The Effect of ENSO and PDO on Three Airborne Pollutants in Phoenix, Arizona

Abstract

ABSTRACT Previous research has suggested that the El Nino-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) teleconnections have a large impact on precipitation across the Desert Southwest. El Nino years, particularly those that occur in concert with the warm phase of the PDO, have been associated with increased precipitation while La Nina years have had the opposite effect. There has been very little research examining the impact of teleconnections on pollution in the Southwest. Here, we examine the impact of both ENSO and PDO on winter pollution levels in Phoenix. By first examining the impact of precipitation events on pollution, and then by determining the impact of ENSO and PDO on the number of precipitation events, we can estimate the role of these two teleconnections on winter pollution in Phoenix. We find that ENSO and PDO have a large impact on pollution, with some pollutants increasing over 10% during La Nina compared to years experiencing El Nino.