3,724 results on '"Oschlies, A."'
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2. Emergent constraint on oxygenation of the upper South Eastern Pacific oxygen minimum zone in the twenty-first century
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Almendra, Ivan, Dewitte, Boris, Garçon, Véronique, Muñoz, Praxedes, Parada, Carolina, Montes, Ivonne, Duteil, Olaf, Paulmier, Aurélien, Pizarro, Oscar, Ramos, Marcel, Koeve, Wolfgang, and Oschlies, Andreas
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- 2024
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3. Emergent constraint on oxygenation of the upper South Eastern Pacific oxygen minimum zone in the twenty-first century
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Ivan Almendra, Boris Dewitte, Véronique Garçon, Praxedes Muñoz, Carolina Parada, Ivonne Montes, Olaf Duteil, Aurélien Paulmier, Oscar Pizarro, Marcel Ramos, Wolfgang Koeve, and Andreas Oschlies
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Geology ,QE1-996.5 ,Environmental sciences ,GE1-350 - Abstract
Abstract As a consequence of on-going global warming, the ocean is losing oxygen, which has implications not only in terms of marine resources management and food supply but also in terms of the potentially important feedback on the global carbon cycle and climate. Of particular scrutiny are the extended zones of already low levels of oxygen called the oxygen minimum zones (OMZs) embedded in the subsurface waters of the productive Eastern Boundary Upwelling Systems (EBUS). These OMZs are currently diversely simulated by state-of-the-art Earth System Models (ESM) hampering a reliable projection of ocean deoxygenation on marine ecosystem services in these regions. Here we focus on the most emblematic EBUS OMZs of the planet, that of the South Eastern Pacific (SEP), which is under the direct influence of the El Niño Southern Oscillation (ENSO), the main climate mode on interannual timescales at global scale. We show that, despite the low consensus among ESM long-term projections of oxygen levels, the sensitivity of the depth of the upper margin (oxycline) of the SEP OMZ to El Niño events in an ensemble of ESMs can be used as a predictor of its long-term trend, which establishes an emergent constraint for the SEP OMZ. Because the oxycline along the coast of Peru and Chile deepens during El Niño events, the upper bound of the SEP OMZ is thus likely to deepen in the future climate, therefore oxygenating the SEP OMZ. This has implications not only for understanding the nitrogen and carbon cycles at global scale but also for designing adaptation strategies for regional upper-ocean ecosystem services.
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- 2024
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4. Southern Ocean phytoplankton under climate change: a shifting balance of bottom-up and top-down control
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T. Xue, J. Terhaar, A. E. F. Prowe, T. L. Frölicher, A. Oschlies, and I. Frenger
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
Phytoplankton form the base of the marine food web by transforming CO2 into organic carbon via photosynthesis. Despite the importance of phytoplankton for marine ecosystems and global carbon cycling, projections of phytoplankton biomass in response to climate change differ strongly across Earth system models, illustrating uncertainty in our understanding of the underlying processes. Differences are especially large in the Southern Ocean, a region that is notoriously difficult to represent in models. Here, we argue that total (depth-integrated) phytoplankton biomass in the Southern Ocean is projected to largely remain unchanged under climate change by the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model ensemble because of a shifting balance of bottom-up and top-down processes driven by a shoaling mixed-layer depth. A shallower mixed layer is projected on average to improve growth conditions, consequently weaken bottom-up control, and confine phytoplankton closer to the surface. An increase in the phytoplankton concentration promotes zooplankton grazing efficiency, thus intensifying top-down control. However, large differences across the model ensemble exist, with some models simulating a decrease in surface phytoplankton concentrations. To reduce uncertainties in projections of surface phytoplankton concentrations, we employ an emergent constraint approach using the observed sensitivity of surface chlorophyll concentration, taken as an observable proxy for phytoplankton, to seasonal changes in the mixed-layer depth as an indicator for future changes in surface phytoplankton concentrations. The emergent constraint reduces uncertainties in surface phytoplankton concentration projections by around one-third and increases confidence that surface phytoplankton concentrations will indeed rise due to shoaling mixed layers under global warming, thus favouring intensified top-down control. Overall, our results suggest that while changes in bottom-up conditions stimulate enhanced growth, intensified top-down control opposes an increase in phytoplankton and becomes increasingly important for the phytoplankton response to climate change in the Southern Ocean.
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- 2024
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5. The role of trephine bone marrow biopsies in the era of measurable residual disease—Results from the CLL10 trial of the German CLL Study Group (GCLLSG)
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Nadine Kutsch, Sandra Robrecht, Anna Fink, Elisabeth Lange, Rudolf Weide, Michael G. Kiehl, Martin Sökler, Rudolf Schlag, Ursula Vehling‐Kaiser, Georg Köchling, Christoph Plöger, Michael Gregor, Torben Plesner, Michael R. Clausen, Ilske Oschlies, Matthias Ritgen, Marco Herling, Kirsten Fischer, Hartmut Döhner, Clemens‐Martin Wendtner, Karl‐Anton Kreuzer, Stephan Stilgenbauer, Michael Hallek, Sebastian Böttcher, Wolfram Klapper, and Barbara Eichhorst
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Diseases of the blood and blood-forming organs ,RC633-647.5 - Published
- 2024
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6. SPRAT: A Spatially-Explicit Marine Ecosystem Model Based on Population Balance Equations
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Johanson, Arne N., Oschlies, Andreas, Hasselbring, Wilhelm, and Worm, Boris
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Quantitative Biology - Populations and Evolution ,Computer Science - Computational Engineering, Finance, and Science ,I.6.5 - Abstract
To successfully manage marine fisheries using an ecosystem-based approach, long-term predictions of fish stock development considering changing environmental conditions are necessary. Such predictions can be provided by end-to-end ecosystem models, which couple existing physical and biogeochemical ocean models with newly developed spatially-explicit fish stock models. Typically, Individual-Based Models (IBMs) and models based on Advection-Diffusion-Reaction (ADR) equations are employed for the fish stock models. In this paper, we present a novel fish stock model called SPRAT for end-to\hyp{}end ecosystem modeling based on Population Balance Equations (PBEs) that combines the advantages of IBMs and ADR models while avoiding their main drawbacks. SPRAT accomplishes this by describing the modeled ecosystem processes from the perspective of individuals while still being based on partial differential equations. We apply the SPRAT model to explore a well-documented regime shift observed on the eastern Scotian Shelf in the 1990s from a cod-dominated to a herring-dominated ecosystem. Model simulations are able to reconcile the observed multitrophic dynamics with documented changes in both fishing pressure and water temperature, followed by a predator-prey reversal that may have impeded recovery of depleted cod stocks. We conclude that our model can be used to generate new hypotheses and test ideas about spatially interacting fish populations, and their joint responses to both environmental and fisheries forcing., Comment: 20 pages
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- 2022
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7. A Comprehensive Assessment of Carbon Dioxide Removal Options for Germany
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Malgorzata Borchers, Johannes Förster, Daniela Thrän, Silke Beck, Terese Thoni, Klaas Korte, Erik Gawel, Till Markus, Romina Schaller, Imke Rhoden, Yaxuan Chi, Nicolaus Dahmen, Roland Dittmeyer, Tobias Dolch, Christian Dold, Michael Herbst, Dominik Heß, Aram Kalhori, Ketil Koop‐Jakobsen, Zhan Li, Andreas Oschlies, Thorsten B. H. Reusch, Torsten Sachs, Cornelia Schmidt‐Hattenberger, Angela Stevenson, Jiajun Wu, Christopher Yeates, and Nadine Mengis
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context‐specific assessments of carbon dioxide removal ,bioenergy with carbon capture and storage (BECCS) ,direct air carbon capture and storage (DACCS) ,natural sink enhancement (NSE) ,climate mitigation ,feasibility assessment framework ,Environmental sciences ,GE1-350 ,Ecology ,QH540-549.5 - Abstract
Abstract To reach their net‐zero targets, countries will have to compensate hard‐to‐abate CO2 emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio‐cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context‐specific feasibility assessment of CDR options for the example of Germany. We assess 14 CDR options, including three chemical carbon capture options, six options for bioenergy combined with carbon capture and storage (BECCS), and five options that aim to increase ecosystem carbon uptake. The assessment addresses technological, economic, environmental, institutional, social‐cultural and systemic considerations using a traffic‐light system to evaluate implementation opportunities and hurdles. We find that in Germany CDR options like cover crops or seagrass restoration currently face comparably low implementation hurdles in terms of technological, economic, or environmental feasibility and low institutional or social opposition but show comparably small CO2 removal potentials. In contrast, some BECCS options that show high CDR potentials face significant techno‐economic, societal and institutional hurdles when it comes to the geological storage of CO2. While a combination of CDR options is likely required to meet the net‐zero target in Germany, the current climate protection law includes a limited set of options. Our analysis aims to provide comprehensive information on CDR hurdles and possibilities for Germany for use in further research on CDR options, climate, and energy scenario development, as well as an effective decision support basis for various actors.
