Articles | Volume 20, issue 14
https://doi.org/10.5194/bg-20-2837-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-20-2837-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Jul 2023
Research article |
| 17 Jul 2023
| 17 Jul 2023
Simulated methane emissions from Arctic ponds are highly sensitive to warming
Department of Climate Variability, Max Planck Institute for Meteorology, Hamburg, Germany
Thomas Kleinen
Department of Climate Variability, Max Planck Institute for Meteorology, Hamburg, Germany
Lars Kutzbach
Institute of Soil Science, Department of Earth System Sciences, Universität Hamburg, Hamburg, Germany
Center for Earth System Research and Sustainability, Universität Hamburg, Hamburg, Germany
Victor Stepanenko
Research Computing Center, Moscow State University, Moscow, Russia
Faculty of Geography, Moscow State University, Moscow, Russia
Moscow Center of Fundamental and Applied Mathematics, Moscow, Russia
Moritz Langer
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
Victor Brovkin
Department of Climate Variability, Max Planck Institute for Meteorology, Hamburg, Germany
Center for Earth System Research and Sustainability, Universität Hamburg, Hamburg, Germany
Related authors
Lutz Beckebanze, Zoé Rehder, David Holl, Christian Wille, Charlotta Mirbach, and Lars Kutzbach
Biogeosciences, 19, 1225–1244, https://doi.org/10.5194/bg-19-1225-2022, https://doi.org/10.5194/bg-19-1225-2022, 2022
Short summary
Short summary
Arctic permafrost landscapes feature many water bodies. In contrast to the terrestrial parts of the landscape, the water bodies release carbon to the atmosphere. We compare carbon dioxide and methane fluxes from small water bodies to the surrounding tundra and find not accounting for the carbon dioxide emissions leads to an overestimation of the tundra uptake by 11 %. Consequently, changes in hydrology and water body distribution may substantially impact the overall carbon budget of the Arctic.
Zoé Rehder, Anne Laura Niederdrenk, Lars Kaleschke, and Lars Kutzbach
The Cryosphere, 14, 4201–4215, https://doi.org/10.5194/tc-14-4201-2020, https://doi.org/10.5194/tc-14-4201-2020, 2020
Short summary
Short summary
To better understand the connection between sea ice and permafrost, we investigate how sea ice interacts with the atmosphere over the adjacent landmass in the Laptev Sea region using a climate model. Melt of sea ice in spring is mainly controlled by the atmosphere; in fall, feedback mechanisms are important. Throughout summer, lower-than-usual sea ice leads to more southward transport of heat and moisture, but these links from sea ice to the atmosphere over land are weak.
Mehriban Aliyeva, Michael Angelopoulos, Julia Boike, Moritz Langer, Frederieke Miesner, Scott Dallimore, Dustin Whalen, Lukas U. Arenson, and Pier Paul Overduin
EGUsphere, https://doi.org/10.5194/egusphere-2025-2675, https://doi.org/10.5194/egusphere-2025-2675, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
In this study, we investigate the ongoing transformation of terrestrial permafrost into subsea permafrost on a rapidly eroding Arctic island using electrical resistivity tomography and numerical modelling. We draw on 60 years of shoreline data to support our findings. This work is important for understanding permafrost loss in Arctic coastal areas and for guiding future efforts to protect vulnerable shorelines.
Marius Moser, Lara Kaiser, Victor Brovkin, and Christian Beer
EGUsphere, https://doi.org/10.5194/egusphere-2025-3159, https://doi.org/10.5194/egusphere-2025-3159, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Arctic warming might lead to increased carbon dioxide and methane emissions. Process-based prediction of their ratio is key to projecting the future carbon cycle. However, land surface models often assume a constant ratio. To overcome this limitation, we identify three core processes for representing methanogenesis accurately in land surface models: fermentation, acetoclastic methanogenesis, and hydrogenotrophic methanogenesis.
Victor Brovkin, Benjamin M. Sanderson, Noel G. Brizuela, Tomohiro Hajima, Tatiana Ilyina, Chris D. Jones, Charles Koven, David Lawrence, Peter Lawrence, Hongmei Li, Spencer Liddcoat, Anastasia Romanou, Roland Séférian, Lori T. Sentman, Abigail L. S. Swann, Jerry Tjiputra, Tilo Ziehn, and Alexander J. Winkler
EGUsphere, https://doi.org/10.5194/egusphere-2025-3270, https://doi.org/10.5194/egusphere-2025-3270, 2025
This preprint is open for discussion and under review for Earth System Dynamics (ESD).
Short summary
Short summary
Idealized experiments with Earth system models provide a basis for understanding the response of the carbon cycle to emissions. We show that most models exhibit a quasi-linear relationship between cumulative carbon uptake on land and in the ocean and hypothesize that this relationship does not depend on emission pathways. We reduce the coupled system to only one differential equation, which represents a powerful simplification of the Earth system dynamics as a function of fossil fuel emissions.
Constanze Reinken, Victor Brovkin, Philipp de Vrese, Ingmar Nitze, Helena Bergstedt, and Guido Grosse
EGUsphere, https://doi.org/10.5194/egusphere-2025-1817, https://doi.org/10.5194/egusphere-2025-1817, 2025
This preprint is open for discussion and under review for The Cryosphere (TC).
Short summary
Short summary
Thermokarst lakes are dynamic features of ice-rich permafrost landscapes, altering energy, water and carbon cycles, but have so far mostly been modeled on site-level scale. A deterministic modelling approach would be challenging on larger scales due to the lack of extensive high-resolution data of sub-surface conditions. We therefore develop a conceptual stochastic model of thermokarst lake dynamics that treats the involved processes as probabilistic.
Ricarda Winkelmann, Donovan P. Dennis, Jonathan F. Donges, Sina Loriani, Ann Kristin Klose, Jesse F. Abrams, Jorge Alvarez-Solas, Torsten Albrecht, David Armstrong McKay, Sebastian Bathiany, Javier Blasco Navarro, Victor Brovkin, Eleanor Burke, Gokhan Danabasoglu, Reik V. Donner, Markus Drüke, Goran Georgievski, Heiko Goelzer, Anna B. Harper, Gabriele Hegerl, Marina Hirota, Aixue Hu, Laura C. Jackson, Colin Jones, Hyungjun Kim, Torben Koenigk, Peter Lawrence, Timothy M. Lenton, Hannah Liddy, José Licón-Saláiz, Maxence Menthon, Marisa Montoya, Jan Nitzbon, Sophie Nowicki, Bette Otto-Bliesner, Francesco Pausata, Stefan Rahmstorf, Karoline Ramin, Alexander Robinson, Johan Rockström, Anastasia Romanou, Boris Sakschewski, Christina Schädel, Steven Sherwood, Robin S. Smith, Norman J. Steinert, Didier Swingedouw, Matteo Willeit, Wilbert Weijer, Richard Wood, Klaus Wyser, and Shuting Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-1899, https://doi.org/10.5194/egusphere-2025-1899, 2025
This preprint is open for discussion and under review for Earth System Dynamics (ESD).
Short summary
Short summary
The Tipping Points Modelling Intercomparison Project (TIPMIP) is an international collaborative effort to systematically assess tipping point risks in the Earth system using state-of-the-art coupled and stand-alone domain models. TIPMIP will provide a first global atlas of potential tipping dynamics, respective critical thresholds and key uncertainties, generating an important building block towards a comprehensive scientific basis for policy- and decision-making.
Wolfgang A. Müller, Stephan Lorenz, Trang V. Pham, Andrea Schneidereit, Renate Brokopf, Victor Brovkin, Nils Brüggemann, Fatemeh Chegini, Dietmar Dommenget, Kristina Fröhlich, Barbara Früh, Veronika Gayler, Helmuth Haak, Stefan Hagemann, Moritz Hanke, Tatiana Ilyina, Johann Jungclaus, Martin Köhler, Peter Korn, Luis Kornblüh, Clarissa Kroll, Julian Krüger, Karel Castro-Morales, Ulrike Niemeier, Holger Pohlmann, Iuliia Polkova, Roland Potthast, Thomas Riddick, Manuel Schlund, Tobias Stacke, Roland Wirth, Dakuan Yu, and Jochem Marotzke
EGUsphere, https://doi.org/10.5194/egusphere-2025-2473, https://doi.org/10.5194/egusphere-2025-2473, 2025
Short summary
Short summary
ICON XPP is a newly developed Earth System model configuration based on the ICON modeling framework. It merges accomplishments from the recent operational numerical weather prediction model with well-established climate components for the ocean, land and ocean-biogeochemistry. ICON XPP reaches typical targets of a coupled climate simulation, and is able to run long integrations and large-ensemble experiments, making it suitable for climate predictions and projections, and for climate research.
Amali A. Amali, Clemens Schwingshackl, Akihiko Ito, Alina Barbu, Christine Delire, Daniele Peano, David M. Lawrence, David Wårlind, Eddy Robertson, Edouard L. Davin, Elena Shevliakova, Ian N. Harman, Nicolas Vuichard, Paul A. Miller, Peter J. Lawrence, Tilo Ziehn, Tomohiro Hajima, Victor Brovkin, Yanwu Zhang, Vivek K. Arora, and Julia Pongratz
Earth Syst. Dynam., 16, 803–840, https://doi.org/10.5194/esd-16-803-2025, https://doi.org/10.5194/esd-16-803-2025, 2025
Short summary
Short summary
Our study explored the impact of anthropogenic land-use change (LUC) on climate dynamics, focusing on biogeophysical (BGP) and biogeochemical (BGC) effects using data from the Land Use Model Intercomparison Project (LUMIP) and the Coupled Model Intercomparison Project Phase 6 (CMIP6). We found that LUC-induced carbon emissions contribute to a BGC warming of 0.21 °C, with BGC effects dominating globally over BGP effects, which show regional variability. Our findings highlight discrepancies in model simulations and emphasize the need for improved representations of LUC processes.
Pauline Walz, Oliver Fritz, Sabrina Marx, Marlin M. Mueller, Christian Thiel, Josefine Lenz, Soraya Kaiser, Roxanne Frappier, Alexander Zipf, and Moritz Langer
EGUsphere, https://doi.org/10.5194/egusphere-2025-1778, https://doi.org/10.5194/egusphere-2025-1778, 2025
Short summary
Short summary
We explored how citizen scientists can help map changes in Arctic landscapes. Using a web tool we created, more than 100 volunteers contributed the approximate center points of particular ground patterns called ice-wedge polygons in aerial images from Alaska and Canada. Our work shows that the data created by volunteers can be used to reconstruct ice-wedge polygon networks and provide valuable insights on the state of frozen ground in the Arctic.
Marielle Saunois, Adrien Martinez, Benjamin Poulter, Zhen Zhang, Peter A. Raymond, Pierre Regnier, Josep G. Canadell, Robert B. Jackson, Prabir K. Patra, Philippe Bousquet, Philippe Ciais, Edward J. Dlugokencky, Xin Lan, George H. Allen, David Bastviken, David J. Beerling, Dmitry A. Belikov, Donald R. Blake, Simona Castaldi, Monica Crippa, Bridget R. Deemer, Fraser Dennison, Giuseppe Etiope, Nicola Gedney, Lena Höglund-Isaksson, Meredith A. Holgerson, Peter O. Hopcroft, Gustaf Hugelius, Akihiko Ito, Atul K. Jain, Rajesh Janardanan, Matthew S. Johnson, Thomas Kleinen, Paul B. Krummel, Ronny Lauerwald, Tingting Li, Xiangyu Liu, Kyle C. McDonald, Joe R. Melton, Jens Mühle, Jurek Müller, Fabiola Murguia-Flores, Yosuke Niwa, Sergio Noce, Shufen Pan, Robert J. Parker, Changhui Peng, Michel Ramonet, William J. Riley, Gerard Rocher-Ros, Judith A. Rosentreter, Motoki Sasakawa, Arjo Segers, Steven J. Smith, Emily H. Stanley, Joël Thanwerdas, Hanqin Tian, Aki Tsuruta, Francesco N. Tubiello, Thomas S. Weber, Guido R. van der Werf, Douglas E. J. Worthy, Yi Xi, Yukio Yoshida, Wenxin Zhang, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 17, 1873–1958, https://doi.org/10.5194/essd-17-1873-2025, https://doi.org/10.5194/essd-17-1873-2025, 2025
Short summary
Short summary
Methane (CH4) is the second most important human-influenced greenhouse gas in terms of climate forcing after carbon dioxide (CO2). A consortium of multi-disciplinary scientists synthesise and update the budget of the sources and sinks of CH4. This edition benefits from important progress in estimating emissions from lakes and ponds, reservoirs, and streams and rivers. For the 2010s decade, global CH4 emissions are estimated at 575 Tg CH4 yr-1, including ~65 % from anthropogenic sources.
