Study Data

Overview of Great Smoky Mountains National Park data for May - July:

The preliminary ozone data has been reviewed to see the difference in concentrations due to sampling height, the ozone gradient in different parts of the park, and the distribution of values from nearby sites.

The figure below compares the frequency distribution for samplers at two heights at the Clingmans Dome location. Dome3 is sampler at 60 ft on the tower near the inlet for the O3 analyzer - the observed passive data is close to the analyzer data. The sampler at 7 ft above the ground has lower ozoneconcentrations (Dome4). This is a forested site without a significant clearing. Prior studies had showed that forested areas had the highest ozone at the canopy and decreased towards the surface.

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

The Upper Thomas Ridge trail provides an opportunity to look at sites with an elevation gradient. The frequency distribution is fairly similar except for an outlier at site 2 (GRSM53). Looking at the 12 ppb sample carefully; if the data is plotted by elevation of the sites, a gradient in ozone is obtained with ozone increasing at higher elevation. The south side data gives the plot below.

The Bryson city site at 2000 ft acts as a pivot point that can change the observed slope of the line. The slope has remained about the same even though more data is now included in the mean concentrations for each location.

Look Rock is on the parkway that runs along the Chilhowee mountain ridge on the northwest side of the park. There is an ozone concentration difference between the ozone analyzer intake at 30 ft on the tower and the 7ft passive sampler pole at this site (Look2 vs Look3).

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 and mountain peaks to be under-represented.

The plot of ozone vs. elevation for the north side of the park shows a gradient with a slightly lower slope. The sites are not up a single ridge or drainage; thus, other spatial variation can complicate the north side analysis. Weekly ozone concentrations are a factor of 2 different between low and high elevation.

Compare these results to the 3-week study spatial distribution map for 1994.