33 results on '"Butzin, Martin"'
Search Results
2. Fossil organic carbon utilization in marine Arctic fjord sediments by subsurface micro-organisms
- Author
-
Ruben, Manuel, Hefter, Jens, Schubotz, Florence, Geibert, Walter, Butzin, Martin, Gentz, Torben, Grotheer, Hendrik, Forwick, Matthias, Szczuciński, Witold, and Mollenhauer, Gesine
- Published
- 2023
- Full Text
- View/download PDF
3. Reply to: methodological inconsistencies define thermal bottlenecks in fish life cycle
- Author
-
Dahlke, Flemming, Butzin, Martin, Wohlrab, Sylke, and Pörtner, Hans-Otto
- Published
- 2022
- Full Text
- View/download PDF
4. Carbon isotopes in the marine biogeochemistry model FESOM2.1-REcoM3.
- Author
-
Butzin, Martin, Ye, Ying, Völker, Christoph, Gürses, Özgür, Hauck, Judith, and Köhler, Peter
- Subjects
- *
CARBON isotopes , *MERIDIONAL overturning circulation , *GENERAL circulation model , *OCEAN circulation , *BIOGEOCHEMISTRY , *CIRCULATION models , *CHEMICAL weathering - Abstract
In this paper we describe the implementation of the carbon isotopes 13 C and 14 C (radiocarbon) into the marine biogeochemistry model REcoM3. The implementation is tested in long-term equilibrium simulations where REcoM3 is coupled with the ocean general circulation model FESOM2.1, applying a low-resolution configuration and idealized climate forcing. Focusing on the carbon-isotopic composition of dissolved inorganic carbon (δ13 C DIC and Δ14 C DIC), our model results are largely consistent with reconstructions for the pre-anthropogenic period. Our simulations also exhibit discrepancies, e.g. in upwelling regions and the interior of the North Pacific. Some of these differences are due to the limitations of our ocean circulation model setup, which results in a rather shallow meridional overturning circulation. We additionally study the accuracy of two simplified modelling approaches for dissolved inorganic 14 C, which are faster (15 % and about a factor of five, respectively) than the complete consideration of the marine radiocarbon cycle. The accuracy of both simplified approaches is better than 5 %, which should be sufficient for most studies of Δ14 C DIC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Glacial heterogeneity in Southern Ocean carbon storage abated by fast South Indian deglacial carbon release
- Author
-
Gottschalk, Julia, Michel, Elisabeth, Thöle, Lena M., Studer, Anja S., Hasenfratz, Adam P., Schmid, Nicole, Butzin, Martin, Mazaud, Alain, Martínez-García, Alfredo, Szidat, Sönke, and Jaccard, Samuel L.
- Published
- 2020
- Full Text
- View/download PDF
6. FESOM2.1-REcoM3-MEDUSA2: an ocean-sea ice-biogeochemistry model coupled to a sediment model.
- Author
-
Ying Ye, Munhoven, Guy, Köhler, Peter, Butzin, Martin, Hauck, Judith, Gürses, Özgür, and Völker, Christoph
- Subjects
SURFACE chemistry ,SEDIMENTS ,ENVIRONMENTAL engineering ,ATMOSPHERIC models ,DIAGENESIS ,SEA ice - Abstract
This study describes the coupling of the process-based Model of Early Diagenesis in the Upper Sediment (MEDUSA version 2) to an existing ocean biogeochemistry model consisting of the Finite-volumE Sea ice-Ocean Model (FESOM version 2.1) and the Regulated Ecosystem Model (REcoM version 3). Atmospheric CO
2 in the model is a prognostic variable which is determined by the carbonate chemistry in the surface ocean. The model setup and its application to a pre-industrial control climate state is described in detail. In the coupled model 400 PgC are stored in equilibrium in the top 10 cm of the bioturbated sediment, mainly as calcite, but also to 5% as organic matter. Simulated atmospheric CO2 is in equilibrium at 286 ppm in the coupled simulation, which is close to the initially assumed value of the pre-industrial CO2 level. Sediment burial of carbon, alkalinity and nutrients in the coupled simulation is set to be partly compensated by riverine input. The spatial distribution of biological production is altered depending on the location of riverine input and the strength of local nutrient limitation, while the global productivity is not affected substantially. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
