Articles | Volume 22, issue 1
https://doi.org/10.5194/bg-22-55-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-22-55-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Jan 2025
Research article |
| 07 Jan 2025
| 07 Jan 2025
A long-term drought reconstruction based on oxygen isotope tree ring data for central and eastern parts of Europe (Romania)
Viorica Nagavciuc
CORRESPONDING AUTHOR
Paleoclimate Dynamics, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven 27570, Germany
Forest Biometrics Laboratory – Faculty of Forestry, “Stefan cel Mare” University of Suceava, Universităţii Street No. 13, Suceava 720229, Romania
Gerhard Helle
German Research Centre for Geosciences GFZ, 4.3 Climate Dynamics and Landscape Evolution, Telegrafenberg, Potsdam 14473, Germany
Maria Rădoane
Forest Biometrics Laboratory – Faculty of Forestry, “Stefan cel Mare” University of Suceava, Universităţii Street No. 13, Suceava 720229, Romania
Cătălin-Constantin Roibu
Forest Biometrics Laboratory – Faculty of Forestry, “Stefan cel Mare” University of Suceava, Universităţii Street No. 13, Suceava 720229, Romania
Mihai-Gabriel Cotos
Forest Biometrics Laboratory – Faculty of Forestry, “Stefan cel Mare” University of Suceava, Universităţii Street No. 13, Suceava 720229, Romania
Paleoclimate Dynamics, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven 27570, Germany
Forest Biometrics Laboratory – Faculty of Forestry, “Stefan cel Mare” University of Suceava, Universităţii Street No. 13, Suceava 720229, Romania
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This preprint is open for discussion and under review for Natural Hazards and Earth System Sciences (NHESS).
Short summary
Short summary
This research by the Drought in the Anthropocene (DitA) network highlights the crucial role of forecasting systems and Drought Management Plans in European drought risk management. Based on a survey of water managers during the 2022 European drought, it underscores the impact of preparedness on response and the evolution of drought management strategies across the continent. The study concludes with a plea for a European Drought Directive.
Riccardo Biella, Ansastasiya Shyrokaya, Monica Ionita, Raffaele Vignola, Samuel Sutanto, Andrijana Todorovic, Claudia Teutschbein, Daniela Cid, Maria Carmen Llasat, Pedro Alencar, Alessia Matanó, Elena Ridolfi, Benedetta Moccia, Ilias Pechlivanidis, Anne van Loon, Doris Wendt, Elin Stenfors, Fabio Russo, Jean-Philippe Vidal, Lucy Barker, Mariana Madruga de Brito, Marleen Lam, Monika Bláhová, Patricia Trambauer, Raed Hamed, Scott J. McGrane, Serena Ceola, Sigrid Jørgensen Bakke, Svitlana Krakovska, Viorica Nagavciuc, Faranak Tootoonchi, Giuliano Di Baldassarre, Sandra Hauswirth, Shreedhar Maskey, Svitlana Zubkovych, Marthe Wens, and Lena Merete Tallaksen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2069, https://doi.org/10.5194/egusphere-2024-2069, 2024
This preprint is open for discussion and under review for Natural Hazards and Earth System Sciences (NHESS).
Short summary
Short summary
This research by the Drought in the Anthropocene (DitA) network highlights gaps in European drought management exposed by the 2022 drought and proposes a new direction. Using a Europe-wide survey of water managers, we examine four areas: increasing drought risk, impacts, drought management strategies, and their evolution. Despite growing risks, management remains fragmented and short-term. However, signs of improvement suggest readiness for change. We advocate for a European Drought Directive.
Viorica Nagavciuc, Simon L. L. Michel, Daniel F. Balting, Gerhard Helle, Mandy Freund, Gerhard H. Schleser, David N. Steger, Gerrit Lohmann, and Monica Ionita
Clim. Past, 20, 573–595, https://doi.org/10.5194/cp-20-573-2024, https://doi.org/10.5194/cp-20-573-2024, 2024
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Di Cai, Gerrit Lohmann, Xianyao Chen, and Monica Ionita
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Preprint archived
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Viorica Nagavciuc, Patrick Scholz, and Monica Ionita
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Short summary
Short summary
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Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-47, https://doi.org/10.5194/essd-2022-47, 2022
Preprint withdrawn
Short summary
Short summary
Vapor pressure deficit is a key component of vegetation dynamics, soil science, meteorology, and soil science. In this study, we reconstruct the variability of the vapor pressure deficit in the past and examine the changes in future scenarios using climate models. In this way, past, present and future changes of the vapor pressure deficit can be detected locally, regionally, and continentally with higher statistical significance.
Petru Cosmin Vaideanu, Mihai Dima, Monica Ionita, and Mirela Voiculescu
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2021-75, https://doi.org/10.5194/esd-2021-75, 2021
Revised manuscript not accepted
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Observing clouds and their properties is not straightforward, however, these are important for reducing climate models uncertainties. Ground-based observations are spatially limited while satellite data are accompanied by various artefacts. In this paper, we use corrected observational and state-of-the-art reanalysis cloud data to show that the recent evolution of total cloud cover on a global scale is linked to the Eastern Pacific and the Central Pacific El Niño–Southern Oscillation.
Franziska Slotta, Lukas Wacker, Frank Riedel, Karl-Uwe Heußner, Kai Hartmann, and Gerhard Helle
Biogeosciences, 18, 3539–3564, https://doi.org/10.5194/bg-18-3539-2021, https://doi.org/10.5194/bg-18-3539-2021, 2021
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The African baobab is a challenging climate and environmental archive for its semi-arid habitat due to dating uncertainties and parenchyma-rich wood anatomy. Annually resolved F14C data of tree-ring cellulose (1941–2005) from a tree in Oman show the annual character of the baobab’s growth rings but were up to 8.8 % lower than expected for 1964–1967. Subseasonal δ13C and δ18O patterns reveal years with low average monsoon rain as well as heavy rainfall events from pre-monsoonal cyclones.
Monica Ionita and Viorica Nagavciuc
Nat. Hazards Earth Syst. Sci., 21, 1685–1701, https://doi.org/10.5194/nhess-21-1685-2021, https://doi.org/10.5194/nhess-21-1685-2021, 2021
Short summary
Short summary
By analyzing the joint frequency of compound events (e.g., high temperatures and droughts), we show that the potential evapotranspiration and mean air temperature are becoming essential components for drought occurrence over Central Europe and the Mediterranean region. This, together with the projected increase in potential evapotranspiration under a warming climate, has significant implications concerning the future occurrence of drought events over these regions.
Aurel Perşoiu, Nenad Buzjak, Alexandru Onaca, Christos Pennos, Yorgos Sotiriadis, Monica Ionita, Stavros Zachariadis, Michael Styllas, Jure Kosutnik, Alexandru Hegyi, and Valerija Butorac
The Cryosphere, 15, 2383–2399, https://doi.org/10.5194/tc-15-2383-2021, https://doi.org/10.5194/tc-15-2383-2021, 2021
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Extreme precipitation events in summer 2019 led to catastrophic loss of cave and surface ice in SE Europe at levels unprecedented during the last century. The projected continuous warming and increase in precipitation extremes could pose an additional threat to glaciers in southern Europe, resulting in a potentially ice-free SE Europe by the middle of the next decade (2035 CE).
Daniel F. Balting, Monica Ionita, Martin Wegmann, Gerhard Helle, Gerhard H. Schleser, Norel Rimbu, Mandy B. Freund, Ingo Heinrich, Diana Caldarescu, and Gerrit Lohmann
Clim. Past, 17, 1005–1023, https://doi.org/10.5194/cp-17-1005-2021, https://doi.org/10.5194/cp-17-1005-2021, 2021
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To extend climate information back in time, we investigate the climate sensitivity of a δ18O network from tree rings, consisting of 26 European sites and covering the last 400 years. Our results suggest that the δ18O variability is associated with large-scale anomaly patterns that resemble those observed for the El Niño–Southern Oscillation. We conclude that the investigation of large-scale climate signals far beyond instrumental records can be done with a δ18O network derived from tree rings.
Carmen-Andreea Bădăluţă, Aurel Perșoiu, Monica Ionita, and Natalia Piotrowska
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We present a reconstruction of summer temperature for the last millennium in east-central Europe that shows little summer temperature differences between the Medieval Warm Period and the Little Ice Age on centennial scales as well as the fact that well-expressed minima and maxima occurred synchronously with periods of low and high solar activity, respectively. Furthermore, summer temperatures fluctuated with a periodicity similar to that of the Atlantic Multidecadal Oscillation.
Sigrid J. Bakke, Monica Ionita, and Lena M. Tallaksen
Hydrol. Earth Syst. Sci., 24, 5621–5653, https://doi.org/10.5194/hess-24-5621-2020, https://doi.org/10.5194/hess-24-5621-2020, 2020
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This study provides an in-depth analysis of the 2018 northern European drought. Large parts of the region experienced 60-year record-breaking temperatures, linked to high-pressure systems and warm surrounding seas. Meteorological drought developed from May and, depending on local conditions, led to extreme low flows and groundwater drought in the following months. The 2018 event was unique in that it affected most of Fennoscandia as compared to previous droughts.
