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Dr. Henning Kuhnert
Name: | Dr. Henning Kuhnert | |
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Department: | Marine Geology | |
Job: | Research Scientist | |
Room: | ||
Phone: | +49 421 218 - 65071 | |
Fax: | +49 421 218 - 65505 | |
E-Mail: |
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Current Research Projects
- Middle Miocene surface hydrography of the Southern Ocean.
Shifts in the latitudinal positions of oceanic fronts are expressed in concurrent changes of sea surface temperature and salinity. These precede the major expansion of the Antarctic ice sheet.
Method: Mg/Ca and d18O in planktonic foraminifera - Middle Miocene deep ocean carbonate system.
The lower and middle Miocene are charecterized by anomalies in the global carbon cycle (evidenced by d13C excursions), where the role of the deep ocean is poorly constrained. The reconstructions of the carbonate ion saturation state and alkalinity allow the estimation of the remaining parameters of the carbonate system.
Method: U/Ca and Ba/Ca in benthic foraminifera - Relationship between African monsoon rainfall and sea surface temperature variability on multidecadal to centennial timescales over the Holocene.
Regions include West Africa (Senegal River) and East Africa (Rufiji and Pangani Rivers). The location and latitudinal extent of the rainbelt is influenced by the contrast between oceanic and continental temperatures. Monsoon rainfall is reflected in the discharge of major rivers, which in turn determines salinity off the river mouths. Major climate phenomena influencing the monsoon include the Atlantic Multidecadal Oscillation (AMO) and Indian Ocean Dipole (IOD).
Method: Mg/Ca and d18O in planktonic foraminifera from high resolution (10-50 years) sediment cores - Sea-surface temperature variability and seasonality during the Holocene in the Red Sea.
Holocene temperature seasonality is influenced by orbitally forced insolation changes. This effect is amplified through the North Atlantic Oscillation (NAO).
Method: Sr/Ca and d18O in corals
Publications
Kuhnert, H., and Mulitza, S. (2011) Multidecadal variability and late medieval cooling of near-coastal sea surface temperatures in the eastern tropical North Atlantic. Paleoceanography, in press, doi: 10.1029/2011PA002130.
Raitzsch, M., Hathorne, E.C., Kuhnert, H., Groeneveld, J., and Bickert, T. (2011) Modern and late Pleistocene B/Ca ratios of the benthic foraminifer Planulina wuellerstorfi determined with laser ablation ICP-MS. Geology, in press, doi: 10.1130/G32009.1.
Rackebrandt, M., Kuhnert, H., Groeneveld, J., and Bickert, T. (2011) Persisting maximum Agulhas leakage during MIS 14 indicated by massive Ethmodiscus oozes in the subtropical South Atlantic. Paleoceanography, 26, PA3202, doi: 10.1029/2010PA001990.
Raitzsch, M., Kuhnert, H., Hathorne, E.C., Groeneveld, J., Bickert, T. (2011) U/Ca in benthic foraminifers: A proxy for the deep-sea carbonate saturation. Geochem., Geophys., Geosyst. 12, Q06019, doi:10.1029/2010GC003344.
Felis, T., Suzuki, A., Kuhnert, H., Rimbu, N., and Kawahata, H. (2010) Pacific Decadal Oscillation documented in a coral record of North Pacific winter temperature since 1873. Geophys. Res. Lett. 37, L14605, doi:10.1029/2010GL043572.
Heindel, K., Birgel, D., Peckmann, J., Kuhnert, H., and Westphal, H. (2010) Formation of deglacial microbialites in coral reefs off Tahiti (IODP 310) involving sulfate-reducing bacteria. Palaios 25, 618-635.
Mulitza, S., Heslop, D., Pittauerova, D., Fischer, H.W., Meyer, I., Stuut, J.-B., Zabel, M., Mollenhauer, G., Collins, J.A., Kuhnert, H., Schulz, M. (2010) Increase in African dust flux at the onset of commercial agriculture in the Sahel region. Nature 466, 226-228.
Gussone, N., Zonneveld, K., Kuhnert, H. (2010) Minor element and Ca isotope composition of calcareous dinoflagellate cysts of cultured Thoracosphaera heimii. Earth Planet. Sci. Lett. 289, 180-188.
Felis, T., Suzuki, A., Kuhnert, H., Dima, M., Lohmann, G., and Kawahata, H. (2009) Subtropical coral reveals abrupt early-twentieth-century freshening in the western North Pacific Ocean. Geology 37, 527-530.
Kuhnert, H., Bickert, T., and Paulsen, H. (2009) Southern Ocean frontal system changes precede Antarctic ice sheet growth during the middle Miocene. Earth Planet. Sci. Lett. 284, 630-638.
Friedrich O., Erbacher J., Moriya K., Wilson P. A., and Kuhnert H. (2008) Warm saline intermediate waters in the Cretaceous tropical Atlantic Ocean. Nature Geoscience 1, 453-457.
Rathmann S. and Kuhnert H. (2008) Carbonate ion effect on Mg/Ca, Sr/Ca and stable isotopes on the benthic foraminifera Oridorsalis umbonatus off Namibia. Mar. Micropaleontol. 66, 120-133.
Raitzsch M., Kuhnert H., Groeneveld J., and Bickert T. (2008) Benthic foraminifer Mg/Ca anomalies in South Atlantic core top sediments and their implications for paleothermometry. Geochem., Geophys., Geosyst. 9, Q05010, doi:10.1029/2007GC001788.
Crueger T., Kuhnert H., Pätzold J., and Zorita E. (2006) Calibrations of Bermuda corals against large-scale sea surface temperature and sea level pressure pattern time series and implications for climate reconstructions. J. Geophys. Res., D 111, D23103, doi: 10.1029/2005JD006903.
Epplé V.M., Brey T., Witbaard R., Kuhnert H., Pätzold J. (2006) Sclerochronological records of Arctica islandica from the inner German Bight. The Holocene, 16, 763-769.
Langer G., Gussone N., Gehrke G., Riebesell U., Eisenhauer A., Kuhnert H., Rost B., Trimborn S., and Thoms S. (2006) Coccolith strontium to calcium ratios in Emiliania huxleyi: The dependance on seawater strontium and calcium concentrations. Limnol. Oceanogr. 51, 310-320.
Kuhnert H., Crüger T., and Pätzold J. (2005) NAO signature in a Bermuda coral Sr/Ca record. Geochem., Geophys., Geosyst. 6, Q04004, doi: 10.1029/2004GC000786.
Rathmann S., Hess S., Kuhnert H., and Mulitza S. (2004) Mg/Ca ratios of the benthic foraminifera Oridorsalis umbonatus obtained by laser ablation from core top sediments: Relationship to bottom water temperatures. Geochem., Geophys., Geosyst. 5, Q12013, doi: 10.1029/2004GC000808.
Felis T., Lohmann G., Kuhnert H., Lorenz S. J., Scholz D., Pätzold J., Al-Rousan S. A., and Al-Moghrabi S. (2004) Increased seasonality in Middle East temperatures during the last interglacial period. Nature 429, 164-168.
Kuhnert H., Pätzold J., Schnetger B., and Wefer G. (2002) Sea-surface temperature variability in the 16th century at Bermuda inferred from coral records. Palaeogeogr., Palaeoclim., Palaeoecol. 179, 159-171.
Kuhnert H., Pätzold J., Wyrwoll K.-H., and Wefer G. (2000) Monitoring climate variability over the past 116 years in coral oxygen isotopes from Ningaloo Reef, Western Australia. Int. J. Earth Sci. 88, 725-732.
Kuhnert H., Pätzold J., Hatcher B. G., Wyrwoll K.-H., Eisenhauer A., Collins L. B., Zhu Z. R., and Wefer G. (1999) A 200-year coral stable oxygen isotope record from a high-latitude reef off Western Australia. Coral Reefs 18, 1-12.