7. Carbon isotopes in the marine biogeochemistry model FESOM2.1-REcoM3.
- Author
-
Butzin, Martin, Ye, Ying, Völker, Christoph, Gürses, Özgür, Hauck, Judith, and Köhler, Peter
- Subjects
CARBON isotopes ,MERIDIONAL overturning circulation ,GENERAL circulation model ,OCEAN circulation ,BIOGEOCHEMISTRY ,CIRCULATION models ,CHEMICAL weathering - Abstract
In this paper we describe the implementation of the carbon isotopes
13 C and14 C (radiocarbon) into the marine biogeochemistry model REcoM3. The implementation is tested in long-term equilibrium simulations where REcoM3 is coupled with the ocean general circulation model FESOM2.1, applying a low-resolution configuration and idealized climate forcing. Focusing on the carbon-isotopic composition of dissolved inorganic carbon (δ13 CDIC and Δ14 CDIC ), our model results are largely consistent with reconstructions for the pre-anthropogenic period. Our simulations also exhibit discrepancies, e.g., in upwelling regions and the interior of the North Pacific. Some of these differences are due to the limitations of our ocean circulation model setup which results in a rather shallow meridional overturning circulation. We additionally study the accuracy of two simplified modelling approaches for dissolved inorganic14 C, which are faster (15 % and about a factor of five, respectively) than the complete consideration of the marine radiocarbon cycle. The accuracy of both simplified approaches is better than 5 % which should be sufficient for most studies of Δ14 CDIC . [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
8. Ocean biogeochemistry in the coupled ocean–sea ice–biogeochemistry model FESOM2.1–REcoM3.
- Author
-
Gürses, Özgür, Oziel, Laurent, Karakuş, Onur, Sidorenko, Dmitry, Völker, Christoph, Ye, Ying, Zeising, Moritz, Butzin, Martin, and Hauck, Judith
- Subjects
WATER vapor ,CLIMATE feedbacks ,BIOGEOCHEMISTRY ,ATMOSPHERIC carbon dioxide ,OCEAN ,CARBON cycle ,FOOD chains ,SEA ice - Abstract
The cycling of carbon in the oceans is affected by feedbacks driven by changes in climate and atmospheric CO2. Understanding these feedbacks is therefore an important prerequisite for projecting future climate. Marine biogeochemistry models are a useful tool but, as with any model, are a simplification and need to be continually improved. In this study, we coupled the Finite-volumE Sea ice–Ocean Model (FESOM2.1) to the Regulated Ecosystem Model version 3 (REcoM3). FESOM2.1 is an update of the Finite-Element Sea ice–Ocean Model (FESOM1.4) and operates on unstructured meshes. Unlike standard structured-mesh ocean models, the mesh flexibility allows for a realistic representation of small-scale dynamics in key regions at an affordable computational cost. Compared to the previous coupled model version of FESOM1.4–REcoM2, the model FESOM2.1–REcoM3 utilizes a new dynamical core, based on a finite-volume discretization instead of finite elements, and retains central parts of the biogeochemistry model. As a new feature, carbonate chemistry, including water vapour correction, is computed by mocsy 2.0. Moreover, REcoM3 has an extended food web that includes macrozooplankton and fast-sinking detritus. Dissolved oxygen is also added as a new tracer. In this study, we assess the ocean and biogeochemical state simulated with FESOM2.1–REcoM3 in a global set-up at relatively low spatial resolution forced with JRA55-do atmospheric reanalysis. The focus is on the recent period (1958–2021) to assess how well the model can be used for present-day and future climate change scenarios on decadal to centennial timescales. A bias in the global ocean–atmosphere preindustrial CO2 flux present in the previous model version (FESOM1.4–REcoM2) could be significantly reduced. In addition, the computational efficiency is 2–3 times higher than that of FESOM1.4–REcoM2. Overall, it is found that FESOM2.1–REcoM3 is a skilful tool for ocean biogeochemical modelling applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
