@article{StueblerKloftHuisinga2023,
  author    = {St{\"u}bler, Sabine and Kloft, Charlotte and Huisinga, Wilhelm},
  title     = {Cell-level systems biology model to study inflammatory bowel diseases and their treatment options},
  series = {CPT: pharmacometrics \& systems pharmacology},
  volume    = {12},
  journal   = {CPT: pharmacometrics \& systems pharmacology},
  number    = {5},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2163-8306},
  doi       = {10.1002/psp4.12932},
  pages     = {690 -- 705},
  year      = {2023},
  abstract  = {To help understand the complex and therapeutically challenging inflammatory bowel diseases (IBDs), we developed a systems biology model of the intestinal immune system that is able to describe main aspects of IBD and different treatment modalities thereof. The model, including key cell types and processes of the mucosal immune response, compiles a large amount of isolated experimental findings from literature into a larger context and allows for simulations of different inflammation scenarios based on the underlying data and assumptions. In the context of a large and diverse virtual IBD population, we characterized the patients based on their phenotype (in contrast to healthy individuals, they developed persistent inflammation after a trigger event) rather than on a priori assumptions on parameter differences to a healthy individual. This allowed to reproduce the enormous diversity of predispositions known to lead to IBD. Analyzing different treatment effects, the model provides insight into characteristics of individual drug therapy. We illustrate for anti-TNF-alpha therapy, how the model can be used (i) to decide for alternative treatments with best prospects in the case of nonresponse, and (ii) to identify promising combination therapies with other available treatment options.},
  language  = {en}
}
@article{KayaDupontNivetFrielingetal.2022,
  author    = {Kaya, Mustafa Y{\"u}cel and Dupont-Nivet, Guillaume and Frieling, Joost and Fioroni, Chiara and Rohrmann, Alexander and Alt{\i}ner, Sevin{\c{c}} {\"O}zkan and Vardar, Ezgi and Tanyas, Hakan and Mamtimin, Mehmut and Zhaojie, Guo},
  title     = {The Eurasian epicontinental sea was an important carbon sink during the Palaeocene-Eocene thermal maximum},
  series = {Communications earth and environment},
  volume    = {3},
  journal   = {Communications earth and environment},
  number    = {1},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2662-4435},
  doi       = {10.1038/s43247-022-00451-4},
  pages     = {10},
  year      = {2022},
  abstract  = {The Palaeocene-Eocene Thermal Maximum (ca. 56 million years ago) offers a primary analogue for future global warming and carbon cycle recovery. Yet, where and how massive carbon emissions were mitigated during this climate warming event remains largely unknown. Here we show that organic carbon burial in the vast epicontinental seaways that extended over Eurasia provided a major carbon sink during the Palaeocene-Eocene Thermal Maximum. We coupled new and existing stratigraphic analyses to a detailed paleogeographic framework and using spatiotemporal interpolation calculated ca. 720-1300 Gt organic carbon excess burial, focused in the eastern parts of the Eurasian epicontinental seaways. A much larger amount (2160-3900 Gt C, and when accounting for the increase in inundated shelf area 7400-10300 Gt C) could have been sequestered in similar environments globally. With the disappearance of most epicontinental seas since the Oligocene-Miocene, an effective negative carbon cycle feedback also disappeared making the modern carbon cycle critically dependent on the slower silicate weathering feedback.},
  language  = {en}
}
@article{vanSoestAleluiaReisBaptistaetal.2021,
  author    = {van Soest, Heleen L. and Aleluia Reis, Lara and Baptista, Luiz Bernardo and Bertram, Christoph and Despr{\´e}s, Jacques and Drouet, Laurent and den Elzen, Michel and Fragkos, Panagiotis and Fricko, Oliver and Fujimori, Shinichiro and Grant, Neil and Harmsen, Mathijs and Iyer, Gokul and Keramidas, Kimon and K{\"o}berle, Alexandre C. and Kriegler, Elmar and Malik, Aman and Mittal, Shivika and Oshiro, Ken and Riahi, Keywan and Roelfsema, Mark and van Ruijven, Bas and Schaeffer, Roberto and Silva Herran, Diego and Tavoni, Massimo and {\"U}nl{\"u}, Gamze and Vandyck, Toon and van Vuuren, Detlef P.},
  title     = {Global roll-out of comprehensive policy measures may aid in bridging emissions gap},
  series = {Nature communications},
  volume    = {12},
  journal   = {Nature communications},
  number    = {1},
  publisher = {Nature Publishing Group UK},
  address   = {London},
  doi       = {10.1038/s41467-021-26595-z},
  pages     = {10},
  year      = {2021},
