Three-year ground based measurements of aerosol optical depth over the Eastern Mediterranean: The urban environment of Athens

Gerasopoulos, E; Amiridis, V; Kazadzis, S; Kokkalis, P; Eleftheratos, K; Andreae, MO; Andreae, TW; El-Askary, H; Zerefos, CS

dc.contributor.author	Gerasopoulos, E	en
dc.contributor.author	Amiridis, V	en
dc.contributor.author	Kazadzis, S	en
dc.contributor.author	Kokkalis, P	en
dc.contributor.author	Eleftheratos, K	en
dc.contributor.author	Andreae, MO	en
dc.contributor.author	Andreae, TW	en
dc.contributor.author	El-Askary, H	en
dc.contributor.author	Zerefos, CS	en
dc.date.accessioned	2014-03-01T01:37:29Z
dc.date.available	2014-03-01T01:37:29Z
dc.date.issued	2011	en
dc.identifier.issn	1680-7316	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/21514
dc.subject.classification	Meteorology & Atmospheric Sciences	en
dc.subject.other	aerosol composition	en
dc.subject.other	aerosol property	en
dc.subject.other	diurnal variation	en
dc.subject.other	dust	en
dc.subject.other	ground-based measurement	en
dc.subject.other	optical depth	en
dc.subject.other	particle size	en
dc.subject.other	suspended particulate matter	en
dc.subject.other	Athens [Attica]	en
dc.subject.other	Attica	en
dc.subject.other	Greece	en
dc.subject.other	Mediterranean Region	en
dc.title	Three-year ground based measurements of aerosol optical depth over the Eastern Mediterranean: The urban environment of Athens	en
heal.type	journalArticle	en
heal.identifier.primary	10.5194/acp-11-2145-2011	en
heal.identifier.secondary	http://dx.doi.org/10.5194/acp-11-2145-2011	en
heal.language	English	en
heal.publicationDate	2011	en
heal.abstract	Three years (2006-2008) of ground-based observations of the Aerosol Optical Depth (AOD) in the urban environment of Athens, in the Eastern Mediterranean, are analysed in this work. Measurements were acquired with a Multi-Filter Rotating Shadowband Radiometer at five wavelengths. The daily average AOD at 500 nm is 0.23, and the mean Ångström coefficient calculated between 415 and 867 nm is 1.41. The annual variability of AOD has a spring maximum dominated by coarse dust particles from the Sahara (AOD 0.34-0.42), while the diurnal pattern is typical for urban sites, with AOD steadily increasing throughout the day. The greatest contribution to the annually averaged AOD, accounting for almost 40%, comes from regional and local sources (namely the Istanbul metropolitan area, the extended areas of biomass burning around the north coast of the Black Sea, power plants spread throughout the Balkans and the industrial area in the Po valley, with average daily AOD in the range of 0.25-0.35). An additional important contribution (23%) is dust from Africa, whereas the rest of Europe contributes another 22%. The geographical distribution of the above sources in conjunction with the prevailing synoptic situation and contribution of local sources, lead to mixed types of aerosols over Athens, with highly variable contribution of fine and coarse particles to AOD in the range 10%-90%. This is the first long-term, ground based data set available for Athens, and it has also been used for the validation of satellite derived AOD by MODIS, showing good agreement on an annual basis, but with an overestimation of satellite AODs in the warm period. © 2011 Author(s).	en
heal.publisher	COPERNICUS GESELLSCHAFT MBH	en
heal.journalName	Atmospheric Chemistry and Physics	en
dc.identifier.doi	10.5194/acp-11-2145-2011	en
dc.identifier.isi	ISI:000288368900019	en
dc.identifier.volume	11	en
dc.identifier.issue	5	en
dc.identifier.spage	2145	en
dc.identifier.epage	2159	en