Monica Ionita, Viorica Nagavciuc, and Bin Guan
Hydrol. Earth Syst. Sci., 24, 5125–5147, https://doi.org/10.5194/hess-24-5125-2020, https://doi.org/10.5194/hess-24-5125-2020, 2020
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Analysis of the largest 10 floods in the lower Rhine, between 1817 and 2015, shows that all these extreme flood peaks have been preceded, up to 7 d in advance, by intense moisture transport from the tropical North Atlantic basin in the form of narrow bands also known as atmospheric rivers. The results presented in this study offer new insights regarding the importance of moisture transport as the driver of extreme flooding in the lower part of the Rhine catchment area.
Aurel Perşoiu, Monica Ionita, and Harvey Weiss
Clim. Past, 15, 781–793, https://doi.org/10.5194/cp-15-781-2019, https://doi.org/10.5194/cp-15-781-2019, 2019
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We present a reconstruction of winter climate around 4.2 ka cal BP in Europe, west Asia, and northern Africa that shows generally low temperatures and heterogeneously distributed precipitation. We hypothesize that in the extratropical Northern Hemisphere the 4.2 ka BP event was caused by the strengthening and expansion of the Siberian High, which effectively blocked the moisture-carrying westerlies from reaching west Asia and also resulted in outbreaks of northerly cold and dry winds.
Monica Ionita, Klaus Grosfeld, Patrick Scholz, Renate Treffeisen, and Gerrit Lohmann
Earth Syst. Dynam., 10, 189–203, https://doi.org/10.5194/esd-10-189-2019, https://doi.org/10.5194/esd-10-189-2019, 2019
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Based on a simple statistical model we show that the September sea ice extent has a high predictive skill, up to 4 months ahead, based on previous months' oceanic and atmospheric conditions. Our statistical model skillfully captures the interannual variability of the September sea ice extent and could provide a valuable tool for identifying relevant regions and oceanic and atmospheric parameters that are important for the sea ice development in the Arctic.
Monica Ionita, Patrick Scholz, Klaus Grosfeld, and Renate Treffeisen
Earth Syst. Dynam., 9, 939–954, https://doi.org/10.5194/esd-9-939-2018, https://doi.org/10.5194/esd-9-939-2018, 2018
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In austral spring 2016 the Antarctic region experienced anomalous sea ice retreat in all sectors, with sea ice extent in October and November 2016 being the lowest in the Southern Hemisphere over the observational record (1979–present). The extreme sea ice retreat was accompanied by the wettest and warmest spring on record, over large areas covering the Indian ocean, the Ross Sea, and the Weddell Sea.
Carmen-Andreea Bădăluță, Aurel Perșoiu, Monica Ionita, Viorica Nagavciuc, and Petruț-Ionel Bistricean
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2018-6, https://doi.org/10.5194/hess-2018-6, 2018
Manuscript not accepted for further review
Dennis Meißner, Bastian Klein, and Monica Ionita
Hydrol. Earth Syst. Sci., 21, 6401–6423, https://doi.org/10.5194/hess-21-6401-2017, https://doi.org/10.5194/hess-21-6401-2017, 2017
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Inland waterway transport is a commercial sector relying on hydrological forecasts on different timescales. This paper describes the set-up of a monthly to seasonal forecasting system for the German waterways. Multiple approaches are tested, compared and combined. Despite the predictive limitations on longer lead times, this study reveals the existence of a valuable predictability on monthly up to seasonal timescales. Forecast quality depends on forecast location, lead time and season.
Norel Rimbu, Monica Ionita, Markus Czymzik, Achim Brauer, and Gerrit Lohmann
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-137, https://doi.org/10.5194/cp-2017-137, 2017
Manuscript not accepted for further review
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Multi-decadal to millennial flood frequency variations in the Mid- to Late Holocene in a flood layer record from Lake Ammersee is strongly related to the occurrence of extreme precipitation and temperatures in the northeastern Europe.
Virgil Drăguşin, Sorin Balan, Dominique Blamart, Ferenc Lázár Forray, Constantin Marin, Ionuţ Mirea, Viorica Nagavciuc, Iancu Orăşeanu, Aurel Perşoiu, Laura Tîrlă, Alin Tudorache, and Marius Vlaicu
Hydrol. Earth Syst. Sci., 21, 5357–5373, https://doi.org/10.5194/hess-21-5357-2017, https://doi.org/10.5194/hess-21-5357-2017, 2017
Gregor Laaha, Tobias Gauster, Lena M. Tallaksen, Jean-Philippe Vidal, Kerstin Stahl, Christel Prudhomme, Benedikt Heudorfer, Radek Vlnas, Monica Ionita, Henny A. J. Van Lanen, Mary-Jeanne Adler, Laurie Caillouet, Claire Delus, Miriam Fendekova, Sebastien Gailliez, Jamie Hannaford, Daniel Kingston, Anne F. Van Loon, Luis Mediero, Marzena Osuch, Renata Romanowicz, Eric Sauquet, James H. Stagge, and Wai K. Wong
Hydrol. Earth Syst. Sci., 21, 3001–3024, https://doi.org/10.5194/hess-21-3001-2017, https://doi.org/10.5194/hess-21-3001-2017, 2017
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In 2015 large parts of Europe were affected by a drought. In terms of low flow magnitude, a region around the Czech Republic was most affected, with return periods > 100 yr. In terms of deficit volumes, the drought was particularly severe around S. Germany where the event lasted notably long. Meteorological and hydrological events developed differently in space and time. For an assessment of drought impacts on water resources, hydrological data are required in addition to meteorological indices.
Monica Ionita, Lena M. Tallaksen, Daniel G. Kingston, James H. Stagge, Gregor Laaha, Henny A. J. Van Lanen, Patrick Scholz, Silvia M. Chelcea, and Klaus Haslinger
Hydrol. Earth Syst. Sci., 21, 1397–1419, https://doi.org/10.5194/hess-21-1397-2017, https://doi.org/10.5194/hess-21-1397-2017, 2017
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This paper analyses the European summer drought of 2015 from a climatological perspective, including its origin and spatial and temporal development, and how it compares with the 2003 event. It discusses the main contributing factors controlling the occurrence and persistence of the event: temperature and precipitation anomalies, blocking episodes and sea surface temperatures. The results represent the outcome of a collaborative initiative of members of UNESCO’s FRIEND-Water program.
Norel Rimbu, Markus Czymzik, Monica Ionita, Gerrit Lohmann, and Achim Brauer
Clim. Past, 12, 377–385, https://doi.org/10.5194/cp-12-377-2016, https://doi.org/10.5194/cp-12-377-2016, 2016
K. Schollaen, C. Karamperidou, P. Krusic, E. Cook, and G. Helle
Clim. Past, 11, 1325–1333, https://doi.org/10.5194/cp-11-1325-2015, https://doi.org/10.5194/cp-11-1325-2015, 2015
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Indonesia’s climate has been linked to El Niño-Southern Oscillation (ENSO) events that often result in extensive droughts and floods over Indonesia. In this study we investigate ENSO-related signals in a tree-ring δ18O record of Javanese teak. Our results reveal a clear influence of Warm Pool El Niño events on Javanese tree-ring δ18O. These results illustrate the importance of considering ENSO flavors when interpreting palaeoclimate proxy records in the tropics.
