THE ROLE OF WIND IN THE CONFIGURATION OF THE AMBIENT AIR QUALITY IN ATHENS, GREECE

摘要

It is well-known that natural and anthropogenic emissions of ambient pollutants affect air quality, and as a consequence the public health. Air pollution indices are commonly used to indicate the level of severity of air pollution to the public. The objective of this study is the assessment of the air quality levels in the urban environment of Athens, Greece using the Air Quality Index (AQI), which presents advantages as an administrative tool for early warning in the context of public health protection. The AQI is a complex index and calculated by compounding appropriately the concentrations of surface ozone (O_3), nitrogen dioxide (NO_2), sulphur dioxide (SO_2), carbon monoxide (CO) and particles with aerodynamic diameter less than 10 urn (PM_(10)). For this purpose, available hourly data of the above ambient pollutants recorded by the Athens air pollution monitoring network, during the period 2001-2006, were analyzed for the development of the proposed index. The temporal and spatial distribution of the mean annual AQI values within greater Athens area (GAA) is examined, and the results are analyzed in terms of the meteorological conditions. The effect of wind speed and direction on AQI levels is found to be significant, among the other meteorological parameters such as air temperature, relative humidity, sunshine and total solar radiation. The analysis revealed that the higher values of AQI, during the warm period of the year, are strongly associated with sea breeze than with northern wind flow. The knowledge of the sea breeze characteristics over GAA contributes to the comprehension of the local air quality formation levels.