Application of the urbanized MM5 to the Houston-Galveston region

byR. Bornstein*, H. Taha, R. Balmori, SJSU

S. Dupont, J. Ching, RTP/EPA/NOAAA. Martilli, UBC

S. Stetson, SWS, Inc.D. Byun, U of Houston

S. Burian, U of Utah*pblmodel@hotmail.com

27th NATO/CCMS/ITM MeetingBanff, Alberta, Canada

October 2004

OUTLINEOUTLINE

PROJECTPROJECT GOALS GOALS uMM5uMM5 CONFIGURATION CONFIGURATION SYNOPTICSYNOPTIC SUMMARY: 700 MB & SUMMARY: 700 MB &

SFCSFC DOMAIN 1DOMAIN 1: MM5 WINDS VS NWS: MM5 WINDS VS NWS

MM5 WINDS (MM5 WINDS (MESOMESO CONVENTION) CONVENTION) FULL BARB = 1 M/SFULL BARB = 1 M/S FLAG = 5 M/SFLAG = 5 M/S

DOMAINS 2-4DOMAINS 2-4: MM5 WINDs: MM5 WINDs DOMAIN 5DOMAIN 5: uMM5 TEMPs & UHIs: uMM5 TEMPs & UHIs CONCLUSIONCONCLUSION

Overall: Evaluate impacts of de- & re-forestation on Houston O3 levels (Byun, USFS)

SIP Episode: Aug-Sept Texas2000 in Houston MetModel: EPA uMM5 (Martilli, Dupont, Ching) Improved: uMM5 input (Burian, Stetson) Machine: SJSU 96 CPU cluster (Balmori) Evaluate (Taha):

uMM5 vs. MM5 performance uMM5 sensitivity to LU/LC changes

Project Summary:

5-domain configuration, D5 is “urbanized”

Resolution: 108, 36, 12, 4, 1 kmGrid dimensions (excluding surface):43×53×28, 55×55×28, 100×100×28, 136×151×28, 133×141×48.

Urbanization TechniquesUrbanization Techniques

Urbanize:Urbanize: surface, SBL, & PBL momentum, surface, SBL, & PBL momentum, thermo, & TKE Eqs thermo, & TKE Eqs

Allows prediction Allows prediction withinwithin UCL UCL From From vegetationvegetation canopy-model of canopy-model of Yamada Yamada

(1982)(1982) Veg parameters Veg parameters replacedreplaced with urban (GIS/RS) with urban (GIS/RS)

terms terms Brown and Williams 1998Brown and Williams 1998 Masson 2000Masson 2000 Sievers 2001Sievers 2001 Martilli et al. 2001 (in TVM)Martilli et al. 2001 (in TVM) Dupont et al. 2003 (in MM5)Dupont et al. 2003 (in MM5) LLNL 2004LLNL 2004

From Masson (2000)

uMM5 input + as f (x, y) in D-05(from Burian, Stetson, USFS)

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-densitiesε, cρ, α, etc. of walls and roofs

From Stetson: From Stetson: high- resolution Houston zhigh- resolution Houston zoo

datadata

Base-case (current) vegetation cover (urban min)

Modeled increases in vegetation cover (urban max)Values are 0.1 of those in previous chart

MM5 vs. uMM5: Preview of MM5 vs. uMM5: Preview of ResultsResults

uMM5 takes longer than MM5uMM5 takes longer than MM5 with 1-CPU: 8 times longerwith 1-CPU: 8 times longer with 96-CPU: only 3 times longerwith 96-CPU: only 3 times longer each-day of our uMM5 simulation tookeach-day of our uMM5 simulation took

16.0 days with 1-CPU16.0 days with 1-CPU 4.5 hours with 96-CPU4.5 hours with 96-CPU

uMM5 gives better: uMM5 gives better: TKE, UHIs, & windsTKE, UHIs, & winds

Performance for 18 hour prediction

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Synoptic PreviewSynoptic Preview Pre-episode day Pre-episode day

700 hPa:700 hPa: flow NE of Houston was from SE flow NE of Houston was from SE Sfc:Sfc: Sea-breeze frontal formation Sea-breeze frontal formation

Episode dayEpisode day 700 hPa:700 hPa: flow now from NE flow now from NE

opposition to onshore sea-breeze flowopposition to onshore sea-breeze flow Sfc:Sfc: offshore cold-core low forms offshore cold-core low forms

along-shore (NE to SW) coastal-flow along-shore (NE to SW) coastal-flow ozone episode ozone episode

NWS vs. MM5 NWS vs. MM5 NWS NWS charts show only subtle changescharts show only subtle changes MM5 MM5 provides the detailsprovides the details

