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10. From desiccation to wetlands and outflow: Rapid re-filling of Lake Victoria during the Latest Pleistocene 14–13 ka

Author

Wienhues, Giulia, Temoltzin-Loranca, Yunuen, Vogel, Hendrik, Morlock, Marina A., Cohen, Andrew S., Anselmetti, Flavio S., Bernasconi, Stefano M., Jaggi, Madalina, Tylmann, Wojciech, Kishe, Mary A., King, Leighton, Ngoepe, Nare, Courtney-Mustaphi, Colin J., Muschick, Moritz, Matthews, Blake, Mwaiko, Salome, Seehausen, Ole, Tinner, Willy, and Grosjean, Martin

Published
2024
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12. Latest Pleistocene and Holocene primary producer communities and hydroclimate in Lake Victoria, eastern Africa

Author

Wienhues, Giulia, Lami, Andrea, Bernasconi, Stefano, Jaggi, Madalina, Morlock, Marina A., Vogel, Hendrik, Cohen, Andrew S., Courtney Mustaphi, Colin J., Heiri, Oliver, King, Leighton, Kishe, Mary A., Misra, Pavani, Muschick, Moritz, Ngoepe, Nare, Matthews, Blake, Seehausen, Ole, Temoltzin-Loranca, Yunuen, Tinner, Willy, and Grosjean, Martin

Published
2024
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14. Long-term ecological successions of vegetation around Lake Victoria (East Africa) in response to latest Pleistocene and Early Holocene climatic changes

Author

Temoltzin-Loranca, Yunuén, Gobet, Erika, Vannière, Boris, van Leeuwen, Jacqueline F.N., Wienhues, Giulia, Courtney-Mustaphi, Colin, Kishe, Mary, Muschick, Moritz, King, Leighton, Misra, Pavani, Ngoepe, Nare, Matthews, Blake, Vogel, Hendrik, Heiri, Oliver, Seehausen, Ole, Grosjean, Martin, and Tinner, Willy

Published
2023
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15. Deep drilling reveals massive shifts in evolutionary dynamics after formation of ancient ecosystem

Author

Wilke, Thomas, Hauffe, Torsten, Jovanovska, Elena, Cvetkoska, Aleksandra, Donders, Timme, Ekschmitt, Klemens, Francke, Alexander, Lacey, Jack H, Levkov, Zlatko, Marshall, Charles R, Neubauer, Thomas A, Silvestro, Daniele, Stelbrink, Björn, Vogel, Hendrik, Albrecht, Christian, Holtvoeth, Jens, Krastel, Sebastian, Leicher, Niklas, Leng, Melanie J, Lindhorst, Katja, Masi, Alessia, Ognjanova-Rumenova, Nadja, Panagiotopoulos, Konstantinos, Reed, Jane M, Sadori, Laura, Tofilovska, Slavica, Van Bocxlaer, Bert, Wagner-Cremer, Friederike, Wesselingh, Frank P, Wolters, Volkmar, Zanchetta, Giovanni, Zhang, Xiaosen, and Wagner, Bernd

Subjects
Biological Sciences, Ecology, Evolutionary Biology, Earth Sciences, Geology, Biodiversity, Biological Evolution, Climate Change, Ecosystem, Fossils, Lakes
Abstract

The scarcity of high-resolution empirical data directly tracking diversity over time limits our understanding of speciation and extinction dynamics and the drivers of rate changes. Here, we analyze a continuous species-level fossil record of endemic diatoms from ancient Lake Ohrid, along with environmental and climate indicator time series since lake formation 1.36 million years (Ma) ago. We show that speciation and extinction rates nearly simultaneously decreased in the environmentally dynamic phase after ecosystem formation and stabilized after deep-water conditions established in Lake Ohrid. As the lake deepens, we also see a switch in the macroevolutionary trade-off, resulting in a transition from a volatile assemblage of short-lived endemic species to a stable community of long-lived species. Our results emphasize the importance of the interplay between environmental/climate change, ecosystem stability, and environmental limits to diversity for diversification processes. The study also provides a new understanding of evolutionary dynamics in long-lived ecosystems.

Published
2020

17. Paleoproductivity drivers in the Banggai Waters, Sulawesi, Indonesia: Insights from elemental analysis of marine surface sediment

Author

Wiguna Taufan, Yuwono Fareza Sasongko, Zuraida Rina, Atmadipoera Agus, Vogel Hendrik, Damanik Adrianus, Tournier Nicolas, and Cahyarini Sri Yudawati

Subjects
Microbiology, QR1-502, Physiology, QP1-981, Zoology, QL1-991
Abstract

Marine productivity, a pivotal factor in marine ecosystems and global carbon cycling, is influenced by various factors including upwelling and terrigenous nutrient influx. We investigated past marine productivity in Banggai Waters, Indonesia, using sediment samples (BUDEE22-29BC and BUDEE22-57BC) and Micro X-Ray Fluorescence (micro-XRF) analyses. Geochemical proxies (K/Ti, Ba/Al, and Zr/Al) help to assess terrigenous influx, upwelling events, and paleoproductivity. Our methodology categorizes productivity into upwelling-driven (UPW), terrigenous influx-driven (TER), and TUP (combined). The incorporation of geochemical proxy data has enabled a comprehensive understanding of historical marine productivity patterns. In BUDEE22-29BC, the K/Ti ratio initially rises and then falls below its threshold, whereas Ba/Al shows spikes and declines before rising again. Zr/Al ratios vary across depths, indicating different paleoproductivity drivers such as terrigenous influence and upwelling. BUDEE22-57BC displayed similar trends in K/Ti, Ba/Al, and Zr/Al ratios, with fluctuations indicating changes in paleoproductivity drivers, including mixing and upwelling effects. The unique positioning of Banggai Waters allows interactions between upwelling, terrigenous influx, and productivity. This study lays the groundwork for further research on past productivity changes and their drivers, thereby enhancing our understanding of marine dynamics.

Published
2024
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18. Diffuse axion-like particle searches

Author

Vogel, Hendrik, Laha, Ranjan, and Meyer, Manuel

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, Nuclear Experiment
Abstract

We propose a new method to search for axion-like particles (ALPs) based on the gamma-rays produced concomitant with high-energy astrophysical neutrinos. The existence of high-energy neutrinos implies production of gamma-rays in the same sources. Photons can convert into ALPs in the sources' magnetic fields, and will travel as ALPs through extragalactic space. Back-conversion in the Milky Way's magnetic field leads to a diffuse anisotropic high-energy photon flux that existing and upcoming gamma-ray detectors, like HAWC, CTA, and LHAASO can detect. This method probes unexplored ALP parameter space, with LHAASO being realistically sensitive to couplings above $10^{-11}\, \rm{GeV^{-1}}$ and masses up to $3\times 10^{-6} \, \rm{eV}$ in ten years. Our technique also explores viable ALP dark matter parameter space., Comment: v1: 9 pages, 3 figures. Comments welcome

Published
2017

20. Postglacial evolution of Lake Constance: sedimentological and geochemical evidence from a deep-basin sediment core

Author

Schaller, Sebastian, Böttcher, Michael E., Buechi, Marius W., Epp, Laura S., Fabbri, Stefano C., Gribenski, Natacha, Harms, Ulrich, Krastel, Sebastian, Liebezeit, Alina, Lindhorst, Katja, Marxen, Hanna, Raschke, Ulli, Schleheck, David, Schmiedinger, Iris, Schwalb, Antje, Vogel, Hendrik, Wessels, Martin, and Anselmetti, Flavio S.

Published
2022
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21. Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years

Author

Weber, Michael E., Bailey, Ian, Hemming, Sidney R., Martos, Yasmina M., Reilly, Brendan T., Ronge, Thomas A., Brachfeld, Stefanie, Williams, Trevor, Raymo, Maureen, Belt, Simon T., Smik, Lukas, Vogel, Hendrik, Peck, Victoria L., Armbrecht, Linda, Cage, Alix, Cardillo, Fabricio G., Du, Zhiheng, Fauth, Gerson, Fogwill, Christopher J., Garcia, Marga, Garnsworthy, Marlo, Glüder, Anna, Guitard, Michelle, Gutjahr, Marcus, Hernández-Almeida, Iván, Hoem, Frida S., Hwang, Ji-Hwan, Iizuka, Mutsumi, Kato, Yuji, Kenlee, Bridget, OConnell, Suzanne, Pérez, Lara F., Seki, Osamu, Stevens, Lee, Tauxe, Lisa, Tripathi, Shubham, Warnock, Jonathan, and Zheng, Xufeng

Published
2022
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24. A 1 Ma sedimentary ancient DNA (sedaDNA) record of catchment vegetation changes and the developmental history of tropical Lake Towuti (Sulawesi, Indonesia)

Author

Ekram, Md Akhtar‐E, primary, Campbell, Matthew, additional, Kose, Sureyya H., additional, Plet, Chloe, additional, Hamilton, Rebecca, additional, Bijaksana, Satria, additional, Grice, Kliti, additional, Russell, James, additional, Stevenson, Janelle, additional, Vogel, Hendrik, additional, and Coolen, Marco J. L., additional

Published
2024
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26. Temporal dynamics of invertebrate community assembly in Lake Victoria since the late Pleistocene based on chitinous remains

Author

King, Leighton, primary, Courtney‐Mustaphi, Colin, additional, Cuenca‐Cambronero, Maria, additional, Wienhues, Giulia, additional, Ngoepe, Nare, additional, Muschick, Moritz, additional, Temoltzin‐Loranca, Yunuen, additional, Vogel, Hendrik, additional, Grosjean, Martin, additional, Tinner, Willy, additional, Cohen, Andrew, additional, Kishe, Mary, additional, Heiri, Oliver, additional, Seehausen, Ole, additional, and Matthews, Blake, additional

Published
2024
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30. Lepton asymmetry from mixing and oscillations

Author

Kartavtsev, Alexander, Millington, Peter, and Vogel, Hendrik

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Theory
Abstract

We show how the two physically-distinct sources of CP-asymmetry relevant to scenarios of leptogenesis: (i) resonant mixing and (ii) oscillations between different flavours can be unambiguously identified within the Kadanoff-Baym formalism. These contributions are isolated by analyzing the spectral structure of the non-equilibrium propagators without relying on the definition of particle number densities. The mixing source is associated with the usual mass shells, whereas the oscillation source is identified with a third intermediate shell. In addition, we identify terms lying on the oscillation shell that can be interpreted as the destructive interference between mixing and oscillation. We confirm that identical shell structure is obtained in both the Heisenberg- and interaction-picture realizations of the Kadanoff-Baym formalism. In so doing, we illustrate the self-consistency and complementarity of these two approaches. The interaction-picture approach in particular has the advantage that it may be used to analyze all forms of mass spectra from quasi-degenerate through to hierarchical., Comment: 54 pages, 6 figures. To match published version: the discussion of the interaction-picture resummation procedure (section 3) expanded, further comments and clarification included, references added, and typos corrected

Published
2015
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32. A novel, continuous high-resolution palaeoecological record from central Italy suggests comparable land-use dynamics in Southern and Central Europe during the Neolithic

Author

Beffa, Giorgia, Gobet, Erika, Hächler, Luc, Isola, Ilaria, Morlock, Marina A., Sadori, Laura, Schläfli, Patrick, Rey, Fabian, van Vugt, Lieveke, Vogel, Hendrik, Zander, Paul D, Zanchetta, Giovanni, Grosjean, Martin, Tinner, Willy, Beffa, Giorgia, Gobet, Erika, Hächler, Luc, Isola, Ilaria, Morlock, Marina A., Sadori, Laura, Schläfli, Patrick, Rey, Fabian, van Vugt, Lieveke, Vogel, Hendrik, Zander, Paul D, Zanchetta, Giovanni, Grosjean, Martin, and Tinner, Willy

Abstract

Although rare, temporally and taxonomically highly-resolved palaeoecological studies with high chronological precision are essential to perform detailed comparisons with precisely dated independent evidence such as archaeological findings, historical events, or palaeoclimatic data. Using a new highly-resolved and chronologically precise sedimentary record from Lago di Mezzano (central Italy), we reconstruct decadal-scale vegetation, species diversity, and fire dynamics, aiming to better understand the linkages between climate, land use, fire, and plant communities from the Neolithic to the Copper Age (c. 5100–3100 cal. BC). Closed, mixed beech-oak forests, including evergreen Quercus ilex, dominated the landscape around Lago di Mezzano during the Neolithic and were disturbed by repeated opening phases, with important implications for lake biogeochemistry and mixing regimes. This was in conjunction with increasing fire activity to promote agro-pastoral practices, as inferred from increasing charcoal, Cerealia type, Triticum type, Hordeum type, Plantago lanceolata type, and Urtica pollen. Fires, on their turn, augmented species diversity (richness and evenness). The comparison of the Mediterranean record from Lago di Mezzano with available continuous and high-precision submediterranean and cool-temperate palynological sequences suggests comparable land use pulses across Southern and Central European regions, most likely in connection with climate change. The outcomes of this study are not only of palaeoecological and archaeological interest; they may also help to improve projections of ecosystem dynamics under future global change.

Published
2024
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33. Minicharged Particles from the Sun: A Cutting-Edge Bound

Author

Vinyoles, Núria and Vogel, Hendrik

Subjects
High Energy Physics - Phenomenology, Astrophysics - Solar and Stellar Astrophysics
Abstract

We study the impact on the Sun of an exotic energy-loss channel caused by plasmon decay into fermionic minicharged particles with charge $\epsilon e$ and mass $m_f$. We compare solar models with this extra emission to helioseismological and neutrino data, obtaining a bound $\epsilon <2.2\times 10^{-14}\ ({\rm 95\%\, CL})$ for $m_f\lesssim 25 \, \text{eV}$. Our result is comparable to previous limits from the cooling of globular cluster stars, while at the same time it is better understood and takes theoretical and observational errors into account., Comment: Improved statistical treatment, figures and bounds updated, matches the version accepted in JCAP

Published
2015
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34. Dark Radiation from a hidden U(1)

Author

Vogel, Hendrik and Redondo, Javier

Subjects
High Energy Physics - Phenomenology
Abstract

We discuss the impact of a hidden sector consisting of Minicharged Particles (MCPs) and massless hidden photons on the expansion history of our Universe. We present parameter scans for the amount of extra relativistic particles (Neff) and the abundance of light nuclei for fermionic MCPs with masses between ~100 keV and 10 GeV and minicharges in the range 10^(-11)-1. Current CMB and BBN data significantly constrain the available parameter space of MCPs. The shown results are a valuable indicator for future experimental searches and are presented in a flexible way so that more accurate results on Neff can be easily interpreted., Comment: Contributed to the 10th Patras Workshop on Axions, WIMPs and WISPs, CERN, June 29 to July 4, 2014

Published
2015

36. First lacustrine application of the diatom‐bound nitrogen isotope paleo‐proxy reveals coupling of denitrification and N2 fixation in a hyper‐eutrophic lake.

Author

Studer, Anja S., Wörmer, Lars, Vogel, Hendrik, Dubois, Nathalie, Bartosiewicz, Maciej, Hinrichs, Kai‐Uwe, Lepori, Fabio, and Lehmann, Moritz F.

Subjects
LAKE sediments, NITROGEN isotopes, NUTRIENT cycles, ORGANIC compounds, DENITRIFICATION
Abstract

