[Show abstract][Hide abstract] ABSTRACT: The impacts of anthropogenic emissions from the maritime transport and from the countries neighboring Greece on the maximum ground-level ozone concentrations over Greece were studied. Ozone concentrations were simulated across a part of the Eastern Mediterranean during a summer period using a modeling system that consisted of the photochemical Urban Airshed Model known as UAM-V coupled with the meteorological mesoscale model known as MM5. Simulated, maximum hourly ozone concentrations were higher over continental and maritime areas of Greece influenced by the emissions of the large urban agglomerations. When air quality simulations were performed assuming zero maritime transport emissions, the greater part of Greece experienced reductions in maximum ozone levels. Over the continental part of the country, the largest ozone reductions occurred along the coastline of southern and western Greece and were approximately 20 ppb. Over maritime areas, the decreases in maximum ozone concentrations were more pronounced. However, in the regions influenced by high amounts of nitrogen oxides emitted from the sea transport activities, the O3 concentrations were increased. The impact of anthropogenic emissions from all continental areas within the modeling domain, other than Greece, on the maximum ozone concentrations over Greece was small. Considering that the emission inventory for Greece was more detailed, while the official emission data for some of the countries in the modeling domain were generally poor, the assessed impact might have been underestimated.
Full-text · Article · Sep 2008 · Atmospheric Research
[Show abstract][Hide abstract] ABSTRACT: Ground-level ozone concentrations were estimated for Greece during a summer period of the year 2000 using the regional air
quality model UAM-V off-line coupled with the mesoscale meteorological model MM5. An anthropogenic NOx, NMVOCs and CO emission inventory and biogenic NMVOCs emission data were used to support model simulations. The evaluation
analysis indicates a quite satisfactory model performance in reproducing ozone levels. The simulated mean ozone concentrations
are above the 32-ppb EU phytotoxicity limit over almost all continental and maritime areas of Greece. Over the greater part
of the country, the background mean ozone levels range from 40 to 55ppb. Ozone values higher than the 55-ppb EU human health
protection limit reaching 60ppb dominate part of the southern Aegean Sea that is influenced by the Athens urban plume. In
the areas where anthropogenic emission densities are high, the mean ozone levels vary between 20 and 40ppb. Over the greater
part of Greece, the simulated mean daily maximum ozone concentrations range from 50 to 65ppb. More enhanced maximum ozone
concentrations up to 95ppb mainly dominate over the greater areas of the two largest Greek urban centres (Athens and Thessaloniki)
and over the continental and maritime areas south of Athens which are under the influence of the urban plume.
Full-text · Article · Jun 2008 · Water Air and Soil Pollution
[Show abstract][Hide abstract] ABSTRACT: This paper examines the effect of the total solar eclipse of 29 March 2006 on meteorological variables across Greece. Integrated micrometeorological measurements were conducted at Kastelorizo, a small island within the path of totality, and other sites within the Greek domain, with various degrees of solar obscuration. The observations showed a dramatic reduction in the incoming global radiation and subsequent, pronounced changes in surface air temperature with the lowest temperature values occurring about 15 min after the full phase. The amplitude of the air temperature drop was not analogous to the obscuration percentage but was principally determined by the surrounding environment (mainly the sea influence), the background meteorological conditions and local cloudiness. Surface wind-speed decreased in most sites as a result of the cooling and stabilization of the atmospheric boundary layer. This perturbation provided a unique opportunity to apply a sensitivity analysis on the effect of the eclipse to the Weather Research and Forecast (WRF) numerical mesoscale meteorological model. Strong anomalies, not associated with a dynamic response, were simulated over land especially in surface air temperature. The simulated temperature drop pattern was consistent with the observations.
Full-text · Article · Nov 2007 · Atmospheric Chemistry and Physics