Dr. Nicolas Nowald

As a PostDoc within the MARUM project GB1 "Particle flux and alteration of organic matter in the water column", I am working on aggregation- and particletransport processes in the ocean.

Particulate matter in the ocean (Marine Snow), plays a keyrole in the global carbon cycle. Marine Snow transfers large amounts of organic carbon from the ocean surface to the deep sea, having a major impact on the global climate.

I am interested in in-situ characteristics and properties of Marine Snow, such as size, abundance and settling speeds. These parameters are important in order to quantify particle fluxes.

Fur this purpose, we are deploying a number of optical systems: a vertically profiling still image camera system (ParCa), a moored HD Video Camera with CTD probe (Multi Sensor Device) and a Remotely Operated Vehicle (Cherokee).

A part of the aqcuired data are used for the Regional Ocean Modelling System (ROMS).

Within our research project, I am responsible for the technical support and deployment of our optical systems. I further provide data extraction with aid of digital image analysis software tools.

I am in charge for the cruise planning and maintenance of the 1000m depth rated Cherokee ROV and pilot of the 4000m depth rated Quest ROV

Iversen, M.H., Nowald, N., Ploug, H., Jackson, G.A. and G. Fischer (2010), High resolution profiles of vertical particulate organic matter export off Cape Blanc, Mauritania:Degradation processes and ballasting effects, Deep-Sea Research I, 57, 771-784, doi:10.1016/j.dsr.2010.03.007

G. Karakaş, N. Nowald, C. Schäfer-Neth, M. Iversen, W. Barkmann, G. Fischer, P. Marchesiello and R. Schlitzer (2009), Impact of particle aggregation on vertical fluxes of organic matter, Progress in Oceanography, 83, 331-341, doi:10.1016/j.pocean.2009.07.047

N. Nowald, G. Fischer, V. Ratmeyer, M. Iversen, C. Reuter and G. Wefer (2009), In-situ sinking speed measurements of marine snow aggregates acquired with a settling chamber mounted to the Cherokee ROV, OCEANS'09 IEEE Bremen

De La Rocha, C. L., N. Nowald, and U. Passow (2008), Interactions between diatom aggregates, minerals, POC, and DOM: further implications for the ballast hypothesis, Global Biogeochem. Cycles, doi:10.1029/2007GB003156

Fischer, G., Karakas, G., Blaas, M., Ratmeyer, V., Nowald, N., Schlitzer, R., Helmke, P., Davenport, R., Donner, B., Neuer, S., Wefer, G. (2007) Mineral ballast and particle settling rates in the coastal upwelling system off NW Africa and the South Atlantic, Int J Earth Sci (Geol Rundsch) (2009) 98:281-298, DOI 10.1007/S00531-007-0234-7

Karakas, G., Nowald, N., Blaas, M., Marchesiello, M., Frickenhaus, S. and R. Schlitzer (2006) High resolution modelling of sediment erosion and particle transport across the NW African shelf. Journal of Geophysical Research, 111, C06025, doi:10.1029/2005JC003296, 2006.

N. Nowald, G. Karakas, V. Ratmeyer, G. Fischer, R. Schlitzer, R. A. Davenport, G. Wefer (2006), Distribution and transport processes of marine particulate matter off Cape Blanc (NW-Africa): results from vertical camera profiles, Ocean Science Discussions, Vol. 3, pp 903-938, 25-7-2006

 Oceans_2009_Nowald_et_al.pdf