资源描述
Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,1,Designations for the 2006 PM,2.5,Standards:Evaluating the Nine Factors in Setting Nonattainment Area Boundaries,1Designations for the 2006 PM2,2,The 9 Designation Factors,To Help Determine,Nearby Area of Influence for 24-hr NAAQS,Violations,Emissions,Air,Quality,Meteorology,Topography,Political,and Other,Boundaries,Current,Emission,Controls,Growth,Traffic&,Commuting,Population,and,Urbanization,Non,Attainment,Boundaries,Air Quality is one of the most Important Designation Factors,2 The 9 Designation Factors T,3,Topics to be Covered,Conceptual model for high PM days,Seasons when exceedances occur,Composition of the high days,Analytical tools,SLICE technique-for evaluating urban contributions to high days,Residence time analysis for assessing nearby contributing source regions using back trajectories and emissions data,Gradient analysis for identifying days with potential high source-oriented impacts,3Topics to be CoveredConceptua,4,Conceptual Model for High PM2.5 Days,How to define high PM2.5 days?,What is the typical“daily increment”for high PM days in relation to the annual average?,What is the urban contribution above regional levels?,4Conceptual Model for High PM2,5,Conceptual Model for High PM2.5 Days,What high PM2.5 days to consider?,“High PM2.5 Days”Associated with the 98,th,percentile,Not just one day per year,Select all candidate days,e.g.top 5%or days 30-35ug/m3,Summarize by season to distinguish varying conditions,5Conceptual Model for High PM2,6,40ug/m3,16,24,PM2.5,High Day,Value,Seasonal,Average,+,Typical,Daily,Increment,Example,Typical Daily Increment-Example,The annual average PM2.5(urban background)is the stuff that is there on a day-to-day basis.,Comes from nearby and more distant areas,Can be estimated by seasonal average PM2.5 concentration of non-high days,Includes contributions from,all,nearby surrounding counties,Can be estimated using the traditional urban increment approach,The daily increment(on top of annual average urban background)also has regional and local contributions.,-Key issue:what counties and sources from the urban area contribute to the typical daily increment?,Conceptual Model for High PM2.5 Days,High Daily PM2.5 has Urban and Regional Components,640ug/m31624PM2.5 Seasonal+Typ,7,Conceptual Model for High PM2.5 Days,An approach to partition,typical,levels into urban and regional components,Urban Increment Analyses as used in 2004/2005 PM,2.5,Designations,Urban sources in the Eastern US contribute at least 4-6 ug/m3 to annual average PM,2.5,Probably even larger urban contribution in western US cities,Carbon is significant component of average PM2.5 mass,but metro area emissions typically are much less than SO,2,and NOx,Weighted emissions score developed to give additional weight to,nearby,direct carbon emissions as they contribute to the urban background,7Conceptual Model for High PM2,8,urban increment,PM g/m,natural background,Urban areas,14-20 ug/m3,Countryside,10-12 ug/m3,10,15,20,30,25,35,40,Conceptual Diagram,-Annual Average PM2.5,Air Quality-Annual Average PM,2.5,regional contribution,Western US urban areas may have smaller regional contribution,8urban incrementPM g/mnatu,9,urban increment,PM g/m,natural background,10,15,20,30,25,35,40,Conceptual Diagram,-High Daily PM2.5 Concentrations,Air Quality -High Daily PM2.5 Concentrations,regional contribution,Urban areas,30-40 ug/m3,Countryside,18-30 ug/m3,Larger “urban island”on peak days,Focus of new analyses:understanding what,emissions contribute to urban increment,Western US urban areas may have smaller regional contribution,9urban incrementPM g/mnatu,10,Conceptual Model for High PM2.5 Days,Source region considerations,Role of Regional vs Urban vs Micro-scale Influences,On high days particularly in the east,regional emissions often provide a“base”amount of pollution,Urban-wide and nearby emissions,also,contribute significantly to high days:“urban island”effect,In some cases,there may be a micro-scale effect from a single source or small group of sources,Does not help define NA boundaries,unless it is the only contributing source,(Note:“urban”can mean large metropolitan area or smaller city),Air,Quality,10Conceptual Model for High PM,11,Conceptual Model for High PM2.5 Days,Seasons when exceedances occur,Time of Year for Exceedances-varies by Geographic Region,SE,:,Mostly summer,Industrial Midwest(IMW),Mid-Atlantic,So.CA,:,Winter and summer,NW,UT,NM,Middle CA,:,Mostly or exclusively Winter,11Conceptual Model for High PM,12,%,50,25,0,NW,UT,IMW,Mid CA,S.CA,S
展开阅读全文