9. Climate Induced Thermocline Aging and Ventilation in the Eastern Atlantic Over the Last 32,000 Years.
- Author
-
Beisel, Elvira, Frank, Norbert, Robinson, Laura F., Lausecker, Marleen, Friedrich, Ronny, Therre, Steffen, Schröder‐Ritzrau, Andrea, and Butzin, Martin
- Subjects
FRONTS (Meteorology) ,LAST Glacial Maximum ,WATER masses ,GENERAL circulation model ,YOUNGER Dryas ,MINE ventilation ,OCEAN ,OCEAN circulation - Abstract
The radiocarbon analysis of uranium‐thorium‐dated cold‐water corals (CWCs) provides an excellent opportunity for qualitative reconstruction of past ocean circulation and water mass aging. While mid‐depth water mass aging has been studied in the Atlantic Ocean, the evolution of the thermocline is still largely unknown. Here we present a combined 14C and 230Th/U age record obtained from thermocline dwelling CWCs at various sites in the eastern Atlantic Ocean, with intermittently centennial resolution over the last 32 ka. Shallow dwelling CWCs off Angola, located in the South Atlantic, infer a link between the mid‐depth equatorial Atlantic and Southern Ocean. They confirm a 14C drawdown during the Last Glacial Maximum (LGM) and advocate for a consistent Southern Hemisphere radiocarbon aging of upper thermocline waters, as well as strong depth gradients and high variability. Direct comparison with 14C simulations carried out with an Ocean General Circulation Model yield good agreement for Angola. In contrast, the North Atlantic thermocline shows well‐ventilated water with strong variations near the position of today's Azores Front (AF), neither of which are captured by the model. During the Bølling‐Allerød, we confirm the important role of the AF in separating North and South Atlantic thermocline waters and provide further evidence of a 500 year long deep convection interruption within the Younger Dryas (YD). We conclude that the North and South Atlantic thermocline waters were separately acting carbon reservoirs during the LGM and subsequent deglaciation until the modern circulation was established during the YD. Key Points: North Atlantic cold‐water corals trace well‐ventilated thermocline waters near major oceanic fronts since the Last Glacial MaximumAcross the South Atlantic into the Southern Ocean, aged waters with large variability and connectivity are evident during the last glacialThe modern state of radiocarbon ventilation of the thermocline Atlantic is initiated during the Younger Dryas cold reversal [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
10. Influence of the opening of the Drake Passage on the Cenozoic Antarctic Ice Sheet: A modeling approach
- Author
-
Cristini, Luisa, Grosfeld, Klaus, Butzin, Martin, and Lohmann, Gerrit
- Published
- 2012
- Full Text
- View/download PDF
11. Radiocarbon depleted intermediate water masses during the LGM in the equatorial Indian Ocean
- Author
-
Raddatz, Jacek, Beisel, Elvira, Butzin, Martin, Schröder-Ritzrau, Andrea, Betzler, Christian, and Frank, Norbert
- Abstract
Ocean circulation and changes in ventilation represent one of the crucial regulation screws in the Earth´s climate system. For the Last Glacial Maximum (LGM, 21 kyr BP), characterized by a 100 ppm lower atmospheric CO2 concentration, growing evidence exists for enhanced storage of CO2 in the deep-sea. However, inasmuch the intermediate depth of the oceans opposed or amplified this sequestration is poorly constrained. Here we present coupled 230Th/U and 14C measurements on scleractinian cold-water corals retrieved from ~450m water depth off the Maldives in the Indian Ocean. Based on these measurements we calculate ∆14C, ∆∆14C and Benthic-Atmosphere (Batm) ages in order to understand ventilation dynamics of Indian Ocean intermediate water masses. Our results exhibit radiocarbon depleted intermediate water masses as low as -340 ‰ (∆∆14C), corresponding to ~2100 years (Batm) at the LGM. Such extremely radiocarbon depleted intermediate water masses suggest abyssal upwelling of southern-sourced deep-water masses, being strongly enriched in respired carbon and thus highlighting the oceanic carbon storage capacity even at upper thermocline depth. Nevertheless, Batm ages reveal a pronounced short-term centennial variability, that demonstrates the dynamic nature of thisoceanographic phenomena. Thus, reduced intermediate ocean ventilation off the Maldives and resulting carbon storage may help to improve our understanding of the role of the thermocline Ocean with respect to the Earth´s carbon cycle.
- Published
- 2022
- Full Text
- View/download PDF
12. The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0-55 kcal BP)
- Author
-
Reimer, Paula J., Austin, William E.N., Baird, Edouard, Bayliss, Alex, Blackwell, Paul G., Bronk Ramsey, Christopher, Butzin, Martin, Cheng, Hai, Edwards, R. Lawrence, Friedrich, Michael, Grootes, Pieter M., Guilderson, Thomas P., Hajdas, Irka, Heaton, Timothy J., Hogg, Alan G., Hughen, Konrad A., Kromer, Bernd, Manning, Sturt W., Muscheler, Raimund, Palmer, Jonathan G., Pearson, Charlotte, van der Plicht, Johannes, Reimer, Ron W., Richards, David A., Scott, E. Marian, Southon, John R., Turney, Christian S.M., Wacker, Lukas, Adolphi, Florian, Büntgen, Ulf, Capano, Manuela, Fahrni, Simon M., Fogtmann-Schulz, Alexandra, Freidrich, Ronny, Köhler, Peter, Kudsk, Sabrina, Miyake, Fusa, Olsen, Jesper, Reinig, Frederick, Sakamoto, Minoru, Sookdeo, Adam, and Talamo, Sahra
