CORRECTABLE CORRECTABLE BC-ERRORS BC-ERRORS WITHIN MESO-MET MODELS WITHIN MESO-MET MODELS R. Bornstein R. Bornstein San Jose State University San Jose State University San Jose, CA San Jose, CA [email protected]Presented at Presented at 86th AMS Annual Meeting, Atlanta, GA 86th AMS Annual Meeting, Atlanta, GA 30 January 2006 30 January 2006
CORRECTABLE BC-ERRORS WITHIN MESO-MET MODELS. R. Bornstein San Jose State University San Jose, CA [email protected] Presented at 86th AMS Annual Meeting, Atlanta, GA 30 January 2006. Acknowledgements. H. Taha, Altostratus & SJSU D. Hitchock & P. Smith, State of Texas - PowerPoint PPT Presentation
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CORRECTABLE CORRECTABLE BC-ERRORS BC-ERRORS WITHIN MESO-MET MODELSWITHIN MESO-MET MODELS
R. BornsteinR. Bornstein
San Jose State UniversitySan Jose State University
AcknowledgementsAcknowledgements H. Taha, Altostratus & SJSUH. Taha, Altostratus & SJSU D. Hitchock & P. Smith, D. Hitchock & P. Smith, State of TexasState of Texas D. Byun, D. Byun, U. of HoustonU. of Houston J. Ching & S. Dupont, US EPAJ. Ching & S. Dupont, US EPA S. Stetson, SWS Inc.S. Stetson, SWS Inc. S. Burian, U. of UtahS. Burian, U. of Utah D. Nowak, USFSD. Nowak, USFS Funded by:Funded by: NSF, USAID, DHS, LBL, LMMS, NSF, USAID, DHS, LBL, LMMS,
NASANASA MY M.S.MY M.S. (ex)(ex) STUDENTS:STUDENTS: J. Cheng, C. Lozej, J. Cheng, C. Lozej,
F. Freedman, T. Ghidey, K. Craig,F. Freedman, T. Ghidey, K. Craig, S. S. Kasakseh, R. Balmori Kasakseh, R. Balmori
OUTLINEOUTLINE
INTRODUCTIONINTRODUCTION SYNOPTIC FORCINGSYNOPTIC FORCING POORLY (AT BEST) KNOWN POORLY (AT BEST) KNOWN INPUT DATAINPUT DATA
DEEP SOIL TEMP IC/C DEEP SOIL TEMP IC/C SOIL MOISTURE ICSOIL MOISTURE IC SST IC/BCSST IC/BC
Theme of Talk:Theme of Talk:MESO-MET ATM-MODELS MUST CAPTURE MESO-MET ATM-MODELS MUST CAPTURE B.C. FORCINGS IN B.C. FORCINGS IN CORRECT ORDERCORRECT ORDER (1 of (1 of
2)2)e.g., AN Oe.g., AN O33 EPISODES OCCURS ON A GIVEN DAY: EPISODES OCCURS ON A GIVEN DAY: NOT NOT FROM CHANGING: TOPOGRAPHY & EMISSIONSFROM CHANGING: TOPOGRAPHY & EMISSIONS
BUTBUT DUE TO CHANGING (UPPER-LEVEL &/OR SFC)DUE TO CHANGING (UPPER-LEVEL &/OR SFC)
GC/SYNOPTIC PRESSURE-GC/SYNOPTIC PRESSURE-PATTERNS, PATTERNS, WHICH WHICH ENTER OUR MESO-SOLUTIONSENTER OUR MESO-SOLUTIONS FROM EITHER FROM EITHER
CORRECT OR IMPRECISE CORRECT OR IMPRECISE LARGER-SCALE MODEL-LARGER-SCALE MODEL-VALUES & WHICH VALUES & WHICH
THUS ALLOWTHUS ALLOW SCF MESO THERMAL-FORCINGS SCF MESO THERMAL-FORCINGS (i.e., (i.e., UP/DOWN SLOPE, LAND/SEA, URBAN, CLOUDS/FOG) UP/DOWN SLOPE, LAND/SEA, URBAN, CLOUDS/FOG) TO DEVELOP TO DEVELOP CORRECTLY OR INCORRECTLYCORRECTLY OR INCORRECTLY
CORRECT ORDER CORRECT ORDER (2 of 2)(2 of 2)
MUST THUS MUST THUS CORRECTLY CORRECTLY REPRODUCE:REPRODUCE: UPPER-LEVEL Syn/GC FORCING UPPER-LEVEL Syn/GC FORCING FIRST FIRST
pressurepressure (the GC/Syn driver), which (the GC/Syn driver), which produces Syn/GC windsproduces Syn/GC winds
Methodology:Methodology: Check large-scale forcingCheck large-scale forcing before before simulations:simulations:
NWS charts vs. large-scale model input-fieldsNWS charts vs. large-scale model input-fields If correct If correct use use analysis-nudginganalysis-nudging FDDA FDDA
correct correct synoptic-trendssynoptic-trends Case studies:Case studies:
SFBA Winter SFBA Winter synoptic-storm synoptic-storm (Lozej 1996)(Lozej 1996) Atlanta Atlanta urban-thunderstormurban-thunderstorm (Craig 2000) (Craig 2000) OzoneOzone-episodes -episodes
LA (Boucouvala et al. 2003) LA (Boucouvala et al. 2003) SFBA (Ghidey 2005)SFBA (Ghidey 2005)
Obs stormObs storm went over SFBA went over SFBA Wrong input large-scale IC/BCWrong input large-scale IC/BC caused storm caused storm
toto move too zonally and thus too fastmove too zonally and thus too fast pass (and precipitate) too far northpass (and precipitate) too far north
