Meteorologically adjusted ground-level ozone trend at the Preila background site

Abstract

Using a multiple low-pass Kolmogorov-Zurbenko filter, the separation of the original signal based on ozone and temperature data into long-term (annual), seasonal, and short-term (synoptic scale) components was applied for removing the effects of meteorological factors at the Preila background station (Lithuania). Meteorologically adjusted hourly ozone concentration data revealed long-term variations. Based on this approach a decline of 0.36 µg m −3 yr −1 in the meteorologically adjusted ozone concentration was determined for the period of 1999-2004.