Mateo Duque-Villegas, Martin Claussen, Thomas Kleinen, Jürgen Bader, and Christian H. Reick
Clim. Past, 21, 773–794, https://doi.org/10.5194/cp-21-773-2025, https://doi.org/10.5194/cp-21-773-2025, 2025
Short summary
Short summary
We simulate the last glacial cycle with a comprehensive model of the Earth system and investigate vegetation cover change in northern Africa during the last four African Humid Periods (AHPs). We find a common pattern of vegetation change and relate it with climatic factors in order to discuss how vegetation might have evolved during even older AHPs. This scaling relationship we find according to past AHPs fails to account for projected changes in northern Africa under strong greenhouse gas warming.
Tomohiro Hajima, Michio Kawamiya, Akihiko Ito, Kaoru Tachiiri, Chris D. Jones, Vivek Arora, Victor Brovkin, Roland Séférian, Spencer Liddicoat, Pierre Friedlingstein, and Elena Shevliakova
Biogeosciences, 22, 1447–1473, https://doi.org/10.5194/bg-22-1447-2025, https://doi.org/10.5194/bg-22-1447-2025, 2025
Short summary
Short summary
This study analyzes atmospheric CO2 concentrations and global carbon budgets simulated by multiple Earth system models, using several types of simulations (CO2 concentration- and emission-driven experiments). We successfully identified problems with regard to the global carbon budget in each model. We also found urgent issues with regard to land use change CO2 emissions that should be solved in the latest generation of models.
Tuula Aalto, Aki Tsuruta, Jarmo Mäkelä, Jurek Müller, Maria Tenkanen, Eleanor Burke, Sarah Chadburn, Yao Gao, Vilma Mannisenaho, Thomas Kleinen, Hanna Lee, Antti Leppänen, Tiina Markkanen, Stefano Materia, Paul A. Miller, Daniele Peano, Olli Peltola, Benjamin Poulter, Maarit Raivonen, Marielle Saunois, David Wårlind, and Sönke Zaehle
Biogeosciences, 22, 323–340, https://doi.org/10.5194/bg-22-323-2025, https://doi.org/10.5194/bg-22-323-2025, 2025
Short summary
Short summary
Wetland methane responses to temperature and precipitation were studied in a boreal wetland-rich region in northern Europe using ecosystem models, atmospheric inversions, and upscaled flux observations. The ecosystem models differed in their responses to temperature and precipitation and in their seasonality. However, multi-model means, inversions, and upscaled fluxes had similar seasonality, and they suggested co-limitation by temperature and precipitation.
Zhen Zhang, Benjamin Poulter, Joe R. Melton, William J. Riley, George H. Allen, David J. Beerling, Philippe Bousquet, Josep G. Canadell, Etienne Fluet-Chouinard, Philippe Ciais, Nicola Gedney, Peter O. Hopcroft, Akihiko Ito, Robert B. Jackson, Atul K. Jain, Katherine Jensen, Fortunat Joos, Thomas Kleinen, Sara H. Knox, Tingting Li, Xin Li, Xiangyu Liu, Kyle McDonald, Gavin McNicol, Paul A. Miller, Jurek Müller, Prabir K. Patra, Changhui Peng, Shushi Peng, Zhangcai Qin, Ryan M. Riggs, Marielle Saunois, Qing Sun, Hanqin Tian, Xiaoming Xu, Yuanzhi Yao, Yi Xi, Wenxin Zhang, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Biogeosciences, 22, 305–321, https://doi.org/10.5194/bg-22-305-2025, https://doi.org/10.5194/bg-22-305-2025, 2025
Short summary
Short summary
This study assesses global methane emissions from wetlands between 2000 and 2020 using multiple models. We found that wetland emissions increased by 6–7 Tg CH4 yr-1 in the 2010s compared to the 2000s. Rising temperatures primarily drove this increase, while changes in precipitation and CO2 levels also played roles. Our findings highlight the importance of wetlands in the global methane budget and the need for continuous monitoring to understand their impact on climate change.
Yona Silvy, Thomas L. Frölicher, Jens Terhaar, Fortunat Joos, Friedrich A. Burger, Fabrice Lacroix, Myles Allen, Raffaele Bernardello, Laurent Bopp, Victor Brovkin, Jonathan R. Buzan, Patricia Cadule, Martin Dix, John Dunne, Pierre Friedlingstein, Goran Georgievski, Tomohiro Hajima, Stuart Jenkins, Michio Kawamiya, Nancy Y. Kiang, Vladimir Lapin, Donghyun Lee, Paul Lerner, Nadine Mengis, Estela A. Monteiro, David Paynter, Glen P. Peters, Anastasia Romanou, Jörg Schwinger, Sarah Sparrow, Eric Stofferahn, Jerry Tjiputra, Etienne Tourigny, and Tilo Ziehn
Earth Syst. Dynam., 15, 1591–1628, https://doi.org/10.5194/esd-15-1591-2024, https://doi.org/10.5194/esd-15-1591-2024, 2024
Short summary
Short summary
The adaptive emission reduction approach is applied with Earth system models to generate temperature stabilization simulations. These simulations provide compatible emission pathways and budgets for a given warming level, uncovering uncertainty ranges previously missing in the Coupled Model Intercomparison Project scenarios. These target-based emission-driven simulations offer a more coherent assessment across models for studying both the carbon cycle and its impacts under climate stabilization.
Nathaelle Bouttes, Lester Kwiatkowski, Elodie Bougeot, Manon Berger, Victor Brovkin, and Guy Munhoven
EGUsphere, https://doi.org/10.5194/egusphere-2024-3738, https://doi.org/10.5194/egusphere-2024-3738, 2024
Short summary
Short summary
Coral reefs are under threat due to warming and ocean acidification. It is difficult to project future coral reef production due to uncertainties in climate models, socio-economic scenarios and coral adaptation to warming. Here we have included a coral reef module within a climate model for the first time to evaluate the range of possible futures. We show that coral reef production decreases in most future scenarios, but in some cases coral reef carbonate production can persist.
Benjamin Mark Sanderson, Victor Brovkin, Rosie Fisher, David Hohn, Tatiana Ilyina, Chris Jones, Torben Koenigk, Charles Koven, Hongmei Li, David Lawrence, Peter Lawrence, Spencer Liddicoat, Andrew Macdougall, Nadine Mengis, Zebedee Nicholls, Eleanor O'Rourke, Anastasia Romanou, Marit Sandstad, Jörg Schwinger, Roland Seferian, Lori Sentman, Isla Simpson, Chris Smith, Norman Steinert, Abigail Swann, Jerry Tjiputra, and Tilo Ziehn
EGUsphere, https://doi.org/10.5194/egusphere-2024-3356, https://doi.org/10.5194/egusphere-2024-3356, 2024
Short summary
Short summary
This study investigates how climate models warm in response to simplified carbon emissions trajectories, refining understanding of climate reversibility and commitment. Metrics are defined for warming response to cumulative emissions and for the cessation or ramp-down to net-zero and net-negative levels. Results indicate that previous concentration-driven experiments may have overstated zero emissions commitment due to emissions rates exceeding historical levels.
Colin G. Jones, Fanny Adloff, Ben B. B. Booth, Peter M. Cox, Veronika Eyring, Pierre Friedlingstein, Katja Frieler, Helene T. Hewitt, Hazel A. Jeffery, Sylvie Joussaume, Torben Koenigk, Bryan N. Lawrence, Eleanor O'Rourke, Malcolm J. Roberts, Benjamin M. Sanderson, Roland Séférian, Samuel Somot, Pier Luigi Vidale, Detlef van Vuuren, Mario Acosta, Mats Bentsen, Raffaele Bernardello, Richard Betts, Ed Blockley, Julien Boé, Tom Bracegirdle, Pascale Braconnot, Victor Brovkin, Carlo Buontempo, Francisco Doblas-Reyes, Markus Donat, Italo Epicoco, Pete Falloon, Sandro Fiore, Thomas Frölicher, Neven S. Fučkar, Matthew J. Gidden, Helge F. Goessling, Rune Grand Graversen, Silvio Gualdi, José M. Gutiérrez, Tatiana Ilyina, Daniela Jacob, Chris D. Jones, Martin Juckes, Elizabeth Kendon, Erik Kjellström, Reto Knutti, Jason Lowe, Matthew Mizielinski, Paola Nassisi, Michael Obersteiner, Pierre Regnier, Romain Roehrig, David Salas y Mélia, Carl-Friedrich Schleussner, Michael Schulz, Enrico Scoccimarro, Laurent Terray, Hannes Thiemann, Richard A. Wood, Shuting Yang, and Sönke Zaehle
Earth Syst. Dynam., 15, 1319–1351, https://doi.org/10.5194/esd-15-1319-2024, https://doi.org/10.5194/esd-15-1319-2024, 2024
Short summary
Short summary
We propose a number of priority areas for the international climate research community to address over the coming decade. Advances in these areas will both increase our understanding of past and future Earth system change, including the societal and environmental impacts of this change, and deliver significantly improved scientific support to international climate policy, such as future IPCC assessments and the UNFCCC Global Stocktake.
Nathaelle Bouttes, Lester Kwiatkowski, Manon Berger, Victor Brovkin, and Guy Munhoven
Geosci. Model Dev., 17, 6513–6528, https://doi.org/10.5194/gmd-17-6513-2024, https://doi.org/10.5194/gmd-17-6513-2024, 2024
Short summary
Short summary
Coral reefs are crucial for biodiversity, but they also play a role in the carbon cycle on long time scales of a few thousand years. To better simulate the future and past evolution of coral reefs and their effect on the global carbon cycle, hence on atmospheric CO2 concentration, it is necessary to include coral reefs within a climate model. Here we describe the inclusion of coral reef carbonate production in a carbon–climate model and its validation in comparison to existing modern data.
Soraya Kaiser, Julia Boike, Guido Grosse, and Moritz Langer
Earth Syst. Sci. Data, 16, 3719–3753, https://doi.org/10.5194/essd-16-3719-2024, https://doi.org/10.5194/essd-16-3719-2024, 2024
Short summary
Short summary
Arctic warming, leading to permafrost degradation, poses primary threats to infrastructure and secondary ecological hazards from possible infrastructure failure. Our study created a comprehensive Alaska inventory combining various data sources with which we improved infrastructure classification and data on contaminated sites. This resource is presented as a GeoPackage allowing planning of infrastructure damage and possible implications for Arctic communities facing permafrost challenges.
Nora Farina Specht, Martin Claussen, and Thomas Kleinen
Clim. Past, 20, 1595–1613, https://doi.org/10.5194/cp-20-1595-2024, https://doi.org/10.5194/cp-20-1595-2024, 2024
Short summary
Short summary
We close the terrestrial water cycle across the Sahara and Sahel by integrating a new endorheic-lake model into a climate model. A factor analysis of mid-Holocene simulations shows that both dynamic lakes and dynamic vegetation individually contribute to a precipitation increase over northern Africa that is collectively greater than that caused by the interaction between lake and vegetation dynamics. Thus, the lake–vegetation interaction causes a relative drying response across the entire Sahel.
