Download - MM5 SIMMULATIONS OF SFBA TO SAC/SJV TRANSPORT DURING 30 JULY- 2 AUG 2000 CCOS OZONE EPISODE by
MM5 SIMMULATIONS OF SFBA TO SAC/SJV TRANSPORT DURING 30 JULY- 2 AUG 2000 CCOS
OZONE EPISODE
by
Robert D. Bornstein: [email protected]
Tesfamichael B. Ghidey: LBNL, SJSU
Robert Van Buskirk: LBNL
Prepared for GMU WorkshopJuly 2004
OUTLINEOUTLINE
• SYNOPTIC SUMMARY SYNOPTIC SUMMARY – 700 MB (NO MESO INFLUENCES OVER CALIF)700 MB (NO MESO INFLUENCES OVER CALIF)– SFCSFC
• MM5 CONFIGURATIONMM5 CONFIGURATION• DOMAIN 1: SYNOPTIC WINDSDOMAIN 1: SYNOPTIC WINDS• DOMAIN 3: MEOS WINDSDOMAIN 3: MEOS WINDS
– LIV, SAC, & SJV SEQUENTIAL OZONE EPISODE DAYSLIV, SAC, & SJV SEQUENTIAL OZONE EPISODE DAYS• STAT MESO-EVALUATIONSTAT MESO-EVALUATION
– TEMP TEMP • MESOSCALE: TEMP DRIVES WINDSMESOSCALE: TEMP DRIVES WINDS• SYN SCALE: MASS/PRESSURE DRIVES WINDSSYN SCALE: MASS/PRESSURE DRIVES WINDS
– WINDS (MESO CONVENTION)WINDS (MESO CONVENTION)• FULL BARB = 1 M/SFULL BARB = 1 M/S• FLAG = 5 M/SFLAG = 5 M/S
• CONCLUSIONCONCLUSION
FORCINGSFORCINGS• EPISODES OCCUR ON GIVEN DAYS EPISODES OCCUR ON GIVEN DAYS
– NOT B/CNOT B/C TOPO, EMISSIONS, OR SFC MESO- TOPO, EMISSIONS, OR SFC MESO-FORCING (EXCEPT FOR FOG) CHANGESFORCING (EXCEPT FOR FOG) CHANGES
– BUT B/CBUT B/C UPPER LEVEL SYNOPTICS CHANGE, UPPER LEVEL SYNOPTICS CHANGE, WHICH ALTERS MESO-FORCINGS (TOPO, WHICH ALTERS MESO-FORCINGS (TOPO, LAND/SEA, URBAN) VIA T AND LAND/SEA, URBAN) VIA T AND THUSTHUS V V
• MUST THUS EVAL ALL ABOVE FACTORS:MUST THUS EVAL ALL ABOVE FACTORS:
SYN, TOPO (grid spacing), MESO T & VSYN, TOPO (grid spacing), MESO T & V
700 hPa NWS PREVIEW:700 hPa NWS PREVIEW:1200 UTC OR 0500 PDT1200 UTC OR 0500 PDT
Movement of inland H causes episodes Movement of inland H causes episodes
• Pre-episode: over Nevada Pre-episode: over Nevada
• Episode days: moves SW to over SJVEpisode days: moves SW to over SJV
and intensifiesand intensifies
• Post-episode: dissipatesPost-episode: dissipates
Before ozone episodes: offshore G. C. High; synoptic High in Nevada; Before ozone episodes: offshore G. C. High; synoptic High in Nevada; boundary-Low between Highs; SSW-flow over SFBAboundary-Low between Highs; SSW-flow over SFBA
SAC ozone day: SJV Syn H at max intensity; SW flow over SFBASAC ozone day: SJV Syn H at max intensity; SW flow over SFBA
Surface NWS PREVIEW: Surface NWS PREVIEW: 1200 UTC or 0500 PDT1200 UTC or 0500 PDT
• Warm-core upper-H projects down to Warm-core upper-H projects down to a sfc inverted thermal-L a sfc inverted thermal-L – Pre-episode: over Nevada Pre-episode: over Nevada – Episode days: moves over SJV and Episode days: moves over SJV and
intensifiesintensifies– Post-episode: weakensPost-episode: weakens
B/F ozone episodes: warm core “inverted thermal L” from Sea of Cortez to B/F ozone episodes: warm core “inverted thermal L” from Sea of Cortez to S-Nevada; 2S-Nevada; 2ndnd open-L into northern CA; NW-flow over SFBA and S-flow over open-L into northern CA; NW-flow over SFBA and S-flow over
SAC SAC
LIV episode day: trough moves NW, forms closed low, with N-S axis thru LIV episode day: trough moves NW, forms closed low, with N-S axis thru central CA; SE-flow over Sac central CA; SE-flow over Sac
MM5 configurationMM5 configuration• Version 3.6.0Version 3.6.0• Three domains Three domains
– 36, 12, 4 km36, 12, 4 km– 55 x 55, 91 x 91, 190 x 190 grid points 55 x 55, 91 x 91, 190 x 190 grid points
• 32 sigma levels 32 sigma levels – up to 100 mbup to 100 mb– first full sigma level at 19 m first full sigma level at 19 m
