urbanized mm5 simulations of houston: land-use, uhis, and august 2000 ozone transport patterns...
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Urbanized MM5Urbanized MM5 simulations simulations of of HoustonHouston: : land-useland-use, , UHIsUHIs, ,
and and August 2000 August 2000 ozoneozone transport transport
patternspatterns
Presented atPresented at
8686thth AMS Annual Meeting, Atlanta, GA AMS Annual Meeting, Atlanta, GA
30 January 200630 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
OutlineOutline• INTRODUCTIONINTRODUCTION
• Previous efforts on this casePrevious efforts on this case• Objective of current studyObjective of current study
• METHODOLOGYMETHODOLOGY• uMM5uMM5• Current applicationCurrent application
• RESULTSRESULTS• GCGC/Synoptic forcing /Synoptic forcing • Analysis of Analysis of meso-obsmeso-obs for ozone for ozone
transporttransport• Model results: Model results: temp and windtemp and wind
• CONCLUSIONS/FUTURE WORKCONCLUSIONS/FUTURE WORK
Previous Study of Aug 2000 (Nielsen-Previous Study of Aug 2000 (Nielsen-Gammon 2002)Gammon 2002)
Houston Houston High-OHigh-O33 days typically occur with days typically occur with coastal coastal sfc-windssfc-winds rotate as inertial circle rotate as inertial circle *morning northerly/offshore*morning northerly/offshore flow (+ inland flow (+ inland
precursors) precursors) stagnationstagnation for several hours over Galveston Bay for several hours over Galveston Bay *afternoon *afternoon SE Bay BreezeSE Bay Breeze flow transports polluted flow transports polluted
air from Ship Channel to Houston air from Ship Channel to Houston SW Gulf BreezeSW Gulf Breeze flow (from rotation) from Houston flow (from rotation) from Houston
transports air over Channel again (new emissions)transports air over Channel again (new emissions)
or or
*Houston Heat Pump: (UHI) *Houston Heat Pump: (UHI) convergenceconvergence into into HoustonHouston
OBJECTIVE:OBJECTIVE: “non-emitting” “non-emitting” tree-plantingtree-planting
(shading) (shading)
reduced reduced daytimedaytime MM5 MM5 UHIsUHIs (reduced air (reduced air conditioning, isoprene emissions, & photolysis conditioning, isoprene emissions, & photolysis rates) rates)
reduced CMAQ daytime reduced CMAQ daytime OO33
EPA emission-reduction credits EPA emission-reduction credits save $ save $ STUDY DID NOT INCLUDE:STUDY DID NOT INCLUDE:
uMM5uMM5 urban morphology dataurban morphology data
Previous study of Aug 2000 case Previous study of Aug 2000 case (Byun et al. 2004)(Byun et al. 2004)
Current ObjectiveCurrent Objective
More accurate urban/rural More accurate urban/rural temptemp & & windwind patterns for patterns for Aug 2000 OAug 2000 O33 episode by use of episode by use of
urbanized MM5 (i.e., urbanized MM5 (i.e., uMM5uMM5) plus:) plus: TexAQS2000 field-study dataTexAQS2000 field-study data New EPA/UofU New EPA/UofU urban morphological dataurban morphological data Corrected MM5 inputs: deep-soil Corrected MM5 inputs: deep-soil
tempera-ture, initial soil-moisture, tempera-ture, initial soil-moisture, roughness length, and SSTroughness length, and SST
USFS USFS urban-reforestation scenariosurban-reforestation scenarios to to estimate resulting estimate resulting UHI-intensityUHI-intensity and O and O33 changeschanges
uMM5 FormulationuMM5 Formulation uMM5: uMM5: Martilli Martilli et al. 2002; et al. 2002; DupontDupont et al. 2003 et al. 2003
Drag-force (instead of roughness-length) Drag-force (instead of roughness-length) approachapproach
Includes Includes additional sink/source termsadditional sink/source terms in all in all prognosticprognostic PBL equations due to PBL equations due to roofs & roofs & sidessides
Simulates urban areas at Simulates urban areas at finer resolutionfiner resolution (100s of meters in horizontal and few (100s of meters in horizontal and few meters in vertical)meters in vertical)
TahaTaha/SJSU: modification of Houston LU/LC & /SJSU: modification of Houston LU/LC & urban morphologyurban morphology parameters by parameters by Additional processing of Additional processing of BurianBurian parameters parameters Modification of uMM5 to accept these data Modification of uMM5 to accept these data
