Project Outline: Technical Support to EPA and RPOs Estimation of Natural Visibility Conditions over the US Project Period: June May 2008 Reports: 2005, 2008

The Haze Rules require States to establish and update Baseline, Natural and Current Visibility Conditions Baseline conditions represent visibility at the time the regional haze program is established Natural conditions represent the visibility conditions that would be experienced in the absence of human-caused impairment. Current condition is the most recent multiyear average, to be revised for each SIP revision. It includes showing progress from the last revision and from the baseline period. All three visibility parameters are to be derived from multiyear averaging of the best and worst 20% days

EPA Haze Rule on Natural Conditions Reaching the natural visibility conditions is the goal of the EPA visibility program. Estimating the natural and current conditions establishes how ‘‘close’’ a Class I area is to the goal, i.e. the magnitude of the human-induced ‘exceedance’ over the natural. The default annual natural visibility is 11-2 deciview for the East, 8 dv for the West. The regional natural visibility is to be derived from sulfate, nitrate, organic carbon, elemental carbon, and crustal material estimates using IMPROVE methodology. EPA along with States, tribes, and FLMs to develop and refine the technical guidance on estimating natural conditions (e.g. natural fire and dust) - hence this project?? States, in turn, will work with the FLMs, tribes and EPA in estimating their natural conditions using these guidelines at each Class I area in the time frame (2003–2005??)

Project Goal and Objective The goal of the project is to provide technical support to EPA & RPOs on: Estimation of Natural Visibility Conditions over the US Tasks and Approach: 1.Conceptual Evaluation of Natural PM and Visibility Conditions Establish Virtual Workgroup with representatives from EPA, RPOs, scientific community 2.Quantitative Estimation of Recent Regional Natural Contribution Statistics Conduct Data Analysis for estimating natural contributions (1995+, surf. and satellite obs) 3.Real-Time Estimation of Natural Aerosols and Visibility Implement a Web-based Tool for routine real-time estimation of natural aerosols/visibility

Task 1: Conceptual Evaluation of Natural PM and Visibility Conditions Establishing the main natural source types, e.g. –Windblown dust (local and distant) –Biomass smoke (forest, grass and other uncontrolled fires, local and distant) –Biogenic emissions (trees, marshes, oceans) –Sea salt Physico-chemical properties of natural aerosols –Size distribution –Chemical composition –Optical properties Evaluate suitable metrics for statistically describing natural conditions –Relevant aerosol components (e.g. SO4, NO3, OC, EC, Dust) –Spatial scales and resolution of natural events/conditions –Temporal scales and resolution of natural events/conditions

Task 2: Quantitative Estimation of Regional Natural Contributions Approach: Study each natural aerosol type in detail (dust, smoke, biogenic, sea salt) Use ALL available aerosol observations (surface and satellite) and model results Establish source strength/variability and spatio-temporal pattern at relevant scales (e.g.natural aerosol statistics) Example Natural Aerosol Analyses: Fine Dust In July, in the Southeast, Sahara dust contributes 4-8  g.m 3, about 2-4 times the local fine dust. July SeaWiFS satellite image of Sahara dust approaching the continent (July 24,1998). For more detail see: Local and Global Dust Over N. AmericaLocal and Global Dust Over N. America

Example Natural Aerosol Analyses: Biomass Smoke Satellite data show numerous small fires in the Southeast but the nature of fires is not known. Prescribed burning? Wild fires? PM2.5 conc., smoke pattern and SeaWiFS image of plumes originating from Kentucky, Nov 15, 1999.SeaWiFS For more detail see: Carbonaceous Aerosol and Smoke over the Eastern USCarbonaceous Aerosol and Smoke over the Eastern US Nov 15, 1999 Oct 5, 1998 Smoke Plumes Regional Smoke?

Task 3. Real-Time Estimation of Natural Aerosols and Visibility Real-time Aerosol Watch System (RAW) Real-Time Virtual PM Monitoring Dashboard. A web-page for one-stop access to views of current PM/Visibility monitoring data (aerosol, weather) and model output for nowcasting and forecasting. Virtual Workgroup Website. An interactive website which facilitates the active participation of diverse members in the interpretation, discussion, summary and assessment of the aerosol events. Air Quality Managers Console. Delivers a packaged PM data and summary reports prepared by the Virtual workgroups. Helps PM managers make decisions during major aerosol events. Rationale The dominant natural aerosol sources are from windblown dust and biomass smoke. Dust and smoke events can be monitored real-time by numerous surface and satellite sensors. Both are ‘episodic’, i.e. short-term extreme concentrations that require AQ management actions. The development and implementation of RAW is already being supported at CAPITA by grants from NSF, NOAA, EPA/EMAP, NASA(pending). Incremental funding from this project would support estimating ‘Natural PM/Visibility Contributions’ during such events.

Right. SeaWiFS satellite and METAR surface haze shown near-real time in the Voyager distributed data browser Below. SeaWiFS, METAR and TOMS Absorbing Aerosol Index superimposed Satellite data are fetched from NASA GSFC; surface data from NWS/CAPITA servers Illustration of RAW: Quebec Smoke, July 6, 2002

Schedule: Phase I: 2003 – Conceptual evaluation of natural conditions Analyze natural events Regional natural aerosol statistics 2005 – Interim report Phase II: 2005 – Re-evaluation of natural condition definitions Analyze natural events including model results Revised regional natural aerosol statistics 2008 – Final report