Bereichsbild

Sedimentology & Marine Paleoenvironmental Dynamics

 

PD Dr. André Bahr



Address:

                

 

 

Institute of Earth Sciences

Ruprecht-Karls-Universität Heidelberg

Im Neuenheimer Feld 234

D-69120 Heidelberg

Room:

211

Phone:

Fax:

+49 (0)6221-54 6062

+49 (0)6221-54 5503

E-mail:

andre.bahr@geow.uni-heidelberg.de

A_Bahr_Profile

 


 

Research Focus:

Deciphering the drivers of climate variability has become paramount in face of an ever more anthropogenically influenced world. With my research, I aim to advance the current debate on climate change from a paleo-perspective to provide new insights into the feedbacks within the Earth’s climate system. In particular, I concentrate on the ocean-atmosphere feedbacks governing the global monsoonal rain belt, home to nearly two-thirds of the world’s population. The strong seasonality and interannual variability of monsoonal rainfall makes those areas highly vulnerable to climatic changes – it is therefore crucial to understand the factors driving the spatio-temporal monsoonal variability. The glimpse into Earth’s history thereby allows to study past climate dynamics under different boundary conditions, providing much-needed insights into the sensitivity of tropical hydroclimates. Thus, my research projects comprise different timeframes, reaching from the Late Triassic “Mega Monsoon” over the Eocene hothouse climate and the Plio-/Pleistocene ice-house world to the Anthropocene.

To extract paleo-environmental information, I combine sedimentological (grain size, end-member modelling), geochemical (XRF scanning), mineralogical (XRD) and micropaleontological methods (Mg/Ca-paleothermometry, Ba/Ca as a river water proxy) on marine and terrestrial sedimentary archives.

 

 

Ongoing projects:

 

1. The South American Monsoon during the Pleistocene and Holocene

The South American Monsoon supplies the majority of annual precipitation over (sub)tropical South America, yet its variability and sensitivity to climatic disturbances are not well-constrained so far. To study the drivers influencing the South American Monsoon System (e.g. insolation, atmospheric CO2 concentrations, ocean circulation), I utilize sediment cores obtained offshore East Brazil during R/V METEOR Expedition M125 in March/April 2016, offshore eastern Brazil. These cores were gathered close to river mouths and allow insights into continental hydroclimate as well as oceanic changes on different time scales – from orbital-scale climatic changes over the past 900,000 years to high-resolution records detailing the anthropogenic impact on soil erosion.

 

2. Taiwanese lake sediment records: East Asian Monsoon and typhoon variability (co-PI)

While the East Asian Monsoon provides the livelihood for more than 1.5 billion people, it also represents a major natural hazard due to frequent torrential floods, a risk severely reinforced by the frequent occurrence of strong typhoons. Yet, the factors driving monsoon and typhoon variability over East Asia are not well constrained so far. As part of a DAAD-funded student-exchange program, lakes in the Taiwanese Highlands are investigated as archives for Holocene storm activity and monsoonal rainfall intensity. Since tourisms has been an increasing economic factor in the pristine Taiwanese highlands, research is also devoted to detect the potential anthropogenic impact on the landscape evolution.

 

3. Climate and human history in the Mediterranean realm (co-PI)

The Mediterranean realm situates at the cross-roads of mid- and low latitude climatic phenomena (i.e. the westerlies and the North African Monsoon) and witnessed the emergence of the first highly developed human civilizations. Although early Mediterranean societies closely interacted with their environment throughout the Holocene, it remains unclear to what extent climatic and environmental change drove their rise and fall. In particular, the onset, early extent and consequences of anthropogenic change in terrestrial and notably in marine ecosystems are yet poorly constrained. These questions are tackled with sedimentary material retrieved during the R/V METEOR Cruise M144 in December 2017/January 2018. The recovered high-deposition-rate sediment cores from the Aegean and Adriatic Seas provide an ideal archive to decipher the environmental change on land and within the ocean. Integral part of this project is the collaboration with experts from archeology and pre-history from Heidelberg University.