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- 2024
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8. The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms
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Alaggio, Rita, Amador, Catalina, Anagnostopoulos, Ioannis, Attygalle, Ayoma D, Araujo, Iguaracyra Barreto de Oliveira, Berti, Emilio, Bhagat, Govind, Borges, Anita Maria, Boyer, Daniel, Calaminici, Mariarita, Chadburn, Amy, Chan, John KC, Cheuk, Wah, Chng, Wee-Joo, Choi, John K, Chuang, Shih-Sung, Coupland, Sarah E, Czader, Magdalena, Dave, Sandeep S, de Jong, Daphne, Du, Ming-Qing, Elenitoba-Johnson, Kojo S, Ferry, Judith, Geyer, Julia, Gratzinger, Dita, Guitart, Joan, Gujral, Sumeet, Harris, Marian, Harrison, Christine J, Hartmann, Sylvia, Hochhaus, Andreas, Jansen, Patty M, Karube, Kennosuke, Kempf, Werner, Khoury, Joseph, Kimura, Hiroshi, Klapper, Wolfram, Kovach, Alexandra E, Kumar, Shaji, Lazar, Alexander J, Lazzi, Stefano, Leoncini, Lorenzo, Leung, Nelson, Leventaki, Vasiliki, Li, Xiao-Qiu, Lim, Megan S, Liu, Wei-Ping, Louissaint, Abner, Marcogliese, Andrea, Medeiros, L Jeffrey, Michal, Michael, Miranda, Roberto N, Mitteldorf, Christina, Montes-Moreno, Santiago, Morice, William, Nardi, Valentina, Naresh, Kikkeri N, Natkunam, Yasodha, Ng, Siok-Bian, Oschlies, Ilske, Ott, German, Parrens, Marie, Pulitzer, Melissa, Rajkumar, S Vincent, Rawstron, Andrew C, Rech, Karen, Rosenwald, Andreas, Said, Jonathan, Sarkozy, Clémentine, Sayed, Shahin, Saygin, Caner, Schuh, Anna, Sewell, William, Siebert, Reiner, Sohani, Aliyah R, Tooze, Reuben, Traverse-Glehen, Alexandra, Vega, Francisco, Vergier, Beatrice, Wechalekar, Ashutosh D, Wood, Brent, Xerri, Luc, and Xiao, Wenbin
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Cancer ,Hematologic Neoplasms ,Humans ,Lymphoma ,World Health Organization ,Clinical Sciences ,Oncology and Carcinogenesis ,Immunology - Abstract
We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.
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- 2022
9. Correction: “The 5th edition of The World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms” Leukemia. 2022 Jul;36(7):1720–1748
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Alaggio, Rita, Amador, Catalina, Anagnostopoulos, Ioannis, Attygalle, Ayoma D., de Oliveira Araujo, Iguaracyra Barreto, Berti, Emilio, Bhagat, Govind, Borges, Anita Maria, Boyer, Daniel, Calaminici, Mariarita, Chadburn, Amy, Chan, John K. C., Cheuk, Wah, Chng, Wee-Joo, Choi, John K., Chuang, Shih-Sung, Coupland, Sarah E., Czader, Magdalena, Dave, Sandeep S., de Jong, Daphne, Di Napoli, Arianna, Du, Ming-Qing, Elenitoba-Johnson, Kojo S., Ferry, Judith, Geyer, Julia, Gratzinger, Dita, Guitart, Joan, Gujral, Sumeet, Harris, Marian, Harrison, Christine J., Hartmann, Sylvia, Hochhaus, Andreas, Jansen, Patty M., Karube, Kennosuke, Kempf, Werner, Khoury, Joseph, Kimura, Hiroshi, Klapper, Wolfram, Kovach, Alexandra E., Kumar, Shaji, Lazar, Alexander J., Lazzi, Stefano, Leoncini, Lorenzo, Leung, Nelson, Leventaki, Vasiliki, Li, Xiao-Qiu, Lim, Megan S., Liu, Wei-Ping, Louissaint, Jr, Abner, Marcogliese, Andrea, Medeiros, L. Jeffrey, Michal, Michael, Miranda, Roberto N., Mitteldorf, Christina, Montes-Moreno, Santiago, Morice, William, Nardi, Valentina, Naresh, Kikkeri N., Natkunam, Yasodha, Ng, Siok-Bian, Oschlies, Ilske, Ott, German, Parrens, Marie, Pulitzer, Melissa, Rajkumar, S. Vincent, Rawstron, Andrew C., Rech, Karen, Rosenwald, Andreas, Said, Jonathan, Sarkozy, Clémentine, Sayed, Shahin, Saygin, Caner, Schuh, Anna, Sewell, William, Siebert, Reiner, Sohani, Aliyah R., Suzuki, Ritsuro, Tooze, Reuben, Traverse-Glehen, Alexandra, Vega, Francisco, Vergier, Beatrice, Wechalekar, Ashutosh D., Wood, Brent, Xerri, Luc, and Xiao, Wenbin
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- 2023
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10. Mögliche Beiträge geologischer und mariner Kohlenstoffspeicher zur Dekarbonisierung
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Oschlies, Andreas, Mengis, Nadine, Rehder, Gregor, Schill, Eva, Thomas, Helmuth, Wallmann, Klaus, Zimmer, Martin, Brasseur, Guy P., editor, Jacob, Daniela, editor, and Schuck-Zöller, Susanne, editor
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- 2023
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11. Exploring the role of different data types and timescales in the quality of marine biogeochemical model calibration
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I. Kriest, J. Getzlaff, A. Landolfi, V. Sauerland, M. Schartau, and A. Oschlies
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
Global biogeochemical ocean models help to investigate the present and potential future state of the ocean, its productivity and cascading effects on higher trophic levels such as fish. They are often subjectively tuned against data sets of inorganic tracers and surface chlorophyll and only very rarely against organic components such as particulate organic carbon or zooplankton. The resulting uncertainty in biogeochemical model parameters (and parameterisations) associated with these components can explain some of the large spread of global model solutions with regard to the cycling of organic matter and its impacts on biogeochemical tracer distributions, such as oxygen minimum zones (OMZs). A second source of uncertainty arises from differences in the model spin-up length as, so far, there seems to be no agreement on the required simulation time that should elapse before a global model is assessed against observations. We investigated these two sources of uncertainty by optimising a global biogeochemical ocean model against the root-mean-squared error (RMSE) of six different combinations of data sets and different spin-up times. Besides nutrients and oxygen, the observational data sets also included phyto- and zooplankton, as well as dissolved and particulate organic phosphorus (DOP and POP, respectively). We further analysed the optimised model performance with regard to global biogeochemical fluxes, oxygen inventory and OMZ volume. Following the optimisation procedure, we evaluated the RMSE for all tracers located in the upper 100 m (except for POP, for which we considered the entire vertical domain), regardless of their consideration during optimisation. For the different optimal model solutions, we find a narrow range of the RMSE, between 14 % of the average RMSE after 10 years and 24 % after 3000 years of simulation. Global biogeochemical fluxes, global oxygen bias and OMZ volume showed a much stronger divergence among the models and over time than RMSE, indicating that even models that are similar with regard to local surface tracer concentrations can perform very differently when assessed against the global diagnostics for oxygen. Considering organic tracers in the optimisation had a strong impact on the particle flux exponent (Martin b) and may reduce much of the uncertainty in this parameter and the resulting deep particle flux. Independent of the optimisation setup, the OMZ volume showed a particularly sensitive response with strong trends over time, even after 3000 years of simulation time (despite the constant physical forcing); a high sensitivity to simulation time; and the highest sensitivity to model parameters arising from the tuning strategy setup (variation of almost 80 % of the ensemble mean). In conclusion, calibration against observations of organic tracers can help to improve global biogeochemical models even after short spin-up times; here especially, observations of deep particle flux could provide a powerful constraint. However, a large uncertainty remains with regard to global OMZ volume and its evolution over time, which can show very dynamic behaviour during the model spin-up, which renders temporal extrapolation to a final equilibrium state difficult if not impossible. Given that the real ocean shows variations on many timescales, the assumption of observations representing a steady-state ocean may require some reconsideration.