Past changes in the input/output, and internal cycling, of bioavailable nitrogen (N) in marine and lacustrine environments can be reconstructed by analyzing the N isotopic composition (δ15N) of organic matter in the sedimentary record. To verify, and eliminate, potential biases of bulk sedimentary δ15N (δ15Nbulk) signatures by diagenetic alteration and external N inputs, we applied, for the first time, the diatom‐bound N isotope (δ15Ndb) paleo‐proxy to lake sediments. By comparing δ15Nbulk and δ15Ndb in a sedimentary record from eutrophic Lake Lugano (Switzerland), we demonstrate that changing redox conditions influence the degree of N‐isotopic alteration of the bulk sediment, emphasizing the need for caution when interpreting δ15Nbulk in paleolimnological studies. Furthermore, in combining δ15Ndb measurements with X‐ray fluorescence scanning and state‐of‐the‐art molecular biomarker analyses, we reconstruct nutrient cycling and paleoenvironmental conditions in the lake over the past ~ 125 yr. Coeval with the period of severe eutrophication in Lake Lugano in the 1960s, our proxy data indicate that export production, δ15Ndb, and the concentration of heterocyst glycolipids (a biomarker for N2‐fixing cyanobacteria) increased simultaneously. Together, these data suggest that the rise in δ15Ndb is likely the result of enhanced water‐column denitrification in response to increased phytoplankton productivity. We hypothesize that greater export production during eutrophication led to anoxic conditions in the hypolimnion as a result of enhanced organic matter remineralization, raising water‐column denitrification. Enhanced N loss and remobilization of phosphorous (P) from the sediments under anoxic conditions lowered the N : P ratio in the lake, fostering cyanobacterial N2 fixation in surface waters. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Insights into the evolution of the young Lake Ohrid ecosystem and vegetation succession from a southern European refugium during the Early Pleistocene

Author

Panagiotopoulos, Konstantinos, Holtvoeth, Jens, Kouli, Katerina, Marinova, Elena, Francke, Alexander, Cvetkoska, Aleksandra, Jovanovska, Elena, Lacey, Jack H., Lyons, Emma T., Buckel, Connie, Bertini, Adele, Donders, Timme, Just, Janna, Leicher, Niklas, Leng, Melanie J., Melles, Martin, Pancost, Richard D., Sadori, Laura, Tauber, Paul, Vogel, Hendrik, Wagner, Bernd, and Wilke, Thomas

Published
2020
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42. Dark Radiation constraints on minicharged particles in models with a hidden photon

Author

Vogel, Hendrik and Redondo, Javier

Subjects
High Energy Physics - Phenomenology
Abstract

We compute the thermalization of a hidden sector consisting of minicharged fermions (MCPs) and massless hidden photons in the early Universe. The precise measurement of the anisotropies of the cosmic microwave background (CMB) by Planck and the relic abundance of light nuclei produced during big bang nucleosynthesis (BBN) constrain the amount of dark radiation of this hidden sector through the effective number of neutrino species, Neff. This study presents novel and accurate predictions of dark radiation in the strongly and weakly coupled regime for a wide range of model parameters. We give the value of Neff for MCP masses between 100 keV and 10 GeV and minicharges in the range 10^(-11)-1. Our results can be used to constrain MCPs with the current data and they are also a valuable indicator for future experimental searches, should the hint for dark radiation manifest itself in the next release of Planck's data., Comment: 27 pages, 13 figures, matches the version accepted in JCAP

Published
2013
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44. First lacustrine application of the diatom‐bound nitrogen isotope paleo‐proxy reveals coupling of denitrification and N2fixation in a hyper‐eutrophic lake

Author

Studer, Anja S., Wörmer, Lars, Vogel, Hendrik, Dubois, Nathalie, Bartosiewicz, Maciej, Hinrichs, Kai‐Uwe, Lepori, Fabio, and Lehmann, Moritz F.