 

4. Mediterranean Outflow Water (MOW) variability

Understanding MOW variability is pivotal as its salty waters constitute an important component of the intermediate thermohaline circulation in the North Atlantic. Due to its source in the Eastern Mediterranean Sea, the MOW is further a prime recorder of the North African Monsoonal strength, providing a prime example to study the potential influence of monsoonal systems on the global ocean circulation. Scientific drill cores from the Gulf of Cadiz, retrieved during IODP Expedition 339, provide unique archives for high-resolution studies of the MOW variability across the Plio-/Pleistocene. For this purpose sedimentological and geochemical tools are used to decipher past current speed, reflecting MOW variability.

 

5. Plio-Pleistocene subtropical gyre variability

The Plio-Pleistocene is marked by a persistent growth of glacial ice shields and a shift in the interglacial/glacial rhythms from a 41 kyr to a ~100 kyr-cyclicity, approx. 900 ka ago. Within two projects, it is investigated if a strong subtropical gyre circulation enhanced continental ice shield growth via increasing the moisture transport from mid to high-latitudes. A particular attention is paid on the influence of heat and salt injection by the MOW on the gyre dynamics. For this purpose foraminifera-based reconstructions of the upper water column structure from IODP Sites U1385 (Iberian Margin), U1313 (central mid-latitude North Atlantic), and ODP Site 1058 (western subtropical North Atlantic) covering the past ~3 Myrs.

 

6. “ENSO-Modoki” on the rise?

Recent observational studies have shown that aside of the “classical” El Niño Southern Oscillation (ENSO), a third type of ENSO has become more prominent. During these events SST anomalies are located in the Central Equatorial Pacific leading to alternate ENSO states coined “El Niño/La Niña Modoki”. A consequence of ENSO Modoki is increased warming in the subpolar realms of both hemispheres potentially accelerating high latitude ice sheet demise. To shed light onto the potential further evolution of ENSO Modoki, this project provides insights from a paleo-perspective via assessing the occurrence of ENSO Modoki-like climatic states during varying climatic background states. For this purpose, high-resolution proxy records of sea surface temperature variability are generated on ODP/IODP Sites from the western, central, and eastern Equatorial Pacific covering two time slices: (i) the mid-Pleistocene to Holocene and (ii) the Early Pliocene.

 

7. The Messel oil shale as an archive of Eocene hothouse climate variability (co-PI)

As the world warms due to rising greenhouse gas concentrations, the Earth system moves toward climate states without historic precedent. However, Earth’s history offers possible analogues for the warming world of the coming decades such as the early Eocene (~50 Ma). An exceptional sedimentary archive to study early to middle Eocene climate variability is presented by the maar-lake sediments of the Messel fossil-pit. While Messel is famous for its exceptionally well-preserved faunal and floral remains its sediments represent a unique archive for short-term climate dynamics operating during the geologically most recent greenhouse period. In this project, geochemical data is obtained via high-resolution XRF core scanning of the Messel FB2001 drill core to decipher the hydrologic variability in decadal to at maximum annual resolution.

 

8. Are there any “hyperthermals” in the upper Cretaceous? (Co-PI)

The principal objective of this project is to test for the occurrence or absence of so-called “hyperthermals” in the Maastrichtian in order to obtain a mechanistic understanding of greenhouse climates. This objective will be reached through the generation of paleoclimate proxy records (Mg/Ca-based SST, XRF-scanning) from two sites from the North Atlantic and Pacific Ocean, respectively, across a selected time interval (67–68.5 Ma). The high-resolutions records will allow detailed insight into the controlling mechanisms of greenhouse climates and therefore provide a test if the use of hyperthermal events might serve as analogues for future climate warming.

 

9. The Late Triassic in the German Basin: “Mega-Monsoon” and cyclostratigraphy

In this project, Late Triassic playa-alluvial fan sediments from the Gipsmergel-Keuper in SW Germany are investigated via facies analyses and physical properties (color reflectance, elemental composition) to reconstruct the factors driving the so-called “Mega-Monsoon” affecting large parts of (sub)tropical Pangea. Besides paleoclimatic questions (e.g. about the role of the paleogeographic configuration on the Mega-Monsoon strength), astrochronological methods are used to better constrain the still controversial Late Triassic stratigraphy of the Germanic Basin.