Daniel Kwakye, Sabrina Marx, Benjamin Herfort, Moritz Langer, and Sven Lautenbach
AGILE GIScience Ser., 5, 34, https://doi.org/10.5194/agile-giss-5-34-2024, https://doi.org/10.5194/agile-giss-5-34-2024, 2024
Nils Weitzel, Heather Andres, Jean-Philippe Baudouin, Marie-Luise Kapsch, Uwe Mikolajewicz, Lukas Jonkers, Oliver Bothe, Elisa Ziegler, Thomas Kleinen, André Paul, and Kira Rehfeld
Clim. Past, 20, 865–890, https://doi.org/10.5194/cp-20-865-2024, https://doi.org/10.5194/cp-20-865-2024, 2024
Short summary
Short summary
The ability of climate models to faithfully reproduce past warming episodes is a valuable test considering potentially large future warming. We develop a new method to compare simulations of the last deglaciation with temperature reconstructions. We find that reconstructions differ more between regions than simulations, potentially due to deficiencies in the simulation design, models, or reconstructions. Our work is a promising step towards benchmarking simulations of past climate transitions.
Moritz Langer, Jan Nitzbon, Brian Groenke, Lisa-Marie Assmann, Thomas Schneider von Deimling, Simone Maria Stuenzi, and Sebastian Westermann
The Cryosphere, 18, 363–385, https://doi.org/10.5194/tc-18-363-2024, https://doi.org/10.5194/tc-18-363-2024, 2024
Short summary
Short summary
Using a model that can simulate the evolution of Arctic permafrost over centuries to millennia, we find that post-industrialization permafrost warming has three "hotspots" in NE Canada, N Alaska, and W Siberia. The extent of near-surface permafrost has decreased substantially since 1850, with the largest area losses occurring in the last 50 years. The simulations also show that volcanic eruptions have in some cases counteracted the loss of near-surface permafrost for a few decades.
Nico Wunderling, Anna S. von der Heydt, Yevgeny Aksenov, Stephen Barker, Robbin Bastiaansen, Victor Brovkin, Maura Brunetti, Victor Couplet, Thomas Kleinen, Caroline H. Lear, Johannes Lohmann, Rosa Maria Roman-Cuesta, Sacha Sinet, Didier Swingedouw, Ricarda Winkelmann, Pallavi Anand, Jonathan Barichivich, Sebastian Bathiany, Mara Baudena, John T. Bruun, Cristiano M. Chiessi, Helen K. Coxall, David Docquier, Jonathan F. Donges, Swinda K. J. Falkena, Ann Kristin Klose, David Obura, Juan Rocha, Stefanie Rynders, Norman Julius Steinert, and Matteo Willeit
Earth Syst. Dynam., 15, 41–74, https://doi.org/10.5194/esd-15-41-2024, https://doi.org/10.5194/esd-15-41-2024, 2024
Short summary
Short summary
This paper maps out the state-of-the-art literature on interactions between tipping elements relevant for current global warming pathways. We find indications that many of the interactions between tipping elements are destabilizing. This means that tipping cascades cannot be ruled out on centennial to millennial timescales at global warming levels between 1.5 and 2.0 °C or on shorter timescales if global warming surpasses 2.0 °C.
Léo C. P. Martin, Sebastian Westermann, Michele Magni, Fanny Brun, Joel Fiddes, Yanbin Lei, Philip Kraaijenbrink, Tamara Mathys, Moritz Langer, Simon Allen, and Walter W. Immerzeel
Hydrol. Earth Syst. Sci., 27, 4409–4436, https://doi.org/10.5194/hess-27-4409-2023, https://doi.org/10.5194/hess-27-4409-2023, 2023
Short summary
Short summary
Across the Tibetan Plateau, many large lakes have been changing level during the last decades as a response to climate change. In high-mountain environments, water fluxes from the land to the lakes are linked to the ground temperature of the land and to the energy fluxes between the ground and the atmosphere, which are modified by climate change. With a numerical model, we test how these water and energy fluxes have changed over the last decades and how they influence the lake level variations.
Juditha Aga, Julia Boike, Moritz Langer, Thomas Ingeman-Nielsen, and Sebastian Westermann
The Cryosphere, 17, 4179–4206, https://doi.org/10.5194/tc-17-4179-2023, https://doi.org/10.5194/tc-17-4179-2023, 2023
Short summary
Short summary
This study presents a new model scheme for simulating ice segregation and thaw consolidation in permafrost environments, depending on ground properties and climatic forcing. It is embedded in the CryoGrid community model, a land surface model for the terrestrial cryosphere. We describe the model physics and functionalities, followed by a model validation and a sensitivity study of controlling factors.
Brian Groenke, Moritz Langer, Jan Nitzbon, Sebastian Westermann, Guillermo Gallego, and Julia Boike
The Cryosphere, 17, 3505–3533, https://doi.org/10.5194/tc-17-3505-2023, https://doi.org/10.5194/tc-17-3505-2023, 2023
Short summary
Short summary
It is now well known from long-term temperature measurements that Arctic permafrost, i.e., ground that remains continuously frozen for at least 2 years, is warming in response to climate change. Temperature, however, only tells half of the story. In this study, we use computer modeling to better understand how the thawing and freezing of water in the ground affects the way permafrost responds to climate change and what temperature trends can and cannot tell us about how permafrost is changing.
István Dunkl, Nicole Lovenduski, Alessio Collalti, Vivek K. Arora, Tatiana Ilyina, and Victor Brovkin
Biogeosciences, 20, 3523–3538, https://doi.org/10.5194/bg-20-3523-2023, https://doi.org/10.5194/bg-20-3523-2023, 2023
Short summary
Short summary
Despite differences in the reproduction of gross primary productivity (GPP) by Earth system models (ESMs), ESMs have similar predictability of the global carbon cycle. We found that, although GPP variability originates from different regions and is driven by different climatic variables across the ESMs, the ESMs rely on the same mechanisms to predict their own GPP. This shows that the predictability of the carbon cycle is limited by our understanding of variability rather than predictability.
Matteo Willeit, Tatiana Ilyina, Bo Liu, Christoph Heinze, Mahé Perrette, Malte Heinemann, Daniela Dalmonech, Victor Brovkin, Guy Munhoven, Janine Börker, Jens Hartmann, Gibran Romero-Mujalli, and Andrey Ganopolski
Geosci. Model Dev., 16, 3501–3534, https://doi.org/10.5194/gmd-16-3501-2023, https://doi.org/10.5194/gmd-16-3501-2023, 2023
Short summary
Short summary
In this paper we present the carbon cycle component of the newly developed fast Earth system model CLIMBER-X. The model can be run with interactive atmospheric CO2 to investigate the feedbacks between climate and the carbon cycle on temporal scales ranging from decades to > 100 000 years. CLIMBER-X is expected to be a useful tool for studying past climate–carbon cycle changes and for the investigation of the long-term future evolution of the Earth system.
Thomas Kleinen, Sergey Gromov, Benedikt Steil, and Victor Brovkin
Clim. Past, 19, 1081–1099, https://doi.org/10.5194/cp-19-1081-2023, https://doi.org/10.5194/cp-19-1081-2023, 2023
Short summary
Short summary
We modelled atmospheric methane continuously from the last glacial maximum to the present using a state-of-the-art Earth system model. Our model results compare well with reconstructions from ice cores and improve our understanding of a very intriguing period of Earth system history, the deglaciation, when atmospheric methane changed quickly and strongly. Deglacial methane changes are driven by emissions from tropical wetlands, with wetlands in high northern latitudes being secondary.
Philipp de Vrese, Goran Georgievski, Jesus Fidel Gonzalez Rouco, Dirk Notz, Tobias Stacke, Norman Julius Steinert, Stiig Wilkenskjeld, and Victor Brovkin
The Cryosphere, 17, 2095–2118, https://doi.org/10.5194/tc-17-2095-2023, https://doi.org/10.5194/tc-17-2095-2023, 2023
Short summary
Short summary
The current generation of Earth system models exhibits large inter-model differences in the simulated climate of the Arctic and subarctic zone. We used an adapted version of the Max Planck Institute (MPI) Earth System Model to show that differences in the representation of the soil hydrology in permafrost-affected regions could help explain a large part of this inter-model spread and have pronounced impacts on important elements of Earth systems as far to the south as the tropics.
Francisco José Cuesta-Valero, Hugo Beltrami, Almudena García-García, Gerhard Krinner, Moritz Langer, Andrew H. MacDougall, Jan Nitzbon, Jian Peng, Karina von Schuckmann, Sonia I. Seneviratne, Wim Thiery, Inne Vanderkelen, and Tonghua Wu
Earth Syst. Dynam., 14, 609–627, https://doi.org/10.5194/esd-14-609-2023, https://doi.org/10.5194/esd-14-609-2023, 2023
Short summary
Short summary
Climate change is caused by the accumulated heat in the Earth system, with the land storing the second largest amount of this extra heat. Here, new estimates of continental heat storage are obtained, including changes in inland-water heat storage and permafrost heat storage in addition to changes in ground heat storage. We also argue that heat gains in all three components should be monitored independently of their magnitude due to heat-dependent processes affecting society and ecosystems.
Sebastian Westermann, Thomas Ingeman-Nielsen, Johanna Scheer, Kristoffer Aalstad, Juditha Aga, Nitin Chaudhary, Bernd Etzelmüller, Simon Filhol, Andreas Kääb, Cas Renette, Louise Steffensen Schmidt, Thomas Vikhamar Schuler, Robin B. Zweigel, Léo Martin, Sarah Morard, Matan Ben-Asher, Michael Angelopoulos, Julia Boike, Brian Groenke, Frederieke Miesner, Jan Nitzbon, Paul Overduin, Simone M. Stuenzi, and Moritz Langer
Geosci. Model Dev., 16, 2607–2647, https://doi.org/10.5194/gmd-16-2607-2023, https://doi.org/10.5194/gmd-16-2607-2023, 2023
Short summary
Short summary
The CryoGrid community model is a new tool for simulating ground temperatures and the water and ice balance in cold regions. It is a modular design, which makes it possible to test different schemes to simulate, for example, permafrost ground in an efficient way. The model contains tools to simulate frozen and unfrozen ground, snow, glaciers, and other massive ice bodies, as well as water bodies.
Karina von Schuckmann, Audrey Minière, Flora Gues, Francisco José Cuesta-Valero, Gottfried Kirchengast, Susheel Adusumilli, Fiammetta Straneo, Michaël Ablain, Richard P. Allan, Paul M. Barker, Hugo Beltrami, Alejandro Blazquez, Tim Boyer, Lijing Cheng, John Church, Damien Desbruyeres, Han Dolman, Catia M. Domingues, Almudena García-García, Donata Giglio, John E. Gilson, Maximilian Gorfer, Leopold Haimberger, Maria Z. Hakuba, Stefan Hendricks, Shigeki Hosoda, Gregory C. Johnson, Rachel Killick, Brian King, Nicolas Kolodziejczyk, Anton Korosov, Gerhard Krinner, Mikael Kuusela, Felix W. Landerer, Moritz Langer, Thomas Lavergne, Isobel Lawrence, Yuehua Li, John Lyman, Florence Marti, Ben Marzeion, Michael Mayer, Andrew H. MacDougall, Trevor McDougall, Didier Paolo Monselesan, Jan Nitzbon, Inès Otosaka, Jian Peng, Sarah Purkey, Dean Roemmich, Kanako Sato, Katsunari Sato, Abhishek Savita, Axel Schweiger, Andrew Shepherd, Sonia I. Seneviratne, Leon Simons, Donald A. Slater, Thomas Slater, Andrea K. Steiner, Toshio Suga, Tanguy Szekely, Wim Thiery, Mary-Louise Timmermans, Inne Vanderkelen, Susan E. Wjiffels, Tonghua Wu, and Michael Zemp
Earth Syst. Sci. Data, 15, 1675–1709, https://doi.org/10.5194/essd-15-1675-2023, https://doi.org/10.5194/essd-15-1675-2023, 2023
Short summary
Short summary
Earth's climate is out of energy balance, and this study quantifies how much heat has consequently accumulated over the past decades (ocean: 89 %, land: 6 %, cryosphere: 4 %, atmosphere: 1 %). Since 1971, this accumulated heat reached record values at an increasing pace. The Earth heat inventory provides a comprehensive view on the status and expectation of global warming, and we call for an implementation of this global climate indicator into the Paris Agreement’s Global Stocktake.