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- 2023
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12. Frequency and prognostic implications of KMT2A rearrangements in children with precursor B-cell lymphoma
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Au-Yeung, Rex K. H., Padilla, Laura Arias, Zimmermann, Martin, Reinke, Sarah, Oschlies, Ilske, Escherich, Gabriele, Woessmann, Wilhelm, Burkhardt, Birgit, and Klapper, Wolfram
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- 2023
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13. A Global Ocean Oxygen Database and Atlas for Assessing and Predicting Deoxygenation and Ocean Health in the Open and Coastal Ocean
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Grégoire, Marilaure, Garçon, Véronique, Garcia, Hernan, Breitburg, Denise, Isensee, Kirsten, Oschlies, Andreas, Telszewski, Maciej, Barth, Alexander, Bittig, Henry C, Carstensen, Jacob, Carval, Thierry, Chai, Fei, Chavez, Francisco, Conley, Daniel, Coppola, Laurent, Crowe, Sean, Currie, Kim, Dai, Minhan, Deflandre, Bruno, Dewitte, Boris, Diaz, Robert, Garcia-Robledo, Emilio, Gilbert, Denis, Giorgetti, Alessandra, Glud, Ronnie, Gutierrez, Dimitri, Hosoda, Shigeki, Ishii, Masao, Jacinto, Gil, Langdon, Chris, Lauvset, Siv K, Levin, Lisa A, Limburg, Karin E, Mehrtens, Hela, Montes, Ivonne, Naqvi, Wajih, Paulmier, Aurélien, Pfeil, Benjamin, Pitcher, Grant, Pouliquen, Sylvie, Rabalais, Nancy, Rabouille, Christophe, Recape, Virginie, Roman, Michaël, Rose, Kenneth, Rudnick, Daniel, Rummer, Jodie, Schmechtig, Catherine, Schmidtko, Sunke, Seibel, Brad, Slomp, Caroline, Sumalia, U Rashid, Tanhua, Toste, Thierry, Virginie, Uchida, Hiroshi, Wanninkhof, Rik, and Yasuhara, Moriaki
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Earth Sciences ,Oceanography ,Life Below Water ,oxygen ,atlas ,database ,observing ,mapping ,data-products ,open and coastal ocean ,deoxygenation ,Ecology ,Geology - Abstract
In this paper, we outline the need for a coordinated international effort toward the building of an open-access Global Ocean Oxygen Database and ATlas (GO2DAT) complying with the FAIR principles (Findable, Accessible, Interoperable, and Reusable). GO2DAT will combine data from the coastal and open ocean, as measured by the chemical Winkler titration method or by sensors (e.g., optodes, electrodes) from Eulerian and Lagrangian platforms (e.g., ships, moorings, profiling floats, gliders, ships of opportunities, marine mammals, cabled observatories). GO2DAT will further adopt a community-agreed, fully documented metadata format and a consistent quality control (QC) procedure and quality flagging (QF) system. GO2DAT will serve to support the development of advanced data analysis and biogeochemical models for improving our mapping, understanding and forecasting capabilities for ocean O2 changes and deoxygenation trends. It will offer the opportunity to develop quality-controlled data synthesis products with unprecedented spatial (vertical and horizontal) and temporal (sub-seasonal to multi-decadal) resolution. These products will support model assessment, improvement and evaluation as well as the development of climate and ocean health indicators. They will further support the decision-making processes associated with the emerging blue economy, the conservation of marine resources and their associated ecosystem services and the development of management tools required by a diverse community of users (e.g., environmental agencies, aquaculture, and fishing sectors). A better knowledge base of the spatial and temporal variations of marine O2 will improve our understanding of the ocean O2 budget, and allow better quantification of the Earth’s carbon and heat budgets. With the ever-increasing need to protect and sustainably manage ocean services, GO2DAT will allow scientists to fully harness the increasing volumes of O2 data already delivered by the expanding global ocean observing system and enable smooth incorporation of much higher quantities of data from autonomous platforms in the open ocean and coastal areas into comprehensive data products in the years to come. This paper aims at engaging the community (e.g., scientists, data managers, policy makers, service users) toward the development of GO2DAT within the framework of the UN Global Ocean Oxygen Decade (GOOD) program recently endorsed by IOC-UNESCO. A roadmap toward GO2DAT is proposed highlighting the efforts needed (e.g., in terms of human resources).
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- 2021
14. Carbon dioxide removal via macroalgae open-ocean mariculture and sinking: an Earth system modeling study
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J. Wu, D. P. Keller, and A. Oschlies
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Science ,Geology ,QE1-996.5 ,Dynamic and structural geology ,QE500-639.5 - Abstract
In this study, we investigate the maximum physical and biogeochemical potential of macroalgae open-ocean mariculture and sinking (MOS) as an ocean-based carbon dioxide removal (CDR) method. Embedding a macroalgae model into an Earth system model, we simulate macroalgae mariculture in the open-ocean surface layer followed by fast sinking of the carbon-rich macroalgal biomass to the deep seafloor (depth>3000 m), which assumes no remineralization of the harvested biomass during the quick sinking. We also test the combination of MOS with artificial upwelling (AU), which fertilizes the macroalgae by pumping nutrient-rich deeper water to the surface. The simulations are done under RCP 4.5, a moderate-emissions pathway. When deployed globally between years 2020 and 2100, the carbon captured and exported by MOS is 270 PgC, which is further boosted by AU of 447 PgC. Because of feedbacks in the Earth system, the oceanic carbon inventory only increases by 171.8 PgC (283.9 PgC with AU) in the idealized simulations. More than half of this carbon remains in the ocean after cessation at year 2100 until year 3000. The major side effect of MOS on pelagic ecosystems is the reduction of phytoplankton net primary production (PNPP) due to the competition for nutrients with macroalgae and due to canopy shading. MOS shrinks the mid-layer oxygen-minimum zones (OMZs) by reducing the organic matter export to, and remineralization in, subsurface and intermediate waters, while it creates new OMZs on the seafloor by oxygen consumption from remineralization of sunken biomass. MOS also impacts the global carbon cycle by reducing the atmospheric and terrestrial carbon reservoirs when enhancing the ocean carbon reservoir. MOS also enriches dissolved inorganic carbon in the deep ocean. Effects are mostly reversible after cessation of MOS, though recovery is not complete by year 3000. In a sensitivity experiment without remineralization of sunken MOS biomass, the whole of the MOS-captured carbon is permanently stored in the ocean, but the lack of remineralized nutrients causes a long-term nutrient decline in the surface layers and thus reduces PNPP. Our results suggest that MOS has, theoretically, considerable CDR potential as an ocean-based CDR method. However, our simulations also suggest that such large-scale deployment of MOS would have substantial side effects on marine ecosystems and biogeochemistry, up to a reorganization of food webs over large parts of the ocean.
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- 2023
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15. Lymphome und andere hämatologische Neoplasien im Hoden
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Koch, Karoline, Oschlies, Ilske, and Klapper, Wolfram
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- 2022
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16. Modified risk-stratified sequential treatment (subcutaneous rituximab with or without chemotherapy) in B-cell Post-transplant lymphoproliferative disorder (PTLD) after Solid organ transplantation (SOT): the prospective multicentre phase II PTLD-2 trial
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Zimmermann, Heiner, Koenecke, Christian, Dreyling, Martin H., Pott, Christiane, Dührsen, Ulrich, Hahn, Dennis, Meidenbauer, Norbert, Hauser, Ingeborg A., Rummel, Mathias J., Wolf, Dominik, Heuser, Michael, Schmidt, Christian, Schlattmann, Peter, Ritgen, Matthias, Siebert, Reiner, Oschlies, Ilske, Anagnostopoulos, Ioannis, and Trappe, Ralf U.
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- 2022
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17. Mechanisms regulating trophic transfer in the Humboldt Upwelling System differ across time scales
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Tianfei Xue, Ivy Frenger, Jaard Hauschildt, and Andreas Oschlies
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Humboldt upwelling system ,plankton dynamics ,El Niño ,food chain efficiency ,offshore surface flow ,mixed layer depth ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Science ,Physics ,QC1-999 - Abstract
The Humboldt Upwelling System hosts a highly productive ecosystem with central importance for global fisheries, yet with strong seasonal and interannual variability in the planktonic base of the food chain ultimately affecting fish yield. Understanding the variability in energy transfer within the plankton community in the contemporary climate can provide valuable insights for future projections of planktonic dynamics. Therefore, we use a regional physical-biogeochemical ocean model simulation (CROCO-BioEBUS) from 1990 to 2010 to investigate the underlying mechanisms of seasonal and interannual variability of the trophic transfer. Our model simulations suggest that, on an interannual scale, variations in trophic transfer are governed by variations in the offshore surface flow that modulate the plankton cross-shore distribution. Weak offshore surface flow, as simulated during the El Niño period, allows the zooplankton to stay relatively close to the shore, leading to more efficient grazing and trophic transfer compared to years with strong offshore flow. This mechanism differs from the seasonal one, where the mixed layer depth is the primary driver of variations in plankton dynamics, including trophic transfer. Our results highlight that mechanisms controlling plankton trophic transfer differ across time scales, and thus stress that extrapolating solely from seasonal findings to understand long-term trophic transfer changes in the context of climate change may be insufficient.