 

 

Scientific Career and Education:

since 10/2014

Scientific assistant („Akademischer Rat“), Institute of Earth Sciences (Heidelberg)

12/2009-09/2014

Scientific assistant, Institute of Geosciences (Frankfurt)

01/2008-11/2009

Postdoc, GEOMAR, (Kiel)

08/2007-12/2007

Postdoc, MARUM (Bremen)

02/2007-08/2007

Postdoc, NIOZ (den Burg, Texel, The Netherlands)

02/2006-02/2007

Postdoc, MARUM (Bremen)

10/2002-12/2005

Doktorand, MARUM (Bremen)

10/1995-02/2002

Studies of Geology and Paleontology, University Hamburg

 

Publications:

 

(as of 01/2022)

 

2021

  • Moal-Darrigade, P., Ducassou, E., Giraudeau, J., Bahr, A., Kaboth-Bahr, S., Hanquiez, V. (2021): MOW strengthening and contourite development over two analog climate cycles (MIS 11/12 and MIS 1/2) in the Gulf of Cadíz: an impact on North Atlantic climate during terminations and interglacials? Global and Planetary Change, 208, 103721.
  • Bahr, A., Kaboth-Bahr, S., Karas, C. (in press): The opening and closure of oceanic seaways during the Cenozoic: pacemaker of global climate change? In: Rossi, V., Longhitano, S., Olariu, C, Chiocci, F. (eds.): Straits and Seaways: controls, processes and implications in modern and ancient systems. Geological Society of London, Special Publications. doi: 10.1144/SP523-2021-54.
  • Bahr, A., Kaboth-Bahr, S., Geppert, P., Jaeschke, A., Chiessi, C., Cruz, F., Rethemeyer, J., Schefuß, E., Albuquerque, A.L., Pross, J., Friedrich, O. (2021): Growing impact of high-latitude forcing on the South American monsoon during the Holocene. Submitted to Paleoceanography and Paleoclimatology, 36, e2021PA004223 .
  • Kaboth-Bahr, S., Bahr, A., Yamoah, K., Chuang, C.K., Li, H.C., Su, C.C., Wei, K.Y. (2021): Rapid humidity changes across the Northern South 1 China Sea during the last ~40 kyrs. Marine Geology, 440, 106579.
  • Kaboth-Bahr, S., Bahr, A., Stepanek, C., Catunda, M.C.A., Karas, C., Ziegler, M., García-Gallardo, A., Grunert, P. (2021): Anomalous North Atlantic sea-surface warming before the intensification of Northern Hemisphere glaciations. Communications Earth & Environment, 2, doi: 10.1038/s43247-021-00232-5.
  • Bahr, A., Doubrawa, M., Titschack, J., Austermann, G., Koutsodendris, A., Nürnberg, D., Albuquerque, A.L., Friedrich, O., Raddatz, J. (2021): Monsoonal forcing controlled cold water coral growth off south-eastern Brazil during the past 160 kyrs. Biogeosciences, doi: 10.5194/bg-17-1-2020.
  • Catunda, M.C.A., Bahr, A., Kaboth-Bahr, S., Foukal, N.,  Zhang, X., Friedrich, O. (2021): Oceanic subsurface heat pathway fueled ice-sheet growth across the Mid-Pleistocene Transition. Geophysical Research Letters, 28, e2020GL091899.
  • Kaboth-Bahr, S., Bahr, A., Zeeden, C., Yamoah, K., Lone, M., Chuang, C.K., Lövemark, L., Wei, K.Y. (2021): A tale of shifting relations: East Asian summer and winter monsoon variability during the Holocene. Scientific Reports, 11, doi: 10.1038/s41598-021-85444-7.
  • Kaboth-Bahr, S., Gosling, W.D., Vogelsang, R., Bahr, A., Asfawossen, A., Cohen, A.S., Düsing, W., Foerster, V.E., Lamb, H.F., Maslin, M.A., Roberts, H.M., Schäbitz, F., Trauth, M.H. (2021): Paleo-ENSO impacted habitat availability for early modern humans. PNAS, 118, e2018277118.
  • Lin, T.W., Kaboth-Bahr, S., Yamoah, K.A., Bahr, A., Burr, G., Li, H.C., Su, C.C., Yam, R., Lövemark, L. (2021): East Asian winter monsoon variation during the last 3,000 years as recorded in a subtropical mountain lake, northeastern Taiwan. The Holocene.
  • Meier, K., Bahr, A., Chiessi, C., Albuquerque, A.L., Friedrich, O. (2021): Role of the tropical Atlantic for the interhemispheric heat transport during the last deglaciation. Paleoceanography and Paleoclimatology, 36, e2020PA004107.
  • Nürnberg, D., Riff, T., Bahr, A., Karas, C., Meier, K., Lippold, J. (2021): Atlantic Subtropical Gyre in relation to Western Boundary Current dynamics during abrupt glacial climate fluctuations. Global and Planetary Change, 21, 103497.
  • Pinho, T.M.L., Chiessi, C.M., Portilho-Ramos, R.C., Campos, M.C., Crivellari, S., Nascimento, R.A., Albuquerque, A. L., Bahr, A., Mulitza, S. (2021): Meridional changes in the South Atlantic Subtropical Gyre during Heinrich Stadials. Scientific Reports, 11, doi: 10.1038/s41598-021-88817-0.

2020

  • Bahr, A., Kolber, G, Kaboth, S., Reinhardt, L., Friedrich, O, Pross, J. (2020): Mega-monsoon variability during the late Triassic: Re-assessing the role of orbital forcing in 1 the deposition of playa sediments in the Germanic Basin. Sedimentology, 67, 951-970.
  • Campos, M., Chiessi, C.M., Venancio, I.M., Pino, T.M.L., Crivellari S., Kuhnert, H., Schmiedl, S., Diaz, R.A., Albuquerque, A.L., Portilho-Ramos, R.C., Bahr, A., Mulitza, S. (2020): Constraining millennial-scale changes in Northern Component Water ventilation in the western tropical South Atlantic. Paleoceanography and Paleoclimatology, 35, PA3876.
  • Hou, A., Bahr, A., Raddatz, J., Voigt, S., Keppler, F., Albuquerque, A.L., Chiessi, C., Friedrich, O. (2020): Insolation and greenhouse gas forcing of the South American Monsoon System across three glacial-interglacial cycles. Geophysical Research Letters, 47, e2020GL087948.
  • Hou, A., Bahr, A., Schmidt, S., Strebl, C., Albuquerque, A.L., Chiessi, C., Friedrich, O. (2020): Forcing of western tropical South Atlantic SST across three glacial-interglacial cycles. Global and Planetary Change, 188, 103150.
  • Karas, C., Khelifi, N., Bahr, A., Naafs, D., Nürnberg, D., Herrle, J. (2020): Weakening of the Atlantic Meridional Overturning Circulation during the onset of Northern Hemisphere Glaciation, 3.6-3.3 Ma. Global and Planetary Changes, 185, 103085.
  • Sierro, F.J., Hodell, D.A., Andersen, N., Azibeiro, L.A., Jimenez-Espejo, F.J., Bahr, A., Flores, J.A., Ausin, B., Rogerson, M., Lozano-Luz, R., Lebreiro, S., Hernandez-Molina, F.J. (2020): Mediterranean Overflow over the last 250 ky. Freshwater forcing from the tropics to the ice sheets. Submitted to Paleoceanography and Paleoclimatology, 35, e2020PA003931.

2019

  • Raddatz, J., Titschack, J., Frank, N., Freiwald, A., Conforti, A., Osborne, A., Skornitzke, S., Stiller, W., Rüggeberg, A., Voigt, S., Albuquerque, A.L.S., Vertino, A., Schröder-Ritzrau, A., Bahr, A. (2019): Formation patterns of Solenosmilia variabilis-bearing mounds off Brazil. Coral Reefs, doi: 10.1007/s00338-019-01882-w.
  • Campos, M., Chiessi, C. M., Prange, M., Mulitza, S., Kuhnert, H., Paul, A., Venancio, I.M., Albuquerque, A.L., Cruz, F.W., Bahr, A. (accepted): A new mechanism for millennial scale positive precipitation anomalies over tropical South America. Quaternary Science Reviews.
  • Reißig, S., Nürnberg, D., Bahr, A., Poggemann, D.W., Hoffmann, J. (2019): Southward displacement of the Subtropical Gyre circulation system during North Atlantic cold spells. Paleoceanography and Paleoclimatology, 34, doi: 10.1029/2018PA003376.
  • Warken, S.F., Scholz, D., Spötl, C., Jochum, K.P., Pachón, J.M., Bahr, A., Mangini, A. (2019): Caribbean hydroclimate and vegetation history across the last glacial period. Quaternary Science Reviews, 218, 75-90.
  • Skornitzke, S., Raddatz, J., Bahr, A., Pahn, G., Kauczor, H.U., Stiller, W. (2019): Experimental application of an automated alignment correction algorithm for geological CT imaging: phantom study and application to sediment cores from cold water coral mounds. European Radiology Experimental, 3, doi: 10.1186/s41747-019-0091-8.

2018

  • Poggemann, D.W., Nürnberg, D., Hathorne, E.D., Frank, M., Rath, W., Reißig, S., Bahr, A. (2018): Deglacial heat deprivation from the atmosphere in the Southern Ocean via Antarctic Intermediate Water. Paleoceanography and Paleoclimatology, 33, 1292-1305.
  • Bahr, A., Kaboth, S., Hodell, D., Zeeden, C., Fiebig, J., Friedrich, O., 2018. Oceanic heat pulses fueling moisture transport towards continental Europe across the mid-Pleistocene Transition. Quaternary Science Reviews, 179, 48-58.
  • Voelker, A.H.L., Jimenez-Espejo, F.J., Bahr, A., Rebotim, A., Cavaleiro, C., Salgueiro, E., Röhl, U. (2018). Data report: IODP Site U1387: the revised splice between Sections U1387B-18X-3 and U1387C-8R-3 (>171.6 mcd). Proceedings of the Integrated Ocean Drilling Program, 339, doi:10.2204/iodp.proc.339.204.2018.
  • Kaboth-Bahr, S., Bahr, A., Zeeden, C., Toucanne, S., Eynaud, F., Jiménez‐Espejo, F., Röhl, U., Friedrich, O., Pross, J., Löwemark, L. (2018): Monsoonal forcing of European ice‐sheet dynamics during the Late Quaternary. Geophysical Research Letters, 45, 7066-7074.
  • Bahr, A., Hoffmann, J., Schönfeld, J., Schmidt, M.W., Nürnberg, D., Batenburg, S.J., Voigt, S., 2018. Low-latitude expressions of high-latitude forcing during Heinrich Stadial 1 and the Younger Dryas in northern South America. Global and Planetary Change, 116, 1-9.
  • Jimenez-Espejo,F.J., García-Alix, A., Harada, N., Bahr, A., Sakai, S., Chang, Q., Sato, K, Suzuki, K., Okhouchi, N. (2018): Changes in detrital input, ventilation and productivity in the central Okhotsk Sea during the marine isotope stage 5e, penultimate interglacial period. Journal of Asian Earth Sciences, 156, 189-200.
  • Egger, L., van Peer, T., Lippert, P., Friedrich, O., Wilson, P.A., Liebrand, D., Norris, R., Bahr, A., Pross, J., 2018. Sea-level and surface-water change in the western North Atlantic across the Oligocene–Miocene Transition: a palynological perspective from IODP Site U1406 (Newfoundland margin). Marine Micropaleontology, 139, 57-71.

2017

  • Voigt, S., Weber, Y, Frisch, K., Bartenstein, A., Hellwig, A., Petschick, R., Bahr, A., Pross, J., Koutsodendris, A., Voigt, T., Verestek, V. Appel, E., 2017. Orbitally forced moisture supply, sediment flux and pedogenesis in Miocene mudflat deposits of SE Kazakhstan, Central Asia. Depositional Systems, 3, no. 2, 209-232.
  • Kaboth, S., de Boer, B., Bahr, A., Zeeden, Z., Lourens, L.J.: Paleoceanographic history of the Gulf of Cadiz during the past ~570 kyr, 2017. Inferences from IODP 339 Site U1386. Paleoceanography, 32, 634-647.
  • Poggemann, D.-W., Hathorne, E.C., Nürnberg, D., Frank, M., Bruhn, I., Reißig, S., Bahr, A., 2017. Rapid deglacial injection of nutrients into the tropical Atlantic via Antarctic Intermediate Water. Earth and Planetary Science Letters, 463, 118-126.
  • Jakob, K.A., Bolton, C.T., Wilson, P.A., Bahr, A., Pross, J., Fiebig, J., Kähler, K., Friedrich, O., 2017. Glacial-interglacial changes in equatorial Pacific surface-water structure during Plio-Pleistocene intensification of Northern Hemisphere Glaciation. Earth and Planetary Science Letters, 463, 69-80.

