Role of Transport on Aerosol Concentration at Crater Lake, Oregon USA
This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3~1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss SO42-, nss S, NO3-, K and C showed the double peak pattern, high in April~May and August~September and showed the lowest concentration in Winter. The other constituents concentration except for Cl-, Na, Mg was high in local trajectory than marine trajectory. A ratio nss SO42- to SO42- was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss SO42- and nss S decreased but the the springtime concentration increased.