Note: Note: IC/BC more important for IC/BC more important for synopticsynoptic storms than for storms than for mesomeso-systems (they are -systems (they are driven by surface-conditions)driven by surface-conditions)
Obs and MM5:Obs and MM5: next next 3 3 slidesslides
GOES IR & SFC NWS 12 March, 12 UTC:Storm over SFBA
SFBA
SFBA
NCEP(2.50)/MM5 (27 km) (solid blue) & ETA (dash pink) 500 mb heights (dam) at 12 UTC Left: slight IC/BC errors in NCEP
ETA: digs deeper vsNCEP/MM5: more zonal
Right: storm goes too far N of SFBA & moves too quickly
11 March
12 March
L
L
MM5 (upper) 3 hr precip maxis thus N of observed precip (lower) max (at 50-km S of SFBA)
SFBA
Atlanta Summer Thunderstorm Atlanta Summer Thunderstorm (Craig)(Craig)
Obs: Obs: weak-cold front N of Atlantaweak-cold front N of Atlanta Large-scale IC/BC:Large-scale IC/BC: front S of city front S of city MM5 UHI-induced thunderstorm:MM5 UHI-induced thunderstorm: 5-km 5-km
deep, wdeep, wmaxmax 6-m/s, 8-cm precip 6-m/s, 8-cm precip Should be:Should be: 9-km, 12-m/s, 14-cm 9-km, 12-m/s, 14-cm Source of problem:Source of problem:
MM5-storm formed in MM5-storm formed in stable-flow stable-flow from N & not in from N & not in unstable-flowunstable-flow from Sfrom S
Data & MM5 results:Data & MM5 results: next slide next slide
ATLANTA UHI-INITIATED STORM: OBS SAT & PRECIP (UPPER) & MM5 W & PRECIP (LOWER)
LA Summer OLA Summer O33-episode -episode (Boucouvula)(Boucouvula) Obs of large scale IC/BC:Obs of large scale IC/BC:
Shift of Shift of meso-700 hPa highmeso-700 hPa high
good good analysis-nudginganalysis-nudging good sfc-wind good sfc-wind
H
H
L
SAC episode day:SAC episode day: D-1 700 hPa Syn H moved to Utah with coastal “bulge” & L D-1 700 hPa Syn H moved to Utah with coastal “bulge” & L in S-Calin S-Calcorrect SW correct SW flow from SFBA to Sacflow from SFBA to Sac
L
H
SJV episode day:SJV episode day: D-3 700 hPa Fresno eddy moved N & H moves D-3 700 hPa Fresno eddy moved N & H moves inlandinland 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
Controls min-TControls min-T Values unknown & MM5-estimation is Values unknown & MM5-estimation is flawedflawed
Soil-moisture: ICSoil-moisture: IC Controls max-TControls max-T Values unknown & MM5-table values Values unknown & MM5-table values too specifictoo specific
SST: IC/BCSST: IC/BC Horiz coastal T-Horiz coastal T-gradgrad controls sea-breeze flow controls sea-breeze flow We usually focus only on We usually focus only on land-sfcland-sfc temptemp IC/BC SST values from IC/BC SST values from large-scale modellarge-scale model
too too coarse & not f(t) coarse & not f(t)
Summary for MM5:Summary for MM5: deep soil deep soil temptemp
Calculated as Calculated as average large-scale model average large-scale model inputinput surface-Tsurface-T during simulation-period during simulation-period
This assumes a This assumes a zero time-lagzero time-lag b/t sfc and b/t sfc and lower-level (about 1 m) soil-tempslower-level (about 1 m) soil-temps
But obs show But obs show 2-3 month time-lag b/t these 2 temps2-3 month time-lag b/t these 2 temps Larger-lag in low-conductivity dry-soilsLarger-lag in low-conductivity dry-soils
Thus MM5 min-temps will always be too-Thus MM5 min-temps will always be too-high in high in summersummer and too-low in and too-low in winterwinter
We need to We need to develop techdevelop tech (beyond current (beyond current trial and error) to account for lag: trial and error) to account for lag: next 2 next 2 slidesslides
Mid-east Obs vs. MM5: 2 m tempMid-east Obs vs. MM5: 2 m temp (Kasakech ’06 (Kasakech ’06 AMS)AMS)
July 29 August 1 August 2
July 31 Aug 1 Aug2
Standard-MM5 summer night-time min-T,
But lower input deep-soil temp better 2-m T results better winds better O3
obs
Run 1
MM5:Run 4
Obs
Run 4:ReducedSeep-soil T
First 2 days show GC/Syn trend not in MM5, as MM5-runs had no analysis nudging
SCOS96SCOS96 LA Temps (Boucouvual et LA Temps (Boucouvual et al.)al.)
