Skip common site navigation and headers
United States Environmental Protection Agency
Exposure Research
Begin Hierarchical Links EPA Home > Research & Development > Exposure Research > Publications/Presentations > End Hierarchical Links

 

Cloud Chemistry in the Eastern United States, as Sampled from Three High-Elevation Sites Along the Appalachian Mountains

spacer
spacer
Abstract:Atmospheric deposition of acidic cloud water is thought to be one of the causes for the recent forest decline in industrialized areas of the world. The present paper presents results from the Mountain Acid Deposition Program (MADPro), a part of EPA's Clean Air Status and Trends Network, (CASTNet). We used automated cloud water collectors at three selected mountain sites (Whiteface Mt., NY; Whitetop Mt., VA; and Clingman's Dome,TN) to take hourly samples from non-precipitating clouds during temperature (non-freezing) seasons of each year from 1994 to 1997. Samples were promptly analyzed for pH, conductivity, and concentration of dissolved ions. Cloud liquid water content (LWC) and meteorological parameters were measured at each site. Mean cloud frequencies and LWC of clouds were higher at Whiteface Mt., NY, than in the Southern Appalachians. The four most prevalent ions found in cloud water samples were usually, in order of decreasing concentration: sulfate (SO42-) hydrogen (H+), ammonium (NH4+), and nitrate (NO3~). Within cloud events the concentration of these major ions tended to co-vary. Typically there was an inverse relationship between LWC of the cloud and ionic concentration of the cloud water. During the sampling season, the highest ionic concentrations were seen during mid-summer. Ionic concentration of samples from the southern sites were significantly higher than samples from Whiteface Mt., but further analysis indicates that this is a least partially due to the north-south difference in the LWC of clouds. MADPro results are shown to be comparable with previous studies of cloud chemistry in North America.
spacer
Citation:Anderson, J. B., R. E. Baumgardner, J. Bowser, and V. A. Mohnen. Cloud Chemistry in the Eastern United States, as Sampled from Three High-Elevation Sites Along the Appalachian Mountains. ATMOSPHERIC ENVIRONMENT 33:5105-5114, (1999).
spacer
spacer
Contact: Chris Siebert - (702) 798-2234 or siebert.christopher@epa.gov
spacer
Division: Environmental Sciences Division
spacer
Branch: Landscape Characterization Branch (RTP)
spacer
Product Type: Journal
spacer
Published: 09/10/1999
spacer
Related Entries:
spacer
Bullet Item Atmospheric Ecosystem Stressor Pattern and Trend Analysis
spacer Relationship Reason:   A Project of the Product
spacer
spacer
spacer

 

ORD Home | Search EPA | Search NERL | Search EIMS | Contacts | Help

 
Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us

Last Updated on Monday, October 22, 2007
URL: http://cfpub.epa.gov