Assessment of ozone variations and meteorological influences at a rural site in Northern Xinjiang.

Ozone concentrations and meteorological data were continuously monitored online from June to December 2013 at the Akedala regional atmosphere station in an arid region of Central Asia. We present daily, monthly, and seasonal variations of ozone concentrations in the atmosphere and elucidate possible emission sources. The ozone concentrations of this region varied from 14.7 to 58.6 ppb. A remarkable seasonal variation of ozone in aerosols was observed with highest level in summer, followed by autumn and winter. The daily peak value of ozone was observed at 9:00-11:00 a.m. while the lowest was at 17:00-19:00 p.m. The backward trajectories of air masses showed potential emission sources to be from the northwest and south during the measurement period. The backward trajectory also revealed that ozone concentrations during the measurement period were likely attributable to the emission from anthropogenic activities, and medium-range atmospheric transport from cities in central Asia and the northern slope of the Tian Shan Mountains.