K. Schollaen, H. Baschek, I. Heinrich, and G. Helle
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-11587-2015, https://doi.org/10.5194/bgd-12-11587-2015, 2015
Revised manuscript not accepted
Related subject area
Paleobiogeoscience: Proxy use, Development & Validation
Deep-sea stylasterid δ18O and δ13C maps inform sampling scheme for paleotemperature reconstructions
Mg/Ca and δ18O in multiple species of planktonic foraminifera from 15 Ma to Recent
Disentangling influences of climate variability and lake-system evolution on climate proxies derived from isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs): the 250 kyr Lake Chala record
Electron backscatter diffraction analysis unveils foraminiferal calcite microstructure and processes of diagenetic alteration
Quantifying the δ15N trophic offset in a cold-water scleractinian coral (CWC): implications for the CWC diet and coral δ15N as a marine N cycle proxy
Stable oxygen isotopes of crocodilian tooth enamel allow tracking Plio-Pleistocene evolution of freshwater environments and climate in the Shungura Formation (Turkana Depression, Ethiopia)
Reviews and syntheses: Review of proxies for low-oxygen paleoceanographic reconstructions
Charcoal morphologies and morphometrics of a Eurasian grass-dominated system for robust interpretation of past fuel and fire type
Single-species dinoflagellate cyst carbon isotope fractionation in core-top sediments: environmental controls, CO2 dependency and proxy potential
Past fire dynamics inferred from polycyclic aromatic hydrocarbons and monosaccharide anhydrides in a stalagmite from the archaeological site of Mayapan, Mexico
Examination of the parameters controlling the triple oxygen isotope composition of grass leaf water and phytoliths at a Mediterranean site: a model–data approach
Biomarker characterization of the North Water Polynya, Baffin Bay: implications for local sea ice and temperature proxies
Technical note: No impact of alkenone extraction on foraminiferal stable isotope, trace element and boron isotope geochemistry
Experimental burial diagenesis of aragonitic biocarbonates: from organic matter loss to abiogenic calcite formation
A modern snapshot of the isotopic composition of lacustrine biogenic carbonates – records of seasonal water temperature variability
Performance of temperature and productivity proxies based on long-chain alkane-1, mid-chain diols at test: a 5-year sediment trap record from the Mauritanian upwelling
Validation of a coupled δ2Hn-alkane–δ18Osugar paleohygrometer approach based on a climate chamber experiment
Experimental production of charcoal morphologies to discriminate fuel source and fire type: an example from Siberian taiga
Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera
Calibration of Mg ∕ Ca and Sr ∕ Ca in coastal marine ostracods as a proxy for temperature
Technical note: Accelerate coccolith size separation via repeated centrifugation
Mg∕Ca, Sr∕Ca and stable isotopes from the planktonic foraminifera T. sacculifer: testing a multi-proxy approach for inferring paleotemperature and paleosalinity
Chemical destaining and the delta correction for blue intensity measurements of stained lake subfossil trees
Modern calibration of Poa flabellata (tussac grass) as a new paleoclimate proxy in the South Atlantic
Seawater pH reconstruction using boron isotopes in multiple planktonic foraminifera species with different depth habitats and their potential to constrain pH and pCO2 gradients
Bottom-water deoxygenation at the Peruvian margin during the last deglaciation recorded by benthic foraminifera
The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii)
Benthic foraminifera as tracers of brine production in the Storfjorden “sea ice factory”
Evaluation of bacterial glycerol dialkyl glycerol tetraether and 2H–18O biomarker proxies along a central European topsoil transect
Leaf wax n-alkane patterns and compound-specific δ13C of plants and topsoils from semi-arid and arid Mongolia
Organic-carbon-rich sediments: benthic foraminifera as bio-indicators of depositional environments
Strong correspondence between nitrogen isotope composition of foliage and chlorin across a rainfall gradient: implications for paleo-reconstruction of the nitrogen cycle
Environmental and biological controls on Na∕Ca ratios in scleractinian cold-water corals
Depth habitat of the planktonic foraminifera Neogloboquadrina pachyderma in the northern high latitudes explained by sea-ice and chlorophyll concentrations
Temporal variability in foraminiferal morphology and geochemistry at the West Antarctic Peninsula: a sediment trap study
Seasonality of archaeal lipid flux and GDGT-based thermometry in sinking particles of high-latitude oceans: Fram Strait (79° N) and Antarctic Polar Front (50° S)
Long-chain diols in settling particles in tropical oceans: insights into sources, seasonality and proxies
Multi-trace-element sea surface temperature coral reconstruction for the southern Mozambique Channel reveals teleconnections with the tropical Atlantic
Oxygen isotope composition of the final chamber of planktic foraminifera provides evidence of vertical migration and depth-integrated growth
Mg ∕ Ca and δ18O in living planktic foraminifers from the Caribbean, Gulf of Mexico and Florida Straits
Manganese incorporation in living (stained) benthic foraminiferal shells: a bathymetric and in-sediment study in the Gulf of Lions (NW Mediterranean)
Effects of light and temperature on Mg uptake, growth, and calcification in the proxy climate archive Clathromorphum compactum
A systematic look at chromium isotopes in modern shells – implications for paleo-environmental reconstructions
Reviews and syntheses: Revisiting the boron systematics of aragonite and their application to coral calcification
Physico-chemical and biological factors influencing dinoflagellate cyst production in the Cariaco Basin
Effects of alkalinity and salinity at low and high light intensity on hydrogen isotope fractionation of long-chain alkenones produced by Emiliania huxleyi
Interplay of community dynamics, temperature, and productivity on the hydrogen isotope signatures of lipid biomarkers
Benthic foraminiferal Mn / Ca ratios reflect microhabitat preferences
The effects of environment on Arctica islandica shell formation and architecture
Diatoms as a paleoproductivity proxy in the NW Iberian coastal upwelling system (NE Atlantic)
Theresa M. King, Brad E. Rosenheim, and Noel P. James
Biogeosciences, 21, 5361–5379, https://doi.org/10.5194/bg-21-5361-2024, https://doi.org/10.5194/bg-21-5361-2024, 2024
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Corals can record ocean properties such as temperature in their skeletons. These records are useful for where and when we have no instrumental record like in the distant past. However, coral growth must be understood to interpret these records. Here, we analyze slices of a branching deep-sea coral from Antarctica to determine how to best sample these corals for past-climate work. We recommend sampling from the innermost portion of a coral skeleton for accurate temperature reconstructions.
Flavia Boscolo-Galazzo, David Evans, Elaine Mawbey, William Gray, Paul Pearson, and Bridget Wade
EGUsphere, https://doi.org/10.5194/egusphere-2024-1608, https://doi.org/10.5194/egusphere-2024-1608, 2024
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Here we present a comparison of results from the Mg/Ca and oxygen stable isotopes paleothermometers obtained from 57 modern to fossil species of planktonic foraminifera from the last 15 million of years. We find that the occurrence (or not) of species-species offsets in Mg/Ca is conservative between ancestor-descendent species, and that taking into account species kinship can significantly improve temperature reconstructions by several degrees.
Allix J. Baxter, Francien Peterse, Dirk Verschuren, Aihemaiti Maitituerdi, Nicolas Waldmann, and Jaap S. Sinninghe Damsté
Biogeosciences, 21, 2877–2908, https://doi.org/10.5194/bg-21-2877-2024, https://doi.org/10.5194/bg-21-2877-2024, 2024
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This study investigates the impact of long-term lake-system evolution on the climate signal recorded by glycerol dialkyl glycerol tetraethers (GDGTs), a popular biomarker in paleoclimate research. It compares downcore changes in GDGTs in the 250 000 year sediment sequence of Lake Chala (Kenya/Tanzania) to independent data for lake mixing and water-column chemistry. These factors influence the GDGT proxies in the earliest depositional phases (before ~180 ka), confounding the climate signal.
Frances A. Procter, Sandra Piazolo, Eleanor H. John, Richard Walshaw, Paul N. Pearson, Caroline H. Lear, and Tracy Aze
Biogeosciences, 21, 1213–1233, https://doi.org/10.5194/bg-21-1213-2024, https://doi.org/10.5194/bg-21-1213-2024, 2024
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This study uses novel techniques to look at the microstructure of planktonic foraminifera (single-celled marine organisms) fossils, to further our understanding of how they form their hard exterior shells and how the microstructure and chemistry of these shells can change as a result of processes that occur after deposition on the seafloor. Understanding these processes is of critical importance for using planktonic foraminifera for robust climate and environmental reconstructions of the past.
Josie L. Mottram, Anne M. Gothmann, Maria G. Prokopenko, Austin Cordova, Veronica Rollinson, Katie Dobkowski, and Julie Granger
Biogeosciences, 21, 1071–1091, https://doi.org/10.5194/bg-21-1071-2024, https://doi.org/10.5194/bg-21-1071-2024, 2024
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Knowledge of ancient ocean N cycling can help illuminate past climate change. Using field and lab studies, this work ground-truths a promising proxy for marine N cycling, the N isotope composition of cold-water coral (CWC) skeletons. Our results estimate N turnover in CWC tissue; quantify the isotope effects between CWC tissue, diet, and skeleton; and suggest that CWCs possibly feed mainly on metazoan zooplankton, suggesting that the marine N proxy may be sensitive to the food web structure.
Axelle Gardin, Emmanuelle Pucéat, Géraldine Garcia, Jean-Renaud Boisserie, Adélaïde Euriat, Michael M. Joachimski, Alexis Nutz, Mathieu Schuster, and Olga Otero
Biogeosciences, 21, 437–454, https://doi.org/10.5194/bg-21-437-2024, https://doi.org/10.5194/bg-21-437-2024, 2024
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We introduce a novel approach using stable oxygen isotopes from crocodilian fossil teeth to unravel palaeohydrological changes in past continental contexts. Applying it to the Plio-Pleistocene Ethiopian Shungura Formation, we found a significant increase in δ18O in the last 3 million years, likely due to monsoonal shifts and reduced rainfall, and that the local diversity of waterbodies (lakes, rivers, ponds) became restricted.
Babette Hoogakker, Catherine Davis, Yi Wang, Stepanie Kusch, Katrina Nilsson-Kerr, Dalton Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya Hess, Katrina Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix Elling, Zeynep Erdem, Helena Filipsson, Sebastian Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallman, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lelia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Raven, Christopher Somes, Anja Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
EGUsphere, https://doi.org/10.5194/egusphere-2023-2981, https://doi.org/10.5194/egusphere-2023-2981, 2024
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Paleo-oxygen proxies can extend current records, bound pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
Angelica Feurdean, Richard S. Vachula, Diana Hanganu, Astrid Stobbe, and Maren Gumnior
Biogeosciences, 20, 5069–5085, https://doi.org/10.5194/bg-20-5069-2023, https://doi.org/10.5194/bg-20-5069-2023, 2023
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This paper presents novel results of laboratory-produced charcoal forms from various grass, forb and shrub taxa from the Eurasian steppe to facilitate more robust interpretations of fuel sources and fire types in grassland-dominated ecosystems. Advancements in identifying fuel sources and changes in fire types make charcoal analysis relevant to studies of plant evolution and fire management.
Joost Frieling, Linda van Roij, Iris Kleij, Gert-Jan Reichart, and Appy Sluijs
Biogeosciences, 20, 4651–4668, https://doi.org/10.5194/bg-20-4651-2023, https://doi.org/10.5194/bg-20-4651-2023, 2023
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We present a first species-specific evaluation of marine core-top dinoflagellate cyst carbon isotope fractionation (εp) to assess natural pCO2 dependency on εp and explore its geological deep-time paleo-pCO2 proxy potential. We find that εp differs between genera and species and that in Operculodinium centrocarpum, εp is controlled by pCO2 and nutrients. Our results highlight the added value of δ13C analyses of individual micrometer-scale sedimentary organic carbon particles.
