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 Interpretation and conclusions are not provided for results that have not been peer reviewed by USGS.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 and published reports.