AoH Conference Call October 8, 2004 Air Resource Specialists, Inc.

Review of IMPROVE Aerosol Data Visibility parameters and equations IMPROVE monitoring Regional Haze Rule data guidelines Review of 2002 IMPROVE data (selected sites) Next steps

Definitions of Visibility Visual Qualities - The color, texture, and clarity of a scene Visual Range (km) - The greatest distance at which a large black object on the horizon can be seen Extinction/Scattering/Absorption (Mm -1 ) - The fraction of light lost per unit length along a sight path Deciview (dv) - An index which is linear with human perception of visibility

Visibility Equations Extinction is the sum of particle scattering, natural atmospheric scattering, and absorption: b ext = b sp + b Rayleigh + b abs Extinction can be converted into Visual Range or Deciview: Visual Range (km) = 3912 / b ext Deciview (dv) = 10 x ln (b ext / 10)

b ext (Mm -1 ) =3 * f(RH) * [Ammonium SULFATE] +3 * f(RH) * [Ammonium NITRATE] +4 * (1.4) * [ORGANIC CARBON] +10 * [ELEMENTAL CARBON] +1 * [SOIL] +0.6 * [COARSE MASS] +Rayleigh scattering (typically use 10 Mm -1 ) Where: f(RH) is the relative humidity enhancement factor Elemental carbon is the only species which absorbs light IMPROVE Extinction Equation

IMPROVE Aerosol Sampler Systems Sulfur>>Sulfate Soil PM2.5>> Coarse Mass Nitrate Sulfate (backup) Organic Carbon Elem. Carbon PM10>> Coarse Mass

Regional Haze Rule Data Guidelines Calculate extinction based on IMPROVE equation, using 6 species and monthly f(RH) Allowed to fill in missing species data with quarterly median values if strict conditions are met Data completeness: –50% for all quarters –75% for the year –No more than 10 consecutive samples missing in a year –Minumum of 3 complete years needed to represent 5 year average Convert extinction to deciview Calculate annual 20% best and worst deciview averages

WRAP Class I Areas

IMPROVE Monitoring Sites

IMPROVE Total Aerosol Extinction Worst 20% for 2002 VIEWS web site:

IMPROVE Ammonium Sulfate Extinction Worst 20% for 2002 VIEWS web site:

IMPROVE Ammonium Nitrate Extinction Worst 20% for 2002 VIEWS web site:

IMPROVE Organic Mass Extinction Worst 20% for 2002 VIEWS web site:

2002 Data from Selected Sites Timeline species extinction plots for 6 sites across WRAP: –Spokane Indian Reservation, WA –Medicine Lake, MT (adjacent to Fort Peck) –Rocky Mountain NP, CO –Grand Canyon NP, AZ –Yosemite NP, CA –Crater Lake, OR

Mm -1 >>

Module A filter clogged – removed data from 2002 data set

Avg. extinction: 24.8 Mm -1 Avg. extinction: 48.9 Mm -1 Crater Lake Recon. Aerosol Extinction Comparison

Avg. extinction: 23.9 Mm -1 Avg. extinction: 24.8 Mm -1

Grand Canyon Recon. Aerosol Extinction Comparison Avg. extinction: 21.8 Mm -1 Avg. extinction: 23.4 Mm -1

Next Steps Conference call week of October 18 Working with RMC to transfer emission and TSSA data files to ARS Begin adding draft documents to the AoH web site (introductory materials first) Prepare samples of CIA reports on AoH web site (currently based on available data) Review agenda for November meeting