2016

  • Bahr, A., Spadano Albuquerque, A.L., Ardenghi, N., Batenburg, S.J., Bayer, M., Catunda, M.C., Conforti, A., Dias, B., Díaz Ramos, R., Egger, L.M., Evers, F., Fischer, T., Hatsukano, K., Hennrich, B., Hoffmann, J., Jivcov, S., Kusch, S., Munz, P., Niedermeyer, E., Osborne, A., Raddatz, J., Raeke, A.W., Reissig, S., Sebastian, U., Taniguchi, N., Martins Venancio, I., Voigt, S., Wachholz, A., 2016. South American Hydrological Balance and Paleoceanography during the Late Pleistocene and Holocene (SAMBA) - Cruise No. M125 - March 21 - April 15, 2016 - Rio de Janeiro (Brazil) - Fortaleza (Brazil). METEOR-Berichte, M125, 1-47.
  • Jakob, K.A., Wilson, P.A., Bahr, A., Bolton, C.T., Pross, J., Fiebig, J., Friedrich, O., 2016. Glacial-interglacial productivity changes in the eastern equatorial Pacific upwelling system and its response to Plio-Pleistocene ice-sheet dynamics. Paleoceanography, 31, 453-470.
  • Kaboth, S., Bahr, A., Reichart, G.-J., Jacobs, B., and Lourens, L. J., in press. New insights into upper MOW variability over the last 150 kyr from IODP 339 Site U1386 in the Gulf of Cadiz. Marine Geology, doi: 10.1016/j.margeo.2015.08.014.
  • Lubos, C., Dreibrodt, S., Bahr, A., 2016. Comparison of different methods for multi-element analysis in the archaeological context - results from sites in Germany and Turkey. Journal of Archaeological Science, 9, 44-53.
  • Lofi, J., Voelker, A., Ducassou, E., Hernández-Molina, F., Sierro, F., Bahr, A., Galvani, A., Lourens, L., Pardo-Igúzquiza, E. and Rodríguez-Tovar, F., 2016. Quaternary chronostratigraphic framework and sedimentary processes for the Gulf of Cadiz and Portuguese Contourite Depositional Systems derived from Natural Gamma Ray records. Marine Geology, 377, 40-57.

2015

  • Bahr, A., Kaboth, S., Jiménez-Espejo, F., Sierro, F., Voelker, A., Lourens, L., Röhl, U., Reichart, G., Escutia, C., Hernández-Molina, F., Pross, J., and Friedrich, O., 2015. Persistent monsoonal forcing of Mediterranean Outflow Water dynamics during the late Pleistocene. Geology, 43, 951-954.
  • Jiménez-Espejo, F., Pardos-Gené, M., Martínez-Ruiz, F., García-Alix, A., van de Flierdt, T., Toyofuku, T., Bahr, A., Kreissig, K., 2015. Geochemical evidence for intermediate water circulation in the westernmost Mediterranean over the last 20 ky cal BP and its impact on the Mediterranean outflow. Global and Planetary Change, 135, 38-46.
  • McCormack, J.M., Bahr, A., Gerdes, A., Tütken, T., and Prinz-Grimm, P., 2015. Preservation of successive diagenetic stages in Middle Triassic bonebeds: Evidence from in situ trace element and strontium isotope analysis of vertebrate fossils. Chemical Geology, 410, 108-123.
  • Voelker, A. H., Salgueiro, E., Rodrigues, T., Jimenez-Espejo, F. J., Bahr, A., Alberto, A., Loureiro, I., Padilha, M., Rebotim, A., Röhl, U. , 2015. Mediterranean Outflow and surface water variability off southern Portugal during the early Pleistocene: A snapshot at Marine Isotope Stages 29 to 34 (1020–1135ka). Global and Planetary Change, 133, 223-237.
  • Nürnberg, D., Bahr, A., Mildner, T., Eden, C., 2015. Loop Current variability - its relation to meridional overturning circulation and the impact of Mississippi discharge. In: Schulz, M., Paul, A.: Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC), Springer, p. 55-62.