• GDAS IC and BCGDAS IC and BC• Analysis nudging only for V and T forAnalysis nudging only for V and T for
– 36 km domain36 km domain– above PBLabove PBL
• No obs nudgingNo obs nudging• Five layer soil model, Gayno-Seaman PBLFive layer soil model, Gayno-Seaman PBL• Start: 1200 UTC on 28 July and went for 7.5 daysStart: 1200 UTC on 28 July and went for 7.5 days• LBNL LINUX single processor: 15 daysLBNL LINUX single processor: 15 days
MM5 Domain-1: 700 hPa WINDS PREVIEW
• NWS charts NWS charts – give only approx p-center locationsgive only approx p-center locations– cannot give flow details in SFBA, cannot give flow details in SFBA,
Carquinez Straits, & SJVCarquinez Straits, & SJV
• Thus need MM5 to showThus need MM5 to show– Pre-episode H: E of SFBA over NEVPre-episode H: E of SFBA over NEV– Episode days: bulge from H extends Episode days: bulge from H extends
westward over SFBAwestward over SFBA– Post-episode H: back-E of SFBA over AZ Post-episode H: back-E of SFBA over AZ
HL
H
(B/F episodes) MM5 correct: offshore GC H; Syn H in SE Nev; boundary-L;(B/F episodes) MM5 correct: offshore GC H; Syn H in SE Nev; boundary-L; but S-flow over SFBA vs. SW NWSbut S-flow over SFBA vs. SW NWS
H
H
L
SAC episode day: Syn H to Utah with max (now NE-SW) “bulge” (vs. NWS-H SAC episode day: Syn H to Utah with max (now NE-SW) “bulge” (vs. NWS-H over SJV) over SJV) L now S in Cal (vs. NWS: E over CA/Az border); correct SW flow over SFBA to L now S in Cal (vs. NWS: E over CA/Az border); correct SW flow over SFBA to SacSac
MM5 Domain-1: SFC WINDS PREVIEW (12 UTC OR 05 PDT)
• Movement to N of thermal L from S-Movement to N of thermal L from S-
CA sequentially cause episodesCA sequentially cause episodes– Convergence into LIVConvergence into LIV– Increased flow to Sac from SFBAIncreased flow to Sac from SFBA– Increased flow into SJV from SFBAIncreased flow into SJV from SFBA– Moves offshoreMoves offshore
• Flow details: in Domain-3Flow details: in Domain-3
L
L
B/F episodes: warm-core thermal-L to S-Nevada & 2B/F episodes: warm-core thermal-L to S-Nevada & 2ndnd CA-L to N (both CA-L to N (both correct); correct); NW-flow over coast & SFBA (correct) and con-flow over SAC (vs NWS S-NW-flow over coast & SFBA (correct) and con-flow over SAC (vs NWS S-flow)flow)
L
SAC episode: S-Low moved N & N-Low moved bit S (NWS showed SAC episode: S-Low moved N & N-Low moved bit S (NWS showed only closed-L gone); now more W-flow to Saconly closed-L gone); now more W-flow to Sac
L
MM5 SFC-TEMP STATSMM5 SFC-TEMP STATS
• DAY AND NIGHT SPATIAL-PATTERNS DAY AND NIGHT SPATIAL-PATTERNS ARE REASONABLE (NOT SHOWN)ARE REASONABLE (NOT SHOWN)
• STATS SHOW SOME BIAS (SHOWN), STATS SHOW SOME BIAS (SHOWN), WHICH CAN BE ELIMINATED BYWHICH CAN BE ELIMINATED BY– SELECTING TRUSTWORTHY SITESSELECTING TRUSTWORTHY SITES– ADJUSTING DEEP SOIL TEMP AND SOIL ADJUSTING DEEP SOIL TEMP AND SOIL
MOISTURE CONTENTMOISTURE CONTENT
DOMAIN-3: 700 hPa PREVIEW (2100 UTC or 0200 PDT)
• Offshore-H formation & Fresno eddy Offshore-H formation & Fresno eddy movement cause episodesmovement cause episodes
• Initial flow from S does not produce SFBA to Initial flow from S does not produce SFBA to Sac transportSac transport
• Syn-H formation directs SFBA flow to Sac & Syn-H formation directs SFBA flow to Sac & con-current Fresno eddy blocks SFBA flow con-current Fresno eddy blocks SFBA flow into SJVinto SJV
• When eddy moves to NWhen eddy moves to N– SFBA flow into Sac is blockedSFBA flow into Sac is blocked– SFBA flow into SJV is allowed SFBA flow into SJV is allowed
