1. Ambient Monitoring Data Summary: Dust WRAP Workshop on Fire, Carbon, and Dust May 24, 2006 Joe Adlhoch - Air Resource Specialists, Inc.

2. Outline Baseline (2000 – 2004) IMPROVE aerosol extinction budgets for the 20% worst and best visibility days Spatial and temporal variations of soil and coarse mass Long-term trends in soil and coarse mass

3. IMPROVE Monitoring Locations

4. Baseline Extinction: 20% Worst Days

5. Spatial and Temporal Patterns in Dust Data shown for 2002 and 2004 20% worst visibility days  2002 and 2004 show similar patterns for fine soil and coarse mass extinction Quarterly summaries, all days included  Seasonal differences exist  Different years show similar seasonal patterns (not shown) Sycamore Canyon, AZ, appears to be the WRAP’s fine soil hot spot, but this is largely due to a flow problem which led to a cut point higher than 2.5 microns Note scaling differences on maps!

6. Soil Extinction for 20% Worst Visibility Days, 2002 and 2004

7. Coarse Mass Extinction for 20% Worst Visibility Days, 2002 and 2004

8. Quarterly Soil Extinction (Mm -1 ), 2002 Numerous hot spots, though contribution to extinction is low Sycamore Canyon fine soil was artificially high due to sampler flow problems 2.4 4.2 3.6 2.5

9. Quarterly Coarse Mass Extinction, 2002 6 12 15 Numerous hot spots, seasonal variations

10. Quarterly Soil Extinction Fraction, 2002 15 16 22 16 Quarterly soil extinction fractions ~0 – 15% (not including Sycamore Canyon)

11. Quarterly Coarse Mass Extinction Fraction, 2002 42 34 39 27 Quarterly coarse mass extinction fractions ~0 – 40%

12. Historical Trends in 20% Worst Days: Total, Soil and Coarse Mass Extinction 16 year trends (1989 – 2004) required 12 complete years of data 8 year trends (1997 – 2004) required 6 complete years of data Theil slopes (Mm -1 /yr) calculated for all sites with sufficient data P-values of 0.2 required to identify trend as significant Changes in monitoring or analytical protocol over the years may affect trends

13. Trend Observations Some correlation between total extinction and soil/coarse mass extinction trends, particularly in the four corners states Many sites show small increasing trends for soil and coarse mass, again, particularly in the four corners states

14. 16-yr Soil or Coarse Mass Extinction Trends 8-yr Soil or Coarse Mass Extinction Trends Layout of Trend Maps 16-yr Total Extinction Trends 8-yr Total Extinction Trends