Ngai-Ham Chan, Moritz Langer, Bennet Juhls, Tabea Rettelbach, Paul Overduin, Kimberly Huppert, and Jean Braun
Earth Surf. Dynam., 11, 259–285, https://doi.org/10.5194/esurf-11-259-2023, https://doi.org/10.5194/esurf-11-259-2023, 2023
Short summary
Short summary
Arctic river deltas influence how nutrients and soil organic carbon, carried by sediments from the Arctic landscape, are retained or released into the Arctic Ocean. Under climate change, the deltas themselves and their ecosystems are becoming more vulnerable. We build upon previous models to reproduce for the first time an important feature ubiquitous to Arctic deltas and simulate its future under climate warming. This can impact the future of Arctic deltas and the carbon release they moderate.
Mengxiao Wang, Lijuan Wen, Zhaoguo Li, Matti Leppäranta, Victor Stepanenko, Yixin Zhao, Ruijia Niu, Liuyiyi Yang, and Georgiy Kirillin
The Cryosphere, 16, 3635–3648, https://doi.org/10.5194/tc-16-3635-2022, https://doi.org/10.5194/tc-16-3635-2022, 2022
Short summary
Short summary
The under-ice water temperature of Ngoring Lake has been rising based on in situ observations. We obtained results showing that strong downward shortwave radiation is the main meteorological factor, and precipitation, wind speed, downward longwave radiation, air temperature, ice albedo, and ice extinction coefficient have an impact on the range and rate of lake temperature rise. Once the ice breaks, the lake body releases more energy than other lakes, whose water temperature remains horizontal.
Lutz Beckebanze, Benjamin R. K. Runkle, Josefine Walz, Christian Wille, David Holl, Manuel Helbig, Julia Boike, Torsten Sachs, and Lars Kutzbach
Biogeosciences, 19, 3863–3876, https://doi.org/10.5194/bg-19-3863-2022, https://doi.org/10.5194/bg-19-3863-2022, 2022
Short summary
Short summary
In this study, we present observations of lateral and vertical carbon fluxes from a permafrost-affected study site in the Russian Arctic. From this dataset we estimate the net ecosystem carbon balance for this study site. We show that lateral carbon export has a low impact on the net ecosystem carbon balance during the complete study period (3 months). Nevertheless, our results also show that lateral carbon export can exceed vertical carbon uptake at the beginning of the growing season.
Mateo Duque-Villegas, Martin Claussen, Victor Brovkin, and Thomas Kleinen
Clim. Past, 18, 1897–1914, https://doi.org/10.5194/cp-18-1897-2022, https://doi.org/10.5194/cp-18-1897-2022, 2022
Short summary
Short summary
Using an Earth system model of intermediate complexity, we quantify contributions of the Earth's orbit, greenhouse gases (GHGs) and ice sheets to the strength of Saharan greening during late Quaternary African humid periods (AHPs). Orbital forcing is found as the dominant factor, having a critical threshold and accounting for most of the changes in the vegetation response. However, results suggest that GHGs may influence the orbital threshold and thus may play a pivotal role for future AHPs.
Malgorzata Golub, Wim Thiery, Rafael Marcé, Don Pierson, Inne Vanderkelen, Daniel Mercado-Bettin, R. Iestyn Woolway, Luke Grant, Eleanor Jennings, Benjamin M. Kraemer, Jacob Schewe, Fang Zhao, Katja Frieler, Matthias Mengel, Vasiliy Y. Bogomolov, Damien Bouffard, Marianne Côté, Raoul-Marie Couture, Andrey V. Debolskiy, Bram Droppers, Gideon Gal, Mingyang Guo, Annette B. G. Janssen, Georgiy Kirillin, Robert Ladwig, Madeline Magee, Tadhg Moore, Marjorie Perroud, Sebastiano Piccolroaz, Love Raaman Vinnaa, Martin Schmid, Tom Shatwell, Victor M. Stepanenko, Zeli Tan, Bronwyn Woodward, Huaxia Yao, Rita Adrian, Mathew Allan, Orlane Anneville, Lauri Arvola, Karen Atkins, Leon Boegman, Cayelan Carey, Kyle Christianson, Elvira de Eyto, Curtis DeGasperi, Maria Grechushnikova, Josef Hejzlar, Klaus Joehnk, Ian D. Jones, Alo Laas, Eleanor B. Mackay, Ivan Mammarella, Hampus Markensten, Chris McBride, Deniz Özkundakci, Miguel Potes, Karsten Rinke, Dale Robertson, James A. Rusak, Rui Salgado, Leon van der Linden, Piet Verburg, Danielle Wain, Nicole K. Ward, Sabine Wollrab, and Galina Zdorovennova
Geosci. Model Dev., 15, 4597–4623, https://doi.org/10.5194/gmd-15-4597-2022, https://doi.org/10.5194/gmd-15-4597-2022, 2022
Short summary
Short summary
Lakes and reservoirs are warming across the globe. To better understand how lakes are changing and to project their future behavior amidst various sources of uncertainty, simulations with a range of lake models are required. This in turn requires international coordination across different lake modelling teams worldwide. Here we present a protocol for and results from coordinated simulations of climate change impacts on lakes worldwide.
Nora Farina Specht, Martin Claussen, and Thomas Kleinen
Clim. Past, 18, 1035–1046, https://doi.org/10.5194/cp-18-1035-2022, https://doi.org/10.5194/cp-18-1035-2022, 2022
Short summary
Short summary
Palaeoenvironmental records only provide a fragmentary picture of the lake and wetland extent in North Africa during the mid-Holocene. Therefore, we investigate the possible range of mid-Holocene precipitation changes caused by an estimated small and maximum lake extent and a maximum wetland extent. Results show a particularly strong monsoon precipitation response to lakes and wetlands over the Western Sahara and an increased monsoon precipitation when replacing lakes with vegetated wetlands.
Elodie Salmon, Fabrice Jégou, Bertrand Guenet, Line Jourdain, Chunjing Qiu, Vladislav Bastrikov, Christophe Guimbaud, Dan Zhu, Philippe Ciais, Philippe Peylin, Sébastien Gogo, Fatima Laggoun-Défarge, Mika Aurela, M. Syndonia Bret-Harte, Jiquan Chen, Bogdan H. Chojnicki, Housen Chu, Colin W. Edgar, Eugenie S. Euskirchen, Lawrence B. Flanagan, Krzysztof Fortuniak, David Holl, Janina Klatt, Olaf Kolle, Natalia Kowalska, Lars Kutzbach, Annalea Lohila, Lutz Merbold, Włodzimierz Pawlak, Torsten Sachs, and Klaudia Ziemblińska
Geosci. Model Dev., 15, 2813–2838, https://doi.org/10.5194/gmd-15-2813-2022, https://doi.org/10.5194/gmd-15-2813-2022, 2022
Short summary
Short summary
A methane model that features methane production and transport by plants, the ebullition process and diffusion in soil, oxidation to CO2, and CH4 fluxes to the atmosphere has been embedded in the ORCHIDEE-PEAT land surface model, which includes an explicit representation of northern peatlands. This model, ORCHIDEE-PCH4, was calibrated and evaluated on 14 peatland sites. Results show that the model is sensitive to temperature and substrate availability over the top 75 cm of soil depth.
Stiig Wilkenskjeld, Frederieke Miesner, Paul P. Overduin, Matteo Puglini, and Victor Brovkin
The Cryosphere, 16, 1057–1069, https://doi.org/10.5194/tc-16-1057-2022, https://doi.org/10.5194/tc-16-1057-2022, 2022
Short summary
Short summary
Thawing permafrost releases carbon to the atmosphere, enhancing global warming. Part of the permafrost soils have been flooded by rising sea levels since the last ice age, becoming subsea permafrost (SSPF). The SSPF is less studied than the part on land. In this study we use a global model to obtain rates of thawing of SSPF under different future climate scenarios until the year 3000. After the year 2100 the scenarios strongly diverge, closely connected to the eventual disappearance of sea ice.
Stefan Kruse, Simone M. Stuenzi, Julia Boike, Moritz Langer, Josias Gloy, and Ulrike Herzschuh
Geosci. Model Dev., 15, 2395–2422, https://doi.org/10.5194/gmd-15-2395-2022, https://doi.org/10.5194/gmd-15-2395-2022, 2022
Short summary
Short summary
We coupled established models for boreal forest (LAVESI) and permafrost dynamics (CryoGrid) in Siberia to investigate interactions of the diverse vegetation layer with permafrost soils. Our tests showed improved active layer depth estimations and newly included species growth according to their species-specific limits. We conclude that the new model system can be applied to simulate boreal forest dynamics and transitions under global warming and disturbances, expanding our knowledge.
Lutz Beckebanze, Zoé Rehder, David Holl, Christian Wille, Charlotta Mirbach, and Lars Kutzbach
Biogeosciences, 19, 1225–1244, https://doi.org/10.5194/bg-19-1225-2022, https://doi.org/10.5194/bg-19-1225-2022, 2022
Short summary
Short summary
Arctic permafrost landscapes feature many water bodies. In contrast to the terrestrial parts of the landscape, the water bodies release carbon to the atmosphere. We compare carbon dioxide and methane fluxes from small water bodies to the surrounding tundra and find not accounting for the carbon dioxide emissions leads to an overestimation of the tundra uptake by 11 %. Consequently, changes in hydrology and water body distribution may substantially impact the overall carbon budget of the Arctic.
Anna-Maria Virkkala, Susan M. Natali, Brendan M. Rogers, Jennifer D. Watts, Kathleen Savage, Sara June Connon, Marguerite Mauritz, Edward A. G. Schuur, Darcy Peter, Christina Minions, Julia Nojeim, Roisin Commane, Craig A. Emmerton, Mathias Goeckede, Manuel Helbig, David Holl, Hiroki Iwata, Hideki Kobayashi, Pasi Kolari, Efrén López-Blanco, Maija E. Marushchak, Mikhail Mastepanov, Lutz Merbold, Frans-Jan W. Parmentier, Matthias Peichl, Torsten Sachs, Oliver Sonnentag, Masahito Ueyama, Carolina Voigt, Mika Aurela, Julia Boike, Gerardo Celis, Namyi Chae, Torben R. Christensen, M. Syndonia Bret-Harte, Sigrid Dengel, Han Dolman, Colin W. Edgar, Bo Elberling, Eugenie Euskirchen, Achim Grelle, Juha Hatakka, Elyn Humphreys, Järvi Järveoja, Ayumi Kotani, Lars Kutzbach, Tuomas Laurila, Annalea Lohila, Ivan Mammarella, Yojiro Matsuura, Gesa Meyer, Mats B. Nilsson, Steven F. Oberbauer, Sang-Jong Park, Roman Petrov, Anatoly S. Prokushkin, Christopher Schulze, Vincent L. St. Louis, Eeva-Stiina Tuittila, Juha-Pekka Tuovinen, William Quinton, Andrej Varlagin, Donatella Zona, and Viacheslav I. Zyryanov
Earth Syst. Sci. Data, 14, 179–208, https://doi.org/10.5194/essd-14-179-2022, https://doi.org/10.5194/essd-14-179-2022, 2022
Short summary
Short summary
The effects of climate warming on carbon cycling across the Arctic–boreal zone (ABZ) remain poorly understood due to the relatively limited distribution of ABZ flux sites. Fortunately, this flux network is constantly increasing, but new measurements are published in various platforms, making it challenging to understand the ABZ carbon cycle as a whole. Here, we compiled a new database of Arctic–boreal CO2 fluxes to help facilitate large-scale assessments of the ABZ carbon cycle.
István Dunkl, Aaron Spring, Pierre Friedlingstein, and Victor Brovkin
Earth Syst. Dynam., 12, 1413–1426, https://doi.org/10.5194/esd-12-1413-2021, https://doi.org/10.5194/esd-12-1413-2021, 2021
Short summary
Short summary
The variability in atmospheric CO2 is largely controlled by terrestrial carbon fluxes. These land–atmosphere fluxes are predictable for around 2 years, but the mechanisms providing the predictability are not well understood. By decomposing the predictability of carbon fluxes into individual contributors we were able to explain the spatial and seasonal patterns and the interannual variability of CO2 flux predictability.
