The Mountain Acid Deposition Program: Comparison of Sulfate and Nitrate Trends in Cloud Water versus Precipitation

Selma S. Isil*, Christopher M. Rogers, Thomas F. Lavery and Holton K. Howell
MACTEC Engineering & Consulting, Inc.
404 SW 140th Terrace
Newberry, FL 32669

The Clean Air Status and Trends Network (CASTNET) was established by the Environmental Protection Agency (EPA) in 1991 to provide an effective monitoring and assessment network for determining the status and trends in air quality and pollutant deposition, as well as relationships among emissions, air quality, deposition, and ecological effects. The Mountain Acid Deposition Program (MADPro) was initiated in 1993 as part of the research necessary to support CASTNET#039;s objectives. MACTEC Engineering and Consulting, Inc. (MACTEC) operates both CASTNET and MADPro on behalf of EPA and other agencies.

MADPro's two main objectives are to develop cloud water measurement systems to be used in a network-monitoring environment and to update the cloud water concentration and deposition data collected in the Appalachian Mountains during the National Acid Precipitation Assessment Program (NAPAP) in the 1980s. MADPro measurements were conducted from 1994 through 1999 during the warm season (May through October) at three mountaintop sampling stations. These sampling stations were located at Whiteface Mountain, NY; Clingmans Dome, TN; and Whitetop Mountain, VA. A mobile manual sampling station also was operated at two locations in the Catskill Mountains in New York during 1995, 1997, and 1998. Measurements during the 2000 and 2001 sampling seasons were collected from two sites: Whiteface Mountain, NY and Clingmans Dome, TN. Since 2001, the EPA, National Park Service (NPS) and the Tennessee Valley Authority (TVA) have exclusively operated only the Clingmans Dome, TN site while the State of New York has been operating the Whiteface Mountain, NY site.

This poster summarizes and compares sulfate and nitrate mean seasonal concentrations and deposition estimates from the MADPro Clingmans Dome site (CLD303) and the National Acid Deposition Program (NADP) Elkmont, TN site (TN11) from 2000 through 2009. There have been significant changes in the last few years in air quality in the Smoky Mountains in part because of emissions reductions enacted by TVA. This comparison assesses the seasonal patterns and recent changes in air quality by examining both the cloud and wet components of total deposition. Both concentrations in cloud water and precipitation and deposition estimates are analyzed to determine correlations between the data sets.

*Corresponding Author: Phone: 352-333-6607, Email: