under review:   Langer G., Nehrke G., Keul N., de Nooijer L., Littmann S., Kuypers M., Bijma J., Mg and Sr banding in the symbiont-barren  foraminifer Ammonmia aomoriensis as revealed by NanoSIMS analyses

2017   Keul N., Peijnenburg K.T.C.A, Andersen, N., Kitidis V., Goetze, E., Schneider, R., Pteropods are excellent recorders of surface temperature and carbonate ion concentration, Sci. Rep., 7: 12645, doi: 10.1038/s41598-017-11708-w.

2017   Manno C., (et al., inkl. Keul N.), Shelled pteropods in peril: Assessing vulnerability in a high CO2 ocean, Ear.-Sci. Rev., 169: 132-145, doi: 10.1016/j.earscirev.2017.04.005.

2016   Keul N., Langer G., Thoms S., de Nooijer L. J.,  Reichart G.-J, Bijma J., Exploring foraminiferal Sr/Ca as a new carbonate system proxy, Geochim. Cosmochim. Acta, 202, 374 – 386, doi: 10.1016/j.gca.2016.11.022.

2016   Langer G., Sadekov A., Thoms S., Keul N., Nehrke G., Mewes A., Greaves M., Misra S., Reichart G.-J., de Nooijer L., Bijma J., Elderfield H., Sr partitioning in the benthic foraminifera Ammonia aomoriensis and  Amphistegina lessonii, Chemical Geology, 440, 206 – 312, doi:10.1016/j.chemgeo.2016.07.018.

2013   Nehrke G., Keul N., Langer G., de Nooijer L. J., Bijma J., Meibom A., A new model for biomineralization and trace-element- signatures of foraminifera tests, Biogeosciences 10, 6759-6767, doi:10.5194/bg-10-6759-2013.

2013   Keul N., Langer G., de Nooijer L. J., Bijma J., Effect of ocean acidification on the benthic foraminifera Ammonia sp. is caused by a decrease in carbonate ion concentration, Biogeosciences 10, 6185-6198, doi:10.5194/bg-10-6185-2013.

2013   Keul N., Langer G., de Nooijer L. J., Nehrke G., Reichart G.-J, Bijma J., Incorporation of uranium in benthic foraminiferal calcite reflects seawater carbonate ion concentration, Geochem. Geophys. Geosyst., doi:10.1029/2012GC004330.

2012   Glas, M., Langer, G., Keul, N., Calcification acidifies the microenvironment of a benthic foraminifer (Ammonia sp.), Journal Mar. Biol. Ecol., 424-425, p53-58.

2010   Keul, N., Morse, J. W., Wanninkhof, R., Gledhill, D. K., Bianchi, T. S., Carbonate Chemistry Dynamics of Surface Waters in the Northern Gulf of Mexico, Aquatic Geochemistry, Vol 16, Nr 3, p337 –351.


2016   Repschläger J., (et al., inkl. Keul N.), NASGAF: North Atlantic Subtropical Gyre and Azores Front Geometry, Cruise No. MSM58- September 10 – October 07, 2016 – Reykjavik (Island)- Ponta Delgada (Portugal), Maria S. Merian Berichte, 2016.

2016    Schneider R., (et al., inkl. Keul N.), LISA: Baltic Sea water budget and sediment transport changes since the Littorina Transgression and their effects on the ecosystem, Cruise No. MSM51-1 – February 01 – February 09, 2016 – Warnemünde (Germany) – Kiel (Germany), Maria S. Merian Berichte, 2016.

2015   Schneider R., (et al., inkl. Keul N.), PULSE: Paleoclimate- Understanding Labrador Sea, PULSE, Cruise No. MSM45 – August 02 – August 21, 2015 – Nuuk (Greenlad) – Halifax (Canada), Maria S. Merian Berichte, 2015.

2015   Keul N., Langer G., de Nooijer L. J., Nehrke G., Reichart G.-J, Bijma J., Schneider R., New Carbonate System Proxies: Foram Culturing and Pteropod Potentials, Nova Acta Leopoldina NF 121 408, 305 – 309.

2007   Hansen I. S., Keul N., Sørensen J. T., Erichsen A., Andersen J. H., Baltic Sea Oxygen Maps 2000- 2006 Balance Interim Report No. 17.