An Overview of the Measurements of the Canadian Air and Precipitation Monitoring Network with a Focus on the Measurements of Nitrogen species
J.M. O'Brien*, R. Vet, D. MacTavish and M. Shaw Environment Canada 4905 Dufferin Street Toronto, ON, M3H 5T4
The Canadian Air and Precipitation Monitoring Network (CAPMoN) was established in 1988 to determine temporal trends and spatial distribution for wet deposition and provide estimates of dry deposition at regional representative sites in Canada. The network currently monitors precipitation, aerosols and trace gases, ozone, PM2.5 mass and PM2.5 speciation, mercury in precipitation, total gaseous mercury and several nitrogen species. An overview of the network measurements, intercomparisons, and future monitoring initiatives will be discussed. A more detailed description of the CAPMoN nitrogen species measurements will be portayed. The continuous measurement of gas phase nitrogen species at selected CAPMoN sites began in 2002 in part to estimate their contributions to the total nitrogen dry deposition flux at selected CAPMoN sites. Current measurements include NO, NO2, NOy, peroxyacetic nitric anhydride (PAN), and ammonia with detection limits of each species of approx. 100 ppt or better. These continuous measurements are complemented by daily integrated filter pack measurements of HNO3 and particle nitrate. A description of the nitrogen measurement system, measurement challenges, and preliminary findings will be presented.