- Abstract
Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
- Published
- 2020
13. Toward Reconciling Radiocarbon Production Rates With Carbon Cycle Changes of the Last 55,000 Years.
- Author
-
Köhler, Peter, Adolphi, Florian, Butzin, Martin, and Muscheler, Raimund
- Subjects
GALACTIC cosmic rays ,CARBON isotopes ,COSMOGENIC nuclides ,RADIOCARBON dating ,LAST Glacial Maximum ,ATMOSPHERIC carbon dioxide ,CARBON cycle - Abstract
Since it is currently not understood how changes in 14C production rate (Q), and in the carbon cycle, can be combined to explain the reconstructed atmospheric Δ14C record, we discuss possible reasons for this knowledge gap. Reviewing the literature, we exclude that changes in the content of atoms in the atmosphere, which produce cosmogenic 14C after being hit by galactic cosmic rays, might be responsible for parts of the observed differences. When combining Q with carbon cycle changes, one needs to understand the changes in the atmospheric 14C inventory, which are partially counterintuitive. For example, during the Last Glacial Maximum, Δ14C was ∼400‰ higher compared with preindustrial times, but the 14C inventory was 10% smaller. Some pronounced changes in atmospheric Δ14C do not correspond to any significant changes in the atmospheric 14C inventory, since CO2 was changing simultaneously. Using two conceptually different models (BICYCLE‐SE and LSG‐OGCM), we derive hypothetical Qs by forcing the models with identical atmospheric CO2 and Δ14C data. Results are compared with the most recent data‐based estimates of Q derived from cosmogenic isotopes. Millennial‐scale climate change connected to the bipolar seesaw is missing in the applied models, which might explain some, but probably not all, of the apparent model‐data disagreement in Q. Furthermore, Q based on either data from marine sediments or ice cores contains offsets, suggesting an interpretation deficit in the current data‐based approaches. Key Points: No important change found in the level of precursor material, which produces cosmogenic radiocarbon after being hit by galactic cosmic raysTransient changes in the bipolar seesaw are needed in applied carbon cycle models to improve interpretation of the radiocarbon cycleSediment core‐ and ice core‐based radiocarbon production rates differ systematically, suggesting missing processes [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
14. The relative role of oceanic heat transport and orography on glacial climate
- Author
-
Romanova, Vanya, Lohmann, Gerrit, Grosfeld, Klaus, and Butzin, Martin
- Published
- 2006
- Full Text
- View/download PDF
15. Modelling tempo-spatial signatures of Heinrich Events: influence of the climatic background state
- Author
-
Prange, Matthias, Lohmann, Gerrit, Romanova, Vanya, and Butzin, Martin
- Published
- 2004
- Full Text
- View/download PDF
16. Exploring the role of temperature in observed inter-population differences of Atlantic cod (Gadus morhua) growth with a 4-dimensional modelling approach.
- Author
-
Sokolova, Nadezhda, Butzin, Martin, Dahlke, Flemming, Werner, Karl Michael, Balting, Daniel, Lohmann, Gerrit, and Pörtner, Hans-Otto
- Subjects
- *
ATLANTIC cod , *WATER temperature , *PHYSIOLOGICAL adaptation , *TEMPERATURE , *SEAWATER - Abstract
Atlantic cod (Gadus morhua) is one of the most commercially important fish species in the North Atlantic. Environmental factors, such as water temperatures, influence growth of individuals over time, thus forming population-specific growth patterns across climatic regions. Here we develop an integrative approach to investigate the role of temperature in shaping geographic differences of cod growth in the Celtic Sea, North Sea, Iceland, and Barents Sea. We combine a physiology-based growth model and 50-years observational temperature data of 0.5 × 0.5° spatial resolution to simulate continuous growth of cod. The model generated weight-at-age data for the period 1959–2007 which we compared to observational data from fishery-independent scientific surveys. In the Celtic and the northern North Sea, simulated growth matches well observational data. We also show that relatively warm temperatures in the Celtic Sea facilitate maximum growth rates; future warming is likely to have a negative impact on growth of these cod stocks. Growth simulations in Icelandic waters and the Barents Sea are less consistent with local observational data. More complex growth patterns in these regions are probably shaped by ontogenetic shifts in temperature regimes, feeding conditions and physiological adaptations. These findings should stimulate further research on critical processes to be considered in population-specific projections of growth of cod and productivity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. Comment on “Scrutinizing the carbon cycle and CO2residence time in the atmosphere” by H. Harde
- Author
-
Köhler, Peter, Hauck, Judith, Völker, Christoph, Wolf-Gladrow, Dieter A., Butzin, Martin, Halpern, Joshua B., Rice, Ken, and Zeebe, Richard E.