RUN 1: hasNo GC warming trendWrong max and min T
3-Aug 4-Aug 5-Aug 6-Aug
RUN 5: corrected, as it used> Analysis nudging > Reduced deep-soil T
problemsproblems WaterWater z z0 = 0.01 cm = 0.01 cm
Only IC Only IC updatedupdated internally by eq = f(MM5 u internally by eq = f(MM5 u*)) But Eq only valid for But Eq only valid for open-seaopen-sea smooth-swell conditions smooth-swell conditions Observed values for rough-sea Observed values for rough-sea coastal-areascoastal-areas ~ 1 cm ~ 1 cm
MM5 coastal-winds are MM5 coastal-winds are over-estimatedover-estimated
UrbanUrban z z0 = 80 cm = 80 cm too low for tall cities: obs up to too low for tall cities: obs up to 3-4 m3-4 m Urban-winds: Urban-winds: too fasttoo fast Must Must adjustadjust input value or input GIS/RS f(x,y) input value or input GIS/RS f(x,y)
From From veg-veg-canopycanopy model (Yamada 1982) model (Yamada 1982) Veg-param Veg-param replacedreplaced with GIS/RS with GIS/RS
urban-param/data urban-param/data Brown and Williams (1998)Brown and Williams (1998) Masson (2000)Masson (2000) Martilli et al. (2001) in Martilli et al. (2001) in TVM/URBMETTVM/URBMET Dupont, Ching,Dupont, Ching, et al. (2003) in et al. (2003) in EPA/MM5EPA/MM5 Taha et al. (2005), Balmori et al. (2006b) in Taha et al. (2005), Balmori et al. (2006b) in
uMM5uMM5 Detailed input urban-parameters as f(x,y) Next: 2 slides
max urban effect
Urbanized meso-met model TKE (z)
__________________________________
hc =building top
1 km 1 km uMM5 uMM5 Houston UHI: 8 PM, 21 Houston UHI: 8 PM, 21 AugAug
Summary of how to obtainSummary of how to obtain good meso-met model resultsgood meso-met model results
1st capture trends in large-scale forcing via 1st capture trends in large-scale forcing via validated large-scale model input validated large-scale model input analysis nudginganalysis nudging
Then simulate correct meso sfc-T via correct Then simulate correct meso sfc-T via correct IC/BC deep soil-T (for min-T) IC/BC deep soil-T (for min-T) IC soil-moisture (for max-T)IC soil-moisture (for max-T)
Get good Get good SSTs SSTs (from obs or ocean-models) (from obs or ocean-models) for good sea-breeze flowsfor good sea-breeze flows
Use good Use good urbanizations urbanizations (scheme & inputs) (scheme & inputs) for good for good temps, turbulence, & windstemps, turbulence, & winds
Overall LessonsOverall Lessons
Models can’t be assumed to be Models can’t be assumed to be perfectperfect black boxesblack boxes
If obs not available, it is OK to make If obs not available, it is OK to make reasonable educated reasonable educated estimates, e.g., forestimates, e.g., for Deep-soil tempDeep-soil temp Soil moisture Soil moisture
Need Need datadata for comparisons with simulated for comparisons with simulated fieldsfields
Need good Need good urbanization,urbanization, e.g., e.g., uMM5uMM5 Need to develop better PBLNeed to develop better PBL