| Popis: |
High values of temperature and ozone (O3) concentrations often coexist revealing the strong relationship between them. In this study, we examine the O3-temperature slopes for two heatwave episodes during the summers of 2003 and 2014 in Europe. In both heatwave episodes, similar slopes of about 3.1 ppb/°C are found, about 1 ppb/°C higher when compared with summers with near normal temperatures. The lowest correlation coefficient calculated for the two variables in the 2003 heatwave is attributed to the break of the O3-temperature relationship in the higher percentiles of both variables, while for the 2014 heatwave the highest correlation coefficient is attributed to the increased isoprene emission fluxes. However, the clear response of O3 to temperature perturbations in 2003 was better manifested when the mean anomalies of the two variables between the heatwave and the normal period were examined, with the calculated slope of about 4.75 ppb/°C. In addition, the slope of about 1.5 days of O3 exceedances/day with Tmax > 90th percentile indicates the role of extreme temperatures to the extension of the O3 exceedance period. This indicates that when future O3 levels are estimated based on the relationship of O3 with meteorological variables (such as temperature), extreme periods (such as heatwaves) should be taken into account in their training periods in order to obtain more realistic results. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature. |
