA/UofU urban morphological data Corrected MM5 inputs: deep-soil tempera-ture, initial soil-moisture, roughness length, and SST Corrected MM5 inputs: deep-soil tempera-ture, initial soil-moisture, roughness length, and SST USFS urban-reforestation scenarios to estimate resulting UHI-intensity and O 3 changes USFS urban-reforestation scenarios to estimate resulting UHI-intensity and O 3 changes

6. uMM5 Formulation uMM5: Martilli et al. 2002; Dupont et al. 2003 uMM5: Martilli et al. 2002; Dupont et al. 2003 Drag-force (instead of roughness-length) approach Drag-force (instead of roughness-length) approach Includes additional sink/source terms in all prognostic PBL equations due to roofs & sides Includes additional sink/source terms in all prognostic PBL equations due to roofs & sidesadditional sink/source terms additional sink/source terms Simulates urban areas at finer resolution (100s of meters in horizontal and few meters in vertical) Simulates urban areas at finer resolution (100s of meters in horizontal and few meters in vertical) Taha/SJSU: modification of Houston LU/LC & urban morphology parameters by Taha/SJSU: modification of Houston LU/LC & urban morphology parameters by Additional processing of Burian parameters Additional processing of Burian parameters Modification of uMM5 to accept these data * Modification of uMM5 to accept these data **

7. Additional sink/source terms * * PBL Momentum: (a) roughness-based effects due to hori- zontal-building & ground sfcs and (b) pressure and drag effects due to vertical building and vegetative sfcs PBL Momentum: (a) roughness-based effects due to hori- zontal-building & ground sfcs and (b) pressure and drag effects due to vertical building and vegetative sfcs PBL TKE: (a) building and vegetation flow-effects via accelerated cascade and wake production, (b) horizontal building-surface effects via shear production, and (c) sensible heat-fluxes from building and vegetation sfcs via buoyant production PBL TKE: (a) building and vegetation flow-effects via accelerated cascade and wake production, (b) horizontal building-surface effects via shear production, and (c) sensible heat-fluxes from building and vegetation sfcs via buoyant production PBL Moisture: (a) urban-canopy (in addition to ground- level sources) vegetative evapotranspiration and (b) evaporation of building- and vegetation-intercepted water PBL Moisture: (a) urban-canopy (in addition to ground- level sources) vegetative evapotranspiration and (b) evaporation of building- and vegetation-intercepted water PBL Thermal-energy: (for liquid-water potential- temperature): (a) sensible heat flux from roofs and vegetation canopies and (b) anthropogenic heat flux PBL Thermal-energy: (for liquid-water potential- temperature): (a) sensible heat flux from roofs and vegetation canopies and (b) anthropogenic heat flux SBL Radiative-energy balance: canyon effects from effective albedo, geometry, and sky-view factor SBL Radiative-energy balance: canyon effects from effective albedo, geometry, and sky-view factor

8. uMM5 Simulation period: 22-26 August 2000 Model configuration Model configuration 5 domains: 108, 36, 12, 4, 1 km 5 domains: 108, 36, 12, 4, 1 km (x, y) grid points: (43x53, 55x55, 100x100, 136x151, 133x141 (x, y) grid points: (43x53, 55x55, 100x100, 136x151, 133x141 full-  levels: 29 in D 1-4 & 49 in D 5; lowest ½  level = 7 m full-  levels: 29 in D 1-4 & 49 in D 5; lowest ½  level = 7 m 2-way feedback in D 1-4 2-way feedback in D 1-4 Parameterizations/physics options Parameterizations/physics options Grell cumulus (D 1-2), ETA or MRF PBL (D 1-4), Grell cumulus (D 1-2), ETA or MRF PBL (D 1-4), Gayno-Seaman PBL (D 5), simple ice moisture, Gayno-Seaman PBL (D 5), simple ice moisture, urbanization module, NOAH LSM, RRTM radiative cooling urbanization module, NOAH LSM, RRTM radiative cooling Inputs Inputs NNRP Reanalysis fields, ADP observational data, NNRP Reanalysis fields, ADP observational data, urban morphology from LIDAR building-data in D-5 (from Burian), LU/LC modifications (from Byun ) urban morphology from LIDAR building-data in D-5 (from Burian), LU/LC modifications (from Byun )

