EULERIAN MODEL EVALUATION FIELD-STUDY (EMEFS) - A SUMMARY OF SURFACE NETWORK MEASUREMENTS AND DATA QUALITY

From June 1988 to May 1990, a Joint Canada-United States measurement p rogram known as EMEFS made daily air and precipitation measurements ac ross eastern North America. Surface data were collected by five partic ipating networks at approximately 130 sites for use in assessing regio nal air pollutant and deposition model performance. This paper describ es the measurement program and focuses on its associated quality assur ance program. The concentration measurements were found to have overal l uncertainties of +/-2.3% for SO42- and NO3- for precipitation and, f or the air concentrations, +/-6.4% for SO2, +/-5.4% for SO42-, and +/- 10.3% for NO3-. These uncertainty levels generally satisfied the progr am data quality objectives for use in model evaluation studies and rep resent the quality of contemporary air precipitation chemistry network s.