Mustafa Koçak

Middle East Technical University

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N. Mihalopoulos

University of Crete

N. Kubilay

Middle East Technical University

C. Theodosi

University of Crete

P. Zarmpas

University of Crete

Barak Herut

Israel Oceanographic and Limnological Research

Ersin Tutsak

Qatar University

Uİ

Ulaş İm

Aarhus University

Malcolm Nimmo

University of Plymouth

Maria Kanakidou

University of Crete

Evangelos Gerasopoulos

National Observatory of Athens

Cooperative Institutions

University of Crete

Middle East Technical University

Centre National de la Recherche Scientifique

University of Bremen

Institut de Ciències del Mar

National Observatory of Athens

Hellenic Centre for Marine Research

Cyprus Institute

Georgia Institute of Technology

Aristotle University of Thessaloniki

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Variability in regional background aerosols within the Mediterranean

Atmospheric chemistry and physics (2009)

Xavier Querol A. Alastuey Jorge Pey Michael Cusack Noemí Pérez

Abstract. The main objective of this study is the identification of major factors controlling levels and chemical composition of aerosols in the regional background (RB) along the Mediterranean Basin (MB). To this end, data on PM levels and speciation from Montseny (MSY, NE Spain), Finokalia (FKL, Southern Greece) and Erdemli (ERL, Southern Turkey) for the period 2001 to 2008 are evaluated. Important differences on PM levels and composition are evident when comparing the Western and Eastern MBs. The results manifest W-E and N-S PM10 and PM2.5 gradients along the MB, attributed to the higher frequency and intensity of African dust outbreaks in the EMB, while for PM1 very similar levels are encountered. PM in the EMB is characterized by higher levels of crustal material and sulphate as compared to WMB (and central European sites), however, RB nitrate and OC + EC levels are relatively constant across the Mediterranean and lower than other European sites. Marked seasonal trends are evidenced for PM levels, nitrate (WMB), ammonium and sulphate. Also relatively higher levels of V and Ni (WMB) are measured in the Mediterranean basin, probably as a consequence of high emissions from fuel-oil combustion (power generation, industrial and shipping emissions). Enhanced sulphate levels in EMB compared to WMB were measured. The high levels of sulphate in the EMB may deplete the available gas-phase NH3 so that little ammonium nitrate can form due to the low NH3 levels. This study illustrates the existence of three very important features within the Mediterranean that need to be accounted for when modeling climate effects of aerosols in the area, namely: a) the increasing gradient of dust from WMB to EMB; b) the change of hygroscopic behavior of mineral aerosols (dust) via nitration and sulfation; and c) the abundance of highly hygroscopic aerosols during high insolation (low cloud formation) periods.

Mediterranean Basin

Ammonium nitrate

10.5194/acp-9-4575-2009

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Citations (235)

Seasonal variability of optical properties of aerosols in the Eastern Mediterranean

Atmospheric Environment (2005)

Mihalis Vrekoussis Eleni Liakakou Mustafa Koçak N. Kubilay Konstantina Oikonomou

Mineral dust

Dust storm

Mass attenuation coefficient

Single-scattering albedo

10.1016/j.atmosenv.2005.08.011

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Citations (108)

Ground‐based assessment of Total Ozone Mapping Spectrometer (TOMS) data for dust transport over the northeastern Mediterranean

Global Biogeochemical Cycles (2005)

N. Kubilay Temel Oǧuz Mustafa Koçak Omar Torres

Multiyear daily surface aerosol aluminum (Al) concentration and sunphotometer measurements at Erdemli (Turkey) sampling station were used to assess the performance of Absorbing Aerosol Index (AAI) and Aerosol Optical Thickness (AOT) retrieved from the daily Total Ozone Mapping Spectrometer (TOMS) over the northeastern Mediterranean. A total of 98 moderate‐to‐high intensity dust events with durations from 1 day to 1 week were identified by aerosol Al concentrations and/or TOMS‐AAI above their threshold values of 1.0 μg m −3 and 0.5, respectively. Only 15 events were found to bring appreciable dust load into the northeastern Mediterranean, predominantly below the 850‐hPa pressure level, and therefore were not detected effectively by TOMS. Eight of these events corresponded to short‐range high intensity intrusions (Al > 3.0 μg m −3 ) from nearby dust sources of the Middle East and Arabian deserts, the rest (seven events) represented moderate‐to‐high intensity (Al > 1.0 μg m −3 ) long‐range transport from North Africa. Given the highly complex dynamics of the region, the use of TOMS‐AAI data is justified for monitoring Saharan dust transport characteristics in the northeastern Mediterranean. Moreover, the TOMS‐AOT data were found to covary linearly with its counterpart obtained by the ground‐based measurements (correlation coefficient 0.86, significant at <0.001), which lies within the range of estimates suggested by earlier studies.

Mineral dust

10.1029/2004gb002370

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Citations (47)

Interaction of the cholesterol reducing agent simvastatin with zwitterionic DPPC and charged DPPG phospholipid membranes

Biochimica et Biophysica Acta (BBA) - Biomembranes (2019)

Ediz Sariisik Mustafa Koçak Fatma Küçük Baloğlu Feride Severcan

Dipalmitoylphosphatidylcholine

10.1016/j.bbamem.2019.01.014

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Citations (28)

The significance of atmospheric inputs of major and trace metals to the Black Sea

Journal of Marine Systems (2012)

C. Theodosi S. Stavrakakis F. Koulaki Ioanna Stavrakaki Snejana Moncheva

Deposition

Biogeochemistry

Trace metal

10.1016/j.jmarsys.2012.02.016

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Citations (36)

Influence of Black Sea and local biogenic activity on the seasonal variation of aerosol sulfur species in the eastern Mediterranean atmosphere