1200 UTC (0700 DST) 24 1200 UTC (0700 DST) 24 AUGAUG

700 mb700 mb Pre-Pre-

episode episode AMAM

SE flowSE flow NE of NE of HoustonHouston

1200 UTC (0700 DST) 25 1200 UTC (0700 DST) 25 AUGAUG

700 mb700 mb EpisodeEpisode AM AM Opposing Opposing

NE flowNE flow NE NE of Houston of Houston

Will cause Will cause concon with sfc with sfc SB VSB V

1200 UTC (0700 DST) 25 1200 UTC (0700 DST) 25 AUGAUG

Sfc chartSfc chart EpisodeEpisode

AMAM Not much Not much

detaildetail SimilarSimilar to to

day b/f & day b/f & afterafter

MM5 results: PreviewMM5 results: Preview

Domain 1:Domain 1: CapturesCaptures NWS synoptic features (change in NWS synoptic features (change in

700 hPa flow-direction NE of Houston)700 hPa flow-direction NE of Houston) IndicatesIndicates off-shore feature (cold-core L) not off-shore feature (cold-core L) not

on NWS chartson NWS charts Domains 2-4:Domains 2-4: shows details of off-shore shows details of off-shore

LL Domain:Domain: 5: shows UHI effects 5: shows UHI effects

Coastal Coastal Cold-Core Cold-Core L Episode L Episode

day day 3 PM 3 PM

Domains Domains 1-31-3

Domain 4 (3 PM) :Domain 4 (3 PM) : Note cold-core L off of Houston on Note cold-core L off of Houston on OO33 day (25 day (25thth))

Domain 4:Domain 4: weak sea weak sea breeze meets inland breeze meets inland

NE-flow NE-flow

Domain 5: Finer details of sea breeze

and NE-flow

4th (MM5) & 5th (uMM5) Domains: Non-episode day at 2 PM

Domain 3 (12 km) 4 PM:Domain 3 (12 km) 4 PM: cold-core L cold-core L (from where?) (from where?)

1 km uMM5 11 PM: 1 km uMM5 11 PM: nocturnal UHInocturnal UHI

1 km uMM5 3 PM: 1 km uMM5 3 PM: daytime UHIdaytime UHI

1 km Domain: 1 km Domain: end of daytime UHIend of daytime UHI (8 (8 PM 21 Aug)PM 21 Aug)

Upper L:Upper L: MM5 MM5

Upper R:Upper R: uMM5 uMM5

Lower L:Lower L: uMM5- uMM5-MM5MM5

uMM5uMM5 1.5 K 1.5 K warmer (warmer (stronger stronger UHIUHI))

BlobBlob is LU/LC error is LU/LC error

1km Domain: 1km Domain: end of night UHIend of night UHI: 9 AM : 9 AM 22 Aug22 Aug

Upper L:Upper L: MM5 MM5

Upper R:Upper R: uMM5 uMM5

Lower LLower L: MM5-: MM5-uMM5uMM5

uMM5uMM5 1.5 K cooler 1.5 K cooler ((weaker UHIweaker UHI))

Explanation of uMM5 UHI Explanation of uMM5 UHI & UCI& UCI

Wet soil TI > Wet soil TI > urban TIurban TI > dry soil TI > dry soil TI Urban an area surrounded by Urban an area surrounded by wetwet soil soil thus thus

hashas Daytime UHIDaytime UHI (as urban area (as urban area warmswarms faster than faster than

soil)soil) Nighttime UCINighttime UCI (as urban area (as urban area coolscools faster than faster than

soil)soil) ReverseReverse true with true with drydry rural soil rural soil Current results thus consistent with Current results thus consistent with wetwet

rural soil (as expected) around Houstonrural soil (as expected) around Houston, as , as uMM5 produced daytime warming & uMM5 produced daytime warming & nighttime cooling over urban Houstonnighttime cooling over urban Houston

Ongoing & future effortsOngoing & future efforts

Additional Additional analysisanalysis of current of current simulation resultssimulation results

Additional Additional simulationssimulations on new on new 106 CPU cluster106 CPU cluster

Use planned 2005-6 Houston Use planned 2005-6 Houston field-study field-study (?) (?) datadata to to determine atm and (GIS/RS) determine atm and (GIS/RS) urban parametersurban parameters

THE ENDTHE END

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Domain 1: 7 AM 24 AUGDomain 1: 7 AM 24 AUG

• 700 mb700 mb• Pre-Pre-episode episode • Weak off- Weak off- shore L shore L (not in (not in NWS) NWS) •Weak NE Weak NE flow NE of flow NE of citycity

Domain 1: 0700 DST 25 Domain 1: 0700 DST 25 AUGAUG

700 mb700 mb Episode AM Episode AM Stronger Stronger

off-shore L off-shore L Stronger NE Stronger NE

ff NE of cityff NE of city Will cause Will cause

con with SB con with SB ffff

Domain 1: 1800 DST 23 Domain 1: 1800 DST 23 AUGAUG Sfc chartSfc chart

Pre-episode Pre-episode On-shore SBOn-shore SB Not much Not much

difference at difference at same time on same time on next 2 daysnext 2 days

Need to see Need to see inner inner domainsdomains