2014

  • Bahr, A., Jiménez-Espejo, F.J., Kolasinac, N., Grunert, P., Hernández-Molina, F., Röhl, U., Voelker, A., Escutia, C., Stow, D.A.V., Hodell, D., and Alvarez Zarikian, C.A., 2014. Deciphering bottom current velocity and paleoclimate signals from contourite deposits in the Gulf of Cádiz during the last 140 kyr: an inorganic geochemical approach, Geochem. Geophys. Geosyst., 15(8), 3145-3160.
  • Hernández-Molina, F.J., Stow, D.A.V., Alvarez-Zarikian, C.A., Acton, G., Bahr, A., Balestra, B., Ducassou, E., Flood, R., Flores, J.-A., Furota, S., Grunert, P., Hodell, D., Jiménez-Espejo, F., Kim, J.K., Krissek, L., Kuroda, J., Li, B., Llave, E., Lofi, J., Lourens, L., Miller, M., Nanayama, F., Nishida, N., Richter, C., Roque, C., Pereira, H., Sanchez Goñi, M.F., Sierro, F.J., Singh, A.D., Sloss, C., Takashimizu, Y., Tzanova, A., Voelker, A., Williams, T., and Xuan, C., 2014. Onset of Mediterranean outflow into the North Atlantic, Science, 344(6189), 1244-1250.
  • Hoffmann, J., Bahr, A., Voigt, S., Schönfeld, J., Nürnberg, D., and Rethemeyer, J., 2014. Disentangling abrupt deglacial hydrological changes in northern South America: Insolation versus oceanic forcing, Geology, 42(7), 579-582.
  • Wacker, U., Fiebig, J., Schöne, B.R., Bahr, A., Friedrich, O., Tütken, T., Gischler, E., and Joachimski, M.M., 2014. Empirical calibration of the clumped isotope paleothermometer using calcites of various origins, Geochimica et Cosmochimica Acta, 141, 127-144.

2013

  • Bahr, A., Nürnberg, D., Karas, C., and Grützner, J., 2013. Millennial-scale versus long-term dynamics in the surface and subsurface of the western North Atlantic Subtropical Gyre during Marine Isotope Stage 5, Global and Planetary Change, 111(0), 77-87.
  • Bahr, A., Schönfeld, J., Hoffmann, J., Voigt, S., Aurahs, R., Kucera, M., Flögel, S., Jentzen, A., and Gerdes, A., 2013. Comparison of Ba/Ca and δ18OWATER as freshwater proxies: A multi-species core-top study on planktonic foraminifera from the vicinity of the Orinoco River mouth, Earth and Planetary Science Letters, 383, 45-57.

2012

  • Henkel, S., Mogollón, J.M., Nöthen, K., Franke, C., Bogus, K., Robin, E., Bahr, A., Blumenberg, M., Pape, T., Seifert, R., März, C., de Lange, G.J., and Kasten, S., 2012. Diagenetic barium cycling in Black Sea sediments – A case study for anoxic marine environments, Geochimica et Cosmochimica Acta, 88(0), 88-105.
  • Römer, M., Sahling, H., Pape, T., Bahr, A., Feseker, T., Wintersteller, P., and Bohrmann, G., 2012. Geological control and magnitude of methane ebullition from a high-flux seep area in the Black Sea – The Kerch Seep Area, Marine Geology, 319-322, 57-74.

2011

  • Bahr, A., Nürnberg, D., Schönfeld, J., and Garbe-Schönberg, D., 2011. Hydrological variability in Florida Straits during Marine Isotope Stage 5 cold events, Paleoceanography, 26(2), PA2214.
  • Pape, T., Bahr, A., Klapp, S.A., Abegg, F., and Bohrmann, G., 2011. High-intensity gas seepage causes rafting of shallow gas hydrates in the southeastern Black Sea, Earth and Planetary Science Letters, 307(1-2), 35-46.