  abstract  = {Closing the emissions gap between Nationally Determined Contributions (NDCs) and the global emissions levels needed to achieve the Paris Agreement's climate goals will require a comprehensive package of policy measures. National and sectoral policies can help fill the gap, but success stories in one country cannot be automatically replicated in other countries. They need to be adapted to the local context. Here, we develop a new Bridge scenario based on nationally relevant, short-term measures informed by interactions with country experts. These good practice policies are rolled out globally between now and 2030 and combined with carbon pricing thereafter. We implement this scenario with an ensemble of global integrated assessment models. We show that the Bridge scenario closes two-thirds of the emissions gap between NDC and 2 °C scenarios by 2030 and enables a pathway in line with the 2 °C goal when combined with the necessary long-term changes, i.e. more comprehensive pricing measures after 2030. The Bridge scenario leads to a scale-up of renewable energy (reaching 52\%-88\% of global electricity supply by 2050), electrification of end-uses, efficiency improvements in energy demand sectors, and enhanced afforestation and reforestation. Our analysis suggests that early action via good-practice policies is less costly than a delay in global climate cooperation.},
  language  = {en}
}
@article{YeZhangWarbyetal.2022,
  author    = {Ye, Fangyuan and Zhang, Shuo and Warby, Jonathan and Wu, Jiawei and Gutierrez-Partida, Emilio and Lang, Felix and Shah, Sahil and Saglamkaya, Elifnaz and Sun, Bowen and Zu, Fengshuo and Shoai, Safa and Wang, Haifeng and Stiller, Burkhard and Neher, Dieter and Zhu, Wei-Hong and Stolterfoht, Martin and Wu, Yongzhen},
  title     = {Overcoming C₆₀-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane},
  series = {Nature Communications},
  volume    = {13},
  journal   = {Nature Communications},
  number    = {1},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-022-34203-x},
  pages     = {12},
  year      = {2022},
  abstract  = {Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23\% with a low non-radiative voltage loss of 110 mV, and retain >97\% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells.},
  language  = {en}
}
@book{OPUS4-64594,
  title     = {Am Ende der Globalisierung},
  series = {Re-Figuration von R{\"a}umen},
  volume    = {1},
  journal   = {Re-Figuration von R{\"a}umen},
  editor    = {L{\"o}w, Martina and Sayman, Volkan and Schwerer, Jona and Wolf, Hannah},
  publisher = {transcript},
  address   = {Bielefeld},
  isbn      = {978-3-8376-5402-8},
  doi       = {10.14361/9783839454022},
  pages     = {481},
  year      = {2021},
  abstract  = {Die Globalisierung ist zur allgegenw{\"a}rtigen Gewissheit geworden. Doch wie zutreffend ist das Konzept »Globalisierung«, wenn zeitgleich nationale Grenzen gest{\"a}rkt und transnationale Freihandelszonen ausgeweitet werden, wenn auf unterschiedlichen scales Territorien {\"u}berwunden und zugleich territoriale Abgrenzungen neu gesetzt werden? Aktuelle Ver{\"a}nderungen als Re-Figuration von R{\"a}umen zu verstehen, erm{\"o}glicht die Analyse und Diskussion widerspr{\"u}chlicher, spannungsreicher und konflikthafter r{\"a}umlicher Prozesse und ihrer allt{\"a}glichen Erfahrung. Die interdisziplin{\"a}ren Beitr{\"a}ge des Bandes liefern theoretische und empirische Analysen zu politischen, digitalen und allt{\"a}glichen R{\"a}umen im Konzept der Re-Figuration.},
  language  = {de}
}
@article{EhrigWagnerWolteretal.2023,
  author    = {Ehrig, Lukas and Wagner, Ann-Christin and Wolter, Heike and Correll, Christoph U. and Geisel, Olga and Konigorski, Stefan},
  title     = {FASDetect as a machine learning-based screening app for FASD in youth with ADHD},
  series = {npj Digital Medicine},
  volume    = {6},
  journal   = {npj Digital Medicine},
  number    = {1},
  publisher = {Macmillan Publishers Limited},
  address   = {Basingstoke},
  issn      = {2398-6352},
  doi       = {10.1038/s41746-023-00864-1},
  pages     = {9},
  year      = {2023},
  abstract  = {Fetal alcohol-spectrum disorder (FASD) is underdiagnosed and often misdiagnosed as attention-deficit/hyperactivity disorder (ADHD). Here, we develop a screening tool for FASD in youth with ADHD symptoms. To develop the prediction model, medical record data from a German University outpatient unit are assessed including 275 patients aged 0-19 years old with FASD with or without ADHD and 170 patients with ADHD without FASD aged 0-19 years old. We train 6 machine learning models based on 13 selected variables and evaluate their performance. Random forest models yield the best prediction models with a cross-validated AUC of 0.92 (95\% confidence interval [0.84, 0.99]). Follow-up analyses indicate that a random forest model with 6 variables - body length and head circumference at birth, IQ, socially intrusive behaviour, poor memory and sleep disturbance - yields equivalent predictive accuracy. We implement the prediction model in a web-based app called FASDetect - a user-friendly, clinically scalable FASD risk calculator that is freely available at https://fasdetect.dhc-lab.hpi.de.},
  language  = {en}
}
@article{SlosarekIbingSchormairetal.2023,
  author    = {Slosarek, Tamara and Ibing, Susanne and Schormair, Barbara and Heyne, Henrike and B{\"o}ttinger, Erwin and Andlauer, Till and Schurmann, Claudia},