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- 2024
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18. Earth system responses to carbon dioxide removal as exemplified by ocean alkalinity enhancement: tradeoffs and lags
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Aurich Jeltsch-Thömmes, Giang Tran, Sebastian Lienert, David P Keller, Andreas Oschlies, and Fortunat Joos
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carbon dioxide removal ,ocean alkalinity enhancement ,climate–carbon cycle projections ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Science ,Physics ,QC1-999 - Abstract
Carbon dioxide removal (CDR) is discussed for offsetting residual greenhouse gas emissions or even reversing climate change. All emissions scenarios of the Intergovernmental Panel on Climate Change that meet the ‘well below 2 °C’ warming target of the Paris Agreement include CDR. Ocean alkalinity enhancement (OAE) may be one possible CDR where the carbon uptake of the ocean is increased by artificial alkalinity addition. Here, we investigate the effect of OAE on modelled carbon reservoirs and fluxes in two observationally-constrained large perturbed parameter ensembles. OAE is assumed to be technically successful and deployed as an additional CDR in the SSP5-3.4 temperature overshoot scenario. Tradeoffs involving feedbacks with atmospheric CO _2 result in a low efficiency of an alkalinity-driven atmospheric CO _2 reduction of −0.35 [−0.37 to −0.33] mol C per mol alkalinity addition (skill-weighted mean and 68% c.i.). The realized atmospheric CO _2 reduction, and correspondingly the efficiency, is more than two times smaller than the direct alkalinity-driven enhancement of ocean uptake. The alkalinity-driven ocean carbon uptake is partly offset by the release of carbon from the land biosphere and a reduced ocean carbon sink in response to lowered atmospheric CO _2 under OAE. In a second step we use the Bern3D-LPX model in CO _2 peak-decline simulations to address hysteresis and temporal lags of surface air temperature change (ΔSAT) in an idealized scenario where ΔSAT increases to ~2 °C and then declines to ~1.5 °C as result of CDR. ΔSAT lags the decline in CO _2 -forcing by 18 [14–22] years, depending close to linearly on the equilibrium climate sensitivity of the respective ensemble member. These tradeoffs and lags are an inherent feature of the Earth system response to changes in atmospheric CO _2 and will therefore be equally important for other CDR methods.
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- 2024
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19. Recovery from microplastic-induced marine deoxygenation may take centuries
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Kvale, Karin and Oschlies, Andreas
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- 2023
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20. Can Oxygen Utilization Rate Be Used to Track the Long‐Term Changes of Aerobic Respiration in the Mesopelagic Atlantic Ocean?
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Haichao Guo, Iris Kriest, Andreas Oschlies, and Wolfgang Koeve
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mesopelagic respiration ,oxygen utilization rate ,Earth system model ,ocean deoxygenation ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Abstract Quantifying changes in oceanic aerobic respiration is essential for understanding marine deoxygenation. Here we use an Earth system model to investigate if and to what extent oxygen utilization rate (OUR) can be used to track the temporal change of true respiration (Rtrue). Rtrue results from the degradation of particulate and dissolved organic matter in the model ocean, acting as ground truth to evaluate the accuracy of OUR. Results show that in thermocline and intermediate waters of the North Atlantic Subtropical Gyre (200–1,000 m), vertically integrated OUR and Rtrue both decrease by 0.2 molO2/m2/yr from 1850 to 2100 under global warming. However, in the mesopelagic Tropical South Atlantic, integrated OUR increases by 0.2 molO2/m2/yr, while the Rtrue integral decreases by 0.3 molO2/m2/yr. A possible reason for the diverging OUR and Rtrue is ocean mixing, which affects water mass composition and maps remote respiration changes to the study region.
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- 2023
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21. Considering the Role of Adaptive Evolution in Models of the Ocean and Climate System.
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Ward, BA, Collins, S, Dutkiewicz, S, Gibbs, S, Bown, P, Ridgwell, A, Sauterey, B, Wilson, JD, and Oschlies, A
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climate ,ecology ,evolution ,ocean ,Atmospheric Sciences - Abstract
Numerical models have been highly successful in simulating global carbon and nutrient cycles in today's ocean, together with observed spatial and temporal patterns of chlorophyll and plankton biomass at the surface. With this success has come some confidence in projecting the century-scale response to continuing anthropogenic warming. There is also increasing interest in using such models to understand the role of plankton ecosystems in past oceans. However, today's marine environment is the product of billions of years of continual evolution-a process that continues today. In this paper, we address the questions of whether an assumption of species invariance is sufficient, and if not, under what circumstances current model projections might break down. To do this, we first identify the key timescales and questions asked of models. We then review how current marine ecosystem models work and what alternative approaches are available to account for evolution. We argue that for timescales of climate change overlapping with evolutionary timescales, accounting for evolution may to lead to very different projected outcomes regarding the timescales of ecosystem response and associated global biogeochemical cycling. This is particularly the case for past extinction events but may also be true in the future, depending on the eventual degree of anthropogenic disruption. The discipline of building new numerical models that incorporate evolution is also hugely beneficial in itself, as it forces us to question what we know about adaptive evolution, irrespective of its quantitative role in any specific event or environmental changes.
- Published
- 2019
22. Improving outcomes of childhood and young adult non-Hodgkin lymphoma: 25 years of research and collaboration within the framework of the European Intergroup for Childhood Non-Hodgkin Lymphoma
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Beishuizen, Auke, Mellgren, Karin, Andrés, Mara, Auperin, Anne, Bacon, Chris M, Bomken, Simon, Burke, G A Amos, Burkhardt, Birgit, Brugieres, Laurence, Chiang, Alan K S, Damm-Welk, Christine, d'Amore, Emanuele, Horibe, Keizo, Kabickova, Edita, Khanam, Tasneem, Kontny, Udo, Klapper, Wolfram, Lamant, Laurence, Le Deley, Marie-Cecile, Loeffen, Jan, Macintyre, Elizabeth, Mann, Georg, Meyer-Wentrup, Friederike, Michgehl, Ulf, Minard-Colin, Veronique, Mussolin, Lara, Oschlies, Ilske, Patte, Catherine, Pillon, Marta, Reiter, Alfred, Rigaud, Charlotte, Ronceray, Leila, Salaverria, Itziar, Simonitsch-Klupp, Ingrid, Uyttebroeck, Anne, Verdu-Amoros, Jaime, Williams, Denise, Woessmann, Wilhelm, Wotherspoon, Andrew, Wrobel, Grazyna, Zimmermann, Martin, Attarbaschi, Andishe, and Turner, Suzanne D
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- 2023
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23. Diagnosis and management of cutaneous lymphomas and lymphoid proliferations in children, adolescents and young adults (CAYA)
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Stokke, Jamie, Tann, Annabelle, El-Mallawany, Nader Kim, and Oschlies, Ilske
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- 2023
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24. Characterization of IG-MYC-breakpoints and their application for quantitative minimal disease monitoring in high-risk pediatric Burkitt-lymphoma and -leukemia
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Möker, Paula, zur Stadt, Udo, Zimmermann, Martin, Alawi, Malik, Mueller, Stephanie, Finger, Jasmin, Knörr, Fabian, Riquelme, Amambay, Oschlies, Ilske, Klapper, Wolfram, Bradtke, Jutta, Burkhardt, Birgit, Woessmann, Wilhelm, and Damm-Welk, Christine
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- 2022
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25. FOCI-MOPS v1 – integration of marine biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model
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C.-T. Chien, J. V. Durgadoo, D. Ehlert, I. Frenger, D. P. Keller, W. Koeve, I. Kriest, A. Landolfi, L. Patara, S. Wahl, and A. Oschlies
- Subjects
Geology ,QE1-996.5 - Abstract
The consideration of marine biogeochemistry is essential for simulating the carbon cycle in an Earth system model. Here we present the implementation and evaluation of a marine biogeochemical model, the Model of Oceanic Pelagic Stoichiometry (MOPS) in the Flexible Ocean and Climate Infrastructure (FOCI) climate model. FOCI-MOPS enables the simulation of marine biological processes, i.e. the marine carbon, nitrogen, and oxygen cycles with prescribed or prognostic atmospheric CO2 concentration. A series of experiments covering the historical period (1850–2014) were performed following the DECK (Diagnostic, Evaluation and Characterization of Klima) and CMIP6 (Coupled Model Intercomparison Project 6) protocols. Overall, modelled biogeochemical tracer distributions and fluxes, transient evolution in surface air temperature, air–sea CO2 fluxes, and changes in ocean carbon and heat contents are in good agreement with observations. Modelled inorganic and organic tracer distributions are quantitatively evaluated by statistically derived metrics. Results of the FOCI-MOPS model, including sea surface temperature, surface pH, oxygen (100–600 m), nitrate (0–100 m), and primary production, are within the range of other CMIP6 model results. Overall, the evaluation of FOCI-MOPS indicates its suitability for Earth climate system simulations.
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- 2022
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26. Clinical relevance of molecular characteristics in Burkitt lymphoma differs according to age
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Birgit Burkhardt, Ulf Michgehl, Jonas Rohde, Tabea Erdmann, Philipp Berning, Katrin Reutter, Marius Rohde, Arndt Borkhardt, Thomas Burmeister, Sandeep Dave, Alexandar Tzankov, Martin Dugas, Sarah Sandmann, Falko Fend, Jasmin Finger, Stephanie Mueller, Nicola Gökbuget, Torsten Haferlach, Wolfgang Kern, Wolfgang Hartmann, Wolfram Klapper, Ilske Oschlies, Julia Richter, Udo Kontny, Mathias Lutz, Britta Maecker-Kolhoff, German Ott, Andreas Rosenwald, Reiner Siebert, Arend von Stackelberg, Brigitte Strahm, Wilhelm Woessmann, Martin Zimmermann, Myroslav Zapukhlyak, Michael Grau, and Georg Lenz
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Science - Abstract
Survival outcomes in Burkitt lymphoma differ between adult and paediatric patients. Here, the authors show differences in mutational frequencies between age groups, and a transition between mutational profiles which occurs between 25 and 40 years.