Additional sink/source terms Additional sink/source terms PBL MomentumPBL Momentum:: (a) roughness-based effects due (a) roughness-based effects due
to hori-zontal-building & ground sfcs and (b) to hori-zontal-building & ground sfcs and (b) pressure and drag effects due to vertical building pressure and drag effects due to vertical building and vegetative sfcsand vegetative sfcs
PBL TKEPBL TKE:: (a) building and vegetation flow-effects (a) building and vegetation flow-effects via accelerated cascade and wake production, (b) via accelerated cascade and wake production, (b) horizontal building-surface effects via shear horizontal building-surface effects via shear production, and (c) sensible heat-fluxes from production, and (c) sensible heat-fluxes from building and vegetation sfcs via buoyant productionbuilding and vegetation sfcs via buoyant production
PBL MoisturePBL Moisture:: (a) urban-canopy (in addition to (a) urban-canopy (in addition to ground-level sources) vegetative evapotranspiration ground-level sources) vegetative evapotranspiration and (b) evaporation of building- and vegetation-and (b) evaporation of building- and vegetation-intercepted waterintercepted water
PBL Thermal-energy:PBL Thermal-energy: (for liquid-water potential-(for liquid-water potential-temperature): (a) sensible heat flux from roofs and temperature): (a) sensible heat flux from roofs and vegetation canopies and (b) anthropogenic heat flux vegetation canopies and (b) anthropogenic heat flux
SBL Radiative-energy balanceSBL Radiative-energy balance:: canyon effects canyon effects from effective albedo, geometry, and sky-view factorfrom effective albedo, geometry, and sky-view factor
uMM5 Simulation period: uMM5 Simulation period: 22-26 22-26
AugustAugust 2000 2000 Model configurationModel configuration
5 domains: 108, 36, 12, 4, 5 domains: 108, 36, 12, 4, 1 km1 km (x, y) grid points: (43x53, 55x55, 100x100, 136x151, (x, y) grid points: (43x53, 55x55, 100x100, 136x151,
133x141133x141 full-full- levels: 29 in D 1-4 & 49 in D 5; levels: 29 in D 1-4 & 49 in D 5; lowest ½ lowest ½
level = 7 mlevel = 7 m 2-way feedback in D 1-42-way feedback in D 1-4
Parameterizations/physics optionsParameterizations/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 PBLGayno-Seaman PBL (D 5), simple ice moisture, (D 5), simple ice moisture, urbanization module urbanization module , NOAH LSM, RRTM radiative , NOAH LSM, RRTM radiative
coolingcooling InputsInputs
NNRP Reanalysis fields, ADP observational data, NNRP Reanalysis fields, ADP observational data, urban morphologyurban morphology from from LIDAR building-data in D-5LIDAR building-data in D-5
(from Burian), LU/LC modifications (from Byun )(from Burian), LU/LC modifications (from Byun )
DomainsDomains Present day Present day
(2000) – (2000) – base base casecase Non-idealized Non-idealized
LU/LCLU/LC change change perturbationsperturbations
Idealized Idealized morphologymorphology-based-based
Idealized Idealized soil-soil-moisturemoisture changes changes
Idealized Idealized albedo-albedo-changeschanges
SimulationsSimulations
Episode-day Episode-day SynopticsSynoptics: 8/25, 12 UTC (08 : 8/25, 12 UTC (08 DST)DST)
HH HH
700 hPa 700 hPa Surface Surface
700 hPa & sfc GC H’s: 700 hPa & sfc GC H’s: at their weakestat their weakest (no gradient) (no gradient) over Texas over Texas meso-scale forcingmeso-scale forcing (sea breeze & UHI convergence) (sea breeze & UHI convergence) will dominate will dominate
Concurrent NNRP fields at 700 Concurrent NNRP fields at 700 hPa & sfchPa & sfc
HH
NNRPNNRP-input to -input to MM5 MM5 (as IC/BC) captured (as IC/BC) captured GC/synoptic features, as location & GC/synoptic features, as location & strength of high were similar to strength of high were similar to NWS NWS chartscharts (previous slide) (previous slide)
p=2 hPa
MM5: episode day, 3 MM5: episode day, 3 PM PM > > D–1D–1: also well : also well reproduces weak GC reproduces weak GC p-grad & flowp-grad & flow> coastal (cold-core) > coastal (cold-core) L emerges in L emerges in D-2D-2 (in (in weak form) & weak form) & D-3D-3 (well formed) & (well formed) & produces produces along-along-shore Vshore V
