regional modeling joseph cassmassi south coast air quality management district usa
TRANSCRIPT
Regional Modeling Applications
• Determine a “carrying capacity” for a region
• Provides a view of current, past and future air quality
• Planning tool to develop a long term control strategy
Expectations vs. Limitations
• Performance of regional models is as good as the worst component
• In data rich environments modeling errors range between 15-50%
• Requires a significant investment -- data
-- man hours-- computation
resources
Modeling Overview
• Goal or purpose
• Conceptual model
• Model selection
• Define modeling domain
• Emissions inventory
• Air quality and meteorological data
• Define an episode for model application
Conceptual Model
• Understanding of the overall picture-- extent of data availability-- confidence in the data-- processes that are contributing to
the observed air quality• Meteorological and air quality description of the
episode• Understanding of why the episode stands apart
from normal or average conditions
Model Selection
• Air quality-- platform (dedicated or family)
-- chemistry module-- dispersion
• Meteorological-- objective analysis
-- diagnostic analysis-- prognostic models
Modeling Domain
• Regional approach-- focus on Delhi?-- up and down wind areas
(from the conceptual model)• Meteorological modeling domain may be
greater than the air quality domain• Grid scales may be different• Need accurate terrain file
General Data Requirements
• Data required is domain dependent-- size
-- complexity of terrain-- pollutant
sensitive• Levels of model applications
-- limited surface and upper air -- moderately dense surface and multiple upper air
-- intensive field study
Ente l
Lo C añas
Esc. Ingeniería
Los T ilos
Lo P in to
San C ristóba l
La P la tina
C uesta C hada
C odigua
M aría P in to
Paine
La C am pana
La D orm ida
Lo P rado
M allarauco
P irque
C uesta Barriga
Q uilap ilún
E l M anzano
La R eina
E l Paico
Polpaico
-71.50 -71.25 -71.00 -70.75 -70.50 -70.25-34.00
-33.75
-33.50
-33.25
-33.00
Entel
Lo C añas
Esc. Ingeniería
Los T ilos
Lo P into
San C ristóbal
La P la tina
C uesta C hada
C odigua
M aría P in to
Paine
La C am pana
La D orm ida
Lo P rado
M allarauco
P irque
C uesta Barriga
Q uilap ilún
E l M anzano
La R eina
E l Pa ico
Polpaico
0
100
200
300
400
500
600
700
800
1000
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1500
2000
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3500
4000
4500
C EN TR O N A C IO N AL D EL M E D IO AM B IEN TE
RED D E ESTACIO NES M ETEO RO LO G ICAS O PERADAS PO R CENM A(ubicadas en la Región M etropolitana)
Air Quality Data Requirements
• Surface-- routine air quality
monitoring -- chemical speciation ` -- define boundaries/initialization
• Upper air-- boundaries/initialization
-- transport
Meteorological Data Requirements
• Surface -- winds, temperature,
humidity -- insolation and cloud cover
• Upper Air-- winds, temperature, moisture
-- lapse rates and stability -- mixing heights
Southern California Monitoring
• Air Quality Monitoring -- 75+ ambient monitoring sites -- 10+ sites speciated data -- upper air characterization - as needed
• Meteorology -- 125+ monitoring or reporting sites -- 5 sounding/aircraft sites -- 10 radar profilers/sounders
Delhi Monitoring
• ~ 6-10 air monitoring sites --fixed & mobile vans --representative of high traffic areas --limited speciation
• Surface meteorological at air monitoring locations
• Twice daily soundings: Delhi, Gwalior, Jodhpur
Emissions
• Gridded emissions inventory -- point-- mobile-- area
• Day specific
• Allocation factor/surrogates
• Temporal profile
• Weekdays vs. weekends
Applications: Episode Selection
• Data Availability-- meteorology-- air quality-- boundary conditions
• Episode severity
• Representative of problem
• Field study data available
Delhi Profile
• Reasonably flat terrain
• Upper air --limited upper air meteorology maycharacterize domain
• Surface meteorology --river valleys will channel winds --urban heat island --Great Indian Desert --need additional monitoring
Delhi Profile (continued)
• Ambient air quality monitoring --may not characterize regional issue --need to characterize background
profile-- identify locations of maximum
pollution impact