- Published
- 2018
- Full Text
- View/download PDF
18. Abrupt Climate and Weather Changes Across Time Scales.
- Author
-
Lohmann, Gerrit, Butzin, Martin, Eissner, Nina, Shi, Xiaoxu, and Stepanek, Christian
- Subjects
CLIMATE change ,WEATHER & climate change ,MERIDIONAL overturning circulation ,MELTWATER ,ICE cores ,OCEAN circulation - Abstract
The past provides evidence of abrupt climate shifts and changes in the frequency of climate and weather extremes. We explore the nonlinear response to orbital forcing and then consider climate millennial variability down to daily weather events. Orbital changes are translated into regional responses in temperature, where the precessional response is related to nonlinearities and seasonal biases in the system. We question regularities found in climate events by analyzing the distribution of interevent waiting times. Periodicities of about 900 and 1,150 yr are found in ice cores besides the prominent 1,500 yr cycle. However, the variability remains indistinguishable from a random process, suggesting that centennial‐to‐millennial variability is stochastic in nature. New numerical techniques are developed allowing for a high resolution in the dynamically relevant regions like coasts, major upwelling regions, and high latitudes. Using this model, we find a strong sensitivity of the Atlantic meridional overturning circulation depending on where the deglacial meltwater is injected into. Meltwater into the Mississippi and near Labrador hardly affect the large‐scale ocean circulation, whereas subpolar hosing mimicking icebergs yields a quasi shutdown. The same multiscale approach is applied to radiocarbon simulations enabling a dynamical interpretation of marine sediment cores. Finally, abrupt climate events also have counterparts in the recent climate records, revealing a close link between climate variability, the statistics of North Atlantic weather patterns, and extreme events. Plain Language Summary: Predicting the future spread of possible climates, the risk of climate extremes and the risk of rapid transitions is of high socioeconomic relevance. The past provides evidence of abrupt climate change and the frequency of extremes. This allows to separate anthropogenic signals from natural climate variability. Earth system models applied both to past and future scenarios will enhance our ability to detect regime shifts which are necessary to potentially predict climate extremes and transitions. We consider the response of the system to regular orbital forcing and then focus on shorter time scales down to weather. The appearance of precession is linked to nonlinear responses of the climate system to external orbital forcing. Furthermore, we find that centennial‐to‐millennial variability is stochastic in nature. We also discuss recent developments of climate models with superior resolution in typical retrieval regions of paleoclimate records, such as continental margins and coasts. Using this model, we find a strong sensitivity of the Atlantic meridional overturning circulation depending on where the deglacial meltwater is injected into. Meltwater into the Mississippi and near Labrador hardly affect the large‐scale ocean circulation, whereas subpolar hosing related to icebergs yields a quasi shutdown. Our multiscale approach is applied to radiocarbon simulations enabling a dynamical interpretation of marine sediment cores. Finally, we explore a close link between climate variability, the statistics of weather patterns, and extreme events. Key Points: Nonlinear response of the climate system to external orbital forcing yields responses in the precessional bandCentennial and millennial variability are stochastic in natureOcean and radiocarbon modeling with high resolution at the coasts and high latitudes provides a suitable framework for multi‐scale dynamicsThe past provides evidences of abrupt climate changes and weather extremes [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
19. Marine20—The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP).
- Author
-
Heaton, Timothy J, Köhler, Peter, Butzin, Martin, Bard, Edouard, Reimer, Ron W, Austin, William E N, Bronk Ramsey, Christopher, Grootes, Pieter M, Hughen, Konrad A, Kromer, Bernd, Reimer, Paula J, Adkins, Jess, Burke, Andrea, Cook, Mea S, Olsen, Jesper, Skinner, Luke C, and Reimer, Paula J.
