1. Tribal Representativeness Analysis: Phase II
Dave DuBois & Mark Green
Desert Research Institute

2. ZoR Phase 2 Methodology
Updated previous work with 2000 to 2004 IMPROVE data
Re-ran correlation analysis, computing inter-site correlations for all regions that have at least one IMPROVE or IMPROVE protocol site
For those regions with less than 3 we choose nearby sites to make up a total of 4 sites to compute correlation
Posted results on COHA website

3. ZoR Summary cont’d
Overall, 84 tribes are not represented by an IMPROVE or IMPROVE protocol site from this task
Those not represented are further away from the nearest IMPROVE site than the representative distance

4. ZoR Results for Mexican Highlands Region

5. Effects of removing Walker River
Including the WARI1 site, the representative distance in the Great Basin region was 98 km
After removing the WARI1 site, the representative distance increased to 180 km
An increase in the region representative distance implies that the WARI1 site may not correlate with the other sites in one or more fine particle species

6. Contributions to extinction in 2004
Walker River
Notice high NO3, (red)
Death Valley
Great Basin National Park
Zion Canyon

7. Effects of removing SPOK
The Spokane tribal site, SPOK1, was discontinued in June 2005 after collecting over three full calendar years of data
Columbia Plateau Region

8. Spokane analysis
Including the SPOK1 site, the representative distance in the Columbia Plateau region was 106 km
After removing the SPOK1 site, the representative distance decreased slightly to 102 km
A small change of 4 km indicates that the SPOK1 site correlates well with the other sites

9. Task 2: Considering Terrain
Purpose: To investigate the effects of terrain on the representativeness assessment
Approached the problem using the HYSPLIT trajectory model
Incorporates terrain in the model
Successfully used this method in the past
Generated trajectories from each IMPROVE site and calculated the number of trajectories passing through an area over each tribe
Computed the ratio of the number passing over tribe compared to all trajectories

10. Example for one day of trajectories
Only showing forward trajectories from Death Valley NP
July 2, 2005
Example

11. Task 2 Summary
Using a strict criteria that the ratio must be at least 1 at one IMPROVE site in order for a tribe to representative
Another choice is to use a ratio of 0.5 (half must go over the tribal area)
49 tribes are not represented by an IMPROVE site considering effects of terrain using ratio = 1

12. Task 2 Summary

13. Task 3: Considering Emission Sources
Developed a method to compare how polluted each airmass pathway is from a tribe to each IMPROVE site
Incorporated the 2002 National Emission Inventory in the data processing for NOx and SO2
Used the 24-hr backward and forward HYSPLIT trajectory database used in previous task

14. Methodology
For each trajectory from an IMPROVE site, calculate the number of times that the trajectory goes over an emission point on route to the tribe
Do this many times: generate a forward and backward trajectory 8 times per day, everyday over one year
Sum up the emissions for each trajectory cluster
Do it for both NOx and SO2 sources
Move to the next IMPROVE site and do the same calculation

15. Ranking Sites
We define sites with lower metric scores a better choice for being representative than those with higher scores
The sum of emissions over all trajectories was weighted by the distance, R, in kilometers from the tribe to the IMPROVE site
The weighting of R2 provides a way to weight the closer sites more than the distant sites

16. Product for Each Tribe
Compare the sum of emissions associated with trajectories from each IMPROVE site
Rank the distance from tribe to IMPROVE and emissions from smallest to largest
The representative site was the closest IMPROVE site that has trajectories that passed over the least emissions