LL
D-1 D-2
D-3
GCGC influences are small influences are small Movement of air-mass first Movement of air-mass first along-shorealong-shore (to (to
east) due to flow along northern-edge of east) due to flow along northern-edge of cold cold core lowcore low
Flow then from Ship Channel to Houston by Flow then from Ship Channel to Houston by Bay BreezeBay Breeze, into Houston by , into Houston by UHI-UHI-convergenceconvergence (when O (when O33 max is reached), and max is reached), and finally beyond Houston finally beyond Houston to NW by Gulf Breezeto NW by Gulf Breeze
Contour interval: Contour interval: 5 ppb5 ppb (00-16 UTC) & (00-16 UTC) &
10 ppb10 ppb afterwards afterwards
D-5 00-23 UTC episode-day obs of meso OD-5 00-23 UTC episode-day obs of meso O33 transport patterns (transport patterns (animationanimation):):
sea breeze + UHI convergence influencessea breeze + UHI convergence influences
L
H
CC
Urban min + UHI Conv
H
Start of N-flow
HL H
L due to titration
HNear-max O3 & O3 trajectory (UTC)
Along-shore flowAlong-shore flow, 8/25 (episode day): obs at , 8/25 (episode day): obs at 1500 UTC1500 UTC vs uMM5 (D-5) at vs uMM5 (D-5) at 2000 UTC2000 UTC
Tx2000
HGA
uMM5 (D-5, red box) cap-tured HGA along-Shore V
HGA
uMM5
Along –shore flow came from Along –shore flow came from Cold-Core LCold-Core L : D-3 MM5 vs Obs : D-3 MM5 vs Obs
TempsTemps
MM5MM5: produces : produces coastal coastal cold-corecold-core lowlow
Obs (18 UTC):Obs (18 UTC):
> > Cold-coreCold-core L L (only 1 ob)(only 1 ob)
> Urban area (blue-dot clump) > Urban area (blue-dot clump) retards cold-air penetrationretards cold-air penetration
C
H
H
8/23 Daytime UHI: obs vs uMM5 (D-5): 8/23 Daytime UHI: obs vs uMM5 (D-5): 2-m Temps2-m Temps
H
OBS: 1 PMOBS: 1 PMuMM5: 3 PMuMM5: 3 PM
Cold
UHI
UHI
UHI-Induced Convergence: UHI-Induced Convergence: obs vs. uMM5obs vs. uMM5
OBSERVEDOBSERVED uMM5uMM5
C
C
Obs speeds (D-5): Obs speeds (D-5): sfc roughness sfc roughness speed-decrease speed-decrease
over cityover city
---+
+
+
+
V
UHI(t) for Base-case minus UHI(t) for Base-case minus Runs 15-18 Runs 15-18
U1
sea
Ru
U2
• UHI = Temp in UHI = Temp in Box-UrbanBox-Urban minus Temp in minus Temp in Box-RuralBox-Rural • Runs 15-18: different urban Runs 15-18: different urban re-forestationre-forestation scenariosscenarios• UHIUHI=Run-17 UHI –Run-13 UHI =Run-17 UHI –Run-13 UHI (max effect, (max effect, green line) green line) • Reduced Reduced UHIUHI lower max-lower max-OO33 (not shown) (not shown)
EPA emission-reduction creditsEPA emission-reduction credits
Urban temp difference between runs at location 1 (3-pt smoothing)
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
20 0 4 8 12 16 20 0 4 8 12 16
LST
Tdi
ff (K
)
run14-run13s
run15-run13s
run16-run13s
run17-run13s
run18-run13s
Max-impact of –0.9 K ofMax-impact of –0.9 K of a a 3.5 K Noon3.5 K Noon-UHI, of which-UHI, of which1.5 K was from uMM51.5 K was from uMM5
CONCLUSIONCONCLUSION
NNRPNNRP captured captured large-scalelarge-scale forcing forcing uMM5uMM5 qualitatively captured qualitatively captured observed observed
urbanizationurbanization characteristics characteristics UHI UHI and urban-and urban-velocityvelocity patterns patterns ozoneozone transport-processes transport-processes
Urban treesUrban trees decreased max daytime decreased max daytime UHIUHI-values-values should thus also decrease should thus also decrease max-Omax-O33 values values
FUTURE WORKFUTURE WORK
Change MM5/uMM5 inputChange MM5/uMM5 input Deep-soilDeep-soil BC temperature to correct min-T BC temperature to correct min-T IC IC soil moisturesoil moisture (post rain-storm case) to (post rain-storm case) to
correct max-Tcorrect max-T SSTSST as f(x,y,t) as f(x,y,t) surface surface roughnessroughness
Final uMM5 met-model outputFinal uMM5 met-model output will will feed into CAMx & CMAQ feed into CAMx & CMAQ OO33--simulationssimulations
ACKNOWLEDGEMENTACKNOWLEDGEMENT
From Dr. B (get this)From Dr. B (get this)