- Subjects
CARBON isotopes ,CALIBRATION ,BAYESIAN analysis ,COMPUTER simulation - Abstract
The concentration of radiocarbon (
14 C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their14 C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-average marine record of radiocarbon from 0–55 cal kBP and serves as a baseline for regional oceanic variation. Marine20 is intended for calibration of marine radiocarbon samples from non-polar regions; it is not suitable for calibration in polar regions where variability in sea ice extent, ocean upwelling and air-sea gas exchange may have caused larger changes to concentrations of marine radiocarbon. The Marine20 curve is based upon 500 simulations with an ocean/atmosphere/biosphere box-model of the global carbon cycle that has been forced by posterior realizations of our Northern Hemispheric atmospheric IntCal2014 C curve and reconstructed changes in CO2 obtained from ice core data. These forcings enable us to incorporate carbon cycle dynamics and temporal changes in the atmospheric14 C level. The box-model simulations of the global-average marine radiocarbon reservoir age are similar to those of a more complex three-dimensional ocean general circulation model. However, simplicity and speed of the box model allow us to use a Monte Carlo approach to rigorously propagate the uncertainty in both the historic concentration of atmospheric14 C and other key parameters of the carbon cycle through to our final Marine20 calibration curve. This robust propagation of uncertainty is fundamental to providing reliable precision for the radiocarbon age calibration of marine based samples. We make a first step towards deconvolving the contributions of different processes to the total uncertainty; discuss the main differences of Marine20 from the previous age calibration curve Marine13; and identify the limitations of our approach together with key areas for further work. The updated values for ΔR, the regional marine radiocarbon reservoir age corrections required to calibrate against Marine20, can be found at the data base http://calib.org/marine/. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
20. The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP).
- Author
-
Reimer, Paula J, Austin, William E N, Bard, Edouard, Bayliss, Alex, Blackwell, Paul G, Bronk Ramsey, Christopher, Butzin, Martin, Cheng, Hai, Edwards, R Lawrence, Friedrich, Michael, Grootes, Pieter M, Guilderson, Thomas P, Hajdas, Irka, Heaton, Timothy J, Hogg, Alan G, Hughen, Konrad A, Kromer, Bernd, Manning, Sturt W, Muscheler, Raimund, and Palmer, Jonathan G
- Subjects
RADIOCARBON dating ,CALIBRATION ,TREE-rings ,RESERVOIRS ,OCEAN circulation - Abstract
Radiocarbon (
14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international14 C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable14 C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the14 C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine14 C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
21. A Short Note on Marine Reservoir Age Simulations Used in IntCal20.
- Author
-
Butzin, Martin, Heaton, Timothy J, Köhler, Peter, Lohmann, Gerrit, and Reimer, Paula J.
- Subjects
CARBON isotopes ,FORAMINIFERA ,ARCHIVES ,RESERVOIRS ,OCEAN circulation - Abstract
Beyond ~13.9 cal kBP, the IntCal20 radiocarbon (
14 C) calibration curve is based upon combining data across a range of different archives including corals and planktic foraminifera. In order to reliably incorporate such marine data into an atmospheric curve, we need to resolve these records into their constituent atmospheric signal and marine reservoir age. We present results of marine reservoir age simulations enabling this resolution, applying the LSG ocean general circulation model forced with various climatic background conditions and with atmospheric radiocarbon changes according to the Hulu Cave speleothem record. Simulating the spatiotemporal evolution of reservoir ages between 54,000 and 10,700 cal BP, we find reservoir ages between 500 and 1400 yr in the low- and mid-latitudes, but also more than 3000 yr in the polar seas. Our results are broadly in agreement with available marine radiocarbon reconstructions, with the caveat that continental margins, marginal seas, or tropical lagoons are not properly resolved in our coarse-resolution model. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
22. Thermal bottlenecks in the life cycle define climate vulnerability of fish.
- Author
-
Dahlke, Flemming T., Wohlrab, Sylke, Butzin, Martin, and Pörtner, Hans-Otto
- Published
- 2020
- Full Text
- View/download PDF
23. Readjustment of glacial radiocarbon chronologies by self-consistent three-dimensional ocean circulation modeling
- Author
-
Butzin, Martin, Prange, Matthias, and Lohmann, Gerrit
- Published
- 2012
- Full Text
- View/download PDF
24. Changes in equatorial Pacific thermocline depth in response to Panamanian seaway closure: Insights from a multi-model study
- Author
-
Zhang, Xiao, Prange, Matthias, Steph, Silke, Butzin, Martin, Krebs, Uta, Lunt, Daniel J., Nisancioglu, Kerim H., Park, Wonsun, Schmittner, Andreas, Schneider, Birgit, and Schulz, Michael
