Mustafa Koçak

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

AbstractTwo-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 fo...

Carbonaceous Aerosols Over the Mediterranean and Black Sea

The role of carbonaceous material (organic and elemental carbon) in the Mediterranean and Black sea atmosphere is yet to be unraveled. To fill this gap the present work is focused on the study of carbonaceous aerosols over the Mediterranean and Black Sea. Thus, aerosol samples were simultaneously collected at a remote site in Greece (Finokalia, Crete), a highly populated urban (Istanbul), a remote (Imbros) and two rural sites in Turkey (Sinop, Erdemli). Approximately 1,200 aerosol samples were collected and analyzed for Organic and elemental carbon (OC and EC), as well as water-soluble organic carbon (WSOC). Their seasonal variation, the factors controlling their variation and their relative contribution to aerosol mass is presented and thoroughly discussed. More specifically, organic matter constitutes a significant part of the total PM10 mass (21–33% of Particulate Organic Matter and 2–11% EC). The percentage of WSOC ranges from 37% to 40% of the OC for the four remote and rural regions, while in Istanbul constitutes 27% of OC and 10% of the total PM10 mass. Correlations with potassium and sulfate showed that the sources of organic matter in Istanbul are mainly due to the anthropogenic activities, while in rural and suburban areas to long range transport and biomass burning.

Concentration and Chemical Composition of PM2.5 and PM10-2.5 in the Northeastern Mediterranean

Two stage aerosol samples (PM10-2.5 and PM2.5) were collected at a rural site (Erdemli) located on the coast of the Northeastern Mediter- ranean, between April 2001 and April 2002. A total of 581 aerosol samples were analysed for trace elements (Fe, Ti, Mn, Ca, V, Ni, Zn, Cr) and water soluble ions (Na + , NH4 + , K + , Mg 2+ , Ca 2+ , Cl - , Br - , NO3 - , SO4 2- , C2O4 2- and MS - ). The annual mean PM10 and PM2.5 levels were 36.4 ± 27.8 µg m -3 and 9.7 ± 5.9, respectively. The highest levels of PM10 were observed during the transition period (March, April and May) due to mineral dust transported from North Africa and during winter due to sea spray generation. However, PM2.5 levels exhibited higher concentrations during summer resulting from an enhanced production of secondary aerosols. PM10, crustal elements, sea salt aerosols and NO3 - were mainly associated with the coarse mode whereas nssSO4 2- , C2O4 2- , MS - , NH4 + , Cr and Ni were found predominantly in the fine fraction. Ionic balance analysis performed in the coarse and fine aerosol fractions indicated anion and cation deficiency due to CO3 2- and H + , respec- tively. A relationship between nssSO4 2- and NH4 + denoted that sulphate particles were partially neutralized (70%) by ammonium. Excess-K/BC pre- sented two distinct ratios for winter and summer, indicating two different sources: Fossil fuel burning in winter and biomass burning in summer.