Julia Homann, Niklas Karbach, Stacy A. Carolin, Daniel H. James, David Hodell, Sebastian F. M. Breitenbach, Ola Kwiecien, Mark Brenner, Carlos Peraza Lope, and Thorsten Hoffmann
Biogeosciences, 20, 3249–3260, https://doi.org/10.5194/bg-20-3249-2023, https://doi.org/10.5194/bg-20-3249-2023, 2023
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Cave stalagmites contain substances that can be used to reconstruct past changes in local and regional environmental conditions. We used two classes of biomarkers (polycyclic aromatic hydrocarbons and monosaccharide anhydrides) to detect the presence of fire and to also explore changes in fire regime (e.g. fire frequency, intensity, and fuel source). We tested our new method on a stalagmite from Mayapan, a large Maya city on the Yucatán Peninsula.
Claudia Voigt, Anne Alexandre, Ilja M. Reiter, Jean-Philippe Orts, Christine Vallet-Coulomb, Clément Piel, Jean-Charles Mazur, Julie C. Aleman, Corinne Sonzogni, Helene Miche, and Jérôme Ogée
Biogeosciences, 20, 2161–2187, https://doi.org/10.5194/bg-20-2161-2023, https://doi.org/10.5194/bg-20-2161-2023, 2023
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Data on past relative humidity (RH) ARE needed to improve its representation in Earth system models. A novel isotope parameter (17O-excess) of plant silica has been developed to quantify past RH. Using comprehensive monitoring and novel methods, we show how environmental and plant physiological parameters influence the 17O-excess of plant silica and leaf water, i.e. its source water. The insights gained from this study will help to improve estimates of RH from fossil plant silica deposits.
David J. Harning, Brooke Holman, Lineke Woelders, Anne E. Jennings, and Julio Sepúlveda
Biogeosciences, 20, 229–249, https://doi.org/10.5194/bg-20-229-2023, https://doi.org/10.5194/bg-20-229-2023, 2023
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In order to better reconstruct the geologic history of the North Water Polynya, we provide modern validations and calibrations of lipid biomarker proxies in Baffin Bay. We find that sterols, rather than HBIs, most accurately capture the current extent of the North Water Polynya and will be a valuable tool to reconstruct its past presence or absence. Our local temperature calibrations for GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations.
Jessica G. M. Crumpton-Banks, Thomas Tanner, Ivan Hernández Almeida, James W. B. Rae, and Heather Stoll
Biogeosciences, 19, 5633–5644, https://doi.org/10.5194/bg-19-5633-2022, https://doi.org/10.5194/bg-19-5633-2022, 2022
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Past ocean carbon is reconstructed using proxies, but it is unknown whether preparing ocean sediment for one proxy might damage the data given by another. We have tested whether the extraction of an organic proxy archive from sediment samples impacts the geochemistry of tiny shells also within the sediment. We find no difference in shell geochemistry between samples which come from treated and untreated sediment. This will help us to maximize scientific return from valuable sediment samples.
Pablo Forjanes, María Simonet Roda, Martina Greiner, Erika Griesshaber, Nelson A. Lagos, Sabino Veintemillas-Verdaguer, José Manuel Astilleros, Lurdes Fernández-Díaz, and Wolfgang W. Schmahl
Biogeosciences, 19, 3791–3823, https://doi.org/10.5194/bg-19-3791-2022, https://doi.org/10.5194/bg-19-3791-2022, 2022
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Aragonitic skeletons are employed to decipher past climate dynamics and environmental change. Unfortunately, the information that these skeletons keep can be destroyed during diagenesis. In this work, we study the first changes undergone by aragonitic skeletons upon hydrothermal alteration. We observe that major changes occur from the very beginning of the alteration, even without mineralogical changes. These results have major implications for the use of these archives to understand the past.
Inga Labuhn, Franziska Tell, Ulrich von Grafenstein, Dan Hammarlund, Henning Kuhnert, and Bénédicte Minster
Biogeosciences, 19, 2759–2777, https://doi.org/10.5194/bg-19-2759-2022, https://doi.org/10.5194/bg-19-2759-2022, 2022
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This study presents the isotopic composition of recent biogenic carbonates from several lacustrine species which calcify during different times of the year. The authors demonstrate that when biological offsets are corrected, the dominant cause of differences between species is the seasonal variation in temperature-dependent fractionation of oxygen isotopes. Consequently, such carbonates from lake sediments can provide proxy records of seasonal water temperature changes in the past.
Gerard J. M. Versteegh, Karin A. F. Zonneveld, Jens Hefter, Oscar E. Romero, Gerhard Fischer, and Gesine Mollenhauer
Biogeosciences, 19, 1587–1610, https://doi.org/10.5194/bg-19-1587-2022, https://doi.org/10.5194/bg-19-1587-2022, 2022
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A 5-year record of long-chain mid-chain diol export flux and composition is presented with a 1- to 3-week resolution sediment trap CBeu (in the NW African upwelling). All environmental parameters as well as the diol composition are dominated by the seasonal cycle, albeit with different phase relations for temperature and upwelling. Most diol-based proxies are dominated by upwelling. The long-chain diol index reflects temperatures of the oligotrophic summer sea surface.
Johannes Hepp, Christoph Mayr, Kazimierz Rozanski, Imke Kathrin Schäfer, Mario Tuthorn, Bruno Glaser, Dieter Juchelka, Willibald Stichler, Roland Zech, and Michael Zech
Biogeosciences, 18, 5363–5380, https://doi.org/10.5194/bg-18-5363-2021, https://doi.org/10.5194/bg-18-5363-2021, 2021
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Deriving more quantitative climate information like relative air humidity is one of the key challenges in paleostudies. Often only qualitative reconstructions can be done when single-biomarker-isotope data are derived from a climate archive. However, the coupling of hemicellulose-derived sugar with leaf-wax-derived n-alkane isotope results has the potential to overcome this limitation and allow a quantitative relative air humidity reconstruction.
Angelica Feurdean
Biogeosciences, 18, 3805–3821, https://doi.org/10.5194/bg-18-3805-2021, https://doi.org/10.5194/bg-18-3805-2021, 2021
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This study characterized the diversity of laboratory-produced charcoal morphological features of various fuel types from Siberia at different temperatures. The results obtained improve the attribution of charcoal particles to fuel types and fire characteristics. This work also provides recommendations for the application of this information to refine the past wildfire history.
Martin Tetard, Laetitia Licari, Ekaterina Ovsepyan, Kazuyo Tachikawa, and Luc Beaufort
Biogeosciences, 18, 2827–2841, https://doi.org/10.5194/bg-18-2827-2021, https://doi.org/10.5194/bg-18-2827-2021, 2021
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Oxygen minimum zones are oceanic regions almost devoid of dissolved oxygen and are currently expanding due to global warming. Investigation of their past behaviour will allow better understanding of these areas and better prediction of their future evolution. A new method to estimate past [O2] was developed based on morphometric measurements of benthic foraminifera. This method and two other approaches based on foraminifera assemblages and porosity were calibrated using 45 core tops worldwide.
Maximiliano Rodríguez and Christelle Not
Biogeosciences, 18, 1987–2001, https://doi.org/10.5194/bg-18-1987-2021, https://doi.org/10.5194/bg-18-1987-2021, 2021
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Mg/Ca in calcium carbonate shells of marine organisms such as foraminifera and ostracods has been used as a proxy to reconstruct water temperature. Here we provide new Mg/Ca–temperature calibrations for two shallow marine species of ostracods. We show that the water temperature in spring produces the best calibrations, which suggests the potential use of ostracod shells to reconstruct this parameter at a seasonal scale.
Hongrui Zhang, Chuanlian Liu, Luz María Mejía, and Heather Stoll
Biogeosciences, 18, 1909–1916, https://doi.org/10.5194/bg-18-1909-2021, https://doi.org/10.5194/bg-18-1909-2021, 2021
Delphine Dissard, Gert Jan Reichart, Christophe Menkes, Morgan Mangeas, Stephan Frickenhaus, and Jelle Bijma
Biogeosciences, 18, 423–439, https://doi.org/10.5194/bg-18-423-2021, https://doi.org/10.5194/bg-18-423-2021, 2021
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Results from a data set acquired from living foraminifera T. sacculifer collected from surface waters are presented, allowing us to establish a new Mg/Ca–Sr/Ca–temperature equation improving temperature reconstructions. When combining equations, δ18Ow can be reconstructed with a precision of ± 0.5 ‰, while successive reconstructions involving Mg/Ca and δ18Oc preclude salinity reconstruction with a precision better than ± 1.69. A new direct linear fit to reconstruct salinity could be established.
Feng Wang, Dominique Arseneault, Étienne Boucher, Shulong Yu, Steeven Ouellet, Gwenaëlle Chaillou, Ann Delwaide, and Lily Wang
Biogeosciences, 17, 4559–4570, https://doi.org/10.5194/bg-17-4559-2020, https://doi.org/10.5194/bg-17-4559-2020, 2020
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Wood stain is challenging the use of the blue intensity technique for dendroclimatic reconstructions. Using stained subfossil trees from eastern Canadian lakes, we compared chemical destaining approaches with the
delta bluemathematical correction of blue intensity data. Although no chemical treatment was completely efficient, the delta blue method is unaffected by the staining problem and thus is promising for climate reconstructions based on lake subfossil material.