  title     = {Implementation and evaluation of personal genetic testing as part of genomics analysis courses in German universities},
  series = {BMC Medical Genomics},
  volume    = {16},
  journal   = {BMC Medical Genomics},
  number    = {1},
  publisher = {BMC},
  address   = {London},
  issn      = {1755-8794},
  doi       = {10.1186/s12920-023-01503-0},
  pages     = {13},
  year      = {2023},
  abstract  = {Purpose Due to the increasing application of genome analysis and interpretation in medical disciplines, professionals require adequate education. Here, we present the implementation of personal genotyping as an educational tool in two genomics courses targeting Digital Health students at the Hasso Plattner Institute (HPI) and medical students at the Technical University of Munich (TUM). Methods We compared and evaluated the courses and the students ' perceptions on the course setup using questionnaires. Results During the course, students changed their attitudes towards genotyping (HPI: 79\% [15 of 19], TUM: 47\% [25 of 53]). Predominantly, students became more critical of personal genotyping (HPI: 73\% [11 of 15], TUM: 72\% [18 of 25]) and most students stated that genetic analyses should not be allowed without genetic counseling (HPI: 79\% [15 of 19], TUM: 70\% [37 of 53]). Students found the personal genotyping component useful (HPI: 89\% [17 of 19], TUM: 92\% [49 of 53]) and recommended its inclusion in future courses (HPI: 95\% [18 of 19], TUM: 98\% [52 of 53]). Conclusion Students perceived the personal genotyping component as valuable in the described genomics courses. The implementation described here can serve as an example for future courses in Europe.},
  language  = {en}
}
@inproceedings{RieskampMirbabaieHofeditzetal.2023,
  author    = {Rieskamp, Jonas and Mirbabaie, Milad and Hofeditz, Lennart and Vischedyk, Justin},
  title     = {Conversational agents and their influence on the well-being of cliniciansclinicians},
  series = {ACIS 2023 proceedings},
  booktitle = {ACIS 2023 proceedings},
  publisher = {Australasian Association for Information Systems},
  address   = {Wellington},
  pages     = {16},
  year      = {2023},
  abstract  = {An increasing number of clinicians (i.e., nurses and physicians) suffer from mental health-related issues like depression and burnout. These, in turn, stress communication, collaboration, and decision- making—areas in which Conversational Agents (CAs) have shown to be useful. Thus, in this work, we followed a mixed-method approach and systematically analysed the literature on factors affecting the well-being of clinicians and CAs' potential to improve said well-being by relieving support in communication, collaboration, and decision-making in hospitals. In this respect, we are guided by Brigham et al. (2018)'s model of factors influencing well-being. Based on an initial number of 840 articles, we further analysed 52 papers in more detail and identified the influences of CAs' fields of application on external and individual factors affecting clinicians' well-being. As our second method, we will conduct interviews with clinicians and experts on CAs to verify and extend these influencing factors.},
  language  = {en}
}
@article{SeroussiNowickiSimonetal.2019,
  author    = {Seroussi, Helene and Nowicki, Sophie and Simon, Erika and Abe-Ouchi, Ayako and Albrecht, Torsten and Brondex, Julien and Cornford, Stephen and Dumas, Christophe and Gillet-Chaulet, Fabien and Goelzer, Heiko and Golledge, Nicholas R. and Gregory, Jonathan M. and Greve, Ralf and Hoffman, Matthew J. and Humbert, Angelika and Huybrechts, Philippe and Kleiner, Thomas and Larourl, Eric and Leguy, Gunter and Lipscomb, William H. and Lowry, Daniel and Mengel, Matthias and Morlighem, Mathieu and Pattyn, Frank and Payne, Anthony J. and Pollard, David and Price, Stephen F. and Quiquet, Aurelien and Reerink, Thomas J. and Reese, Ronja and Rodehacke, Christian B. and Schlegel, Nicole-Jeanne and Shepherd, Andrew and Sun, Sainan and Sutter, Johannes and Van Breedam, Jonas and van de Wal, Roderik S. W. and Winkelmann, Ricarda and Zhang, Tong},
  title     = {initMIP-Antarctica},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {13},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-13-1441-2019},
  pages     = {1441 -- 1471},
  year      = {2019},
