SJV PM10 SIP Modeling & Data Analysis December 5, 2002 Policy Committee Meeting

Presentation Overview n Nature of PM Exceedances n Modeling Approach n Attainment Demonstration Methodology

Nature of Exceedances n When, where, and how frequently do exceedances occur? n What is the composition of these exceedances? n What meteorological conditions are associated with exceedances?

Air Quality Factors n Magnitude n Spatial extent n PM2.5 fraction n Duration of episode n Chemical composition

Meteorological Factors n Temperature n Atmospheric stability n Wind speeds n Period since last rainfall n Humidity/fog

Fall Versus Winter PM10 Exceedances Fall Winter - Low/moderate PM2.5- High PM2.5 - Higher geological- High nitrates/carbon - Light winds- Light winds - Stagnation- Stagnation - Moderate temps- Cold temps - High humidity/fog

PM10 Episodes for SIP 1999 Through 2001 “Fall-Type” Episodes –October 21, 1999 (3 exceedances) –November 9, 2001 (1 exceedance) “Winter-Type” Episodes –January 12, 1999 (1 exceedance) –November 14, 1999 (1 exceedance) –December 17, 1999 (1 exceedance) –January 1, 4, 7, 2001 (12 exceedances)

Example Fall Episode October 21, 1999 PM10 Exceedances at:  Corcoran (174 ug/m3)  Fresno Drummond (162 ug/m3)  Turlock (157 ug/m3)

Fall Episode Spatial Extent October 21, 1999

Fall Episode Duration 10/15/ /27/99 at Corcoran

Fall Episode Chemical Composition October 21, 1999

Fall Episode Chemical Composition Corcoran

Fall Episode Meteorology n Cool temperatures at the surface, warm air aloft n Limited atmospheric mixing for long periods n Light to moderate winds n Cool mornings, with warmer afternoons

Example Winter Episode January 1-7, 2001 PM10 Exceedances at:  Bakersfield-Golden (205 & 174 ug/m3)  Fresno-First (193 ug/m3)  Bakersfield-California (190, 186 &159 ug/m3 )  Fresno Drummond (186 ug/m3)  Hanford (185 ug/m3)  Oildale (158 ug/m3)  Corcoran (165 ug/m3)  Modesto (158 ug/m3)  Clovis (155 ug/m3)

Winter Episode Duration 12/26/01 - 1/10/01 at Bakersfield Golden

Winter Episode Spatial Extent January 1, 2001

Winter Episode Spatial Extent January 7, 2001

Winter Episode PM2.5 Duration 12/23/00 - 1/10/01 at Bakersfield-California

Winter Episode Chemical Composition January 4, 2001

Winter Episode Chemical Composition Bakersfield California

Winter Episode Meteorology n Cool temperatures at the surface, warm air aloft n Limited atmospheric mixing for long periods n Light winds n Cool temperatures n Higher humidity

Modeling Approaches n Receptor model –Determines contributions of primary PM sources n Photochemical model –Evaluates relationships between PM precursors and PM n Attainment demonstration –Combines modeling approaches to evaluate effects of control measures

Receptor Modeling Approach n Model all PM10 exceedances in n Use updated source profiles from CRPAQS

Primary Source Categories n Geological - Agricultural operations - Unpaved roads - Paved roads - Construction n Burning - Residential wood burning - Agricultural & prescribed burning n Direct Mobile - Off-road mobile - On-road mobile

Secondary Source Categories n NOx - Off-road mobile - On-road mobile - Industrial processes - Fuel combustion - Petroleum production n Ammonia - Livestock operations - Fertilizers - Waste treatment facilities - Soils - Mobile sources

Photochemical Modeling Approach n 1995 Integrated Monitoring Study domain n January 4-6, 1996 episode

Attainment Demonstration Process n Receptor Modeling for Each Exceedance n Linear Rollback for Primary Source Categories n Grid-Based Model for Secondary Source Categories

Example Rollback Process

Remaining Tasks n Select final source profiles for receptor modeling n Run receptor model for each exceedance to identify contributing sources n Complete grid-based modeling for IMS95 to evaluate secondary formation n Prepare attainment demonstration for each exceedance