Title: MM5%20SIMMULATIONS%20OF%20SFBA%20TO%20SAC/SJV%20TRANSPORT%20DURING%2030%20JULY-%202%20AUG%202000%20CCOS%20OZONE%20EPISODE
1 MM5 SIMMULATIONS OF SFBA TO SAC/SJV TRANSPORT
DURING 30 JULY- 2 AUG 2000 CCOS OZONE
EPISODE by Tesfamichael B. Ghidey LBNL,
SJSU, DRI
2OUTLINE
- SYNOPTIC SUMMARY
- 700 MB
- SFC
- MM5 CONFIGURATION
- WINDS MESO CONVENTION
- FULL BARB 1 M/S
- FLAG 5 M/S
- RESULTS
- DOMAIN 1 SYNOPTIC WINDS
- DOMAIN 3 MEOS WINDS
- LIV, SAC, SJV SEQUENTIAL OZONE EPISODE DAYS
- CONCLUSION
3NWS 700 hPa PREVIEW1200 UTC ( 0500 PDT)
- Movement of inland-H causes episodes
- Pre-episode over Nevada
- Episode days
- moves SW to SJV
- intensifies
- Post-episode dissipates
4Before ozone episodes offshore G. C. High
synoptic High in Nevada boundary-Low between
Highs SSW-flow over SFBA
H
H
5SAC ozone day SJV-H at max intensity SW flow
over SFBA
H
H
6NWS Surface PREVIEW 1200 UTC or 0500 PDT
-
- Warm-core upper-H projects down to a
- Sfc inverted thermal-L
- Pre-episode over Nevada
- Episode days moves over SJV intensifies
- Post-episode weakens
7B/F ozone episodes warm core inverted thermal
L from Sea of Cortez to S-Nevada secondary
open-L into northern CA NW-flow over SFBA
S-flow over SAC
L
L
8LIV episode day trough moves NW, forms closed
low, with N-S axis thru central CA SE-flow over
Sac
L
9MM5 configuration
- Version 3.6.0
- Three domains
- 36, 12, 4 km
- 55 x 55, 91 x 91, 190 x 190 grid points
- 32 sigma levels
- up to 100 mb
- first full sigma level at 19 m
- GDAS IC and BC
- Analysis nudging only for V and T for
- 36 km domain
- above PBL
- No obs nudging
- Five layer soil model, Gayno-Seaman PBL
- Start 1200 UTC on 28 July and went for 7.5 days
- LBNL LINUX single processor 15 days
10D01
D03
D02
11(No Transcript)
12(No Transcript)
13Validation of 10-m dd
14MM5 Domain-1 700 hPa WINDS PREVIEW
- NWS charts
- gave only approx p-center locations
- cannot give flow details in SFBA, Carquinez
Straits, SJV - Thus need MM5 to show
- Pre-episode H E of SFBA over NEV
- Episode days bulge from H extends westward over
SFBA - Post-episode H back to E of SFBA over AZ
15 (B/F episodes) MM5 correct offshore H H in SE
Nev boundary-L but S-flow over SFBA vs. NWS SW
L
H
H
16SAC episode day Syn H to Utah with (now NE-SW)
bulge (vs. NWS-H over SJV) L now S in Cal (vs.
NWS E over CA/AZ border) correct SW flow over
SFBA to Sac
H
H
L
17MM5 Domain-1 SFC WINDS PREVIEW AT 12 UTC ( 05
PDT)
- Movement to N of thermal L from S-CA sequentially
cause episodes - Convergence into LIV
- Increased flow to Sac from SFBA
- Increased flow into SJV from SFBA
- Moves offshore
- Domain-3 Flow details
18B/F episodes warm-core thermal-L to S-Nevada
2nd CA-L to N (both correct) NW-flow over coast
SFBA (correct) and con-flow over SAC (vs NWS
S-flow)
L
L
19SAC episode S-Low moved N N-Low moved bit S
(NWS showed only closed-L as gone) now more
W-flow to Sac
L
L
20DOMAIN-3 700 hPa PREVIEW (2100 UTC or 0400 PDT)
- Offshore-H formation Fresno-eddy movement cause
episodes - Initial flow from S does not produce SFBA to Sac
transport - Syn-H formation directs SFBA flow to Sac
con-current Fresno-eddy blocks SFBA flow into SJV - When eddy moves to N
- SFBA flow into Sac is blocked
- SFBA flow into SJV is allowed
21Pre-episode uniform S-flow
22SAC 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 SAC
H
L
23SJV 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 SJV
L
H
24DOMAIN-3 SUMMARY OF SFC TRANSPORT TO LIVERMORE
(KEY HOURS)
- Daytime confluence of 3-flows E of LIV (on Mt
peak) causes episode - Flow from N from Carquinez Straits
- Flow from W thru GGG
- Upslope flow on E-side of hills E of LIV
- For episode need
- Strong confluence
- Low speeds
- Obs first and then MM5
25Sfc winds-obs at 0700 PST (1500 UTC) on 31 July
(LIV episode morning) Note con flow into LIV
26- Sfc wind-obs at 1400 PST
- (2100 UTC) on 31 July
- (LIV episode afternoon)
- Note flow from N into LIV and
- out to E
27Pre-episode afternoon (1400 PDT) W flow thru GGG
weak con E of Liv
28Episode afternoon (1400 PDT) W flow thru GGG
strong con E of Liv
29DOMAIN 3 SFC TRANSPORT TO SAC SUMMARY
- TRANSPORT FROM SFBA BLOCKED BY OPPOSING FLOW ON
DAYS BEFORE AND AFTER SAC EPISODE - TRANSPORT FROM SFBA NOT BLOCKED ON DAY OF SAC
EPISODE
30LIV-episode late-afternoon (1800 PDT) flow to
SAC from SFBA blocked
31SAC-episode late-afternoon (1800 PDT) flow to
SAC from SFBA not blocked
32DOMAIN 3 SFC TRANSPORT TO SJV SUMMARY
- TRANSPORT FROM SFBA TO SJV MUST NOT BE BLOCKED BY
OPPOSING FLOWS - FLOW INTO SJV MUST
- NOT BE TOO FAST
- SHOW CONFLUENCE
33SAC EPISODE NIGHT TRANSPORT TO SJV FROM SFBA IS
BLOCKED
34SJV EPISODE NIGHT TRANSPORT TO SJV FROM SFBA
CON WINDS
35CONCLUSION
- SMALL CHANGES IN 700 hPa-H SFC-L POSITIONS
CAUSED SEQUENTIAL DAILY OZONE MAX IN LIV, SAC,
SJV - NWS CHARTS COULD NOT DISCERN DETAILS OF CHANGES,
BUT MM5 COULD - MM5
- MATCHED NWS PATTERNS MESO-OBS REASONABLY WELL
- PROVIDED ADDITIONAL DETAILS