Causes of Haze Assessment Brief Overview and Status
Causes of Haze Assessment Brief Overview and Status Report WRAP Attribution of Haze Workgroup July 22, 2004 Denver
COHA Approach Determine causes of haze at WRAP and CENRAP Class I areas, WRAP Tribal Class I areas and selected CENRAP IMPROVE protocol sites (includes some tribal areas) 5
Project history and schedule overview Multi-year contract Ø Major effort began May 2003 – expect to complete assessment June 2006 Ø Phased approach – preliminary conceptual models by end of 2004Ø Do additional analyses to refine conceptual models until end of study Ø Have added assessments for tribal areas Ø Added In-depth assessment of dust impacts Ø
Use weight of evidence approach to form conclusions regarding the causes of the haze Complete set of descriptive analyses, maps, other graphics for aerosol composition, spatial, temporal variation, emissions, land use, topographic effects, transport patterns, local wind patterns etc Ø Do episode analyses to determine likely causes of haze for various commonly and uncommonly occurring conditions- episode typing- define episode types and frequency of occurrence at each site Ø Do regression analysis of trajectory endpoints and aerosol data for attribution estimates- later PMF? Ø Using above resources form conceptual models of causes of haze Ø
Completed products Website developed Ø Emissions, land use, topography maps by site Ø “Hazagon” animation maps for 1997 -2002 Ø Aerosol analysis- 1997 -2002 or POR completed for all sites with one or more years of data Ø Meteorological description completed for nearly all sites Ø Backtrajectory analysis- 2000 to 2002 - all backtrajectories calculated Ø Trajectory maps completed for about ½ of sitesall sites by end of August Ø
Future Work Evaluation of EDAS wind field used for backtrajectory analysis – when adequate, when misleading- possible use of MM 5 or diagnostic wind fields for trajectory analysis for some sites - end of 2004 Ø Mesoscale meteorological analysis – trajectory analysis? Needed for sites in complex/coastal setting affected by mesoscale source areas 2005 Ø Triangulation of backtrajectories for worst case days to better identify source areas - 2005 Ø Regression analysis of backtrajectories, aerosol data for quantitative attribution to regions- Trajectory Mass Balance Regressionlate 2004 -early 2005 Ø
Future Work (cont. ) Inclusion of nephelometer and transmissometer data analysis where available – 2005 Ø Additional episiode analysis, typing and frequency of occurrence by site-2005 Ø Additional receptor modeling e. g. PMF 2005 early 2006 (group similar sites? ) Ø Refinement of conceptual models – ongoing as additional significant analysis is completed and until mid-2006 Ø
Approach for Tribal Causes of Haze Assessment Full COHA analysis for 5 Tribal Class I areas. For large number of remaining tribal lands, form groups based upon geographic proximity and similarity for meteorology, emissions, etc. Ø Use spatial correlation as a function of distance, etc. to determine spatial scales of aerosol components Ø Use existing IMPROVE sites/ representative Class I areas to infer regional causes of haze for groups of tribal lands as possible Ø Recommend additional monitoring locations as needed unrepresented tribal lands Ø Completion in 2005 Ø Ø
Assessment of the Major Causes of Dust. Resultant Haze in the WRAP Ø Focus on periods when dust was the principal contributor to haze during worst days Ø Aim to assign individual worst dust days at an IMPROVE site within WRAP to one of a set of source classes Ø Much effort to focus on methodology development Ø Use methodology to categorize worst dust days in the WRAP domain over the period 2001 – 2002
Preliminary dust source types Transcontinental Events Ø Regional Windblown Events Ø Local Windblown Dust Ø Wildfire-Related Events Ø Other Events- e. g. road dust, construction, mining, agriculture, sea-spray Ø Unknown Ø Analysis to be completed by early 2005
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