  abstract  = {Ice sheet numerical modeling is an important tool to estimate the dynamic contribution of the Antarctic ice sheet to sea level rise over the coming centuries. The influence of initial conditions on ice sheet model simulations, however, is still unclear. To better understand this influence, an initial state intercomparison exercise (initMIP) has been developed to compare, evaluate, and improve initialization procedures and estimate their impact on century-scale simulations. initMlP is the first set of experiments of the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6), which is the primary Coupled Model Intercomparison Project Phase 6 (CMIP6) activity focusing on the Greenland and Antarctic ice sheets. Following initMlP-Greenland, initMlP-Antarctica has been designed to explore uncertainties associated with model initialization and spin-up and to evaluate the impact of changes in external forcings. Starting from the state of the Antarctic ice sheet at the end of the initialization procedure, three forward experiments are each run for 100 years: a control run, a run with a surface mass balance anomaly, and a run with a basal melting anomaly beneath floating ice. This study presents the results of initMlP-Antarctica from 25 simulations performed by 16 international modeling groups. The submitted results use different initial conditions and initialization methods, as well as ice flow model parameters and reference external forcings. We find a good agreement among model responses to the surface mass balance anomaly but large variations in responses to the basal melting anomaly. These variations can be attributed to differences in the extent of ice shelves and their upstream tributaries, the numerical treatment of grounding line, and the initial ocean conditions applied, suggesting that ongoing efforts to better represent ice shelves in continental-scale models should continue.},
  language  = {en}
}
@article{ReeseAlbrechtMengeletal.2018,
  author    = {Reese, Ronja and Albrecht, Torsten and Mengel, Matthias and Asay-Davis, Xylar and Winkelmann, Ricarda},
  title     = {Antarctic sub-shelf melt rates via PICO},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {12},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {6},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-12-1969-2018},
  pages     = {1969 -- 1985},
  year      = {2018},
  abstract  = {Ocean-induced melting below ice shelves is one of the dominant drivers for mass loss from the Antarctic Ice Sheet at present. An appropriate representation of sub-shelf melt rates is therefore essential for model simulations of marine-based ice sheet evolution. Continental-scale ice sheet models often rely on simple melt-parameterizations, in particular for long-term simulations, when fully coupled ice-ocean interaction becomes computationally too expensive. Such parameterizations can account for the influence of the local depth of the ice-shelf draft or its slope on melting. However, they do not capture the effect of ocean circulation underneath the ice shelf. Here we present the Potsdam Ice-shelf Cavity mOdel (PICO), which simulates the vertical overturning circulation in ice-shelf cavities and thus enables the computation of sub-shelf melt rates consistent with this circulation. PICO is based on an ocean box model that coarsely resolves ice shelf cavities and uses a boundary layer melt formulation. We implement it as a module of the Parallel Ice Sheet Model (PISM) and evaluate its performance under present-day conditions of the Southern Ocean. We identify a set of parameters that yield two-dimensional melt rate fields that qualitatively reproduce the typical pattern of comparably high melting near the grounding line and lower melting or refreezing towards the calving front. PICO captures the wide range of melt rates observed for Antarctic ice shelves, with an average of about 0.1 ma(-1) for cold sub-shelf cavities, for example, underneath Ross or Ronne ice shelves, to 16 ma(-1) for warm cavities such as in the Amundsen Sea region. This makes PICO a computationally feasible and more physical alternative to melt parameterizations purely based on ice draft geometry.},
  language  = {en}
}
@article{ReeseWinkelmannGudmundsson2018,
  author    = {Reese, Ronja and Winkelmann, Ricarda and Gudmundsson, Gudmundur Hilmar},
  title     = {Grounding-line flux formula applied as a flux condition in numerical simulations fails for buttressed Antarctic ice streams},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {12},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {10},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-12-3229-2018},
  pages     = {3229 -- 3242},
  year      = {2018},
  abstract  = {Currently, several large-scale ice-flow models impose a condition on ice flux across grounding lines using an analytically motivated parameterisation of grounding-line flux. It has been suggested that employing this analytical expression alleviates the need for highly resolved computational domains around grounding lines of marine ice sheets. While the analytical flux formula is expected to be accurate in an unbuttressed flow-line setting, its validity has hitherto not been assessed for complex and realistic geometries such as those of the Antarctic Ice Sheet. Here the accuracy of this analytical flux formula is tested against an optimised ice flow model that uses a highly resolved computational mesh around the Antarctic grounding lines. We find that when applied to the Antarctic Ice Sheet the analytical expression provides inaccurate estimates of ice fluxes for almost all grounding lines. Furthermore, in many instances direct application of the analytical formula gives rise to unphysical complex-valued ice fluxes. We conclude that grounding lines of the Antarctic Ice Sheet are, in general, too highly buttressed for the analytical parameterisation to be of practical value for the calculation of grounding-line fluxes.},
