Seasonal variability of optical properties of aerosols in the Eastern Mediterranean

Date

2005-12-01

Author

Vrekoussis, M
Liakakou, E
Koçak, Mustafa
Kubilay, N
Oikonomou, K
Sciare, J
Mihalopoulos, N

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

224
views

0
downloads

The aerosol optical properties (scattering and absorption coefficients) were investigated at two remote locations in the Eastern Mediterranean in conjunction with aerosol ion composition measurements: Finokalia in the Crete Island in Greece (March 2001-June 2002) and Erdemli in Turkey (July 1999-June 2000). Ambient light-scattering coefficient (sigma(sp-532 nm)) at Finokalia had a mean value of 50 +/- 23 Mm(-1) while at Erdemli this value was 90 +/- 160 Mm(-1), due to a severe dust event that occurred from 17 to 19 April 2000. Scattering coefficients up to 5000 Mm(-1) were encountered during the transition periods (spring and autumn) and were associated with dust storm events. During these events significant correlations were observed between dust and a, and mass scattering efficiencies of 0.21 and 0.96m(2) g(-1) were calculated for dust for Finokalia and Erdemli, respectively. Significant correlations were also observed at both locations between non-sea-salt nss-SO42-); and mass scattering efficiencies of 5.9 +/- 1.8 and 5.7 +/- 1.4 m(2)g(-1) were calculated for the nss-SO42- at Finokalia and Erdemli, respectively. At Finokalia absorption measurements were also performed at the same time and the mean absorption coefficient (sigma(ap-565nm)) was found to be 5.6 +/- 3.6 Mm(-1). Maxima of absorption coefficient were associated with two distinct meteorological situations indicative of pollution transported from northern Europe and Saharan dust events. Saharan dust can therefore significantly contribute to both scattering and absorption of solar radiation, the latter due to its hematite content. Based on scattering and absorption measurements, an annual mean single- scattering albedo (omega) adjusted at 550 nm of 0. 89 +/- 0.04 was calculated for Finokalia. Finally, radiative forcing efficiency (RFE) over the sea at 550 mn induced by aerosols has been calculated for Finokalia. RFE follows a clear seasonal variation, with the lowest mean values during summer (-73W(m-2)) and the highest during winter (-30Wm(2)). Using aerosol optical thickness measurements in the area, we obtain radiative forcing estimates at the top of the atmosphere (TOA) ranging from - 12.6 to -2.3 W m(2) for summer and winter, respectively. These values are up to five times higher than that induced by the greenhouse gases (2.4 Wm(-2)) but opposite in sign.

Subject Keywords

Optical properties of aerosols, Seasonal variation, Chemical composition, Radiative forcing, Eastern Mediterranean

URI

https://hdl.handle.net/11511/30463

Journal

ATMOSPHERIC ENVIRONMENT

DOI

https://doi.org/10.1016/j.atmosenv.2005.08.011

Collections

Graduate School of Marine Sciences, Article

Suggestions

OpenMETU
Core

Atmospheric trace element and major ion concentrations over the eastern Mediterranean Sea: Identification of anthropogenic source regions GÜLLÜ, GÜLEN; DOĞAN, GÜRAY; Tuncel, Süleyman Gürdal (2005-11-01) Concentrations of elements and ions measured in aerosol samples collected from March 1992 to the end of December 1993 were investigated to identify source regions affecting chemical composition of aerosols in the eastern Mediterranean atmosphere. Collected samples were analyzed for approximately 40 elements and ions using a combination of atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry. Statistical techniques, such as enrichment factors and a non-...
Temporal variations and sources of Eastern Mediterranean aerosols based on a 9-year observation ÖZTÜRK, FATMA; zararsız, Abdullah; Dutkiewicz, V. A.; Husain, L.; Hopke, P. K.; Tuncel, Süleyman Gürdal (2012-12-01) Concentrations of 48 elements, NO3-, SO42-, CI-, NH4+ and black carbon (BC) were determined in PM10 aerosols collected daily at a rural Eastern Mediterranean (EM) site (Antalya, 30.34 degrees E, 36.47 degrees N) from 1993 to 2001. Temporal variations (daily, seasonal and long term), sources and source regions of EM aerosols were delineated. Concentrations of elements with marine and crustal origin were more episodic as compared to anthropogenic ones. Most of the variables showed well defined seasonal cycles...
Spatio-temporal aerosol trace metal concentrations and sources in the Levantine Basin of the Eastern Mediterranean Koçak, Mustafa; Kubilay, N; Herut, B (2004-05-01) The current study considers the spatial and temporal variability in aerosol trace metal concentrations (Al, Fe, Mn, Cr, Cu, Pb, Cd, Zn) in the Levantine Basin of the Eastern Mediterranean, utilising an extensive sample library (n = 621) collected between 1999 and 2001, at two coastal sites located at the northern, Erdemli (Turkey) and southeastern, Tel Shikmona (TS, Israel), region of the Basin. A critical evaluation of the datasets from the two locations was presented. Enhanced concentrations of Al (1.7 x)...
Summertime aerosol chemical composition in the Eastern Mediterranean and its sensitivity to temperature Im, Ulas; Markakis, Kostas; Koçak, Mustafa; Gerasopoulos, Evangelos; Daskalakis, Nikos; Mihalopoulos, Nikolaos; Poupkou, Anastasia; Kındap, Tayfun; Ünal, Alper; Kanakidou, Maria (2012-04-01) The impact of ambient temperature on the levels and chemical composition of aerosols over the Eastern Mediterranean in July 2004 is investigated using the WRF/CMAQ model system coupled with the MEGAN biogenic emissions model. CMAQ is able to capture the observed mean aerosol concentrations over the studied period. Non-sea-salt sulfate (nss-SO42-) is calculated to be the major aerosol component contributing by 63%, 16% and 40% to the fine (PM2.5), coarse (PM2.5-10) and total particulate matter mass (PM10), r...
Temporal variability of atmospheric trace element concentrations over the eastern Mediterranean Sea GÜLLÜ, GÜLEN; Ölmez, İlhan; Tuncel, Süleyman Gürdal (2000-07-01) Concentrations of elements and ions measured in aerosol samples collected between March 1992 and December 1993 were investigated to understand temporal variability of elemental concentrations. Collected samples were analyzed by atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry for approximately 40 elements and major ionic species. Concentrations of elements were found to vary greatly on time scales ranging from days to seasons. Short-term variations...

Citation Formats

M. Vrekoussis et al., “Seasonal variability of optical properties of aerosols in the Eastern Mediterranean,” ATMOSPHERIC ENVIRONMENT, pp. 7083–7094, 2005, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30463.