Dulcinea V. Groff, David G. Williams, and Jacquelyn L. Gill
Biogeosciences, 17, 4545–4557, https://doi.org/10.5194/bg-17-4545-2020, https://doi.org/10.5194/bg-17-4545-2020, 2020
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Tussock grasses that grow along coastlines of the Falkland Islands are slow to decay and build up thick peat layers over thousands of years. Grass fragments found in ancient peat can be used to reconstruct past climate because grasses can preserve a record of growing conditions in their leaves. We found that modern living tussock grasses in the Falkland Islands reliably record temperature and humidity in their leaves, and the peat they form can be used to understand past climate change.
Maxence Guillermic, Sambuddha Misra, Robert Eagle, Alexandra Villa, Fengming Chang, and Aradhna Tripati
Biogeosciences, 17, 3487–3510, https://doi.org/10.5194/bg-17-3487-2020, https://doi.org/10.5194/bg-17-3487-2020, 2020
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Boron isotope ratios (δ11B) of foraminifera are a promising proxy for seawater pH and can be used to constrain pCO2. In this study, we derived calibrations for new foraminiferal taxa which extend the application of the boron isotope proxy. We discuss the origin of different δ11B signatures in species and also discuss the potential of using multispecies δ11B analyses to constrain vertical pH and pCO2 gradients in ancient water columns to shed light on biogeochemical carbon cycling in the past.
Zeynep Erdem, Joachim Schönfeld, Anthony E. Rathburn, Maria-Elena Pérez, Jorge Cardich, and Nicolaas Glock
Biogeosciences, 17, 3165–3182, https://doi.org/10.5194/bg-17-3165-2020, https://doi.org/10.5194/bg-17-3165-2020, 2020
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Recent observations from today’s oceans revealed that oxygen concentrations are decreasing, and oxygen minimum zones are expanding together with current climate change. With the aim of understanding past climatic events and their relationship with oxygen content, we looked at the fossils, called benthic foraminifera, preserved in the sediment archives from the Peruvian margin and quantified the bottom-water oxygen content for the last 22 000 years.
Hannah K. Donald, Gavin L. Foster, Nico Fröhberg, George E. A. Swann, Alex J. Poulton, C. Mark Moore, and Matthew P. Humphreys
Biogeosciences, 17, 2825–2837, https://doi.org/10.5194/bg-17-2825-2020, https://doi.org/10.5194/bg-17-2825-2020, 2020
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The boron isotope pH proxy is increasingly being used to reconstruct ocean pH in the past. Here we detail a novel analytical methodology for measuring the boron isotopic composition (δ11B) of diatom opal and apply this to the study of the diatom Thalassiosira weissflogii grown in culture over a range of pH. To our knowledge this is the first study of its kind and provides unique insights into the way in which diatoms incorporate boron and their potential as archives of palaeoclimate records.
Eleonora Fossile, Maria Pia Nardelli, Arbia Jouini, Bruno Lansard, Antonio Pusceddu, Davide Moccia, Elisabeth Michel, Olivier Péron, Hélène Howa, and Meryem Mojtahid
Biogeosciences, 17, 1933–1953, https://doi.org/10.5194/bg-17-1933-2020, https://doi.org/10.5194/bg-17-1933-2020, 2020
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This study focuses on benthic foraminiferal distribution in an Arctic fjord characterised by continuous sea ice production during winter and the consequent cascading of salty and corrosive waters (brine) to the seabed. The inner fjord is dominated by calcareous species (C). In the central deep basins, where brines are persistent, calcareous foraminifera are dissolved and agglutinated (A) dominate. The high A/C ratio is suggested as a proxy for brine persistence and sea ice production.
Johannes Hepp, Imke Kathrin Schäfer, Verena Lanny, Jörg Franke, Marcel Bliedtner, Kazimierz Rozanski, Bruno Glaser, Michael Zech, Timothy Ian Eglinton, and Roland Zech
Biogeosciences, 17, 741–756, https://doi.org/10.5194/bg-17-741-2020, https://doi.org/10.5194/bg-17-741-2020, 2020
Julian Struck, Marcel Bliedtner, Paul Strobel, Jens Schumacher, Enkhtuya Bazarradnaa, and Roland Zech
Biogeosciences, 17, 567–580, https://doi.org/10.5194/bg-17-567-2020, https://doi.org/10.5194/bg-17-567-2020, 2020
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We present leaf wax n-alkanes and their compound-specific (CS) δ13C isotopes from semi-arid and/or arid Mongolia to test their potential for paleoenvironmental reconstructions. Plants and topsoils were analysed and checked for climatic control. Chain-length variations are distinct between grasses and Caragana, which are not biased by climate. However CS δ13C is strongly correlated to climate, so n-alkanes and their CS δ13C show great potential for paleoenvironmental reconstruction in Mongolia.
Elena Lo Giudice Cappelli, Jessica Louise Clarke, Craig Smeaton, Keith Davidson, and William Edward Newns Austin
Biogeosciences, 16, 4183–4199, https://doi.org/10.5194/bg-16-4183-2019, https://doi.org/10.5194/bg-16-4183-2019, 2019
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Fjords are known sinks of organic carbon (OC); however, little is known about the long-term fate of the OC stored in these sediments. The reason for this knowledge gap is the post-depositional degradation of OC. This study uses benthic foraminifera (microorganisms with calcite shells) to discriminate between post-depositional OC degradation and actual OC burial and accumulation in fjordic sediments, as foraminifera would only preserve the latter information in their assemblage composition.
Sara K. E. Goulden, Naohiko Ohkouchi, Katherine H. Freeman, Yoshito Chikaraishi, Nanako O. Ogawa, Hisami Suga, Oliver Chadwick, and Benjamin Z. Houlton
Biogeosciences, 16, 3869–3882, https://doi.org/10.5194/bg-16-3869-2019, https://doi.org/10.5194/bg-16-3869-2019, 2019
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We investigate whether soil organic compounds preserve information about nitrogen availability to plants. We isolate chlorophyll degradation products in leaves, litter, and soil and explore possible species and climate effects on preservation and interpretation. We find that compound-specific nitrogen isotope measurements in soil have potential as a new tool to reconstruct changes in nitrogen cycling on a landscape over time, avoiding issues that have limited other proxies.
Nicolai Schleinkofer, Jacek Raddatz, André Freiwald, David Evans, Lydia Beuck, Andres Rüggeberg, and Volker Liebetrau
Biogeosciences, 16, 3565–3582, https://doi.org/10.5194/bg-16-3565-2019, https://doi.org/10.5194/bg-16-3565-2019, 2019
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In this study we tried to correlate Na / Ca ratios from cold-water corals with environmental parameters such as salinity, temperature and pH. We do not observe a correlation between Na / Ca ratios and seawater salinity, but we do observe a strong correlation with temperature. Na / Ca data from warm-water corals (Porites spp.) and bivalves (Mytilus edulis) support this correlation, indicating that similar controls on the incorporation of sodium exist in these aragonitic organisms.
Mattia Greco, Lukas Jonkers, Kerstin Kretschmer, Jelle Bijma, and Michal Kucera
Biogeosciences, 16, 3425–3437, https://doi.org/10.5194/bg-16-3425-2019, https://doi.org/10.5194/bg-16-3425-2019, 2019
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To be able to interpret the paleoecological signal contained in N. pachyderma's shells, its habitat depth must be known. Our investigation on 104 density profiles of this species from the Arctic and North Atlantic shows that specimens reside closer to the surface when sea-ice and/or surface chlorophyll concentrations are high. This is in contrast with previous investigations that pointed at the position of the deep chlorophyll maximum as the main driver of N. pachyderma vertical distribution.
Anna Mikis, Katharine R. Hendry, Jennifer Pike, Daniela N. Schmidt, Kirsty M. Edgar, Victoria Peck, Frank J. C. Peeters, Melanie J. Leng, Michael P. Meredith, Chloe L. C. Jones, Sharon Stammerjohn, and Hugh Ducklow
Biogeosciences, 16, 3267–3282, https://doi.org/10.5194/bg-16-3267-2019, https://doi.org/10.5194/bg-16-3267-2019, 2019
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Antarctic marine calcifying organisms are threatened by regional climate change and ocean acidification. Future projections of regional carbonate production are challenging due to the lack of historical data combined with complex climate variability. We present a 6-year record of flux, morphology and geochemistry of an Antarctic planktonic foraminifera, which shows that their growth is most sensitive to sea ice dynamics and is linked with the El Niño–Southern Oscillation.
Eunmi Park, Jens Hefter, Gerhard Fischer, Morten Hvitfeldt Iversen, Simon Ramondenc, Eva-Maria Nöthig, and Gesine Mollenhauer
Biogeosciences, 16, 2247–2268, https://doi.org/10.5194/bg-16-2247-2019, https://doi.org/10.5194/bg-16-2247-2019, 2019
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We analyzed GDGT-based proxy temperatures in the polar oceans. In the eastern Fram Strait (79° N), the nutrient distribution may determine the depth habit of Thaumarchaeota and thus the proxy temperature. In the Antarctic Polar Front (50° S), the contribution of Euryarchaeota or the nonlinear correlation between the proxy values and temperatures may cause the warm biases of the proxy temperatures relative to SSTs.
Marijke W. de Bar, Jenny E. Ullgren, Robert C. Thunnell, Stuart G. Wakeham, Geert-Jan A. Brummer, Jan-Berend W. Stuut, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 1705–1727, https://doi.org/10.5194/bg-16-1705-2019, https://doi.org/10.5194/bg-16-1705-2019, 2019
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We analyzed sediment traps from the Cariaco Basin, the tropical Atlantic and the Mozambique Channel to evaluate seasonal imprints in the concentrations and fluxes of long-chain diols (LDIs), in addition to the long-chain diol index proxy (sea surface temperature proxy) and the diol index (upwelling indicator). Despite significant degradation, LDI-derived temperatures were very similar for the sediment traps and seafloor sediments, and corresponded to annual mean sea surface temperatures.
