Precipitation Chemistry Quality Assurance Project (PCQA)

Special Studies

Special Studies data, analysis, and interpretation are preliminary and subject to revision. Interpretation and conclusions are not provided for results that have not been peer reviewed by USGS. Descriptions of these studies are provided herein to help NADP data users understand various characteristics and limitations of NADP data. Until these studies can be reviewed and published, data users are encouraged to contact the USGS External Quality Assurance Program for the NADP operated by the BQS PCQA project (see Contacts). Results for these studies have been presented in NADP business meetings and technical symposia, and presentations for these studies are documented in NADP meeting minutes.

For citation purposes, the following in-text reference is suggested:
Greg Wetherbee, U.S. Geological Survey, written communication, date, URL.

• AeroChem / N-CON Collector Comparison



• Arvada, Colorado-Urban Site Instrument Photographs



• Belfort / OTT Rain Gage Comparison for Snow Measurement



• Isopleth Maps Generated Using PRISM Precipitation Estimates



• Sample Evaporation Study



• Does Weather Affect Measurement Error?



• Historical / Discontinued QA Programs



• NTN 2006 Blind Audit of CAL Detection Limits



• Urbanization of NADP/NTN Sites