  language  = {en}
}
@article{CiemerRehmKurthsetal.2020,
  author    = {Ciemer, Catrin and Rehm, Lars and Kurths, J{\"u}rgen and Donner, Reik Volker and Winkelmann, Ricarda and Boers, Niklas},
  title     = {An early-warning indicator for Amazon droughts exclusively based on tropical Atlantic sea surface temperatures},
  series = {Environmental Research Letters},
  volume    = {15},
  journal   = {Environmental Research Letters},
  number    = {9},
  publisher = {IOP - Institute of Physics Publishing},
  address   = {Bristol},
  pages     = {10},
  year      = {2020},
  abstract  = {Droughts in tropical South America have an imminent and severe impact on the Amazon rainforest and affect the livelihoods of millions of people. Extremely dry conditions in Amazonia have been previously linked to sea surface temperature (SST) anomalies in the adjacent tropical oceans. Although the sources and impacts of such droughts have been widely studied, establishing reliable multi-year lead statistical forecasts of their occurrence is still an ongoing challenge. Here, we further investigate the relationship between SST and rainfall anomalies using a complex network approach. We identify four ocean regions which exhibit the strongest overall SST correlations with central Amazon rainfall, including two particularly prominent regions in the northern and southern tropical Atlantic. Based on the time-dependent correlation between SST anomalies in these two regions alone, we establish a new early-warning method for droughts in the central Amazon basin and demonstrate its robustness in hindcasting past major drought events with lead-times up to 18 months.},
  language  = {en}
}
@article{SeroussiNowickiPayneetal.2020,
  author    = {Seroussi, Helene and Nowicki, Sophie and Payne, Antony J. and Goelzer, Heiko and Lipscomb, William H. and Abe-Ouchi, Ayako and Agosta, Cecile and Albrecht, Torsten and Asay-Davis, Xylar and Barthel, Alice and Calov, Reinhard and Cullather, Richard and Dumas, Christophe and Galton-Fenzi, Benjamin K. and Gladstone, Rupert and Golledge, Nicholas R. and Gregory, Jonathan M. and Greve, Ralf and Hattermann, Tore and Hoffman, Matthew J. and Humbert, Angelika and Huybrechts, Philippe and Jourdain, Nicolas C. and Kleiner, Thomas and Larour, Eric and Leguy, Gunter R. and Lowry, Daniel P. and Little, Chistopher M. and Morlighem, Mathieu and Pattyn, Frank and Pelle, Tyler and Price, Stephen F. and Quiquet, Aurelien and Reese, Ronja and Schlegel, Nicole-Jeanne and Shepherd, Andrew and Simon, Erika and Smith, Robin S. and Straneo, Fiammetta and Sun, Sainan and Trusel, Luke D. and Van Breedam, Jonas and van de Wal, Roderik S. W. and Winkelmann, Ricarda and Zhao, Chen and Zhang, Tong and Zwinger, Thomas},
  title     = {ISMIP6 Antarctica},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {9},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-14-3033-2020},
  pages     = {3033 -- 3070},
  year      = {2020},
  abstract  = {Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015-2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between 7:8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between 6 :1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica.},
  language  = {en}
}
@article{ReeseLevermannAlbrechtetal.2020,
  author    = {Reese, Ronja and Levermann, Anders and Albrecht, Torsten and Seroussi, Helene and Winkelmann, Ricarda},
  title     = {The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {9},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-14-3097-2020},
  pages     = {3097 -- 3110},
  year      = {2020},
  abstract  = {Mass loss from the Antarctic Ice Sheet constitutes the largest uncertainty in projections of future sea level rise. Ocean-driven melting underneath the floating ice shelves and subsequent acceleration of the inland ice streams are the major reasons for currently observed mass loss from Antarctica and are expected to become more important in the future. Here we show that for projections of future mass loss from the Antarctic Ice Sheet, it is essential (1) to better constrain the sensitivity of sub-shelf melt rates to ocean warming and (2) to include the historic trajectory of the ice sheet. In particular, we find that while the ice sheet response in simulations using the Parallel Ice Sheet Model is comparable to the median response of models in three Antarctic Ice Sheet Intercomparison projects - initMIP, LARMIP-2 and ISMIP6 - conducted with a range of ice sheet models, the projected 21st century sea level contribution differs significantly depending on these two factors. For the highest emission scenario RCP8.5, this leads to projected ice loss ranging from 1:4 to 4:0 cm of sea level equivalent in simulations in which ISMIP6 ocean forcing drives the PICO ocean box model where parameter tuning leads to a comparably low sub-shelf melt sensitivity and in which no surface forcing is applied. This is opposed