Global Biogeochemical Cycles (2002)

N. Kubilay Mustafa Koçak Tülay Çokacar Temel Oǧuz Giorgos Kouvarakis

Methanesulfonate (MSA) and non‐sea‐salt (nss) sulfate concentrations were measured in bulk aerosol samples collected during January 1996 to December 1999 at two stations along the Turkish and Cretan coastline of the eastern Mediterranean. The data set enabled the origin and variability of biogenically derived sulfate concentrations in the eastern Mediterranean atmosphere to be defined. Although similar seasonal patterns of MSA and nss‐sulfate concentrations for both stations were detected, the mean concentrations at Erdemli (Turkey) over the sampling period (42 ± 52 ng m −3 MSA, and 6.8 ± 5.2 μg m −3 nss sulfate) were found to be almost twice that of those measured at Finokalia, Crete (25.8 ± 14.9 ng m −3 MSA and 3.9 ± 1.7 μg m −3 nss sulfate). Analysis of the air mass back trajectory and the Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) data suggests that the majority of the biogenic contribution at Erdemli is originated from summer coccolithophorid Emiliania huxleyi blooms developed in the Black Sea. The data further points to a significant relationship between Saharan dust transport events and local oceanic production of MSA through occasional fertilization of the eastern Mediterranean during wet deposition events. This process accounts for episodic, strong weekly changes in MSA concentrations during the spring months. Considering that Erdemli and Finokalia are approximately 1000 km apart from each other geographically, large differences in their MSA and nss‐sulfate concentrations indicates a considerable role of regional mesoscale atmospheric transport processes on the spatial structure of biogenically produced atmospheric sulfur aerosols.

Mineral dust

Emiliania huxleyi

SeaWiFS

10.1029/2002gb001880

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Citations (31)

Atmospheric Deposition of Macronutrients (Dissolved Inorganic Nitrogen and Phosphorous) onto the Black Sea and Implications on Marine Productivity*

Journal of the Atmospheric Sciences (2016)

Mustafa Koçak N. Mihalopoulos Ersin Tutsak Kalliopi Violaki C. Theodosi

Abstract Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coastline of the Black Sea. In addition, bulk deposition samples were collected at Varna, located on the west coastline of the Black Sea. Both aerosol and deposition samples were analyzed for the main macronutrients, NO3−, NH4+, and PO43−. The mean aerosol nitrate and ammonium concentrations were 7.1 ± 5.5 and 22.8 ± 17.8 nmol m−3, respectively. The mean aerosol phosphate concentration was 0.69 ± 0.31 nmol m−3, ranging from 0.21 to 2.36 nmol m−3. Interestingly, phosphate concentration over Sinop was substantially higher than those of most Mediterranean sites. Comparison of the atmospheric and riverine inputs for the Black Sea revealed that atmospheric dissolved inorganic nitrogen (DIN) only ranged between 4% and 13%, while the atmospheric dissolved inorganic phosphorus (DIP) fluxes had significantly higher contributions with values ranging from 12% to 37%. The molar N:P ratios in atmospheric deposition for Sinop and Varna were 13 and 14, respectively, both of which were lower than the Redfield ratio (16). The atmospheric molar N:P ratios over the Black Sea were considerably lower than those reported for riverine fluxes (41) and the Mediterranean region (more than 200). The atmospheric P flux can sustain 0.5%–5.2% of the primary production, whereas the N flux can sustain 0.4%–4.8% of the primary production. The contribution of the atmospheric flux may enhance by 2.6 when the new production is considered.

Redfield ratio

Deposition

Mineral dust

New production

Black Sea

10.1175/jas-d-15-0039.1

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Citations (10)

Characteristics of Antarctic Surface Waters in the South Bay, on Livingston Island, South Shetland Islands

Afyon Kocatepe University Journal of Sciences and Engineering (2021)

Mehmet Nuri Bodur Mustafa Koçak

This study presents hydro chemical characteristics of surface waters of the South Bay, Antarctic Peninsula, between the coordinates 62°40′S and 60°28′W. The surface water samples were collected from different stations. Water Depth, salinity, temperature and Secchi Disk Depth measurements were carried out on board of a Zodiac Boat from 05.02.2018 to 19.02.2018. A total of 20 surface water samples were handled by PVC and analyzed for major ions, pH and conductivity. Secchi disk depth, surface water temperatures and water depth values ranged from 1.0 to 4.0 m, 19.1 to 118.5 m and 0.10 to 2.50 oC, respectively. These parameters were mutually comparable with each other, denoting close relationship with suspension. Salinity and conductivity were found to covary, suggesting influence of salt content of on the conductivity. Cl /Na ratio varied from 1.5 to 1.6, being lower than that of 1.8. There was a strong relationship between Cl/Na (r=0.74), reflecting the effect of freshwater input on aforementioned ratio. Na, Mg and K showed strong correlation coefficient (r>0.99). However, Ca exhibited lower correlation coefficients with remaining cations. It might be suggested that Na, Mg and K were conservative cations whilst Ca concentrations were partially affected by processes such as uptake by phytoplankton. Ion balance were predominated by cations, exhibiting missing anion bicarbonate. As a result, these values hopefully reflected some important clues for temporarily and spatially environmental effects onto the partly icy surface water which should be monitored further in detail to get better understanding of its dynamics in the South Bay.

Shetland

10.35414/akufemubid.894444

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Citations (0)

Long-term measurements of aerosol optical and physical properties over the Eastern Mediterranean: Hygroscopic nature and source regions

Atmospheric Environment (2019)

Ersin Tutsak Mustafa Koçak

Angstrom exponent

AERONET

Mineral dust

10.1016/j.atmosenv.2019.03.007

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