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- 2022
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27. Immunodeficiency with susceptibility to lymphoma with complex genotype affecting energy metabolism (FBP1, ACAD9) and vesicle trafficking (RAB27A)
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Nina Brauer, Yuto Maruta, Miriam Lisci, Katharina Strege, Ilske Oschlies, Hikari Nakamura, Svea Böhm, Kai Lehmberg, Leon Brandhoff, Stephan Ehl, Nima Parvaneh, Wolfram Klapper, Mitsunori Fukuda, Gillian M. Griffiths, Hans Christian Hennies, Tim Niehues, and Sandra Ammann
- Subjects
lymphoma ,RAB27A-deficiency ,Griscelli syndrome type 2 ,Epstein-Barr virus ,metabolic diseases ,Immunologic diseases. Allergy ,RC581-607 - Abstract
IntroductionInborn errors of immunity (IEI) are characterized by a dysfunction of the immune system leading to increased susceptibility to infections, impaired immune regulation and cancer. We present a unique consanguineous family with a history of Hodgkin lymphoma, impaired EBV control and a late onset hemophagocytic lymphohistiocytosis (HLH).Methods and resultsOverall, family members presented with variable impairment of NK cell and cytotoxic T cell degranulation and cytotoxicity. Exome sequencing identified homozygous variants in RAB27A, FBP1 (Fructose-1,6-bisphosphatase 1) and ACAD9 (Acyl-CoA dehydrogenase family member 9). Variants in RAB27A lead to Griscelli syndrome type 2, hypopigmentation and HLH predisposition.DiscussionLymphoma is frequently seen in patients with hypomorphic mutations of genes predisposing to HLH. We hypothesize that the variants in FBP1 and ACAD9 might aggravate the clinical and immune phenotype, influence serial killing and lytic granule polarization by CD8 T cells. Understanding of the interplay between the multiple variants identified by whole exome sequencing (WES) is essential for correct interpretation of the immune phenotype and important for critical treatment decisions.
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- 2023
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28. Exploring site-specific carbon dioxide removal options with storage or sequestration in the marine environment - The 10 Mt CO2 yr-1 removal challenge for Germany
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Yao, Wanxuan, primary, Morganti, Teresa, additional, Wu, Jiajun, additional, Borchers, Malgorzata, additional, Anschütz, Anna-Adriana, additional, Bednarz, Lena-Katharina, additional, Bhaumik, Amrita, additional, Boettcher, Miranda, additional, Burkhard, Kremena, additional, Cabus, Tony, additional, Chua, Allison Sueyi, additional, Diercks, Isabel, additional, Mario, Esposito, additional, Fink, Michael, additional, Fouqueray, Mondane, additional, Gasanzade, Firdovsi, additional, Geilert, Sonja, additional, Hauck, Judith, additional, Havermann, Felix, additional, Hellige, Inga, additional, Hoog, Sven, additional, Jürchott, Malte, additional, Kalapurakkal, Habeeb Thanveer, additional, Kemper, Jost, additional, Kremin, Isabel, additional, Lange, Isabel, additional, Lencina-Avila, Jannine Marquez, additional, Liadova, Margarita, additional, Liu, Feifei, additional, Mathesius, Sabine, additional, Mehendale, Neha, additional, Nagwekar, Tanvi, additional, Philippi, Miriam, additional, Luz, Gustavo Leite Neves da, additional, Ramasamy, Murugan, additional, Stahl, Florian, additional, Tank, Lukas, additional, Vorrath, Maria-Elena, additional, Westmark, Lennart, additional, Wey, Hao-Wei, additional, Wollnik, Ronja, additional, Wölfelschneider, Mirco, additional, Bach, Wolfgang, additional, Bischof, Kai, additional, boersma, maarten, additional, Daewel, Ute, additional, Fernández-Méndez, Mar, additional, Geuer, Jana, additional, Keller, David Peter, additional, Kopf, Achim J., additional, Merk, Christine, additional, Moosdorf, Nils, additional, Oppelt, Natascha Maria, additional, Oschlies, Andreas, additional, Pongratz, Julia, additional, Proelss, Alexander, additional, Rehder, Gregor, additional, Rüpke, Lars Helmuth, additional, Szarka, Nora, additional, Thrän, Daniela, additional, Wallmann, Klaus, additional, and Mengis, Nadine, additional
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- 2024
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29. Earth system responses to carbon dioxide removal as exemplified by ocean alkalinity enhancement: tradeoffs and lags
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Jeltsch-Thömmes, Aurich, primary, Tran, Giang, additional, Lienert, Sebastian, additional, Keller, David, additional, Oschlies, Andreas, additional, and Joos, Fortunat, additional
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- 2024
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30. Biogeochemical feedbacks may amplify ongoing and future ocean deoxygenation: a case study from the Peruvian oxygen minimum zone
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Wallmann, Klaus, José, Yonss S., Hopwood, Mark J., Somes, Christopher J., Dale, Andrew W., Scholz, Florian, Achterberg, Eric P., and Oschlies, Andreas
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- 2022
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31. Co-Occurrence of EBV-Positive Mucocutaneous Ulcer (EBV-MCU) and CLL/SLL in the Head and Neck Region
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Patricia Bott, Ilske Oschlies, Andreas Radeloff, and Maureen Loewenthal
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Epstein–Barr virus ,mucocutaneous ulcer ,head and neck ulcer ,EBV-positive mucocutaneous ulcer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
EBV-positive mucocutaneous ulcer (EBV-MCU) was classified as a rare new entity of the lymphoproliferative B-cell diseases by the WHO in 2017 and must be distinguished from head and neck squamous cell carcinoma by early biopsy. The aim of the study is to raise awareness of the disease and to give a review of the current literature and a recommendation for EBV-MCU management. All EBV-MCU cases of the head and neck region published so far were included. We also report a case of a pharyngeal EBV-MCU in an 89-year-old patient who was immunosuppressed by chronic lymphatic leukaemia/small lymphocytic lymphoma (CLL/SLL). In contrast to all previously described cases, histopathology showed a co-infiltration of EBV-MCU and CLL/SLL. A total of 181 cases were identified on PubMed and summarised. EBV-MCU was predominantly caused by immunosuppressive drug therapy. Complete remission could be achieved in 68% of cases and was mainly attributed to a reduction of the immunosuppressive therapy alone (72%). However, some severe cases require more aggressive treatment. Regarding the various histopathologic similarities to other lymphoproliferative disorders, the diagnosis of EBV-MCU can be misleading, with a great impact on patient care and treatment. This diagnosis must be made with caution and requires a combination of clinical, morphological and immunophenotypic features.
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- 2022
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32. A unifying hypothesis for PNMZL and PTFL: morphological variants with a common molecular profile
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Salmeron-Villalobos, Julia, Egan, Caoimhe, Borgmann, Vanessa, Müller, Inga, Gonzalez-Farre, Blanca, Ramis-Zaldivar, Joan Enric, Nann, Dominik, Balagué, Olga, López-Guerra, Mónica, Colomer, Dolors, Oschlies, Ilske, Klapper, Wolfram, Glaser, Selina, Ko, Young Hyeh, Bonzheim, Irina, Siebert, Reiner, Fend, Falko, Pittaluga, Stefania, Campo, Elias, Salaverria, Itziar, Jaffe, Elaine S., and Quintanilla-Martinez, Leticia
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- 2022
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33. Artificial Upwelling—A Refined Narrative
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M. Jürchott, A. Oschlies, and W. Koeve
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carbon dioxide removal method ,artificial upwelling ,biological carbon pump ,solubility pump ,emission scenarios ,UVic ESM ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Abstract The current narrative of artificial upwelling (AU) is to translocate nutrient rich deep water to the ocean surface, thereby stimulating the biological carbon pump (BCP). Our refined narrative takes the response of the solubility pump and the CO2 emission scenario into account. Using global ocean‐atmosphere model experiments we show that the effectiveness of a hypothetical maximum AU deployment in all ocean areas where AU is predicted to lower surface pCO2, the draw down of CO2 from the atmosphere during years 2020–2100 depends strongly on the CO2 emission scenario and ranges from 1.01 Pg C/year (3.70 Pg CO2/year) under RCP 8.5 to 0.32 Pg C/year (1.17 Pg CO2/year) under RCP 2.6. The solubility pump becomes equally effective compared to the BCP under the highest emission scenario (RCP 8.5), but responds with CO2 outgassing under low CO2 emission scenarios.
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- 2023
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34. On the path to net-zero: Establishing a multi-level system to support the complex endeavor of reaching national carbon neutrality
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Fiona Köhnke, Bettina Steuri, Juliane El Zohbi, Knut Görl, Malgorzata Borchers, Johannes Förster, Daniela Thrän, Nadine Mengis, Andreas Oschlies, and Daniela Jacob
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net-zero ,carbon neutrality ,mitigation ,carbon dioxide removal ,decarbonization ,Environmental sciences ,GE1-350 - Abstract
Limiting global warming to well below 2°C and pursuing efforts to limit it to 1.5°C, as agreed in the 2015 Paris Agreement, requires global carbon neutrality by mid-century at the latest. The corresponding carbon budget is decreasing steadily and significantly. To phase out carbon emissions in line with the specified temperature target, countries are formulating their mitigation efforts in their long-term low greenhouse gas emission development strategies (LT-LEDS). However, there are no standardized specifications for preparing these strategies, which is why the reports published to date differ widely in terms of structure and scope. To consider the multiple facets of reaching net-zero from a systemic perspective as comprehensively as possible, the authors propose the Net-Zero-2050 System: A novel, transferrable systems approach that supports the development of national endeavors toward carbon neutrality. The Net-Zero-2050 System is defined by three interconnected components: The Carbon-Emission-Based System, the surrounding Framing System and a set of system boundaries. For both systems levels, IPCC approaches were used as a basis and were then adjusted and supplemented by Net-Zero-2050. We suggest applying the Net-Zero-2050 System—beyond the project environment—in carbon emission based contexts at different levels. Especially at the national level, this would improve the comparability of the different national strategies to achieve carbon neutrality.
