COMPARABILITY OF WET-ONLY PRECIPITATION CHEMISTRY MEASUREMENTS FROM THE UNITED-STATES NATIONAL ATMOSPHERIC DEPOSITION PROGRAM (NADP) TO THOSE OF THE CANADIAN NETWORK FOR SAMPLING ACID PRECIPITATION (CANSAP)

A 3-year, six-site, direct comparison between NADP and CANSAP deposition monitoring programs reveals a positive bias in reported CANSAP values over those reported by NADP. The bias is significant at most locations for most measured analytes. Reasons given for the bias include an inadequate seal on the mechanical lid of the CANSAP collector. Poor siting of the sampling equipment is further shown to exacerbate the problem.