9. Domains Present day (2000) – base case Present day (2000) – base case Non-idealized LU/LC change perturbations Non-idealized LU/LC change perturbations Idealized morphology- based Idealized morphology- based Idealized soil- moisture changes Idealized soil- moisture changes Idealized albedo- changes Idealized albedo- changes Simulations Simulations

10. Episode-day Synoptics: 8/25, 12 UTC (08 DST) H H 700 hPa Surface 700 hPa & sfc GC H’s: at their weakest (no gradient) over Texas  meso-scale forcing (sea breeze & UHI convergence) will dominate

11. Concurrent NNRP fields at 700 hPa & sfc H H NNRP-input to MM5 (as IC/BC) captured GC/synoptic features, as location & strength of high were similar to NWS charts (previous slide) D p=2 hPa

12. MM5: episode day, 3 PM > D–1: also well reproduces weak GC p-grad & flow > coastal (cold-core) L emerges in D-2 (in weak form) & D-3 (well formed) & produces along-shore V L D-1 D-2 D-3

13.  GC influences are small  Movement of air-mass first along-shore (to east) due to flow along northern-edge of cold core low  Flow then from Ship Channel to Houston by Bay Breeze, into Houston by UHI-convergence (when O 3 max is reached), and finally beyond Houston to NW by Gulf Breeze  Contour interval: 5 ppb (00-16 UTC) & 10 ppb afterwards D-5 00-23 UTC episode-day obs of meso O 3 transport patterns (animation): sea breeze + UHI convergence influences animation

14. L H C Urban min + UHI Conv H Start of N-flow H L H L due to titration H Near-max O 3 & O 3 trajectory (UTC)

15. Along-shore flow, 8/25 (episode day): obs at 1500 UTC vs uMM5 (D-5) at 2000 UTC Tx2000 HGA uMM5 (D-5, red box) cap-tured HGA along- Shore V HGA uMM5

16. Along –shore flow came from Cold-Core L : D-3 MM5 vs Obs Temps MM5: produces coastal cold-core low Obs (18 UTC): > Cold-core L (only 1 ob) > Urban area (blue-dot clump) retards cold-air penetration C H H

17. 8/23 Daytime UHI: obs vs uMM5 (D-5): 2-m Temps H OBS: 1 PM uMM5: 3 PM Cold UHI

18. UHI-Induced Convergence: obs vs. uMM5 OBSERVEDuMM5 C C

19. Obs speeds (D-5): sfc roughness  speed-decrease over city - - - + + + + V

20. D UHI(t) for Base-case minus Runs 15-18 D UHI(t) for Base-case minus Runs 15-18 U1 sea Ru U2 UHI = Temp in Box-Urban minus Temp in Box-Rural UHI = Temp in Box-Urban minus Temp in Box-Rural Runs 15-18: different urban re-forestation scenarios Runs 15-18: different urban re-forestation scenarios D UHI=Run-17 UHI –Run-13 UHI (max effect, green line) D UHI=Run-17 UHI –Run-13 UHI (max effect, green line) Reduced UHI  lower max-O 3 (not shown)  Reduced UHI  lower max-O 3 (not shown)  EPA emission-reduction credits  Max-impact of –0.9 K of a 3.5 K Noon-UHI, of which a 3.5 K Noon-UHI, of which 1.5 K was from uMM5

21. CONCLUSION NNRP captured large-scale forcing NNRP captured large-scale forcing uMM5 qualitatively captured observed uMM5 qualitatively captured observed urbanization characteristics urbanization characteristics UHI and urban-velocity patterns UHI and urban-velocity patterns ozone transport-processes ozone transport-processes Urban trees Urban trees decreased max daytime UHI-values decreased max daytime UHI-values should thus also decrease max-O 3 values should thus also decrease max-O 3 values

22. FUTURE WORK Change MM5/uMM5 input Change MM5/uMM5 input Deep-soil BC temperature to correct min-T Deep-soil BC temperature to correct min-T IC soil moisture (post rain-storm case) to correct max-T IC soil moisture (post rain-storm case) to correct max-T SST as f(x,y,t) SST as f(x,y,t) surface roughness surface roughness Final uMM5 met-model output will feed into CAMx & CMAQ O 3 -simulations Final uMM5 met-model output will feed into CAMx & CMAQ O 3 -simulations

23. ACKNOWLEDGEMENT From Dr. B (get this) From Dr. B (get this)