Author(s)

R. Girgzdiene, A. Girgzdys and A. Mikelinskiene

Abstract

Trend Analysis of Ozone in Lithuania A contribution to subproject TOR-2 R. Girgzdiene, A. Girgzdys and A. Mikelinskiene Institute of Physics, A. Gostauto 12, 2600 Vilnius, Lithuania The ozone monitoring data show an increase in annual mean of ozone concentrations at rural Preila station over the period 1980-1997 (Fig. 1). Over this period the upward trend of 1.7 % per year or 0.72 ± 0.12 ng/nr* is established. o P 100 r 80 , -MONTHLY MEAN •12 month running mean - Linear (MONTHLY MEAN) » Fig. 1: Monthly mean, linear trend and 12 month running mean ozone concentrations at Preila. The tabulated analysis of trends over separate periods is provided in Table 1. A positive trend over the 15 years period was determined. However over shorter periods a downward trend could also be observed. A noticeable increase in the ozone annual mean and AOT40 (Girgzdiene, 1995) has been established since

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