Jens Zinke, Juan P. D'Olivo, Christoph J. Gey, Malcolm T. McCulloch, J. Henrich Bruggemann, Janice M. Lough, and Mireille M. M. Guillaume
Biogeosciences, 16, 695–712, https://doi.org/10.5194/bg-16-695-2019, https://doi.org/10.5194/bg-16-695-2019, 2019
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Here we report seasonally resolved sea surface temperature (SST) reconstructions for the southern Mozambique Channel in the SW Indian Ocean, a region located along the thermohaline ocean surface circulation route, based on multi-trace-element temperature proxy records preserved in two Porites sp. coral cores for the past 42 years. Particularly, we show the suitability of both separate and combined Sr / Ca and Li / Mg proxies for improved multielement SST reconstructions.
Hilde Pracht, Brett Metcalfe, and Frank J. C. Peeters
Biogeosciences, 16, 643–661, https://doi.org/10.5194/bg-16-643-2019, https://doi.org/10.5194/bg-16-643-2019, 2019
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In palaeoceanography the shells of single-celled foraminifera are routinely used as proxies to reconstruct the temperature, salinity and circulation of the ocean in the past. Traditionally a number of specimens were pooled for a single stable isotope measurement; however, technical advances now mean that a single shell or chamber of a shell can be measured individually. Three different hypotheses regarding foraminiferal biology and ecology were tested using this approach.
Anna Jentzen, Dirk Nürnberg, Ed C. Hathorne, and Joachim Schönfeld
Biogeosciences, 15, 7077–7095, https://doi.org/10.5194/bg-15-7077-2018, https://doi.org/10.5194/bg-15-7077-2018, 2018
Shauna Ní Fhlaithearta, Christophe Fontanier, Frans Jorissen, Aurélia Mouret, Adriana Dueñas-Bohórquez, Pierre Anschutz, Mattias B. Fricker, Detlef Günther, Gert J. de Lange, and Gert-Jan Reichart
Biogeosciences, 15, 6315–6328, https://doi.org/10.5194/bg-15-6315-2018, https://doi.org/10.5194/bg-15-6315-2018, 2018
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This study looks at how foraminifera interact with their geochemical environment in the seabed. We focus on the incorporation of the trace metal manganese (Mn), with the aim of developing a tool to reconstruct past pore water profiles. Manganese concentrations in foraminifera are investigated relative to their ecological preferences and geochemical environment. This study demonstrates that Mn in foraminiferal tests is a promising tool to reconstruct oxygen conditions in the seabed.
Siobhan Williams, Walter Adey, Jochen Halfar, Andreas Kronz, Patrick Gagnon, David Bélanger, and Merinda Nash
Biogeosciences, 15, 5745–5759, https://doi.org/10.5194/bg-15-5745-2018, https://doi.org/10.5194/bg-15-5745-2018, 2018
Robert Frei, Cora Paulukat, Sylvie Bruggmann, and Robert M. Klaebe
Biogeosciences, 15, 4905–4922, https://doi.org/10.5194/bg-15-4905-2018, https://doi.org/10.5194/bg-15-4905-2018, 2018
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The reconstruction of paleo-redox conditions of seawater has the potential to link to climatic changes on land and therefore to contribute to our understanding of past climate change. The redox-sensitive chromium isotope system is applied to marine calcifiers in order to characterize isotope offsets that result from vital processes during calcification processes and which can be eventually used in fossil equivalents to reconstruct past seawater compositions.
Thomas M. DeCarlo, Michael Holcomb, and Malcolm T. McCulloch
Biogeosciences, 15, 2819–2834, https://doi.org/10.5194/bg-15-2819-2018, https://doi.org/10.5194/bg-15-2819-2018, 2018
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Understanding the mechanisms of coral calcification is limited by the isolation of the calcifying environment. The boron systematics (B / Ca and δ11B) of aragonite have recently been developed as a proxy for the carbonate chemistry of the calcifying fluid, but a variety of approaches have been utilized. We assess the available experimental B / Ca partitioning data and present a computer code for deriving calcifying fluid carbonate chemistry from the boron systematics of coral skeletons.
Manuel Bringué, Robert C. Thunell, Vera Pospelova, James L. Pinckney, Oscar E. Romero, and Eric J. Tappa
Biogeosciences, 15, 2325–2348, https://doi.org/10.5194/bg-15-2325-2018, https://doi.org/10.5194/bg-15-2325-2018, 2018
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We document 2.5 yr of dinoflagellate cyst production in the Cariaco Basin using a sediment trap record. Each species' production pattern is interpreted in the context of the physico-chemical (e.g., temperature, nutrients) and biological (other planktonic groups) environment. Most species respond positively to upwelling, but seem to be negatively impacted by an El Niño event with a 1-year lag. This work helps understanding dinoflagellate ecology and interpreting fossil assemblages in sediments.
Gabriella M. Weiss, Eva Y. Pfannerstill, Stefan Schouten, Jaap S. Sinninghe Damsté, and Marcel T. J. van der Meer
Biogeosciences, 14, 5693–5704, https://doi.org/10.5194/bg-14-5693-2017, https://doi.org/10.5194/bg-14-5693-2017, 2017
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Algal-derived compounds allow us to make assumptions about environmental conditions in the past. In order to better understand how organisms record environmental conditions, we grew microscopic marine algae at different light intensities, salinities, and alkalinities in a temperature-controlled environment. We determined how these environmental parameters affected specific algal-derived compounds, especially their relative deuterium content, which seems to be mainly affected by salinity.
S. Nemiah Ladd, Nathalie Dubois, and Carsten J. Schubert
Biogeosciences, 14, 3979–3994, https://doi.org/10.5194/bg-14-3979-2017, https://doi.org/10.5194/bg-14-3979-2017, 2017
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Hydrogen isotopes of lipids provide valuable information about microbial activity, climate, and environmental stress. We show that heavy hydrogen in fatty acids declines from spring to summer in a nutrient-rich and a nutrient-poor lake and that the effect is nearly 3 times as big in the former. This effect is likely a combination of increased biomass from algae, warmer temperatures, and higher algal growth rates.
Karoliina A. Koho, Lennart J. de Nooijer, Christophe Fontanier, Takashi Toyofuku, Kazumasa Oguri, Hiroshi Kitazato, and Gert-Jan Reichart
Biogeosciences, 14, 3067–3082, https://doi.org/10.5194/bg-14-3067-2017, https://doi.org/10.5194/bg-14-3067-2017, 2017
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Here we report Mn / Ca ratios in living benthic foraminifera from the NE Japan margin. The results show that the Mn incorporation directly reflects the environment where the foraminifera calcify. Foraminifera that live deeper in sediment, under greater redox stress, generally incorporate more Mn into their carbonate skeletons. As such, foraminifera living close to the Mn reduction zone in sediment appear promising tools for paleoceanographic reconstructions of sedimentary redox conditions.
Stefania Milano, Gernot Nehrke, Alan D. Wanamaker Jr., Irene Ballesta-Artero, Thomas Brey, and Bernd R. Schöne
Biogeosciences, 14, 1577–1591, https://doi.org/10.5194/bg-14-1577-2017, https://doi.org/10.5194/bg-14-1577-2017, 2017
Diana Zúñiga, Celia Santos, María Froján, Emilia Salgueiro, Marta M. Rufino, Francisco De la Granda, Francisco G. Figueiras, Carmen G. Castro, and Fátima Abrantes
Biogeosciences, 14, 1165–1179, https://doi.org/10.5194/bg-14-1165-2017, https://doi.org/10.5194/bg-14-1165-2017, 2017
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Diatoms are one of the most important primary producers in highly productive coastal regions. Their silicified valves are susceptible to escape from the upper water column and be preserved in the sediment record, and thus are frequently used to reconstruct environmental conditions in the past from sediment cores. Here, we assess how water column diatom’s community in the NW Iberian coastal upwelling system is seasonally transferred from the surface to the seafloor sediments.
Cited articles
Abdelazim, M. N. and Diaconu, D. C. (Eds.): The Danube River Delta, Earth and., Springer, Cham, Switzerland, 402 pp., https://doi.org/10.1007/978-3-031-03983-6, 2022.
Akkemik, Ü., Dağdeviren, N., and Aras, A.: A Preliminary Reconstruction (A.D. 1635–2000) of Spring Precipitation Using Oak Tree Rings in the Western Black Sea Region of Turkey, Int. J. Biometeorol., 49, 297–302, https://doi.org/10.1007/s00484-004-0249-8, 2005.
Akkemik, Ü., D'arrigo, R., Cherubini, P., Kose, N., and Jacoby, G. C.: Tree-ring reconstructions of precipitation and streamflow for north-western, Int. J. Climatol., 28, 173–183, 2008.
Allen, S. T., Kirchner, J. W., Braun, S., Siegwolf, R. T. W., and Goldsmith, G. R.: Seasonal origins of soil water used by trees, Hydrol. Earth Syst. Sci., 23, 1199–1210, https://doi.org/10.5194/hess-23-1199-2019, 2019.
Baker, J. C. A., Cintra, B. B. L., Gloor, M., Boom, A., Neill, D., Clerici, S., Leng, M. J., Helle, G., and Brienen, R. J. W.: The Changing Amazon Hydrological Cycle Inferences From Over 200 Years of Tree-Ring Oxygen isotope data, J. Geophys. Res.-Biogeo., 127, e2022JG006955, https://doi.org/10.1029/2022JG006955, 2022.
Beguería, S.: sbegueria/SPEIbase: Version 2.7, Zenodo, https://doi.org/10.5281/zenodo.5864391, 2022.
Brázdil, R., Dobrovolný, P., Trnka, M., Büntgen, U., Řezníčková, L., Kotyza, O., Valášek, H., and Štěpánek, P.: Documentary and instrumental-based drought indices for the Czech Lands back to AD 1501, Clim. Res., 70, 103–117, https://doi.org/10.3354/cr01380, 2016.
Brázdil, R., Dobrovolný, P., Trnka, M., Řezníčková, L., Dolák, L., and Kotyza, O.: Extreme droughts and human responses to them: the Czech Lands in the pre-instrumental period, Clim. Past, 15, 1–24, https://doi.org/10.5194/cp-15-1-2019, 2019.
Briffa, K. and Jones, P.: Basic chronology statistics and assessment, in: Methods of dendrochronology, edited by: Cook, E. and Kairiukstis, L., Kluwer, Dordrecht, 137–152, 1992.
Bunn, A. G.: A dendrochronology program library in R (dplR), Dendrochronologia, 26, 115–124, https://doi.org/10.1016/j.dendro.2008.01.002, 2008.
Cernovodeanu, P. and Binder, P.: Cavalerii Apocalipsilui Calamită?ile naturale din trecutul României (până la 1800), SILEX-Casă de Editură, Presă ?i Impresarial S.R.L., Bucuresti, ISBN 973-95477-3-7, 1933.
Coplen, T. B.: Reporting of stable hydrogen, carbon, and oxygen isotopic abundances, Pure Appl. Chem., 66, 273–276, https://doi.org/10.1351/pac199466020273, 1994.
CDendro and CooRecorder: Software tools: CDendro and CooRecorder, http://www.cybis.se/forfun/dendro/index.htm (last access: 20 February 2024), 2010.
Dansgaard, W.: Stable isotopes in precipitation, Tellus, 4, 436–468, https://doi.org/10.3402/tellusa.v16i4.8993, 1964.
Duffy, J. E., McCarroll, D., Loader, N. J., Young, G. H. F., Davies, D., Miles, D., and Bronk Ramsey, C.: Absence of Age-Related Trends in Stable Oxygen Isotope Ratios From Oak Tree Rings, Global Biogeochem. Cy., 33, 841–848, https://doi.org/10.1029/2019GB006195, 2019.
Durbin, J. and Watson, G. S.: Testing for Serial Correlation in Least Squares Regression: I, Biometrika, 37, 409–428, https://doi.org/10.2307/2332391, 1950.
Feng, X., Huang, R., Zhu, H., Liang, E., Bräuning, A., Zhong, L., Gong, Z., Zhang, P., Asad, F., Zhu, X., and Grießinger, J.: Tree-ring cellulose oxygen isotopes indicate atmospheric aridity in the western Kunlun Mountains, Ecol. Indic., 137, 108776, https://doi.org/10.1016/j.ecolind.2022.108776, 2022.
Freund, M. B., Helle, G., Balting, D. F., Ballis, N., Schleser, G. H., and Cubasch, U.: European tree-ring isotopes indicate unusual recent hydroclimate, Commun. Earth Environ., 4, 26, https://doi.org/10.1038/s43247-022-00648-7, 2023.
Gagen, M., Battipaglia, G., Daux, V., Duffy, J., Dorado-Liñán, I., Hayles, L. A., Martínez-Sancho, E., McCarroll, D., Shestakova, T. A., and Treydte, K.: Climate Signals in Stable Isotope Tree-Ring Records, vol 8, Springer, Cham., https://doi.org/10.1007/978-3-030-92698-4_19, 2022.
Gärtner, H. and Nievergelt, D.: The core-microtome: A new tool for surface preparation on cores and time series analysis of varying cell parameters, Dendrochronologia, 28, 85–92, https://doi.org/10.1016/j.dendro.2009.09.002, 2010.
Gessler, A., Ferrio, J. P., Hommel, R., Treydte, K., Werner, R. A., and Monson, R. K.: Stable isotopes in tree rings: Towards a mechanistic understanding of isotope fractionation and mixing processes from the leaves to the wood, Tree Physiol., 34, 796–818, https://doi.org/10.1093/treephys/tpu040, 2014.
Gessler, A., Bächli, L., Rouholahnejad Freund, E., Treydte, K., Schaub, M., Haeni, M., Weiler, M., Seeger, S., Marshall, J., Hug, C., Zweifel, R., Hagedorn, F., Rigling, A., Saurer, M., and Meusburger, K.: Drought reduces water uptake in beech from the drying topsoil, but no compensatory uptake occurs from deeper soil layers, New Phytol., 233, 194–206, https://doi.org/10.1111/nph.17767, 2022.
Harris, I., Osborn, T. J., Jones, P., and Lister, D.: Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset, Sci. Data, 7, 1–18, https://doi.org/10.1038/s41597-020-0453-3, 2020.
Helle, G., Pauly, M., Heinrich, I., Schollän, K., Balanzategui, D., and Schürheck, L.: Stable Isotope Signatures of Wood, its Constituents and Methods of Cellulose Extraction, in: Stable Isotopes in Tree Rings: Inferring Physiological, Climatic and Environmental Responses, edited by: Siegwolf, R. T. W., Brooks, J. R., Roden, J., and Saurer, M., Springer International Publishing, Cham, 135–190, https://doi.org/10.1007/978-3-030-92698-4_5, 2022.
Holmes, R. L.: Computer-assisted quality control in tree-ring dating and measurement, Tree Ring Bull., 43, 69–75, 1983.
Info Clima: Starea Climei Romania, Bucharest, 1–101, https://static1.squarespace.com/static/60b5d21e4796a564a563c771/t/6722504d024790327172d799/1730302041386/Starea_Climei-Raport_2024.pdf (last access: 20 Novermber 2024), 2024.
Ionita, M.: Interannual summer streamflow variability over Romania and its connection to large-scale atmospheric circulation, Int. J. Climatol., 35, 4186–4196, https://doi.org/10.1002/joc.4278, 2015.
Ionita, M. and Nagavciuc, V.: Changes in drought features at the European level over the last 120 years, Nat. Hazards Earth Syst. Sci., 21, 1685–1701, https://doi.org/10.5194/nhess-21-1685-2021, 2021.
Ionita, M., Lohmann, G., and Rimbu, N.: Prediction of spring Elbe discharge Based on stable teleconnections with winter global temperature and precipitation, J. Climate, 21, 6215–6226, https://doi.org/10.1175/2008JCLI2248.1, 2008.
Ionita, M., Dima, M., Lohmann, G., Scholz, P., and Rimbu, N.: Predicting the June 2013 European Flooding Based on Precipitation, Soil Moisture, and Sea Level Pressure, J. Hydrometeorol., 16, 598–614, https://doi.org/10.1175/JHM-D-14-0156.1, 2015.
Ionita, M., Scholz, P., Grosfeld, K., and Treffeisen, R.: Moisture transport and Antarctic sea ice: austral spring 2016 event, Earth Syst. Dynam., 9, 939–954, https://doi.org/10.5194/esd-9-939-2018, 2018.
Ionita, M., Caldarescu, D. E., and Nagavciuc, V.: Compound Hot and Dry Events in Europe: Variability and Large-Scale Drivers, Front. Clim., 3, 688991, https://doi.org/10.3389/fclim.2021.688991, 2021.
Ionita, M., Nagavciuc, V., Scholz, P., and Dima, M.: Long-term drought intensification over Europe driven by the weakening trend of the Atlantic Meridional Overturning Circulation, J. Hydrol. Reg. Stud., 42, 101176, https://doi.org/10.1016/j.ejrh.2022.101176, 2022.
IPCC: Summary for policymakers, in: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R., and Zhou, B., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 3–22, https://doi.org/10.1017/9781009157896.001, 2021.
Laumer, W., Andreu, L., Helle, G., Schleser, G. H., Wieloch, T., and Wissel, H.: A novel approach for the homogenization of cellulose to use micro-amounts for stable isotope analyses, Rapid Commun. Mass Spectrom., 23, 1934–1940, 2009.
Leavitt, S. W.: Tree-ring C–H–O isotope variability and sampling, Sci. Total Environ., 408, 5244–5253, https://doi.org/10.1016/j.scitotenv.2010.07.057, 2010.
Loader, N. J., Young, G. H. F., McCarroll, D., Davies, D., Miles, D., and Bronk Ramsey, C.: Summer precipitation for the England and Wales region, 1201–2000 CE, from stable oxygen isotopes in oak tree rings, J. Quaternary Sci., 35, 731–736, https://doi.org/10.1002/jqs.3226, 2020.
McCarroll, D. and Loader, N. J.: Stable isotopes in tree rings, Quaternary Sci. Rev., 23, 771–801, https://doi.org/10.1016/j.quascirev.2003.06.017, 2004.
Nagavciuc, V., Roibu, C.-C., Ionita, M., Mursa, A., Cotos, M.-G., and Popa, I.: Different climate response of three tree ring proxies of Pinus sylvestris from the Eastern Carpathians, Romania, Dendrochronologia, 54, 56–63, https://doi.org/10.1016/j.dendro.2019.02.007, 2019a.