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- 2023
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35. Clinical relevance of molecular characteristics in Burkitt lymphoma differs according to age
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Burkhardt, Birgit, Michgehl, Ulf, Rohde, Jonas, Erdmann, Tabea, Berning, Philipp, Reutter, Katrin, Rohde, Marius, Borkhardt, Arndt, Burmeister, Thomas, Dave, Sandeep, Tzankov, Alexandar, Dugas, Martin, Sandmann, Sarah, Fend, Falko, Finger, Jasmin, Mueller, Stephanie, Gökbuget, Nicola, Haferlach, Torsten, Kern, Wolfgang, Hartmann, Wolfgang, Klapper, Wolfram, Oschlies, Ilske, Richter, Julia, Kontny, Udo, Lutz, Mathias, Maecker-Kolhoff, Britta, Ott, German, Rosenwald, Andreas, Siebert, Reiner, von Stackelberg, Arend, Strahm, Brigitte, Woessmann, Wilhelm, Zimmermann, Martin, Zapukhlyak, Myroslav, Grau, Michael, and Lenz, Georg
- Published
- 2022
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36. Antibody-Negative Paraneoplastic Autoimmune Multiorgan Syndrome (PAMS) in a Patient with Follicular Lymphoma Accompanied by an Excess of Peripheral Blood CD8+ Lymphocytes
- Author
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Thilo Gambichler, Yi-Pei Lee, Ilske Oschlies, Christina H. Scheel, Wolfram Klapper, Nico Nowack, Martin Doerler, Markus Stücker, Nasreddin Abolmaali, and Laura Susok
- Subjects
paraneoplastic pemphigus ,autoimmune blistering diseases ,cancer ,autoantibodies ,cytotoxic lymphocytes ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Paraneoplastic autoimmune multiorgan syndrome (PAMS) is a life-threatening autoimmune disease associated with malignancies. Here, we present a patient initially misdiagnosed with “chronic” Stevens–Johnson syndrome. Over a year later, the patient was diagnosed with stage IV follicular lymphoma and treated with an anti-CD20 antibody. At this time, his skin condition had significantly worsened, with erythroderma and massive mucosal involvement, including in the mouth, nose, eyes, and genital region. Histopathology revealed lichenoid infiltrates with interface dermatitis, dyskeratoses, necrotic keratinocytes, and a dense CD8+ infiltrate with strong epidermotropism. Direct and indirect immunofluorescence tests for autoantibodies were negative. Remarkably, we retrospectively discovered a chronic increase in peripheral CD8+ lymphocytes, persisting for over a year. Consequently, the patient was diagnosed with antibody-negative PAMS. Three weeks later, he succumbed to respiratory failure. This dramatic case highlights the challenges in diagnosing PAMS, particularly in cases where immunofluorescence assays are negative. Importantly, we observed, for the first time, a chronic excess of CD8+ peripheral blood lymphocytes, associated with PAMS, consistent with the systemic, autoreactive T-cell-driven processes that characterize this condition.
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- 2022
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37. Mixed layer depth dominates over upwelling in regulating the seasonality of ecosystem functioning in the Peruvian upwelling system
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T. Xue, I. Frenger, A. E. F. Prowe, Y. S. José, and A. Oschlies
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
The Peruvian upwelling system hosts a marine ecosystem with extremely high productivity. Observations show that the Peruvian upwelling system is the only eastern boundary upwelling system (EBUS) with an out-of-phase relationship between seasonal surface chlorophyll concentrations and upwelling intensity. This “seasonal paradox” triggers the following questions: (1) what are the unique characteristics of the Peruvian upwelling system, compared with other EBUSs, that lead to the out-of-phase relationship, and (2) how does the seasonal paradox influence ecosystem functioning? Using observational climatologies for four EBUSs, we diagnose that the Peruvian upwelling system is the only one to reveal that intense upwelling coincides with deep mixed layers. We then apply a coupled regional ocean circulation biogeochemical model (CROCO–BioEBUS) to assess how the interplay between mixed layers and upwelling regulates the seasonality of surface chlorophyll in the Peruvian upwelling system. Our model reproduces the “seasonal paradox” within 200 km off the Peruvian coast. We confirm previous findings regarding the main contribution of mixed layer depth to the seasonality of chlorophyll, relative to upwelling. Deep mixed layers in austral winter cause vertical dilution of phytoplankton and strong light limitation, impacting growth. The effect of advection, though second-order, is consistent with previous findings for the Peruvian system and other EBUSs, with enhanced offshore export opposing the coastal build-up of biomass. In addition, we find that the relatively colder temperatures of upwelled waters slightly dampen phytoplankton productivity and further slow the build-up of phytoplankton biomass. This impact from the combination of deep mixed layers and upwelling propagates through the ecosystem, from primary production to export and export efficiency. Our findings emphasize the crucial role of the interplay between mixed layer depth and upwelling and suggest that surface chlorophyll may increase, along with a weakened seasonal paradox, in response to shoaling mixed layers under climate change.
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- 2022
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38. Misconceptions of the marine biological carbon pump in a changing climate: Thinking outside the “export” box
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Frenger, Ivy, Landolfi, Angela, Kvale, Karin F., Somes, Christopher J., Oschlies, Andreas, Yao, Wanxuan, Koeve, Wolfgang, Frenger, Ivy, Landolfi, Angela, Kvale, Karin F., Somes, Christopher J., Oschlies, Andreas, Yao, Wanxuan, and Koeve, Wolfgang
- Abstract
The marine biological carbon pump (BCP) stores carbon in the ocean interior, isolating it from exchange with the atmosphere and thereby coregulating atmospheric carbon dioxide (CO 2 ). As the BCP commonly is equated with the flux of organic material to the ocean interior, termed “export flux,” a change in export flux is perceived to directly impact atmospheric CO 2 , and thus climate. Here, we recap how this perception contrasts with current understanding of the BCP, emphasizing the lack of a direct relationship between global export flux and atmospheric CO 2 . We argue for the use of the storage of carbon of biological origin in the ocean interior as a diagnostic that directly relates to atmospheric CO 2 , as a way forward to quantify the changes in the BCP in a changing climate. The diagnostic is conveniently applicable to both climate model data and increasingly available observational data. It can explain a seemingly paradoxical response under anthropogenic climate change: Despite a decrease in export flux, the BCP intensifies due to a longer reemergence time of biogenically stored carbon back to the ocean surface and thereby provides a negative feedback to increasing atmospheric CO 2 . This feedback is notably small compared with anthropogenic CO 2 emissions and other carbon‐climate feedbacks. In this Opinion paper, we advocate for a comprehensive view of the BCP's impact on atmospheric CO 2 , providing a prerequisite for assessing the effectiveness of marine CO 2 removal approaches that target marine biology.
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- 2024
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39. Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth System Model
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Tivig, Miriam, Keller, David P., Oschlies, Andreas, Tivig, Miriam, Keller, David P., and Oschlies, Andreas
- Abstract
Riverine nutrient export is an important process in marine coastal biogeochemistry and also impacts global marine biology. The nitrogen cycle is a key player here. Internal feedbacks regulate not only nitrogen distribution, but also primary production and thereby oxygen concentrations. Phosphorus is another essential nutrient and interacts with the nitrogen cycle via different feedback mechanisms. After a previous study of the marine nitrogen cycle response to riverine nitrogen supply, we here additionally include phosphorus from river export with different phosphorus burial scenarios and study the impact of phosphorus alone and in combination with nitrogen in a global 3-D ocean biogeochemistry model. Again, we analyse the effects on near coastal and open ocean biogeochemistry. We find that the addition of bio-available riverine phosphorus alone or together with nitrogen affects marine biology on millennial timescales more than riverine nitrogen alone. Biogeochemical feedbacks in the marine nitrogen cycle are strongly influenced by the additional phosphorus. Where bio-available phosphorus is increased by river input, nitrogen concentrations increase as well, except for regions with high denitrification rates. High phosphorus burial rates decrease biological production significantly. Globally, riverine phosphorus leads to elevated primary production rates in the coastal and open oceans.