- Published
- 2012
- Full Text
- View/download PDF
25. Thermal growth potential of Atlantic cod by the end of the 21st century.
- Author
-
Butzin, Martin and Pörtner, Hans‐Otto
- Subjects
- *
CLIMATE change , *EARTH science forecasting , *ECOPHYSIOLOGY , *COLD-blooded animals , *FISH growth , *THERMAL tolerance (Physiology) - Abstract
Ocean warming may lead to smaller body sizes of marine ectotherms, because metabolic rates increase exponentially with temperature while the capacity of the cardiorespiratory system to match enhanced oxygen demands is limited. Here, we explore the impact of rising sea water temperatures on Atlantic cod ( Gadus morhua), an economically important fish species. We focus on changes in the temperature-dependent growth potential by a transfer function model combining growth observations with climate model ensemble temperatures. Growth potential is expressed in terms of asymptotic body weight and depends on water temperature. We consider changes between the periods 1985-2004 and 2081-2100, assuming that future sea water temperatures will evolve according to climate projections for IPCC AR5 scenario RCP8.5. Our model projects a response of Atlantic cod to future warming, differentiated according to ocean regions, leading to increases of asymptotic weight in the Barents Sea, while weights are projected to decline at the southern margin of the biogeographic range. Southern spawning areas will disappear due to thermal limitation of spawning stages. These projections match the currently observed biogeographic shifts and the temperature- and oxygen-dependent decline in routine aerobic scope at southern distribution limits. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
26. Radiocarbon simulations for the glacial ocean: The effects of wind stress, Southern Ocean sea ice and Heinrich events
- Author
-
Butzin, Martin, Prange, Matthias, and Lohmann, Gerrit
- Published
- 2005
- Full Text
- View/download PDF
27. Miocene ocean circulation inferred from marine carbon cycle modeling combined with benthic isotope records.
- Author
-
Butzin, Martin, Lohmann, Gerrit, and Bickert, Torsten
- Published
- 2011
- Full Text
- View/download PDF
28. Alkenone temperature anomalies in the Brazil-Malvinas Confluence area caused by lateral advection of suspended particulate material.
- Author
-
Rühlemann, Carsten and Butzin, Martin
- Published
- 2006
- Full Text
- View/download PDF
29. Tritium budget of the South Atlantic.
- Author
-
Butzin, Martin and Roether, Wolfgang
- Published
- 2004
- Full Text
- View/download PDF
30. The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
- Author
-
Reimer, Paula J., Austin, William E.N., Bard, Edouard, Bayliss, Alex, Blackwell, Paul, Bronk Ramsey, Christopher, Butzin, Martin, Cheng, Hai, Edwards, R. Lawrence, Friedrich, Michael, Grootes, Pieter M., Guilderson, Thomas P., Hajdas, Irka, Heaton, Timothy, Hogg, Alan, Hughen, Konrad, Kromer, Bernd, Manning, Sturt, Muscheler, Raimund, Palmer, Jonathan, Pearson, Charlotte, van der Plicht, Johannes, Reimer, Ron, Richards, David A., Scott, Marian, Southon, John, Turney, Chris, Wacker, Lukas, Adolphi, Florian, Büntgen, Ulf, Capano, Manuela, Fahrni, Simon, Fogtmann-Schulz, Alexandra, Friedrich, Ronny, Köhler, Peter, Kudsk, Sabrina, Miyake, Fusa, Olsen, Jesper, Reinig, Frederick, Sakamoto, Minoru, Sookdeo, Adam, and Talamo, Sahra
- Subjects
IntCal20 ,13. Climate action ,14. Life underwater ,Calibration curve ,Radiocarbon - Abstract
Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals., Radiocarbon, 62 (4), ISSN:0033-8222
31. Glacial heterogeneity in Southern Ocean carbon storage abated by fast South Indian deglacial carbon release
- Author
-
Gottschalk, Julia, Michel, Elisabeth, Thöle, Lena M., Studer, Anja S., Hasenfratz, Adam P., Schmid, Nicole, Butzin, Martin, Mazaud, Alain, Martínez-García, Alfredo, Szidat, Sönke, and Jaccard, Samuel L.
