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Ozone Distribution Study

In Great Smoky Mountains National Park

This was a special study using ozone passive samplers at about 60 locations to determine the distribution of ozone pollution within the park. Volunteers did the bulk of the sampling during the summer. The product includes GIS map layers pin-pointing areas within the park where vegetation is most at risk from ozone exposure.

Study dates: May - Sept. with the core sampling from June 19 to August 28, 2000



Plot of Ozone Concentrations at GRSM 2000
The plot above shows weekly ozone concentrations for the summer at four continuous monitoring sites. The passive ozone samplers are tracking these variations. In the year 2000 there have been fewer high episode ozone days than in 1998-1999. Weekly detailed ozone results from the study.

Volunteers deploy a pass sampler.
Volunteers deploying one of the weekly passive ozone samplers


Location of continuous ozone monitoring stations.
Great Smoky Mountains map with ozone monitoring sites marked. The shading on this map is proportional to elevation from green to brown. Compare to the maps below of ozone concentrations.
sampling photograph


Results of the interpolation mapping

From the processed data, detailed maps were created for seasonal ozone concentrations. Note how the model from the normal number of stations available has less detail in the park and predicts slightly higher ozone surrounding the park boundaries. There is an elevation gradient in ozone in that mountain tops see a larger average ozone concentration than low elevations.

1-km resolution model with 60+ stations
1-km resolution model with 60+ stations
1-km resolution regional model from normal stations
1-km resolution regional model from normal stations
30-m resolution model from 60+ stations
30-m resolution model from 60+ stations


Sample map predicting ozone distribution in Great Smoky Mountains. This map used 18 monitoring sites over a three week period in 1994 and a very course elevation grid. Lack of data outside the park causes an under-prediction of ozone in TN. The coarse elevation grid causes some ridges anSpatial distribution map of O3 in Great Smoky Mountainsd mountain peaks to be under-represented.


Program contact information

This was a joint project by Great Smoky Mountains National Park and NPS Air Resources Division with the help of park staff and many volunteers.

  • Jim Renfro, Monitoring Specialist at Great Smoky Mountains NP (865) 436-1708
  • John Ray, Atmospheric Chemist, NPS Air Resources Division, (303) 969-2820
updated on 04/18/2006  I   http://www.nature.nps.gov/air/Studies/psO3/O3study.cfm   I  Email: Webmaster