Aaron Spring, István Dunkl, Hongmei Li, Victor Brovkin, and Tatiana Ilyina
Earth Syst. Dynam., 12, 1139–1167, https://doi.org/10.5194/esd-12-1139-2021, https://doi.org/10.5194/esd-12-1139-2021, 2021
Short summary
Short summary
Numerical carbon cycle prediction models usually do not start from observed carbon states due to sparse observations. Instead, only physical climate is reconstructed, assuming that the carbon cycle follows indirectly. Here, we test in an idealized framework how well this indirect and direct reconstruction with perfect observations works. We find that indirect reconstruction works quite well and that improvements from the direct method are limited, strengthening the current indirect use.
Alexander J. Winkler, Ranga B. Myneni, Alexis Hannart, Stephen Sitch, Vanessa Haverd, Danica Lombardozzi, Vivek K. Arora, Julia Pongratz, Julia E. M. S. Nabel, Daniel S. Goll, Etsushi Kato, Hanqin Tian, Almut Arneth, Pierre Friedlingstein, Atul K. Jain, Sönke Zaehle, and Victor Brovkin
Biogeosciences, 18, 4985–5010, https://doi.org/10.5194/bg-18-4985-2021, https://doi.org/10.5194/bg-18-4985-2021, 2021
Short summary
Short summary
Satellite observations since the early 1980s show that Earth's greening trend is slowing down and that browning clusters have been emerging, especially in the last 2 decades. A collection of model simulations in conjunction with causal theory points at climatic changes as a key driver of vegetation changes in natural ecosystems. Most models underestimate the observed vegetation browning, especially in tropical rainforests, which could be due to an excessive CO2 fertilization effect in models.
Verónica Pancotto, David Holl, Julio Escobar, María Florencia Castagnani, and Lars Kutzbach
Biogeosciences, 18, 4817–4839, https://doi.org/10.5194/bg-18-4817-2021, https://doi.org/10.5194/bg-18-4817-2021, 2021
Short summary
Short summary
We investigated the response of a wetland plant community to elevated temperature conditions in a cushion bog on Tierra del Fuego, Argentina. We measured carbon dioxide fluxes at experimentally warmed plots and at control plots. Warmed plant communities sequestered between 55 % and 85 % less carbon dioxide than untreated control cushions over the main growing season. Our results suggest that even moderate future warming could decrease the carbon sink function of austral cushion bogs.
Léo C. P. Martin, Jan Nitzbon, Johanna Scheer, Kjetil S. Aas, Trond Eiken, Moritz Langer, Simon Filhol, Bernd Etzelmüller, and Sebastian Westermann
The Cryosphere, 15, 3423–3442, https://doi.org/10.5194/tc-15-3423-2021, https://doi.org/10.5194/tc-15-3423-2021, 2021
Short summary
Short summary
It is important to understand how permafrost landscapes respond to climate changes because their thaw can contribute to global warming. We investigate how a common permafrost morphology degrades using both field observations of the surface elevation and numerical modeling. We show that numerical models accounting for topographic changes related to permafrost degradation can reproduce the observed changes in nature and help us understand how parameters such as snow influence this phenomenon.
Juditha Undine Schmidt, Bernd Etzelmüller, Thomas Vikhamar Schuler, Florence Magnin, Julia Boike, Moritz Langer, and Sebastian Westermann
The Cryosphere, 15, 2491–2509, https://doi.org/10.5194/tc-15-2491-2021, https://doi.org/10.5194/tc-15-2491-2021, 2021
Short summary
Short summary
This study presents rock surface temperatures (RSTs) of steep high-Arctic rock walls on Svalbard from 2016 to 2020. The field data show that coastal cliffs are characterized by warmer RSTs than inland locations during winter seasons. By running model simulations, we analyze factors leading to that effect, calculate the surface energy balance and simulate different future scenarios. Both field data and model results can contribute to a further understanding of RST in high-Arctic rock walls.
Thomas Schneider von Deimling, Hanna Lee, Thomas Ingeman-Nielsen, Sebastian Westermann, Vladimir Romanovsky, Scott Lamoureux, Donald A. Walker, Sarah Chadburn, Erin Trochim, Lei Cai, Jan Nitzbon, Stephan Jacobi, and Moritz Langer
The Cryosphere, 15, 2451–2471, https://doi.org/10.5194/tc-15-2451-2021, https://doi.org/10.5194/tc-15-2451-2021, 2021
Short summary
Short summary
Climate warming puts infrastructure built on permafrost at risk of failure. There is a growing need for appropriate model-based risk assessments. Here we present a modelling study and show an exemplary case of how a gravel road in a cold permafrost environment in Alaska might suffer from degrading permafrost under a scenario of intense climate warming. We use this case study to discuss the broader-scale applicability of our model for simulating future Arctic infrastructure failure.
Rebecca Rolph, Pier Paul Overduin, Thomas Ravens, Hugues Lantuit, and Moritz Langer
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2021-28, https://doi.org/10.5194/gmd-2021-28, 2021
Revised manuscript not accepted
Short summary
Short summary
Declining sea ice, larger waves, and increasing air temperatures are contributing to a rapidly eroding Arctic coastline. We simulate water levels using wind speed and direction, which are used with wave height, wave period, and sea surface temperature to drive an erosion model of a partially frozen cliff and beach. This provides a first step to include Arctic erosion in larger-scale earth system models. Simulated cumulative retreat rates agree within the same order of magnitude as observations.
Jan Nitzbon, Moritz Langer, Léo C. P. Martin, Sebastian Westermann, Thomas Schneider von Deimling, and Julia Boike
The Cryosphere, 15, 1399–1422, https://doi.org/10.5194/tc-15-1399-2021, https://doi.org/10.5194/tc-15-1399-2021, 2021
Short summary
Short summary
We used a numerical model to investigate how small-scale landscape heterogeneities affect permafrost thaw under climate-warming scenarios. Our results show that representing small-scale heterogeneities in the model can decide whether a landscape is water-logged or well-drained in the future. This in turn affects how fast permafrost thaws under warming. Our research emphasizes the importance of considering small-scale processes in model assessments of permafrost thaw under climate change.
Philipp de Vrese, Tobias Stacke, Thomas Kleinen, and Victor Brovkin
The Cryosphere, 15, 1097–1130, https://doi.org/10.5194/tc-15-1097-2021, https://doi.org/10.5194/tc-15-1097-2021, 2021
Short summary
Short summary
With large amounts of carbon stored in frozen soils and a highly energy-limited vegetation the Arctic is very sensitive to changes in climate. Here our simulations with the land surface model JSBACH reveal a number of offsetting factors moderating the Arctic's net response to global warming. More importantly we find that the effects of climate change may not be fully reversible on decadal timescales, leading to substantially different CH4 emissions depending on whether the Arctic warms or cools.
Claudia Tebaldi, Kevin Debeire, Veronika Eyring, Erich Fischer, John Fyfe, Pierre Friedlingstein, Reto Knutti, Jason Lowe, Brian O'Neill, Benjamin Sanderson, Detlef van Vuuren, Keywan Riahi, Malte Meinshausen, Zebedee Nicholls, Katarzyna B. Tokarska, George Hurtt, Elmar Kriegler, Jean-Francois Lamarque, Gerald Meehl, Richard Moss, Susanne E. Bauer, Olivier Boucher, Victor Brovkin, Young-Hwa Byun, Martin Dix, Silvio Gualdi, Huan Guo, Jasmin G. John, Slava Kharin, YoungHo Kim, Tsuyoshi Koshiro, Libin Ma, Dirk Olivié, Swapna Panickal, Fangli Qiao, Xinyao Rong, Nan Rosenbloom, Martin Schupfner, Roland Séférian, Alistair Sellar, Tido Semmler, Xiaoying Shi, Zhenya Song, Christian Steger, Ronald Stouffer, Neil Swart, Kaoru Tachiiri, Qi Tang, Hiroaki Tatebe, Aurore Voldoire, Evgeny Volodin, Klaus Wyser, Xiaoge Xin, Shuting Yang, Yongqiang Yu, and Tilo Ziehn
Earth Syst. Dynam., 12, 253–293, https://doi.org/10.5194/esd-12-253-2021, https://doi.org/10.5194/esd-12-253-2021, 2021
Short summary
Short summary
We present an overview of CMIP6 ScenarioMIP outcomes from up to 38 participating ESMs according to the new SSP-based scenarios. Average temperature and precipitation projections according to a wide range of forcings, spanning a wider range than the CMIP5 projections, are documented as global averages and geographic patterns. Times of crossing various warming levels are computed, together with benefits of mitigation for selected pairs of scenarios. Comparisons with CMIP5 are also discussed.
Simone Maria Stuenzi, Julia Boike, William Cable, Ulrike Herzschuh, Stefan Kruse, Luidmila A. Pestryakova, Thomas Schneider von Deimling, Sebastian Westermann, Evgenii S. Zakharov, and Moritz Langer
Biogeosciences, 18, 343–365, https://doi.org/10.5194/bg-18-343-2021, https://doi.org/10.5194/bg-18-343-2021, 2021
Short summary
Short summary
Boreal forests in eastern Siberia are an essential component of global climate patterns. We use a physically based model and field measurements to study the interactions between forests, permanently frozen ground and the atmosphere. We find that forests exert a strong control on the thermal state of permafrost through changing snow cover dynamics and altering the surface energy balance, through absorbing most of the incoming solar radiation and suppressing below-canopy turbulent fluxes.
Zoé Rehder, Anne Laura Niederdrenk, Lars Kaleschke, and Lars Kutzbach
The Cryosphere, 14, 4201–4215, https://doi.org/10.5194/tc-14-4201-2020, https://doi.org/10.5194/tc-14-4201-2020, 2020
Short summary
Short summary
To better understand the connection between sea ice and permafrost, we investigate how sea ice interacts with the atmosphere over the adjacent landmass in the Laptev Sea region using a climate model. Melt of sea ice in spring is mainly controlled by the atmosphere; in fall, feedback mechanisms are important. Throughout summer, lower-than-usual sea ice leads to more southward transport of heat and moisture, but these links from sea ice to the atmosphere over land are weak.
Lena R. Boysen, Victor Brovkin, Julia Pongratz, David M. Lawrence, Peter Lawrence, Nicolas Vuichard, Philippe Peylin, Spencer Liddicoat, Tomohiro Hajima, Yanwu Zhang, Matthias Rocher, Christine Delire, Roland Séférian, Vivek K. Arora, Lars Nieradzik, Peter Anthoni, Wim Thiery, Marysa M. Laguë, Deborah Lawrence, and Min-Hui Lo
Biogeosciences, 17, 5615–5638, https://doi.org/10.5194/bg-17-5615-2020, https://doi.org/10.5194/bg-17-5615-2020, 2020
Short summary
Short summary
We find a biogeophysically induced global cooling with strong carbon losses in a 20 million square kilometre idealized deforestation experiment performed by nine CMIP6 Earth system models. It takes many decades for the temperature signal to emerge, with non-local effects playing an important role. Despite a consistent experimental setup, models diverge substantially in their climate responses. This study offers unprecedented insights for understanding land use change effects in CMIP6 models.
