Characteristic of Surface Ozone Concentrations at Lin'an

Abstract

The continuous observation data of surface ozone(O_3) concentrations in Lin'an Atmospheric Background Monitoring Station from November 2003 to November 2004 were used to study the annual overall distribution of surface O_3 and their seasonal and diurnal variations and concentration frequency distribution rules.The results showed that the average concentration of surface O_3 was(32.41×)10~(-9).Diurnal variations of surface O_3 concentrations showed obvious characteristic of a single peak,and showed its minimum at 04:00 in the morning,and maximum at 14:00 in the afternoon.Monthly averaged surface O_3 concentrations reached its maximum during late spring and early summer,and minimum from December to February in the next year.Varying scopes of surface ozone concentration in summer was the broadest which means that there was a strong photochemical reaction in summer in Lin'an area.Surface ozone concentration in every season exceed second-class standard defined in Ambient Air Quality Specification(GB30952-1996) except winter,and about(0.96%) of surface ozone exceeded that standard.