Pre-episode: uniform S-flowPre-episode: uniform S-flow
HL
SAC episode: H moved to W at coast (vs bulge from CV to coast in D-1); Fresno eddy N of D-1 SAC episode: H moved to W at coast (vs bulge from CV to coast in D-1); Fresno eddy N of D-1 position (blocks flow into SJV from SFBA; W flow over SFBA (vs. NWS S-flow) directly to SACposition (blocks flow into SJV from SFBA; W flow over SFBA (vs. NWS S-flow) directly to SAC
L
H
SJV episode: Fresno eddy moved N & H moves inland (both better defined than in D-1); SJV episode: Fresno eddy moved N & H moves inland (both better defined than in D-1); flow around eddy blocks SFBA flow to SAC, but forces it S into SJVflow around eddy blocks SFBA flow to SAC, but forces it S into SJV
DOMAIN-3: SUMMARY OF SFC TRANSPORT TO LIVERMORE (KEY
HOURS)
• Daytime confluence of 3-flows E of Daytime confluence of 3-flows E of LIV (on Mt peak) causes episodeLIV (on Mt peak) causes episode– Flow from N from Carquinez StraitsFlow from N from Carquinez Straits– Flow from W thru GGGFlow from W thru GGG– Upslope from E-side of hills E of LIVUpslope from E-side of hills E of LIV
• For episode needFor episode need– Strong confluenceStrong confluence– Low speedsLow speeds
Sfc winds obs at 0700 PST(1500 UTC) on 31 July, (LIV episode morning)
Note con flow into LIV
Sfc-wind Obs at 1400 PST (2200 UTC) on 31 July (LIV episode afternoon)
Note flow from N into LIV and out to E
Pre-episode afternoon (1400 PDT): W flow thru GGG & weak con into E-LivPre-episode afternoon (1400 PDT): W flow thru GGG & weak con into E-Liv
Episode afternoon (1400 PDT): W flow thru GGG & strong con into E-LivEpisode afternoon (1400 PDT): W flow thru GGG & strong con into E-Liv
DOMAIN 3: SFC TRANSPORT TO SAC SUMMARY
• TRANSPORT FROM SFBA BLOCKED BY TRANSPORT FROM SFBA BLOCKED BY OPPOSING FLOW ON DAYS BEFORE OPPOSING FLOW ON DAYS BEFORE AND AFTER SAC EPISODEAND AFTER SAC EPISODE
• TRANSPORT FROM SFBA NOT TRANSPORT FROM SFBA NOT BLOCKED ON DAY OF SAC EPISODEBLOCKED ON DAY OF SAC EPISODE
LIV-episode late-afternoon (1800 PDT): flow to SAC from SFBA blockedLIV-episode late-afternoon (1800 PDT): flow to SAC from SFBA blocked
SAC-episode late-afternoon (1800 PDT): flow to SAC from SFBA not blockedSAC-episode late-afternoon (1800 PDT): flow to SAC from SFBA not blocked
DOMAIN 3: SFC TRANSPORT TO SJV SUMMARY
• TRANSPORT FROM SFBA TO SJV TRANSPORT FROM SFBA TO SJV MUST NOT BE BLOCKED BY MUST NOT BE BLOCKED BY OPPOSING FLOWSOPPOSING FLOWS
• FLOW INTO SJV MUST FLOW INTO SJV MUST – NOT BE TOO FAST NOT BE TOO FAST – SHOW CONFLUENCESHOW CONFLUENCE
SAC EPISODE NIGHT: TRANSPORT TO SJV FROM SFBA IS BLOCKEDSAC EPISODE NIGHT: TRANSPORT TO SJV FROM SFBA IS BLOCKED
SJV EPISODE NIGHT: TRANSPORT TO SJV FROM SFBA & CON WINDSSJV EPISODE NIGHT: TRANSPORT TO SJV FROM SFBA & CON WINDS
CONCLUSIONCONCLUSION• SMALL CHANGES IN SMALL CHANGES IN 700 MB-H AND SFC-L700 MB-H AND SFC-L
POSITIONS CAUSED SEQUENTIAL DAILY POSITIONS CAUSED SEQUENTIAL DAILY OZONE MAX IN LIV, SAC, AND SJV OZONE MAX IN LIV, SAC, AND SJV
• NWS CHARTS COULD NOT DISCERN NWS CHARTS COULD NOT DISCERN DETAILS OF CHANGES, BUT MM5 COULDDETAILS OF CHANGES, BUT MM5 COULD
• MM5 MM5 – MATCHED NWS PATTERNS MATCHED NWS PATTERNS AND AND MESO-OBS MESO-OBS
REASONABLY WELL REASONABLY WELL – PROVIDED ADDITIONAL DETAILSPROVIDED ADDITIONAL DETAILS
• ADDITIONAL SIMULATIONS SHOULD ADDITIONAL SIMULATIONS SHOULD CORRECT REMAINING DIFFERENCESCORRECT REMAINING DIFFERENCES