Taraka Davies-Barnard, Johannes Meyerholt, Sönke Zaehle, Pierre Friedlingstein, Victor Brovkin, Yuanchao Fan, Rosie A. Fisher, Chris D. Jones, Hanna Lee, Daniele Peano, Benjamin Smith, David Wårlind, and Andy J. Wiltshire
Biogeosciences, 17, 5129–5148, https://doi.org/10.5194/bg-17-5129-2020, https://doi.org/10.5194/bg-17-5129-2020, 2020
Cited articles
Abnizova, A., Siemens, J., Langer, M., and Boike, J.: Small ponds with major
impact: The relevance of ponds and lakes in permafrost landscapes to carbon
dioxide emissions, Global Biogeochem. Cy., 26, GB2041,
https://doi.org/10.1029/2011GB004237, 2012. a, b
Anderson, L., Birks, J., Rover, J., and Guldager, N.: Controls on recent
Alaskan lake changes identified from water isotopes and remote sensing,
Geophys. Res. Lett., 40, 3413–3418,
https://doi.org/10.1002/grl.50672, 2013. a
Andresen, C. G. and Lougheed, V. L.: Disappearing Arctic tundra ponds:
Fine-scale analysis of surface hydrology in drained thaw lake basins over a
65year period (1948–2013), J. Geophys. Res.-Biogeo.,
120, 466–479, https://doi.org/10.1002/2014jg002778, 2015. a, b, c
Bazhin, N. M.: Gas transport in a residual layer of a water basin, Chemosphere, 3, 33–40, https://doi.org/10.1016/S1465-9972(00)00041-6,
2001. a
Bekryaev, R. V., Polyakov, I. V., and Alexeev, V. A.: Role of Polar
Amplification in Long-Term Surface Air Temperature Variations and Modern
Arctic Warming, J. Climate, 23, 3888–3906,
https://doi.org/10.1175/2010jcli3297.1, 2010. a, b
Bhatt, U. S., Walker, D. A., Raynolds, M. K., Bieniek, P. A., Epstein, H. E.,
Comiso, J. C., Pinzon, J. E., Tucker, C. J., and Polyakov, I. V.: Recent
Declines in Warming and Vegetation Greening Trends over Pan-Arctic Tundra,
Remote Sens., 5, 4229–4254, https://doi.org/10.3390/rs5094229, 2013. a, b, c
Boike, J., Nitzbon, J., Anders, K., Grigoriev, M., Bolshiyanov, D., Langer, M., Lange, S., Bornemann, N., Morgenstern, A., Schreiber, P., Wille, C., Chadburn, S., Gouttevin, I., Burke, E., and Kutzbach, L.: A 16-year record (2002–2017) of permafrost, active-layer, and meteorological conditions at the Samoylov Island Arctic permafrost research site, Lena River delta, northern Siberia: an opportunity to validate remote-sensing data and land surface, snow, and permafrost models, Earth Syst. Sci. Data, 11, 261–299, https://doi.org/10.5194/essd-11-261-2019, 2019. a, b
Bouchard, F., Laurion, I., Prėskienis, V., Fortier, D., Xu, X., and Whiticar, M. J.: Modern to millennium-old greenhouse gases emitted from ponds and lakes of the Eastern Canadian Arctic (Bylot Island, Nunavut), Biogeosciences, 12, 7279–7298, https://doi.org/10.5194/bg-12-7279-2015, 2015. a, b, c, d
Bouchard, F., Fortier, D., Paquette, M., Boucher, V., Pienitz, R., and Laurion, I.: Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic, The Cryosphere, 14, 2607–2627, https://doi.org/10.5194/tc-14-2607-2020, 2020. a
Bring, A., Fedorova, I., Dibike, Y., Hinzman, L., Mard, J., Mernild, S. H.,
Prowse, T., Semenova, O., Stuefer, S. L., and Woo, M. K.: Arctic terrestrial
hydrology: A synthesis of processes, regional effects, and research
challenges, J. Geophys. Res.-Biogeo., 121, 621–649,
https://doi.org/10.1002/2015jg003131, 2016. a, b
Chapman, W. L. and Walsh, J. E.: Recent Variations of Sea Ice and Air
Temperature in High Latitudes, B. Am. Meteorol. Soc., 74, 33–48, https://doi.org/10.1175/1520-0477(1993)074<0033:Rvosia>2.0.Co;2,
1993. a
Christensen, T. R., Johansson, T., Åkerman, H. J., Mastepanov, M., Malmer,
N., Friborg, T., Crill, P., and Svensson, B. H.: Thawing sub-arctic
permafrost: Effects on vegetation and methane emissions, Geophys. Res.
Lett., 31, L04501, https://doi.org/10.1029/2003GL018680, 2004. a, b
Colmer, T. D.: Long-distance transport of gases in plants: a perspective on
internal aeration and radial oxygen loss from roots, Plant, Cell &
Environment, 26, 17–36,
https://doi.org/10.1046/j.1365-3040.2003.00846.x, 2003. a
Cresto Aleina, F., Brovkin, V., Muster, S., Boike, J., Kutzbach, L., Sachs, T., and Zuyev, S.: A stochastic model for the polygonal tundra based on Poisson–Voronoi diagrams, Earth Syst. Dynam., 4, 187–198, https://doi.org/10.5194/esd-4-187-2013, 2013. a, b
Cresto Aleina, F., Runkle, B. R. K., Kleinen, T., Kutzbach, L., Schneider, J., and Brovkin, V.: Modeling micro-topographic controls on boreal peatland hydrology and methane fluxes, Biogeosciences, 12, 5689–5704, https://doi.org/10.5194/bg-12-5689-2015, 2015. a
de Jong, A. E. E., in 't Zandt, M. H., Meisel, O. H., Jetten, M. S. M., Dean,
J. F., Rasigraf, O., and Welte, C. U.: Increases in temperature and nutrient
availability positively affect methane-cycling microorganisms in Arctic
thermokarst lake sediments, Environ. Microbiol., 20, 4314–4327,
https://doi.org/10.1111/1462-2920.14345, 2018. a
Dean, J. F., Meisel, O. H., Martyn Rosco, M., Marchesini, L. B., Garnett,
M. H., Lenderink, H., van Logtestijn, R., Borges, A. V., Bouillon, S.,
Lambert, T., Röckmann, T., Maximov, T., Petrov, R., Karsanaev, S., Aerts,
R., van Huissteden, J., Vonk, J. E., and Dolman, A. J.: East Siberian Arctic
inland waters emit mostly contemporary carbon, Nat. Commun., 11,
1627, https://doi.org/10.1038/s41467-020-15511-6, 2020. a, b, c, d
dos Santos Fonseca, A. L., Marinho, C. C., and de Assis Esteves, F.: Potential
Methane Production Associated with Aquatic Macrophytes Detritus in a Tropical
Coastal Lagoon, Wetlands, 37, 763–771, https://doi.org/10.1007/s13157-017-0912-6,
2017. a
Downing, J. A., Prairie, Y. T., Cole, J. J., Duarte, C. M., Tranvik, L. J.,
Striegl, R. G., McDowell, W. H., Kortelainen, P., Caraco, N. F., Melack,
J. M., and Middelburg, J. J.: The global abundance and size distribution of
lakes, ponds, and impoundments, Limnol. Oceanogr., 51, 2388–2397,
https://doi.org/10.4319/lo.2006.51.5.2388, 2006. a
Elmendorf, S. C., Henry, G. H. R., Hollister, R. D., Björk, R. G.,
Bjorkman, A. D., Callaghan, T. V., Collier, L. S., Cooper, E. J.,
Cornelissen, J. H. C., Day, T. A., Fosaa, A. M., Gould, W. A.,
Grétarsdóttir, J., Harte, J., Hermanutz, L., Hik, D. S., Hofgaard,
A., Jarrad, F., Jónsdóttir, I. S., Keuper, F., Klanderud, K., Klein,
J. A., Koh, S., Kudo, G., Lang, S. I., Loewen, V., May, J. L., Mercado, J.,
Michelsen, A., Molau, U., Myers-Smith, I. H., Oberbauer, S. F., Pieper, S.,
Post, E., Rixen, C., Robinson, C. H., Schmidt, N. M., Shaver, G. R.,
Stenström, A., Tolvanen, A., Totland, Ø., Troxler, T., Wahren, C.-H.,
Webber, P. J., Welker, J. M., and Wookey, P. A.: Global assessment of
experimental climate warming on tundra vegetation: heterogeneity over space
and time, Ecol. Lett., 15, 164–175,
https://doi.org/10.1111/j.1461-0248.2011.01716.x, 2012. a
Euskirchen, E. S., McGuire, A. D., Chapin III, F. S., Yi, S., and Thompson,
C. C.: Changes in vegetation in northern Alaska under scenarios of climate
change, 2003–2100: implications for climate feedbacks, Ecol.
Appl., 19, 1022–1043, https://doi.org/10.1890/08-0806.1, 2009. a, b
Eyring, V., Bony, S., Meehl, G. A., Senior, C. A., Stevens, B., Stouffer, R. J., and Taylor, K. E.: Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization, Geosci. Model Dev., 9, 1937–1958, https://doi.org/10.5194/gmd-9-1937-2016, 2016. a
Gifford, R. M.: Plant respiration in productivity models: conceptualisation,
representation and issues for global terrestrial carbon-cycle research,
Funct. Plant Biol., 30, 171–186, 2003. a
Grünfeld, S. and Brix, H.: Methanogenesis and methane emissions: effects of
water table, substrate type and presence of Phragmites australis, Aquat. Botan., 64, 63–75, https://doi.org/10.1016/S0304-3770(99)00010-8, 1999. a
Heiskanen, J. J., Mammarella, I., Haapanala, S., Pumpanen, J., Vesala, T.,
Macintyre, S., and Ojala, A.: Effects of cooling and internal wave motions on
gas transfer coefficients in a boreal lake, Tellus B, 66, 22827,
https://doi.org/10.3402/tellusb.v66.22827, 2014. a
Helbig, M., Boike, J., Langer, M., Schreiber, P., Runkle, B. R. K., and
Kutzbach, L.: Spatial and seasonal variability of polygonal tundra water
balance: Lena River Delta, northern Siberia (Russia), Hydrogeology Journal,
21, 133–147, https://doi.org/10.1007/s10040-012-0933-4, 2013. a, b, c, d
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A.,
Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D.,
Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P.,
Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D.,
Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer,
A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M.,
Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P.,
Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global
reanalysis, Q. J. Roy. Meteor. Soc., 146,
1999–2049, https://doi.org/10.1002/qj.3803, 2020. a
Holgerson, M. A. and Raymond, P. A.: Large contribution to inland water CO2 and
CH4 emissions from very small ponds, Nat. Geosci., 9, 222–226,
https://doi.org/10.1038/ngeo2654, 2016. a, b
Hughes-Allen, L., Bouchard, F., Laurion, I., Séjourné, A., Marlin, C.,
Hatté, C., Costard, F., Fedorov, A., and Desyatkin, A.: Seasonal patterns
in greenhouse gas emissions from thermokarst lakes in Central Yakutia
(Eastern Siberia), Limnol. Oceanogr., 66, 98–116,
https://doi.org/10.1002/lno.11665, 2021. a
Jansen, J., Thornton, B. F., Cortés, A., Snöälv, J., Wik, M., MacIntyre, S., and Crill, P. M.: Drivers of diffusive CH4 emissions from shallow subarctic lakes on daily to multi-year timescales, Biogeosciences, 17, 1911–1932, https://doi.org/10.5194/bg-17-1911-2020, 2020. a
Jansen, J., Woolway, R. I., Kraemer, B. M., Albergel, C., Bastviken, D.,
Weyhenmeyer, G. A., Marcé, R., Sharma, S., Sobek, S., Tranvik, L. J.,
Perroud, M., Golub, M., Moore, T. N., Råman Vinnå, L., La Fuente, S.,
Grant, L., Pierson, D. C., Thiery, W., and Jennings, E.: Global increase in