Abstract

Past changes in the input/output, and internal cycling, of bioavailable nitrogen (N) in marine and lacustrine environments can be reconstructed by analyzing the N isotopic composition (δ15N) of organic matter in the sedimentary record. To verify, and eliminate, potential biases of bulk sedimentary δ15N (δ15Nbulk) signatures by diagenetic alteration and external N inputs, we applied, for the first time, the diatom‐bound N isotope (δ15Ndb) paleo‐proxy to lake sediments. By comparing δ15Nbulkand δ15Ndbin a sedimentary record from eutrophic Lake Lugano (Switzerland), we demonstrate that changing redox conditions influence the degree of N‐isotopic alteration of the bulk sediment, emphasizing the need for caution when interpreting δ15Nbulkin paleolimnological studies. Furthermore, in combining δ15Ndbmeasurements with X‐ray fluorescence scanning and state‐of‐the‐art molecular biomarker analyses, we reconstruct nutrient cycling and paleoenvironmental conditions in the lake over the past ~ 125 yr. Coeval with the period of severe eutrophication in Lake Lugano in the 1960s, our proxy data indicate that export production, δ15Ndb, and the concentration of heterocyst glycolipids (a biomarker for N2‐fixing cyanobacteria) increased simultaneously. Together, these data suggest that the rise in δ15Ndbis likely the result of enhanced water‐column denitrification in response to increased phytoplankton productivity. We hypothesize that greater export production during eutrophication led to anoxic conditions in the hypolimnion as a result of enhanced organic matter remineralization, raising water‐column denitrification. Enhanced N loss and remobilization of phosphorous (P) from the sediments under anoxic conditions lowered the N : P ratio in the lake, fostering cyanobacterial N2fixation in surface waters.

Published
2024
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45. From desiccation to wetlands and outflow: Rapid re-filling of Lake Victoria during the Latest Pleistocene 14–13 ka

Author

Wienhues, Giulia, primary, Temoltzin-Loranca, Yunuen, additional, Vogel, Hendrik, additional, Morlock, Marina A., additional, Cohen, Andrew S., additional, Anselmetti, Flavio S., additional, Bernasconi, Stefano M., additional, Jaggi, Madalina, additional, Tylmann, Wojciech, additional, Kishe, Mary A., additional, King, Leighton, additional, Ngoepe, Nare, additional, Courtney-Mustaphi, Colin J., additional, Muschick, Moritz, additional, Matthews, Blake, additional, Mwaiko, Salome, additional, Seehausen, Ole, additional, Tinner, Willy, additional, and Grosjean, Martin, additional

Published
2023
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48. Mediterranean winter rainfall in phase with African monsoons during the past 1.36 million years

Author

Wagner, Bernd, Vogel, Hendrik, Francke, Alexander, Friedrich, Tobias, Donders, Timme, Lacey, Jack H., and Leng, Melanie J.

Subjects
Africa -- Environmental aspects, Mediterranean region -- Environmental aspects, Paleoclimatology -- Analysis, Precipitation variability -- Analysis, Monsoons -- Analysis, Winter -- Environmental aspects -- Natural history, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Mediterranean climates are characterized by strong seasonal contrasts between dry summers and wet winters. Changes in winter rainfall are critical for regional socioeconomic development, but are difficult to simulate accurately.sup.1 and reconstruct on Quaternary timescales. This is partly because regional hydroclimate records that cover multiple glacial-interglacial cycles.sup.2,3 with different orbital geometries, global ice volume and atmospheric greenhouse gas concentrations are scarce. Moreover, the underlying mechanisms of change and their persistence remain unexplored. Here we show that, over the past 1.36 million years, wet winters in the northcentral Mediterranean tend to occur with high contrasts in local, seasonal insolation and a vigorous African summer monsoon. Our proxy time series from Lake Ohrid on the Balkan Peninsula, together with a 784,000-year transient climate model hindcast, suggest that increased sea surface temperatures amplify local cyclone development and refuel North Atlantic low-pressure systems that enter the Mediterranean during phases of low continental ice volume and high concentrations of atmospheric greenhouse gases. A comparison with modern reanalysis data shows that current drivers of the amount of rainfall in the Mediterranean share some similarities to those that drive the reconstructed increases in precipitation. Our data cover multiple insolation maxima and are therefore an important benchmark for testing climate model performance. Comparisons between past regional drivers of precipitation extremes found time series data from Lake Ohrid and modern climate models of the Mediterranean may help to reduce simulation uncertainties in predictions of the Mediterranean climate., Author(s): Bernd Wagner [sup.1] , Hendrik Vogel [sup.2] , Alexander Francke [sup.1] [sup.3] , Tobias Friedrich [sup.4] , Timme Donders [sup.5] , Jack H. Lacey [sup.6] , Melanie J. Leng [...]

Published
2019
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