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- 2024
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40. Southern Ocean phytoplankton under climate change: a shifting balance of bottom-up and top-down control
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Xue, Tianfei, Frenger, Ivy, Terhaar, Jens, Prowe, A. E. Friederike, Frölicher, Thomas L., Oschlies, Andreas, Xue, Tianfei, Frenger, Ivy, Terhaar, Jens, Prowe, A. E. Friederike, Frölicher, Thomas L., and Oschlies, Andreas
- Abstract
Phytoplankton form the base of the marine food web by transforming CO2 into organic carbon via photosynthesis. Despite the importance of phytoplankton for marine ecosystems and global carbon cycling, projections of phytoplankton biomass in response to climate change differ strongly across Earth system models, illustrating uncertainty in our understanding of the underlying processes. Differences are especially large in the Southern Ocean, a region that is notoriously difficult to represent in models. Here, we argue that total (depth-integrated) phytoplankton biomass in the Southern Ocean is projected to largely remain unchanged under climate change by the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model ensemble because of a shifting balance of bottom-up and top-down processes driven by a shoaling mixed-layer depth. A shallower mixed layer is projected on average to improve growth conditions, consequently weaken bottom-up control, and confine phytoplankton closer to the surface. An increase in the phytoplankton concentration promotes zooplankton grazing efficiency, thus intensifying top-down control. However, large differences across the model ensemble exist, with some models simulating a decrease in surface phytoplankton concentrations. To reduce uncertainties in projections of surface phytoplankton concentrations, we employ an emergent constraint approach using the observed sensitivity of surface chlorophyll concentration, taken as an observable proxy for phytoplankton, to seasonal changes in the mixed-layer depth as an indicator for future changes in surface phytoplankton concentrations. The emergent constraint reduces uncertainties in surface phytoplankton concentration projections by around one-third and increases confidence that surface phytoplankton concentrations will indeed rise due to shoaling mixed layers under global warming, thus favouring intensified top-down control. Overall, our results suggest that while changes in bottom-up conditio
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- 2024
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41. World Ocean Review: The Ocean – A Climate Champion? How to Boost Marine Carbon Dioxide Uptake
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Amann, Thorben, Baatz, Christian, Böttcher, Miranda, Geden, Oliver, Keller, David P., Kopf, Achim, Merk, Christine, Milinski, Sebastian, Mintenbeck, Katja, Oschlies, Andreas, Pongratz, Julia, Proelß, Alexander, Rehder, Gregor, Rickels, Wilfried, Riebesell, Ulf, Sswat, Michael, Tank, Lukas, Wallmann, Klaus, Westmark, Lennart, Wölfelschneider, Mirco, Zimmer, Martin, Amann, Thorben, Baatz, Christian, Böttcher, Miranda, Geden, Oliver, Keller, David P., Kopf, Achim, Merk, Christine, Milinski, Sebastian, Mintenbeck, Katja, Oschlies, Andreas, Pongratz, Julia, Proelß, Alexander, Rehder, Gregor, Rickels, Wilfried, Riebesell, Ulf, Sswat, Michael, Tank, Lukas, Wallmann, Klaus, Westmark, Lennart, Wölfelschneider, Mirco, and Zimmer, Martin
- Abstract
What action should we take for the effective mitigation of climate change? Measures to avoid greenhouse gas emissions are surely the main priority – but the truth is that in the coming decades, we will also have to remove large quantities of carbon dioxide from the atmosphere and store it securely. Can – indeed, should – the ocean aid us in this task? The new World Ocean Review (WOR 8) explores this issue with reference to the oceans' role in the Earth's carbon cycle and looks at the benefits, risks and knowledge gaps around the main marine carbon dioxide removal techniques.
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- 2024
42. Mögliche Beiträge geologischer und mariner Kohlenstoffspeicher zur Dekarbonisierung
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Brasseur, Guy P., Jacob, Daniela, Schuck-Zöller, Susanne, Oschlies, Andreas, Mengis, Nadine, Rehder, Gregor, Schill, Eva, Thomas, Helmuth, Wallmann, Klaus, Zimmer, Martin, Brasseur, Guy P., Jacob, Daniela, Schuck-Zöller, Susanne, Oschlies, Andreas, Mengis, Nadine, Rehder, Gregor, Schill, Eva, Thomas, Helmuth, Wallmann, Klaus, and Zimmer, Martin
- Abstract
Es werden mögliche Beiträge geologischer und mariner Kohlenstoffspeicher für die Vermeidung von CO2-Emissionen in die Atmosphäre oder für die Entnahme von bereits emittiertem CO2 aus der Atmosphäre vorgestellt. Neben der Einlagerung von CO2 in geologischen Speichern unter Land und unter dem Meeresboden werden eine forcierte CO2-Entnahme aus der Atmosphäre und Abgabe in den Ozean durch Erhöhung der Alkalinität, durch Ozeandüngung und durch das Management vegetationsreicher Küstenökosysteme untersucht. Alle Optionen können sowohl global als auch aus deutscher Perspektive eine Rolle für das Erreichen der Klimaziele spielen. Umweltverträglichkeit, Permanenz der Speicherung sowie infrastrukturelle und rechtliche Voraussetzungen, gesellschaftliche Akzeptanz und wirtschaftliche Realisierbarkeit bedürfen für alle Ansätze weiterer Klärung, bevor hieraus realisierbare Optionen werden können.
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- 2024
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43. Competing effects of wind and buoyancy forcing on recent ocean oxygen trends
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Hollitzer, Helene, Patara, Lavinia, Terhaar, Jens, Oschlies, Andreas, Hollitzer, Helene, Patara, Lavinia, Terhaar, Jens, and Oschlies, Andreas
- Abstract
Ocean deoxygenation is becoming a major stressor for marine ecosystems. Climate change affects ocean oxygen by altering wind fields and air-sea heat and freshwater fluxes. However, the quantitative contribution of these drivers to ocean deoxygenation remains uncertain. Here, we use a global ocean biogeochemistry model run under historical atmospheric forcing to show that deoxygenation since the late 1960s has been driven mainly by changing air-sea heat and freshwater fluxes and associated changes in solubility and ocean circulation. However, ~60% of this deoxygenation was offset by a wind-driven increase in ventilation and interior oxygen supply, mainly in the Southern Ocean. In the coming decades, the projected slowdown in wind stress intensification, combined with continued ocean warming, could greatly accelerate ocean deoxygenation. While ocean biogeochemistry models under historical atmospheric forcing struggle to reproduce the observed deoxygenation after 2000, fully coupled Earth system models capture the trend, indicating systematic problems in hindcast simulations.
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- 2024
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44. A Comprehensive Assessment of Carbon Dioxide Removal Options for Germany
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Borchers, Malgorzata, Förster, Johannes, Thrän, Daniela, Beck, Silke, Thoni, Terese, Korte, Klaas, Gawel, Erik, Markus, Till, Schaller, Romina, Rhoden, Imke, Chi, Yaxuan, Dahmen, Nicolaus, Dittmeyer, Roland, Dolch, Tobias, Dold, Christian, Herbst, Michael, Heß, Dominik, Kalhori, Aram, Koop‐Jakobsen, Ketil, Li, Zhan, Oschlies, Andreas, Reusch, Thorsten B. H., Sachs, Torsten, Schmidt‐Hattenberger, Cornelia, Stevenson, Angela, Wu, Jiajun, Yeates, Christopher, Mengis, Nadine, Borchers, Malgorzata, Förster, Johannes, Thrän, Daniela, Beck, Silke, Thoni, Terese, Korte, Klaas, Gawel, Erik, Markus, Till, Schaller, Romina, Rhoden, Imke, Chi, Yaxuan, Dahmen, Nicolaus, Dittmeyer, Roland, Dolch, Tobias, Dold, Christian, Herbst, Michael, Heß, Dominik, Kalhori, Aram, Koop‐Jakobsen, Ketil, Li, Zhan, Oschlies, Andreas, Reusch, Thorsten B. H., Sachs, Torsten, Schmidt‐Hattenberger, Cornelia, Stevenson, Angela, Wu, Jiajun, Yeates, Christopher, and Mengis, Nadine
- Abstract
To reach their net-zero targets, countries will have to compensate hard-to-abate CO2 emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio-cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context-specific feasibility assessment of CDR options for the example of Germany. We assess 14 CDR options, including three chemical carbon capture options, six options for bioenergy combined with carbon capture and storage (BECCS), and five options that aim to increase ecosystem carbon uptake. The assessment addresses technological, economic, environmental, institutional, social-cultural and systemic considerations using a traffic-light system to evaluate implementation opportunities and hurdles. We find that in Germany CDR options like cover crops or seagrass restoration currently face comparably low implementation hurdles in terms of technological, economic, or environmental feasibility and low institutional or social opposition but show comparably small CO2 removal potentials. In contrast, some BECCS options that show high CDR potentials face significant techno-economic, societal and institutional hurdles when it comes to the geological storage of CO2. While a combination of CDR options is likely required to meet the net-zero target in Germany, the current climate protection law includes a limited set of options. Our analysis aims to provide comprehensive information on CDR hurdles and possibilities for Germany for use in further research on CDR options, climate, and energy scenario development, as well as an effective decision support basis for various actors. Key Points: - More context-specific assessments of carbon dioxide removal (CDR) options are needed to guide national net-zero decision making - Ecosystem-based CDR options with comparably low implementation hurdles in Germany show relatively small CO2 removal potentials - High CDR potential options in Germany face high in
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- 2024
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45. Mechanisms Underpinning the Net Removal Rates of Dissolved Organic Carbon in the Global Ocean
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Lennartz, Sinikka T., Keller, David P., Oschlies, Andreas, Blasius, Bernd, Dittmar, Thorsten, Lennartz, Sinikka T., Keller, David P., Oschlies, Andreas, Blasius, Bernd, and Dittmar, Thorsten
- Abstract