to a likely range of 9:1 to 35:8 cm using the exact same initial setup, but emulated from the LARMIP-2 experiments with a higher melt sensitivity, even though both projects use forcing from climate models and melt rates are calibrated with previous oceanographic studies. Furthermore, using two initial states, one with a previous historic simulation from 1850 to 2014 and one starting from a steady state, we show that while differences between the ice sheet configurations in 2015 seem marginal at first sight, the historic simulation increases the susceptibility of the ice sheet to ocean warming, thereby increasing mass loss from 2015 to 2100 by 5\% to 50 \%. Hindcasting past ice sheet changes with numerical models would thus provide valuable tools to better constrain projections. Our results emphasize that the uncertainty that arises from the forcing is of the same order of magnitude as the ice dynamic response for future sea level projections.},
  language  = {en}
}
@article{ZeitzLevermannWinkelmann2020,
  author    = {Zeitz, Maria and Levermann, Anders and Winkelmann, Ricarda},
  title     = {Sensitivity of ice loss to uncertainty in flow law parameters in an idealized one-dimensional geometry},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {10},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-14-3537-2020},
  pages     = {3537 -- 3550},
  year      = {2020},
  abstract  = {Acceleration of the flow of ice drives mass losses in both the Antarctic and the Greenland Ice Sheet. The projections of possible future sea-level rise rely on numerical ice-sheet models, which solve the physics of ice flow, melt, and calving. While major advancements have been made by the ice-sheet modeling community in addressing several of the related uncertainties, the flow law, which is at the center of most process-based ice-sheet models, is not in the focus of the current scientific debate. However, recent studies show that the flow law parameters are highly uncertain and might be different from the widely accepted standard values. Here, we use an idealized flow-line setup to investigate how these uncertainties in the flow law translate into uncertainties in flow-driven mass loss. In order to disentangle the effect of future warming on the ice flow from other effects, we perform a suite of experiments with the Parallel Ice Sheet Model (PISM), deliberately excluding changes in the surface mass balance. We find that changes in the flow parameters within the observed range can lead up to a doubling of the flow-driven mass loss within the first centuries of warming, compared to standard parameters. The spread of ice loss due to the uncertainty in flow parameters is on the same order of magnitude as the increase in mass loss due to surface warming. While this study focuses on an idealized flow-line geometry, it is likely that this uncertainty carries over to realistic three-dimensional simulations of Greenland and Antarctica.},
  language  = {en}
}
@article{AlbrechtWinkelmannLevermann2020,
  author    = {Albrecht, Torsten and Winkelmann, Ricarda and Levermann, Anders},
  title     = {Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {2},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-14-599-2020},
  pages     = {599 -- 632},
  year      = {2020},
  abstract  = {Simulations of the glacial-interglacial history of the Antarctic Ice Sheet provide insights into dynamic threshold behavior and estimates of the ice sheet's contributions to global sea-level changes for the past, present and future. However, boundary conditions are weakly constrained, in particular at the interface of the ice sheet and the bedrock. Also climatic forcing covering the last glacial cycles is uncertain, as it is based on sparse proxy data. <br /> We use the Parallel Ice Sheet Model (PISM) to investigate the dynamic effects of different choices of input data, e.g., for modern basal heat flux or reconstructions of past changes of sea level and surface temperature. As computational resources are limited, glacial-cycle simulations are performed using a comparably coarse model grid of 16 km and various parameterizations, e.g., for basal sliding, iceberg calving, or for past variations in precipitation and ocean temperatures. In this study we evaluate the model's transient sensitivity to corresponding parameter choices and to different boundary conditions over the last two glacial cycles and provide estimates of involved uncertainties. We also discuss isolated and combined effects of climate and sea-level forcing. Hence, this study serves as a "cookbook" for the growing community of PISM users and paleo-ice sheet modelers in general. <br /> For each of the different model uncertainties with regard to climatic forcing, ice and Earth dynamics, and basal processes, we select one representative model parameter that captures relevant uncertainties and motivates corresponding parameter ranges that bound the observed ice volume at present. The four selected parameters are systematically varied in a parameter ensemble analysis, which is described in a companion paper.},