methane production under future warming of lake bottom waters, Global Change Biol., 28, 5427–5440, https://doi.org/10.1111/gcb.16298, 2022. a, b
Jepsen, S. M., Voss, C. I., Walvoord, M. A., Rose, J. R., Minsley, B. J., and
Smith, B. D.: Sensitivity analysis of lake mass balance in discontinuous
permafrost: the example of disappearing Twelvemile Lake, Yukon Flats, Alaska
(USA), Hydrogeol. J., 21, 185–200, https://doi.org/10.1007/s10040-012-0896-5,
2013. a
Joabsson, A., Christensen, T. R., and Wallén, B.: Vascular plant controls
on methane emissions from northern peatforming wetlands, Trend. Ecol. Evol., 14, 385–388, https://doi.org/10.1016/S0169-5347(99)01649-3,
1999. a, b
Jones, B. M., Grosse, G., Farquharson, L. M., Roy-Léveillée, P.,
Veremeeva, A., Kanevskiy, M. Z., Gaglioti, B. V., Breen, A. L., Parsekian,
A. D., Ulrich, M., and Hinkel, K. M.: Lake and drained lake basin systems in
lowland permafrost regions, Nat. Rev. Earth Environ., 3, 85–98,
https://doi.org/10.1038/s43017-021-00238-9, 2022. a
Jorgenson, M. T., Shur, Y. L., and Pullman, E. R.: Abrupt increase in
permafrost degradation in Arctic Alaska, Geophys. Res. Lett., 33, L02503,
https://doi.org/10.1029/2005GL024960, 2006. a
Jorgenson, M. T., Kanevskiy, M., Shur, Y., Moskalenko, N., Brown, D. R. N.,
Wickland, K., Striegl, R., and Koch, J.: Role of ground ice dynamics and
ecological feedbacks in recent ice wedge degradation and stabilization,
J. Geophys. Res.-Ea., 120, 2280–2297,
https://doi.org/10.1002/2015JF003602, 2015. a, b
Juhls, B., Antonova, S., Angelopoulos, M., Bobrov, N., Grigoriev, M., Langer,
M., Maksimov, G., Miesner, F., and Overduin, P. P.: Serpentine (Floating) Ice
Channels and their Interaction with Riverbed Permafrost in the Lena River
Delta, Russia, Front. Earth Sci., 9, 689941,
https://doi.org/10.3389/feart.2021.689941, 2021. a
Juutinen, S., Alm, J., Larmola, T., Huttunen, J. T., Morero, M., Martikainen,
P. J., and Silvola, J.: Major implication of the littoral zone for methane
release from boreal lakes, Global Biogeochem. Cy., 17, 1117,
https://doi.org/10.1029/2003GB002105, 2003. a
Juutinen, S., Rantakari, M., Kortelainen, P., Huttunen, J. T., Larmola, T., Alm, J., Silvola, J., and Martikainen, P. J.: Methane dynamics in different boreal lake types, Biogeosciences, 6, 209–223, https://doi.org/10.5194/bg-6-209-2009, 2009. a
Kartoziia, A.: Assessment of the Ice Wedge Polygon Current State by Means of
UAV Imagery Analysis (Samoylov Island, the Lena Delta), Remote Sens., 11, 1627,
https://doi.org/10.3390/rs11131627,
2019. a
Kim, Y.: Effect of thaw depth on fluxes of CO2 and CH4 in manipulated Arctic
coastal tundra of Barrow, Alaska, Sci. Total Environ., 505,
385–389, https://doi.org/10.1016/j.scitotenv.2014.09.046, 2015. a, b
Knoblauch, C., Spott, O., Evgrafova, S., Kutzbach, L., and Pfeiffer, E. M.:
Regulation of methane production, oxidation, and emission by vascular plants
and bryophytes in ponds of the northeast Siberian polygonal tundra, J. Geophys. Res.-Biogeo., 120, 2525–2541,
https://doi.org/10.1002/2015jg003053, 2015. a, b, c, d, e, f, g, h, i
Kuhn, M., Lundin, E. J., Giesler, R., Johansson, M., and Karlsson, J.:
Emissions from thaw ponds largely offset the carbon sink of northern
permafrost wetlands, Sci. Rep., 8, 1–7, 2018. a
Kuhn, M. A., Varner, R. K., Bastviken, D., Crill, P., MacIntyre, S., Turetsky, M., Walter Anthony, K., McGuire, A. D., and Olefeldt, D.: BAWLD-CH4: a comprehensive dataset of methane fluxes from boreal and arctic ecosystems, Earth Syst. Sci. Data, 13, 5151–5189, https://doi.org/10.5194/essd-13-5151-2021, 2021. a, b, c, d
Kutzbach, L., Wagner, D., and Pfeiffer, E. M.: Effect of microrelief and
vegetation on methane emission from wet polygonal tundra, Lena Delta,
Northern Siberia, Biogeochemistry, 69, 341–362, https://doi.org/10.1023/B:BIOG.0000031053.81520.db, 2004. a
Langer, M., Westermann, S., Walter Anthony, K., Wischnewski, K., and Boike, J.: Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta, Biogeosciences, 12, 977–990, https://doi.org/10.5194/bg-12-977-2015, 2015. a, b, c
Langer, M., Westermann, S., Boike, J., Kirillin, G., Grosse, G., Peng, S., and
Krinner, G.: Rapid degradation of permafrost underneath waterbodies in tundra
landscapes-Toward a representation of thermokarst in land surface models,
J. Geophys. Res.-Ea., 121, 2446–2470,
https://doi.org/10.1002/2016jf003956, 2016. a
Langer, M., Nitzbon, J., Groenke, B., Assmann, L.-M., Schneider von Deimling, T., Stuenzi, S. M., and Westermann, S.: The evolution of Arctic permafrost over the last three centuries, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2022-473, 2022. a
Lara, M. J., Lin, D. H., Andresen, C., Lougheed, V. L., and Tweedie, C. E.:
Nutrient Release From Permafrost Thaw Enhances CH4 Emissions From Arctic
Tundra Wetlands, J. Geophys. Res.-Biogeo., 124,
1560–1573, https://doi.org/10.1029/2018JG004641, 2019. a, b, c, d
Liebner, S., Zeyer, J., Wagner, D., Schubert, C., Pfeiffer, E.-M., and
Knoblauch, C.: Methane oxidation associated with submerged brown mosses
reduces methane emissions from Siberian polygonal tundra, J. Ecol.,
99, 914–922, https://doi.org/10.1111/j.1365-2745.2011.01823.x, 2011. a
Liljedahl, A. K., Boike, J., Daanen, R. P., Fedorov, A. N., Frost, G. V.,
Grosse, G., Hinzman, L. D., Iijma, Y., Jorgenson, J. C., Matveyeva, N.,
Necsoiu, M., Raynolds, M. K., Romanovsky, V. E., Schulla, J., Tape, K. D.,
Walker, D. A., Wilson, C. J., Yabuki, H., and Zona, D.: Pan-Arctic ice-wedge
degradation in warming permafrost and its influence on tundra hydrology,
Nat. Geosci., 9, 312–318, https://doi.org/10.1038/ngeo2674, 2016. a, b
Martinez-Cruz, K., Sepulveda-Jauregui, A., Walter Anthony, K., and Thalasso, F.: Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes, Biogeosciences, 12, 4595–4606, https://doi.org/10.5194/bg-12-4595-2015, 2015. a
Mauritsen, T., Bader, J., Becker, T., Behrens, J., Bittner, M., Brokopf, R.,
Brovkin, V., Claussen, M., Crueger, T., Esch, M., Fast, I., Fiedler, S.,
Fläschner, D., Gayler, V., Giorgetta, M., Goll, D. S., Haak, H., Hagemann,
S., Hedemann, C., Hohenegger, C., Ilyina, T., Jahns, T., Jimenéz-de-la
Cuesta, D., Jungclaus, J., Kleinen, T., Kloster, S., Kracher, D., Kinne, S.,
Kleberg, D., Lasslop, G., Kornblueh, L., Marotzke, J., Matei, D., Meraner,
K., Mikolajewicz, U., Modali, K., Möbis, B., Müller, W. A., Nabel, J. E.
M. S., Nam, C. C. W., Notz, D., Nyawira, S.-S., Paulsen, H., Peters, K.,
Pincus, R., Pohlmann, H., Pongratz, J., Popp, M., Raddatz, T. J., Rast, S.,
Redler, R., Reick, C. H., Rohrschneider, T., Schemann, V., Schmidt, H.,
Schnur, R., Schulzweida, U., Six, K. D., Stein, L., Stemmler, I., Stevens,
B., von Storch, J.-S., Tian, F., Voigt, A., Vrese, P., Wieners, K.-H.,
Wilkenskjeld, S., Winkler, A., and Roeckner, E.: Developments in the MPI-M
Earth System Model version 1.2 (MPI-ESM1.2) and Its Response to Increasing
CO2, J. Adv. Model. Earth Syst., 11, 998–1038,
https://doi.org/10.1029/2018MS001400, 2019. a
Minayeva, T., Sirin, A., Kershaw, P., and Bragg, O.: Arctic Peatlands,
1–15, Springer, Dordrecht, https://doi.org/10.1007/978-94-007-6173-5_109-2, 2016. a
Miner, K. R., Turetsky, M. R., Malina, E., Bartsch, A., Tamminen, J., McGuire,
A. D., Fix, A., Sweeney, C., Elder, C. D., and Miller, C. E.: Permafrost
carbon emissions in a changing Arctic, Nat. Rev. Earth Environ.,
3, 55–67, https://doi.org/10.1038/s43017-021-00230-3, 2022. a
Minke, M., Donner, N., Karpov, N. S., de Klerk, P., and Joosten, H.:
Distribution, diversity, development and dynamics of polygon mires: examples
from Northeast Yakutia (Siberia), International Peatland Society, 36–40,
2007. a
Mirbach, C., Rehder, Z., Kutzbach, L., and Boike, J.: Land cover and polygonal
pond classification of the Holocene Terrace on Samoylov Island, PANGAEA,
https://doi.org/10.1594/PANGAEA.944071, 2022. a, b
Mironov, D. V.: Parameterization of Lakes in Numerical Weather Prediction. Part
1: Description of a Lake Model, Report, German Weather Service, COSMO Technical Report, No. 11 2005. a
Muster, S., Langer, M., Heim, B., Westermann, S., and Boike, J.: Subpixel
heterogeneity of ice-wedge polygonal tundra: a multi-scale analysis of land
cover and evapotranspiration in the Lena River Delta, Siberia, Tellus
B, 64, 17301, https://doi.org/10.3402/tellusb.v64i0.17301,
2012. a
Muster, S., Roth, K., Langer, M., Lange, S., Cresto Aleina, F., Bartsch, A., Morgenstern, A., Grosse, G., Jones, B., Sannel, A. B. K., Sjöberg, Y., Günther, F., Andresen, C., Veremeeva, A., Lindgren, P. R., Bouchard, F., Lara, M. J., Fortier, D., Charbonneau, S., Virtanen, T. A., Hugelius, G., Palmtag, J., Siewert, M. B., Riley, W. J., Koven, C. D., and Boike, J.: PeRL: a circum-Arctic Permafrost Region Pond and Lake database, Earth Syst. Sci. Data, 9, 317–348, https://doi.org/10.5194/essd-9-317-2017, 2017. a
Muster, S., Riley, W. J., Roth, K., Langer, M., Cresto Aleina, F., Koven,
C. D., Lange, S., Bartsch, A., Grosse, G., Wilson, C. J., Jones, B. M., and
Boike, J.: Size Distributions of Arctic Waterbodies Reveal Consistent
Relations in Their Statistical Moments in Space and Time, Front. Earth
Sci., 7, https://doi.org/10.3389/feart.2019.00005, 2019. a
Myneni, R., Knyazikhin, Y., and Park, T.: MOD15A2H MODIS/Terra Leaf Area
Index/FAPAR 8-Day L4 Global 500 m SIN Grid V006, NASA EOSDIS Land Processes
DAAC, distributed by the Land Processes Distributed Active Archive Center
(LP DAAC), located at the U.S. Geological Survey (USGS) Earth Resources
Observation and Science (EROS) Center, provided with
de-coded quality flags and per grid cell latitude/longitude information in
netCDF format by the Integrated Climate Data Center (ICDC), CEN, University
of Hamburg, Germany, https://doi.org/10.5067/MODIS/MOD15A2H.006, 2015. a, b
Negandhi, K., Laurion, I., Whiticar, M. J., Galand, P. E., Xu, X. M., and
