Research interests:

I am a marine geochemist and I work on seawater and lake water samples and marine and lacustraine sediments (e.g. drill cores). My main research interest is the biogeochemical interactions between the ocean and the atmosphere, which effects the growth of phytoplankton, marine ecosystems and thereby global climate.

I mainly focus on impacts of atmospheric deposition of desert dust and volcanic ash particles on the surface ocean nutrient budget (dissolved nitrogen species, phosphate, silica and iron). I am also interested in the possible impacts of ocean acidification (the other CO2 problem) on the marine biogeochemistry.

I also work on the marine sediment cores for tephrochrolonology and paleoenvironment studies for understanding the changes in the primary productivity through time. I am moslty concentrated on the the sediment-biomarkers including microfossils (e.g. diatoms and cocoliths), pigments (e.g. chlorin) and organic compounds (e.g. alkenones).

Biography:
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2015, Assistant Profesor, Eurasia Institute of Earth Sciences, ITU, Turkey
2003-2015, PostDoc. (Marie Curie Fellow), Eurasia Institute of Earth Sciences, ITU, Turkey
2007-2012, PhD, Helmholtz-Centre for Ocean Research, GEOMAR, Kiel, Germany
2005-2007, Masters, Coastal Research Laboratory, Christian-Albrechts University, Kiel, Almanya
2000-2005, Bachelors, Geological Engineering, Middle East Technical University (METU), Ankara, Turkey

Most important 5 publications:

Olgun N., Duggen S., Langmann B., Hort M., Waythomas C. F., Hoffmann L., Croot P., 2013. Geochemical evidence for oceanic iron fertilization from the Kasatochi volcanic eruption and evaluation of the potential impacts on the sockeye salmon population, Marine Ecology Progress Series, 488, 81-83. http://www.int-res.com/abstracts/meps/v488/p81-88/

 Olgun N., Duggen S., Kutterolf, S., Croot P.L, Andronico D., Giammanco S, Censi P., Randazzo L., 2013. Possible impacts of volcanic ash emissions of Mount Etna on the oligotrophic Mediterranean Sea: Results from the nutrient-release experiments in seawater, Marine Chemistry, 152, 32-42. http://dx.doi.org/10.1016/j.marchem.2013.04.004

 Hoffmann L., Breitbarth E., V. Ardelan M., Olgun N., Hasselhöv M., Wängberg S. A., 2012. Influence of trace metal release from volcanic ash on Thalassiosira pseudonana and Emiliana huxleyi, Marine Chemistry, 132-133, 28-33. http://www.sciencedirect.com/science/article/pii/S0304420312000229

 Olgun N., Duggen S., Croot P., Delmelle P., Dietze H., Schacht U., Óskarsson N., Siebe C., Auer A., 2011. Surface ocean iron fertilization: The role of airborne volcanic ash from subduction zone and hot spot volcanoes and related iron-fluxes into the Pacific Ocean. Global Biogeochemical Cycles, 25, GB4001, doi: 10.1029/2009GB003761. http://onlinelibrary.wiley.com/doi/10.1029/2009GB003761/abstract

 Duggen S, Olgun N, Hoffmann L, Croot P, Dietze H, Teschner C., 2010. The role of airborne volcanic ash for the surface ocean biogeochemical iron-cycle: A review. Biogeosciences, 7, 827-84. http://www.biogeosciences.net/7/827/2010/bg-7-827-2010.html