  language  = {en}
}
@article{KreuzerReeseHuiskampetal.2021,
  author    = {Kreuzer, Moritz and Reese, Ronja and Huiskamp, Willem Nicholas and Petri, Stefan and Albrecht, Torsten and Feulner, Georg and Winkelmann, Ricarda},
  title     = {Coupling framework (1.0) for the PISM (1.1.4) ice sheet model and the MOMS (5.1.0) ocean model via the PICO ice shelf cavity model in an Antarctic domain},
  series = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {Geoscientific model development : an interactive open access journal of the European Geosciences Union},
  number    = {6},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1991-959X},
  doi       = {10.5194/gmd-14-3697-2021},
  pages     = {3697 -- 3714},
  year      = {2021},
  abstract  = {The past and future evolution of the Antarctic Ice Sheet is largely controlled by interactions between the ocean and floating ice shelves. To investigate these interactions, coupled ocean and ice sheet model configurations are required. Previous modelling studies have mostly relied on high-resolution configurations, limiting these studies to individual glaciers or regions over short timescales of decades to a few centuries. We present a framework to couple the dynamic ice sheet model PISM (Parallel Ice Sheet Model) with the global ocean general circulation model MOM5 (Modular Ocean Model) via the ice shelf cavity model PICO (Pots-dam Ice-shelf Cavity mOdel). As ice shelf cavities are not resolved by MOM5 but are parameterized with the PICO box model, the framework allows the ice sheet and ocean components to be run at resolutions of 16 km and 3 degrees respectively. This approach makes the coupled configuration a useful tool for the analysis of interactions between the Antarctic Ice Sheet and the global ocean over time spans of the order of centuries to millennia. In this study, we describe the technical implementation of this coupling framework: sub-shelf melting in the ice sheet component is calculated by PICO from modelled ocean temperatures and salinities at the depth of the continental shelf, and, vice versa, the resulting mass and energy fluxes from melting at the ice-ocean interface are transferred to the ocean component. Mass and energy fluxes are shown to be conserved to machine precision across the considered component domains. The implementation is computationally efficient as it introduces only minimal overhead. Furthermore, the coupled model is evaluated in a 4000 year simulation under constant present-day climate forcing and is found to be stable with respect to the ocean and ice sheet spin-up states. The framework deals with heterogeneous spatial grid geometries, varying grid resolutions, and timescales between the ice and ocean component in a generic way; thus, it can be adopted to a wide range of model set-ups.},
  language  = {en}
}
@article{ZeitzHaackerDongesetal.2022,
  author    = {Zeitz, Maria and Haacker, Jan M. and Donges, Jonathan and Albrecht, Torsten and Winkelmann, Ricarda},
  title     = {Dynamic regimes of the Greenland Ice Sheet emerging from interacting melt-elevation and glacial isostatic adjustment feedbacks},
  series = {Earth system dynamics},
  volume    = {13},
  journal   = {Earth system dynamics},
  number    = {3},
  publisher = {Copernicus Publ.},
  address   = {G{\"o}ttingen},
  issn      = {2190-4979},
  doi       = {10.5194/esd-13-1077-2022},
  pages     = {1077 -- 1096},
  year      = {2022},
  abstract  = {The stability of the Greenland Ice Sheet under global warming is governed by a number of dynamic processes and interacting feedback mechanisms in the ice sheet, atmosphere and solid Earth. Here we study the long-term effects due to the interplay of the competing melt-elevation and glacial isostatic adjustment (GIA) feedbacks for different temperature step forcing experiments with a coupled ice-sheet and solid-Earth model. Our model results show that for warming levels above 2 degrees C, Greenland could become essentially ice-free within several millennia, mainly as a result of surface melting and acceleration of ice flow. These ice losses are mitigated, however, in some cases with strong GIA feedback even promoting an incomplete recovery of the Greenland ice volume. We further explore the full-factorial parameter space determining the relative strengths of the two feedbacks: our findings suggest distinct dynamic regimes of the Greenland Ice Sheets on the route to destabilization under global warming - from incomplete recovery, via quasi-periodic oscillations in ice volume to ice-sheet collapse. In the incomplete recovery regime, the initial ice loss due to warming is essentially reversed within 50 000 years, and the ice volume stabilizes at 61 \%-93 \% of the present-day volume. For certain combinations of temperature increase, atmospheric lapse rate and mantle viscosity, the interaction of the GIA feedback and the melt-elevation feedback leads to self-sustained, long-term oscillations in ice-sheet volume with oscillation periods between 74 000 and over 300 000 years and oscillation amplitudes between 15 \%-70 \% of present-day ice volume. This oscillatory regime reveals a possible mode of internal climatic variability in the Earth system on timescales on the order of 100 000 years that may be excited by or synchronized with orbital forcing or interact with glacial cycles and other slow modes of variability. Our findings are not meant as scenario-based near-term projections of ice losses but rather providing insight into of the feedback loops governing the "deep future" and, thus, long-term resilience of the Greenland Ice Sheet.},