- Subjects
13. Climate action ,14. Life underwater - Abstract
Past changes in ocean 14C disequilibria have been suggested to reflect the Southern Ocean control on global exogenic carbon cycling. Yet, the volumetric extent of the glacial carbon pool and the deglacial mechanisms contributing to release remineralized carbon, particularly from regions with enhanced mixing today, remain insufficiently constrained. Here, we reconstruct the deglacial ventilation history of the South Indian upwelling hotspot near Kerguelen Island, using high-resolution 14C-dating of smaller-than-conventional foraminiferal samples and multi-proxy deep-ocean oxygen estimates. We find marked regional differences in Southern Ocean overturning with distinct South Indian fingerprints on (early de-)glacial atmospheric CO2 change. The dissipation of this heterogeneity commenced 14.6 kyr ago, signaling the onset of modern-like, strong South Indian Ocean upwelling, likely promoted by rejuvenated Atlantic overturning. Our findings highlight the South Indian Ocean’s capacity to influence atmospheric CO2 levels and amplify the impacts of inter-hemispheric climate variability on global carbon cycling within centuries and millennia., Nature Communications, 11 (1), ISSN:2041-1723
32. Toward Reconciling Radiocarbon Production Rates With Carbon Cycle Changes of the Last 55,000 Years
- Author
-
Peter Köhler, Raimund Muscheler, Florian Adolphi, Martin Butzin, Adolphi, Florian, 1 Alfred‐Wegener‐Institut Helmholtz‐Zentrum für Polar‐und Meeresforschung (AWI) Bremerhaven Germany, Butzin, Martin, Muscheler, Raimund, and 2 Department of Geology Lund University Lund Sweden
- Subjects
Atmospheric Science ,13. Climate action ,ddc:551.9 ,Paleontology ,Oceanography - Abstract
Since it is currently not understood how changes in 14C production rate (Q), and in the carbon cycle, can be combined to explain the reconstructed atmospheric Δ14C record, we discuss possible reasons for this knowledge gap. Reviewing the literature, we exclude that changes in the content of atoms in the atmosphere, which produce cosmogenic 14C after being hit by galactic cosmic rays, might be responsible for parts of the observed differences. When combining Q with carbon cycle changes, one needs to understand the changes in the atmospheric 14C inventory, which are partially counterintuitive. For example, during the Last Glacial Maximum, Δ14C was ∼400‰ higher compared with preindustrial times, but the 14C inventory was 10% smaller. Some pronounced changes in atmospheric Δ14C do not correspond to any significant changes in the atmospheric 14C inventory, since CO2 was changing simultaneously. Using two conceptually different models (BICYCLE‐SE and LSG‐OGCM), we derive hypothetical Qs by forcing the models with identical atmospheric CO2 and Δ14C data. Results are compared with the most recent data‐based estimates of Q derived from cosmogenic isotopes. Millennial‐scale climate change connected to the bipolar seesaw is missing in the applied models, which might explain some, but probably not all, of the apparent model‐data disagreement in Q. Furthermore, Q based on either data from marine sediments or ice cores contains offsets, suggesting an interpretation deficit in the current data‐based approaches., Key Points: No important change found in the level of precursor material, which produces cosmogenic radiocarbon after being hit by galactic cosmic rays. Transient changes in the bipolar seesaw are needed in applied carbon cycle models to improve interpretation of the radiocarbon cycle. Sediment core‐ and ice core‐based radiocarbon production rates differ systematically, suggesting missing processes., Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347, Swedish Research Concil, Helmholtz Association (亥姆霍兹联合会致力) http://dx.doi.org/10.13039/501100009318, https://doi.org/10.1594/PANGAEA.871273, https://www.ncdc.noaa.gov/paleo-search/study/31772, https://doi.org/10.1594/PANGAEA.914500, https://www.iceandclimate.nbi.ku.dk/data/, https://doi.org/10.1594/PANGAEA.932965
- Published
- 2022
33. Northern cod species face spawning habitat losses if global warming exceeds 1.5°C.
- Author
-
Dahlke FT, Butzin M, Nahrgang J, Puvanendran V, Mortensen A, Pörtner HO, and Storch D
- Subjects
- Animals, Hydrogen-Ion Concentration, Oceans and Seas, Salinity, Conservation of Natural Resources, Ecosystem, Gadus morhua physiology, Global Warming, Reproduction
- Abstract
Rapid climate change in the Northeast Atlantic and Arctic poses a threat to some of the world's largest fish populations. Impacts of warming and acidification may become accessible through mechanism-based risk assessments and projections of future habitat suitability. We show that ocean acidification causes a narrowing of embryonic thermal ranges, which identifies the suitability of spawning habitats as a critical life-history bottleneck for two abundant cod species. Embryonic tolerance ranges linked to climate simulations reveal that ever-increasing CO
2 emissions [Representative Concentration Pathway (RCP) 8.5] will deteriorate suitability of present spawning habitat for both Atlantic cod ( Gadus morhua ) and Polar cod ( Boreogadus saida ) by 2100. Moderate warming (RCP4.5) may avert dangerous climate impacts on Atlantic cod but still leaves few spawning areas for the more vulnerable Polar cod, which also loses the benefits of an ice-covered ocean. Emissions following RCP2.6, however, support largely unchanged habitat suitability for both species, suggesting that risks are minimized if warming is held "below 2°C, if not 1.5°C," as pledged by the Paris Agreement.- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.