Open-File Report 2011–1170
AbstractSelected aspects of National Atmospheric Deposition Program / National Trends Network (NADP/NTN) protocols are evaluated in four studies. Meteorological conditions have minor impacts on the error in NADP/NTN sampling. Efficiency of frozen precipitation sample collection is lower than for liquid precipitation samples. Variability of NTN measurements is higher for relatively low-intensity deposition of frozen precipitation than for higher-intensity deposition of liquid precipitation. Urbanization of the landscape surrounding NADP/NTN sites is not affecting trends in wet-deposition chemistry data to a measureable degree. Five NADP siting criteria intended to preserve wet-deposition sample integrity have varying degrees of effectiveness. NADP siting criteria for objects within the 90° cones and trees within the 120° cones projected from the collector bucket to sky are important for protecting sample integrity. Tall vegetation, fences, and other objects located within 5 meters of the collectors are related to the frequency of visible sample contamination, indicating the importance of these factors in NADP siting criteria. |
First posted September 19, 2011 For additional information contact: This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge. |
Wetherbee, G.A., Latysh, N.E., Lehmann, C.M.B., and Rhodes, M.F., 2011, Four studies on effects of environmental factors on the quality of National Atmospheric Deposition Program measurements: U.S. Geological Survey Open-File Report 2011–1170, 36 p.
Abstract
Introduction
Meteorological Effects on Measurement Error
Precipitation Intensity Effects on NTN Samples
Site Urbanization Effects on NTN Trends
Relations of Site Characteristics to Sample Integrity
Summary
References Cited