Nagavciuc, V., Ionita, M., Perşoiu, A., Popa, I., Loader, N. J. N. J., and McCarroll, D.: Stable oxygen isotopes in Romanian oak tree rings record summer droughts and associated large-scale circulation patterns over Europe, Clim. Dynam., 52, 6557–6568, https://doi.org/10.1007/s00382-018-4530-7, 2019b.
Nagavciuc, V., Kern, Z., Ionita, M., Hartl, C., Konter, O., Esper, J., and Popa, I.: Climate signals in carbon and oxygen isotope ratios of Pinus cembra tree-ring cellulose from Călimani Mountains, Romania, Int. J. Climatol., 40, 2539–2556, https://doi.org/10.1002/joc.6349, 2020.
Nagavciuc, V., Ionita, M., Kern, Z., McCarroll, D., and Popa, I.: A ∼ 700 years perspective on the 21st century drying in the eastern part of Europe based on δ18O in tree ring cellulose, Commun. Earth Environ., 3, 277, https://doi.org/10.1038/s43247-022-00605-4, 2022a.
Nagavciuc, V., Scholz, P., and Ionita, M.: Hotspots for warm and dry summers in Romania, Nat. Hazards Earth Syst. Sci., 22, 1347–1369, https://doi.org/10.5194/nhess-22-1347-2022, 2022b.
Nagavciuc, V., Roibu, C.-C., Mursa, A., Ştirbu, M.-I., Popa, I., and Ionita, M.: The first tree-ring reconstrruction of streamflow variability over the last ∼ 250 years in the Lower Danube, J. Hydrol., 617, 129150, https://doi.org/10.1016/j.jhydrol.2023.129150, 2023.
Nagavciuc, V., Michel, S. L. L., Balting, D. F., Helle, G., Freund, M., Schleser, G. H., Steger, D. N., Lohmann, G., and Ionita, M.: A past and present perspective on the European summer vapor pressure deficit, Clim. Past, 20, 573–595, https://doi.org/10.5194/cp-20-573-2024, 2024a.
Nagavciuc, V., Helle, G., Rădoane, M., Roibu, C.-C., Cotos, M.-G., and Ionita, M.: A long-term drought reconstruction (August SPEI9) based on oxygen isotope tree ring data for central and eastern parts of Europe (Romania), Zenodo [data set], https://doi.org/10.5281/zenodo.14536886, 2024b.
Paul, D., Skrzypek, G., and Fórizs, I.: Normalization of measured stable isotopic compositions to isotope reference scales – a review, Rapid Commun. Mass Spectrom., 21, 3006–3014, https://doi.org/10.1002/rcm.3185, 2007.
Penman, H. L.: Natural evaporation from open water, bare soil and grass, P. Roy. Soc. Lond. A. Mat., 193, 120–145, https://doi.org/10.1098/rspa.1948.0037, 1948.
Pfister, C.: Wetternachhersage, 500 Jahre Klimavariationen und Naturkatastrophen (1496–1995), Verlag Paul Haupt, Bern Stuttgart Wien, 301 pp., 1999.
Pumijumnong, N., Bräuning, A., Sano, M., Nakatsuka, T., Muangsong, C., and Buajan, S.: A 338-year tree-ring oxygen isotope record from Thai teak captures the variations in the Asian summer monsoon system, Sci. Rep., 10, 8966, https://doi.org/10.1038/s41598-020-66001-0, 2020.
Rinne, K. T., Boettger, T., Loader, N. J., Robertson, I., Switsur, V. R., and Waterhouse, J. S.: On the purification of α-cellulose from resinous wood for stable isotope (H, C and O) analysis, Chem. Geol., 222, 75–82, https://doi.org/10.1016/j.chemgeo.2005.06.010, 2005.
Robertson, I., Field, E. M., Heaton, T. H. E., Pilcher, J. R., Pollard, A. M., Switsur, V. R., Waterhouse, J. S., Frenzel, B., Stauffer, B., and Weiss, M. M.: Problems of stable isotopes in tree-rings, lake sediments and peat-bogs as climatic evidence for the Holocene, Paläoklima, European Science Foundation, Strasbourg, 141–155, ISBN 3437308173 9783437308178, 1995.
Roden, J., Lin, G., and Ehleringer, J. R.: A mechanistic model for interpretation of hydrogen and oxygen isotope ratios in tree-ring cellulose, Geochim. Cosmochim. Ac., 64, 21–35, 2000.
Roibu, C.-C., Nagavciuc, V., Ionita, M., Popa, I., Horodnic, S.-A., Mursa, A., and Büntgen, U.: A tree ring-based hydroclimate reconstruction for eastern Europe reveals large-scale teleconnection patterns, Clim. Dynam., 59, 2979–2994, https://doi.org/10.1007/s00382-022-06255-8, 2022.
Sandu, I., Pescaru, V. I., and Poiana, I.: Clima Romaniei, Bucureşti: Editura Academiei Române, 365 pp., ISBN 973-27-1674-8, 2008 (in Romanian).
Saurer, M., Kress, A., Leuenberger, M., Rinne, K. T., Treydte, K. S., and Siegwolf, R. T. W.: Influence of atmospheric circulation patterns on the oxygen isotope ratio of tree rings in the Alpine region, J. Geophys. Res.-Atmos., 117, D05118, https://doi.org/10.1029/2011JD016861, 2012.
Schweingruber, F. H.: Tree Rings Basics and Applications of Dendrochronology, 276 pp., https://doi.org/10.1007/978-94-009-1273-1, 1988.
Sharp, Z.: Principles of Stable Isotope Geochemistry, Pearson Pr., edited by: Rapp, C., American Library Association, New Jersey, 344 pp., https://doi.org/10.5860/choice.44-6251, 2007.
Siegwolf, R. T. W., Brooks, J. R., Roden, J., and Saurer, M. (Eds.): Stable Isotopes in Tree Rings Inferring Physiological, Climatic and Environmental Responses, Series Tit., Springer, Cham, Switzerland, 773 pp., https://doi.org/10.1007/978-3-030-92698-4, 2022.
Van der Sleen, P., Groenendijk, P., and Zuidema, P. A.: Tree-ring δ18O in African mahogany (Entandrophragma utile) records regional precipitation and can be used for climate reconstructions, Global Planet. Change, 127, 58–66, https://doi.org/10.1016/j.gloplacha.2015.01.014, 2015.
Van Loon, A. F., Kchouk, S., Matanó, A., Tootoonchi, F., Alvarez-Garreton, C., Hassaballah, K. E. A., Wu, M., Wens, M. L. K., Shyrokaya, A., Ridolfi, E., Biella, R., Nagavciuc, V., Barendrecht, M. H., Bastos, A., Cavalcante, L., de Vries, F. T., Garcia, M., Mård, J., Streefkerk, I. N., Teutschbein, C., Tootoonchi, R., Weesie, R., Aich, V., Boisier, J. P., Di Baldassarre, G., Du, Y., Galleguillos, M., Garreaud, R., Ionita, M., Khatami, S., Koehler, J. K. L., Luce, C. H., Maskey, S., Mendoza, H. D., Mwangi, M. N., Pechlivanidis, I. G., Ribeiro Neto, G. G., Roy, T., Stefanski, R., Trambauer, P., Koebele, E. A., Vico, G., and Werner, M.: Review article: Drought as a continuum – memory effects in interlinked hydrological, ecological, and social systems, Nat. Hazards Earth Syst. Sci., 24, 3173–3205, https://doi.org/10.5194/nhess-24-3173-2024, 2024.
Teodoreanu, E.: În căutarea timpului trecut Schiă de climatologie istorică, Editura Paodeia, Bucuresti, 363 pp., ISBN 9786067482140, 2017.
Topor, N.: Anii ploioşi şi secetoşi din Republica Populară Romînă, C.S.A Institutul Meteorologic, Bucureşti, 1963.
Yang, X., Zeng, G., Zhang, S., Iyakaremye, V., Shen, C., Wang, W.-C., and Chen, D.: Phase-Locked Rossby Wave-4 Pattern Dominates the 2022-Like Concurrent Heat Extremes Across the Northern Hemisphere, Geophys. Res. Lett., 51, e2023GL107106, https://doi.org/10.1029/2023GL107106, 2024.
Young, G. H. F., Loader, N. J., McCarroll, D., Bale, R. J., Demmler, J. C., Miles, D., Nayling, N. T., Rinne, K. T., Robertson, I., Watts, C., and Whitney, M.: Oxygen stable isotope ratios from British oak tree-rings provide a strong and consistent record of past changes in summer rainfall, Clim. Dynam., 45, 3609–3622, https://doi.org/10.1007/s00382-015-2559-4, 2015.
Zang, C. and Biondi, F.: Treeclim: An R package for the numerical calibration of proxy-climate relationships, Ecography, 38, 431–436, https://doi.org/10.1111/ecog.01335, 2015.
Short summary
We reconstructed drought conditions for the past 200 years for central and eastern parts of Europe (Romania) using δ18O in oak tree ring cellulose from Romania, revealing periods of both extreme wetness (e.g., 1905–1915) and dryness (e.g., 1818–1835). The most severe droughts occurred in the 19th and 21st centuries, likely linked to large-scale atmospheric circulation. This research highlights the potential of tree rings to improve our understanding of long-term climate variability in Europe.
We reconstructed drought conditions for the past 200 years for central and eastern parts of...
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