2010

  • Bahr, A., Pape, T., Abegg, F., Bohrmann, G., van Weering, T.C.E., and Ivanov, M.K., 2010. Authigenic carbonates from the eastern Black Sea as an archive for shallow gas hydrate dynamics – results from the combination of CT imaging with mineralogical and stable isotope analyses, Marine and Petroleum Geology, 27, 1819-1829.
  • Kujau, A., Nürnberg, D., Zielhofer, C., Bahr, A., and Röhl, U., 2010. Mississippi River discharge over the last ~560,000 years - Indications from X-ray fluorescence core-scanning, Palaeogeography, Palaeoclimatology, Palaeoecology, 298(3-4), 311-318.
  • Pape, T., Kasten, S., Zabel, M., Bahr, A., Abegg, F., Hohnberg, H.-J., and Bohrmann, G., 2010. Gas hydrates in shallow deposits of the Amsterdam mud volcano, Anaximander Mountains, Northeastern Mediterranean Sea, Geo-Mar. Lett., 30, 187-206.
  • Pape, T., Bahr, A., Rethemeyer, J., Kessler, J.D., Sahling, H., Hinrichs, K.-U., Klapp, S.A., Reeburgh, W.S., and Bohrmann, G., 2010. Molecular and isotopic partitioning of low-molecular-weight hydrocarbons during migration and gas hydrate precipitation in deposits of a high-flux seepage site, Chemical Geology, 269(3-4), 350-363.

2009

  • Bahr, A., Pape, T., Bohrmann, G., Mazzini, A., Haeckel, M., Reitz, A., and Ivanov, M., 2009. Authigenic carbonate precipitates from the NE Black Sea: a mineralogical, geochemical, and lipid biomarker study, International Journal of Earth Sciences, 98, 677–695.
  • Kwiecien, O., Arz, H.W., Lamy, F., Plessen, B., Bahr, A., and Haug, G.H., 2009. North Atlantic control on precipitation pattern in the eastern Mediterranean/Black Sea region during the last glacial, Quaternary Research, 71(3), 375-384.
  • Sahling, H., Bohrmann, G., Artemov, Y.G., Bahr, A., Brüning, M., Klapp, S.A., Klaucke, I., Kozlova, E., Nikolovska, A., Pape, T., Reitz, A., and Wallmann, K., 2009. Vodyanitskii mud volcano, Sorokin trough, Black Sea: Geological characterization and quantification of gas bubble streams, Marine and Petroleum Geology, 26(9), 1799-1811.

2008

  • Bahr, A., Lamy, F., Arz, H.W., Major, C.O., Kwiecien, O., and Wefer, G., 2008. Abrupt changes of temperature and water chemistry in the late Pleistocene and early Holocene Black Sea, Geochemistry, Geophysics, Geosystems, 9(1), Q01004.
  • Bahr, A., Bohrmann, G., and Teichert, B.M.A., 2008. Data report: bulk mineralogical composition of Cascadia margin sediments, IODP Expedition 311, in Proceedings of the Integrated Drilling Program, edited by M. Riedel, et al., p. doi:10.2204/iodp.proc.2311.2201.2008, Integrated Ocean Drilling Program, College Station, TX, USA.
  • Kwiecien, O., Arz, H.W., Lamy, F., Wulf, S., Bahr, A., Röhl, U., and Haug, G.H., 2008. Estimated reservoir ages of the Black Sea since the last glacial, Radiocarbon, 50(1), 99–118.
  • Mazzini, A., Ivanov, M., Nermoen, A., Bahr, A., Bohrmann, G., Svensen, H., and Planke, S., 2008. Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments, Marine and Petroleum Geology, 25, 457-472.

2006

  • Bahr, A., Arz, H.W., Lamy, F., and Wefer, G., 2006. Late glacial to Holocene paleoenvironmental evolution of the Black Sea, reconstructed with stable oxygen isotope records obtained on ostracod shells, Earth and Planetary Science Letters, 241(3-4), 863-875.
  • Lamy, F., Arz, H.W., Bond, G., Bahr, A., and Pätzold, J., 2006. Multicentennial-scale hydrological changes in the Black Sea and northern Red Sea during the Holocene and the Arctic/North Atlantic Oscillation, Paleoceanography, 21(PA1008).

2005

  • Bahr, A., Lamy, F., Arz, H., Kuhlmann, H., and Wefer, G. 2005. Late glacial to Holocene climate and sedimentation history in the NW Black Sea, Marine Geology, 214, 309-322.

2004

  • Bahr, A., Wong, H.K., Yim, W.W.-S., Huang, G., and Lüdmann, T., 2004. Stratigraphy of Quaternary inner-shelf sediments in Tai O Bay, Hong Kong, based on ground-truthed seismic profiles Geo-Mar. Lett., 25(1), 20-33.

 

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Latest Revision: 2022-01-14
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