Μελέτη της επίδρασης διακριτών πηγών ρύπανσης στο τροποσφαιρικό όζον και στο ενεργειακό ισοζύγιο της ατμόσφαιρας στον ελλαδικό χώρο με χρήση παρατηρήσεων εδάφους, δορυφορικών παρατηρήσεων και 3-διάστατων μαθηματικών προσομοιώσεων

Abstract

The current thesis focuses on the study of the influence of distinct pollution sources on the tropospheric ozone and the radiation balance of the atmosphere throughout Greece and the extended East Mediterranean region. Forest and arable areas fires and urban centers, where accumulative human activities generate pollution, can be characterized as distinct pollution sources. The study of tropospheric ozone (O3) is of great interest because it constitutes one of the main oxidants of the troposphere, it is a greenhouse gas and toxic for ecosystems. For better understanding of tropospheric ozone behavior and sources, O3 precursors, mainly, nitrogen dioxide (ΝΟ2), formaldehyde (HCHO) and carbon monoxide (CO) have been studied in parallel. The quantitative determination of the above chemical compounds was accomplished by the use of ground and satellite based observations and 3-dimensional numerical simulations using the 3-dimensional chemical - transport model, ΣΜ4. Satellite- derived data have been collected and the levels for the tropospheric columns of these trace gases have been determined together with meteorological data throughout Greece and the more extensive region of East Mediterranean. The data concern tropospheric columns of Ο3 from the satellite sensor TOMS during the period 2000-2005, of ΝΟ2 and HCHO from the satellite sensors GΟΜΔ and SCIAMACHY during the period 2000-2007, as well as data total column of CO from the satellite sensor MΟPITT during the period 2000-2008. Backward trajectories of air masses have been computed and used for the classification of satellite data and the determination of the levels of ΝΟ2, HCHO and CO for selected locations of the East Mediterranean and the contribution to the tropospheric column of Ο3 of pollution sources due to long range transport or local sources has been evaluated. The observations have been compared with the TM4 model results to evaluate the ability of the model to simulate the observed seasonality and interannual variability in the studied trace gases. The effect of intensive biomass burning events, which occurred throughout Greece during the summer of 2000 and 2007, on the levels of atmospheric pollution due to Ο3, ΝΟ2, HCHO and CO has been observed and simulated. 12 The radiative forcing of the atmosphere due to aerosols and ozone levels in the area based on TM4 simulations or on profile measurements by Lidar has been estimated.