  language  = {en}
}
@article{AlbrechtWinkelmannLevermann2020,
  author    = {Albrecht, Torsten and Winkelmann, Ricarda and Levermann, Anders},
  title     = {Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {14},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {2},
  publisher = {Copernicus Publ.},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-14-633-2020},
  pages     = {633 -- 656},
  year      = {2020},
  abstract  = {The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles (approximate to 210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using full-factorial parameter sampling. Parameters and plausible parameter ranges have been identified in a companion paper (Albrecht et al., 2020) and are associated with ice dynamics, climatic forcing, basal sliding and bed deformation and represent distinct classes of model uncertainties. The model is scored against both modern and geologic data, including reconstructed grounding-line locations, elevation-age data, ice thickness, surface velocities and uplift rates. An aggregated score is computed for each ensemble member that measures the overall model-data misfit, including measurement uncertainty in terms of a Gaussian error model (Briggs and Tarasov, 2013). The statistical method used to analyze the ensemble simulation results follows closely the simple averaging method described in Pollard et al. (2016). This analysis reveals clusters of best-fit parameter combinations, and hence a likely range of relevant model and boundary parameters, rather than individual best-fit parameters. The ensemble of reconstructed histories of Antarctic Ice Sheet volumes provides a score-weighted likely range of sea-level contributions since the Last Glacial Maximum (LGM) of 9.4 +/- 4.1m (or 6.5 +/- 2.0 x 10(6) km(3)), which is at the upper range of most previous studies. The last deglaciation occurs in all ensemble simulations after around 12 000 years before present and hence after the meltwater pulse 1A (MWP1a). Our ensemble analysis also provides an estimate of parametric uncertainty bounds for the present-day state that can be used for PISM projections of future sea-level contributions from the Antarctic Ice Sheet.},
  language  = {en}
}
@article{SchlemmFeldmannWinkelmannetal.2022,
  author    = {Schlemm, Tanja and Feldmann, Johannes and Winkelmann, Ricarda and Levermann, Anders},
  title     = {Stabilizing effect of melange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet},
  series = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  volume    = {16},
  journal   = {The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union},
  number    = {5},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1994-0416},
  doi       = {10.5194/tc-16-1979-2022},
  pages     = {1979 -- 1996},
  year      = {2022},
  abstract  = {Owing to global warming and particularly high regional ocean warming, both Thwaites and Pine Island Glaciers in the Amundsen region of the Antarctic Ice Sheet could lose their buttressing ice shelves over time. We analyse the possible consequences using the parallel ice sheet model (PISM), applying a simple cliff-calving parameterization and an ice melange-buttressing model. We find that the instantaneous loss of ice-shelf buttressing, due to enforced ice-shelf melting, initiates grounding-line retreat and triggers marine ice sheet instability (MISI). As a consequence, the grounding line progresses into the interior of the West Antarctic Ice Sheet and leads to a sea level contribution of 0.6 m within 100 a. By subjecting the exposed ice cliffs to cliff calving using our simplified parameterization, we also analyse marine ice cliff instability (MICI). In our simulations it can double or even triple the sea level contribution depending on the only loosely constrained parameter that determines the maximum cliff-calving rate. The speed of MICI depends on this upper bound of the calving rate, which is given by the ice melange buttressing the glacier. However, stabilization of MICI may occur for geometric reasons. Because the embayment geometry changes as MICI advances into the interior of the ice sheet, the upper bound on calving rates is reduced and the progress of MICI is slowed down. Although we cannot claim that our simulations bear relevant quantitative estimates of the effect of ice-melange buttressing on MICI, the mechanism has the potential to stop the instability. Further research is needed to evaluate its role for the past and future evolution of the Antarctic Ice Sheet.},
  language  = {en}
}