With almost 700 Pg of carbon, marine dissolved organic carbon (DOC) stores more carbon than all living biomass on Earth combined. However, the controls behind the persistence and the spatial patterns of DOC concentrations on the basin scale remain largely unknown, precluding quantitative assessments of the fate of this large carbon pool in a changing climate. Net removal rates of DOC along the overturning circulation suggest lifetimes of millennia. These net removal rates are in stark contrast to the turnover times of days to weeks of heterotrophic microorganisms, which are the main consumers of organic carbon in the ocean. Here, we present a dynamic “MICrobial DOC” model (MICDOC) with an explicit representation of picoheterotrophs to test whether ecological mechanisms may lead to observed decadal to millennial net removal rates. MICDOC is in line with >40,000 DOC observations. Contrary to other global models, the reactivity of DOC fractions is not prescribed, but emerges from a dynamic feedback between microbes and DOC governed by carbon and macronutrient availability. A colimitation of macronutrients and organic carbon on microbial DOC uptake explains >70% of the global variation of DOC concentrations, and governs characteristic features of its distribution. Here, decadal to millennial net removal rates emerge from microbial processes acting on time scales of days to weeks, suggesting that the temporal variability of the marine DOC inventory may be larger than previously thought. With MICDOC, we provide a foundation for assessing global effects on DOC related to changes in heterotrophic microbial communities in a future ocean Plain Language Summary The ocean stores more carbon as dissolved organic compounds (DOC) than all animals and plants on land and the oceans combined. However, numerical models used for future climate scenarios lack an implementation of processes transforming DOC back to CO 2 by marine microorganisms. Here, we present a global dynamical ocean
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- 2024
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46. Global impact of benthic denitrification on marine N 2 fixation and primary production simulated by a variable-stoichiometry Earth system model
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Li, Na, Somes, Christopher J., Landolfi, Angela, Chien, Chia-Te, Pahlow, Markus, Oschlies, Andreas, Li, Na, Somes, Christopher J., Landolfi, Angela, Chien, Chia-Te, Pahlow, Markus, and Oschlies, Andreas
- Abstract
Nitrogen (N) is a crucial limiting nutrient for phytoplankton growth in the ocean. The main source of bioavailable N in the ocean is delivered by N2-fixing diazotrophs in the surface layer. Since field observation of N2 fixation are spatially and temporally sparse, the fundamental processes and mechanisms controlling N2 fixation are not well understood and constrained. Here, we implement benthic denitrification in an Earth System Model of intermediate complexity (UVic-ESCM 2.9) coupled to an optimality-based plankton ecosystem model (OPEM v1.1). Benthic denitrification occurs mostly in coastal upwelling regions and on shallow continental shelves, and is the largest N-loss process in the global ocean. We calibrate our model against three different combinations of observed Chl, NO3-, PO43-, O2 and N* = NO3- −16PO43- +2.9. The inclusion of N* provides a powerful constraint on biogeochemical model behavior. Our new model version including benthic denitrification simulates higher global rates of N2 fixation with a more realistic distribution extending to higher latitudes that are supported by independent estimates based on geochemical data. Oxygen deficient zone volume and water column denitrification rates are reduced in the new version, indicating that including benthic denitrification may improve global biogeochemical models that commonly overestimate anoxic zones. With the improved representation of the ocean N cycle, our new model configuration also yields better global net primary production (NPP) when compared to the independent datasets not included in the calibration. Benthic denitrification plays an important role shaping N2 fixation and NPP throughout the global ocean in our model, and should be considered when evaluating and predicting their response to environmental change.
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- 2024
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47. The role of trephine bone marrow biopsies in the era of measurable residual disease—Results from the CLL10 trial of the German CLL Study Group (GCLLSG).
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Kutsch, Nadine, Robrecht, Sandra, Fink, Anna, Lange, Elisabeth, Weide, Rudolf, Kiehl, Michael G., Sökler, Martin, Schlag, Rudolf, Vehling‐Kaiser, Ursula, Köchling, Georg, Plöger, Christoph, Gregor, Michael, Plesner, Torben, Clausen, Michael R., Oschlies, Ilske, Ritgen, Matthias, Herling, Marco, Fischer, Kirsten, Döhner, Hartmut, and Wendtner, Clemens‐Martin
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- 2024
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48. Biogeochemical Role of Subsurface Coherent Eddies in the Ocean: Tracer Cannonballs, Hypoxic Storms, and Microbial Stewpots?
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Frenger, Ivy, Bianchi, Daniele, Stührenberg, Carolin, Oschlies, Andreas, Dunne, John, Deutsch, Curtis, Galbraith, Eric, and Schütte, Florian
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Life Below Water ,Atmospheric Sciences ,Geochemistry ,Oceanography ,Meteorology & Atmospheric Sciences - Published
- 2018
49. Explicit silicate cycling in the Kiel Marine Biogeochemistry Model version 3 (KMBM3) embedded in the UVic ESCM version 2.9
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K. Kvale, D. P. Keller, W. Koeve, K. J. Meissner, C. J. Somes, W. Yao, and A. Oschlies
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Geology ,QE1-996.5 - Abstract
We describe and test a new model of biological marine silicate cycling, implemented in the Kiel Marine Biogeochemical Model version 3 (KMBM3), embedded in the University of Victoria Earth System Climate Model (UVic ESCM) version 2.9. This new model adds diatoms, which are a key component of the biological carbon pump, to an existing ecosystem model. This new model combines previously published parameterizations of a diatom functional type, opal production and export with a novel, temperature-dependent dissolution scheme. Modelled steady-state biogeochemical rates, carbon and nutrient distributions are similar to those found in previous model versions. The new model performs well against independent ocean biogeochemical indicators and captures the large-scale features of the marine silica cycle to a degree comparable to similar Earth system models. Furthermore, it is computationally efficient, allowing both fully coupled, long-timescale transient simulations and “offline” transport matrix spinups. We assess the fully coupled model against modern ocean observations, the historical record starting from 1960 and a business-as-usual atmospheric CO2 forcing to the year 2300. The model simulates a global decline in net primary production (NPP) of 1.4 % having occurred since the 1960s, with the strongest declines in the tropics, northern midlatitudes and Southern Ocean. The simulated global decline in NPP reverses after the year 2100 (forced by the extended RCP8.5 CO2 concentration scenario), and NPP returns to 98 % of the pre-industrial rate by 2300. This recovery is dominated by increasing primary production in the Southern Ocean, mostly by calcifying phytoplankton. Large increases in calcifying phytoplankton in the Southern Ocean offset a decline in the low latitudes, producing a global net calcite export in 2300 that varies only slightly from pre-industrial rates. Diatom distribution moves southward in our simulations, following the receding Antarctic ice front, but diatoms are outcompeted by calcifiers across most of their pre-industrial Southern Ocean habitat. Global opal export production thus drops to 75 % of its pre-industrial value by 2300. Model nutrients such as phosphate, silicate and nitrate build up along the Southern Ocean particle export pathway, but dissolved iron (for which ocean sources are held constant) increases in the upper ocean. This different behaviour of iron is attributed to a reduction of low-latitude NPP (and consequently, a reduction in both uptake and export and particle, including calcite scavenging), an increase in seawater temperatures (raising the solubility of particulate iron) and stratification that “traps” the iron near the surface. These results are meant to serve as a baseline for sensitivity assessments to be undertaken with this model in the future.
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- 2021
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50. Riverine nitrogen supply to the global ocean and its limited impact on global marine primary production: a feedback study using an Earth system model
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M. Tivig, D. P. Keller, and A. Oschlies
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
A common notion is that negative feedbacks stabilize the natural marine nitrogen inventory. Recent modeling studies have shown, however, some potential for localized positive feedbacks leading to substantial nitrogen losses in regions where nitrogen fixation and denitrification occur in proximity to each other. Here we include dissolved nitrogen from river discharge in a global 3-D ocean biogeochemistry model and study the effects on near-coastal and remote-open-ocean biogeochemistry. We find that at a steady state the biogeochemical feedbacks in the marine nitrogen cycle, nitrogen input from biological N2 fixation, and nitrogen loss via denitrification mostly compensate for the imposed yearly addition of 22.8 to 45.6 Tg of riverine nitrogen and limit the impact on global marine productivity to < 2 %. Global experiments that regionally isolate river nutrient input show that the sign and strength of the feedbacks depend on the location of the river discharge and the oxygen status of the receiving marine environment. Marine productivity generally increases in proximity to the nitrogen input, but we also find a decline in productivity in the modeled Bay of Bengal and near the mouth of the Amazon River. While most of the changes are located in shelf and near-coastal oceans, nitrogen supply from the rivers can impact the open ocean, due to feedbacks or knock-on effects.
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- 2021
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