Lovejoy, C.: Small Thaw Ponds: An Unaccounted Source of Methane in the
Canadian High Arctic, Plos One, 8, e78204,
https://doi.org/10.1371/journal.pone.0078204, 2013. a, b, c
Nitzbon, J., Langer, M., Westermann, S., Martin, L., Aas, K. S., and Boike, J.: Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions, The Cryosphere, 13, 1089–1123, https://doi.org/10.5194/tc-13-1089-2019, 2019. a
Polishchuk, Y. M., Bogdanov, A. N., Muratov, I. N., Polishchuk, V. Y., Lim, A.,
Manasypov, R. M., Shirokova, L. S., and Pokrovsky, O. S.: Minor contribution
of small thaw ponds to the pools of carbon and methane in the inland waters
of the permafrost-affected part of the Western Siberian Lowland,
Environ. Res. Lett., 13, 045002, https://doi.org/10.1088/1748-9326/aab046, 2018. a, b
Praetzel, L. S. E., Schmiedeskamp, M., and Knorr, K.-H.: Temperature and
sediment properties drive spatiotemporal variability of methane ebullition in
a small and shallow temperate lake, Limnol. Oceanogr., 66,
2598–2610, https://doi.org/10.1002/lno.11775, 2021. a
Prėskienis, V., Laurion, I., Bouchard, F., Douglas, P. M. J., Billett,
M. F., Fortier, D., and Xu, X.: Seasonal patterns in greenhouse gas emissions
from lakes and ponds in a High Arctic polygonal landscape, Limnol. Oceanogr., 66, 117–141, https://doi.org/10.1002/lno.11660, 2021. a, b, c, d
Ramsar Convention Secretariat: An introduction to the ramsar convention on
wetlands (previously The Ramsar Convention Manual), Ramsar Convention
Secretariat, Gland, Switzerland, 2016. a
Rantanen, M., Karpechko, A. Y., Lipponen, A., Nordling, K., Hyvärinen, O.,
Ruosteenoja, K., Vihma, T., and Laaksonen, A.: The Arctic has warmed nearly
four times faster than the globe since 1979, Commun. Earth Environ., 3, 168, https://doi.org/10.1038/s43247-022-00498-3, 2022. a, b
Rehder, Z., Kleinen, T., Kutzbach, L., Stepanenko, V., Langer, M., and Brovkin, V.: Methane Emissions from Ponds (MeEP) model in setup for the polygonal tundra in the Lena River Delta (1.0), Zenodo [data set], https://doi.org/10.5281/zenodo.7912973, 2023a. a
Rehder, Z., Kleinen, T., Kutzbach, L., Stepanenko, V., Langer, M., and Brovkin, V.:
Supplemental Material for “Simulated methane emissions from Arctic ponds are highly
sensitive to warming”, https://hdl.handle.net/21.11116/0000-000D-3868-0, last access: 12 July 2023. a
Riordan, B., Verbyla, D., and McGuire, A. D.: Shrinking ponds in subarctic
Alaska based on 1950–2002 remotely sensed images, J. Geophys. Res.-Biogeo., 111, G04002, https://doi.org/10.1029/2005JG000150,
2006. a, b
Sabrekov, A. F., Runkle, B. R. K., Glagolev, M. V., Terentieva, I. E., Stepanenko, V. M., Kotsyurbenko, O. R., Maksyutov, S. S., and Pokrovsky, O. S.: Variability in methane emissions from West Siberia's shallow boreal lakes on a regional scale and its environmental controls, Biogeosciences, 14, 3715–3742, https://doi.org/10.5194/bg-14-3715-2017, 2017. a, b
Sepulveda-Jauregui, A., Walter Anthony, K. M., Martinez-Cruz, K., Greene, S., and Thalasso, F.: Methane and carbon dioxide emissions from 40 lakes along a north–south latitudinal transect in Alaska, Biogeosciences, 12, 3197–3223, https://doi.org/10.5194/bg-12-3197-2015, 2015. a, b
Smith, L. C., Sheng, Y., MacDonald, G. M., and Hinzman, L. D.: Disappearing
Arctic Lakes, Science, 308, 1429–1429, https://doi.org/10.1126/science.1108142,
2005. a
Stepanenko, V. M., Machul'skaya, E. E., Glagolev, M. V., and Lykossov, V. N.:
Numerical Modeling of Methane Emissions from Lakes in the Permafrost Zone,
Izvest. Atmos. Ocean. Phys., 47, 252–264,
https://doi.org/10.1134/S0001433811020113, 2011. a, b, c
Stow, D. A., Hope, A., McGuire, D., Verbyla, D., Gamon, J., Huemmrich, F.,
Houston, S., Racine, C., Sturm, M., Tape, K., Hinzman, L., Yoshikawa, K.,
Tweedie, C., Noyle, B., Silapaswan, C., Douglas, D., Griffith, B., Jia, G.,
Epstein, H., Walker, D., Daeschner, S., Petersen, A., Zhou, L., and Myneni,
R.: Remote sensing of vegetation and land-cover change in Arctic Tundra
Ecosystems, Remote Sens. Environ., 89, 281–308,
https://doi.org/10.1016/j.rse.2003.10.018, 2004. a
Ström, L., Ekberg, A., Mastepanov, M., and Røjle Christensen, T.: The
effect of vascular plants on carbon turnover and methane emissions from a
tundra wetland, Global Change Biol., 9, 1185–1192,
https://doi.org/10.1046/j.1365-2486.2003.00655.x, 2003. a
Ström, L., Mastepanov, M., and Christensen, T. R.: Species-specific Effects
of Vascular Plants on Carbon Turnover and Methane Emissions from Wetlands,
Biogeochemistry, 75, 65–82, https://doi.org/10.1007/s10533-004-6124-1, 2005. a, b
Ström, L., Tagesson, T., Mastepanov, M., and Christensen, T. R.: Presence
of Eriophorum scheuchzeri enhances substrate availability and methane
emission in an Arctic wetland, Soil Biol. Biochem., 45, 61–70,
https://doi.org/10.1016/j.soilbio.2011.09.005, 2012. a, b
Swaminathan, C. R. and Voller, V. R.: A general enthalpy method for modeling
solidification processes, Metall. Trans. B, 23, 651–664,
https://doi.org/10.1007/BF02649725, 1992. a
Turner, J. C., Moorberg, C. J., Wong, A., Shea, K., Waldrop, M. P., Turetsky,
M. R., and Neumann, R. B.: Getting to the Root of Plant-Mediated Methane
Emissions and Oxidation in a Thermokarst Bog, J. Geophys. Res.-Biogeo., 125, e2020JG005825,
https://doi.org/10.1029/2020JG005825, 2020. a, b
van Huissteden, J., Berrittella, C., Parmentier, F. J. W., Mi, Y., Maximov,
T. C., and Dolman, A. J.: Methane emissions from permafrost thaw lakes
limited by lake drainage, Nat. Clim. Change, 1, 119–123,
https://doi.org/10.1038/nclimate1101, 2011. a
Villarreal, S., Hollister, R. D., Johnson, D. R., Lara, M. J., Webber, P. J.,
and Tweedie, C. E.: Tundra vegetation change near Barrow, Alaska
(1972–2010), Environ. Res. Lett., 7, 015508,
https://doi.org/10.1088/1748-9326/7/1/015508, 2012. a, b, c
Vizza, C., West, W. E., Jones, S. E., Hart, J. A., and Lamberti, G. A.: Regulators of coastal wetland methane production and responses to simulated global change, Biogeosciences, 14, 431–446, https://doi.org/10.5194/bg-14-431-2017, 2017. a
Walter, B. P. and Heimann, M.: A process-based, climate-sensitive model to
derive methane emissions from natural wetlands: Application to five wetland
sites, sensitivity to model parameters, and climate, Global Biogeochem. Cy., 14, 745–765, https://doi.org/10.1029/1999GB001204, 2000. a, b
Walter, B. P., Heimann, M., Shannon, R. D., and White, J. R.: A process-based
model to derive methane emissions from natural wetlands, Geophys. Res. Lett., 23, 3731–3734, https://doi.org/10.1029/96gl03577, 1996. a
Walter, B. P., Heimann, M., and Matthews, E.: Modeling modern methane emissions
from natural wetlands 1. Model description and results, J.
Geophys. Res.-Atmos., 106, 34189–34206,
https://doi.org/10.1029/2001JD900165, 2001. a, b
Walz, J., Knoblauch, C., Böhme, L., and Pfeiffer, E.-M.: Regulation of soil
organic matter decomposition in permafrost-affected Siberian tundra soils -
Impact of oxygen availability, freezing and thawing, temperature, and labile
organic matter, Soil Biol. Biochem., 110, 34–43,
https://doi.org/10.1016/j.soilbio.2017.03.001, 2017. a, b, c, d
Waring, R., Landsberg, J., and Williams, M.: Net primary production of forests:
A constant fraction of gross primary production?, Tree Physiol., 18,
129–134, https://doi.org/10.1093/treephys/18.2.129, 1998. a
Whiting, G. J. and Chanton, J. P.: Plant-dependent CH4 emission in a subarctic
Canadian fen, Global Biogeochem. Cy., 6, 225–231,
https://doi.org/10.1029/92GB00710, 1992. a, b, c
Wickland, K. P., Jorgenson, M. T., Koch, J. C., Kanevskiy, M., and Striegl,
R. G.: Carbon Dioxide and Methane Flux in a Dynamic Arctic Tundra Landscape:
Decadal-Scale Impacts of Ice Wedge Degradation and Stabilization, Geophys.
Res. Lett., 47, e2020GL089894,
https://doi.org/10.1029/2020GL089894, 2020. a, b
Wieners, K.-H., Giorgetta, M., Jungclaus, J., Reick, C., Esch, M., Bittner, M.,
Legutke, S., Schupfner, M., Wachsmann, F., Gayler, V., Haak, H., de Vrese,
P., Raddatz, T., Mauritsen, T., von Storch, J.-S., Behrens, J., Brovkin, V.,
Claussen, M., Crueger, T., Fast, I., Fiedler, S., Hagemann, S., Hohenegger,
C., Jahns, T., Kloster, S., Kinne, S., Lasslop, G., Kornblueh, L., Marotzke,
J., Matei, D., Meraner, K., Mikolajewicz, U., Modali, K., Müller, W.,
Nabel, J., Notz, D., Peters-von Gehlen, K., Pincus, R., Pohlmann, H.,
Pongratz, J., Rast, S., Schmidt, H., Schnur, R., Schulzweida, U., Six, K.,
Stevens, B., Voigt, A., and Roeckner, E.: MPI-M MPI-ESM1.2-LR model output
prepared for CMIP6 CMIP 1pctCO2, https://doi.org/10.22033/ESGF/CMIP6.6435, 2019. a
Wik, M., Varner, R. K., Anthony, K. W., MacIntyre, S., and Bastviken, D.:
Climate-sensitive northern lakes and ponds are critical components of methane
release, Nat. Geosci., 9, 99–105, https://doi.org/10.1038/ngeo2578, 2016. a, b, c, d
Wille, C., Kutzbach, L., Sachs, T., Wagner, D., and Pfeiffer, E.-M.: Methane
emission from Siberian arctic polygonal tundra: eddy covariance measurements
and modeling, Global Change Biol., 14, 1395–1408,
https://doi.org/10.1111/j.1365-2486.2008.01586.x, 2008. a, b, c
Winkler, A. J., Myneni, R. B., Hannart, A., Sitch, S., Haverd, V., Lombardozzi, D., Arora, V. K., Pongratz, J., Nabel, J. E. M. S., Goll, D. S., Kato, E., Tian, H., Arneth, A., Friedlingstein, P., Jain, A. K., Zaehle, S., and Brovkin, V.: Slowdown of the greening trend in natural vegetation with further rise in atmospheric CO2, Biogeosciences, 18, 4985–5010, https://doi.org/10.5194/bg-18-4985-2021, 2021. a, b
Wrona, F. J., Johansson, M., Culp, J. M., Jenkins, A., Mård, J.,
Myers-Smith, I. H., Prowse, T. D., Vincent, W. F., and Wookey, P. A.:
Transitions in Arctic ecosystems: Ecological implications of a changing
hydrological regime, J. Geophys. Res.-Biogeo., 121,
650–674, https://doi.org/10.1002/2015JG003133, 2016. a, b
Yoshikawa, K. and Hinzman, L. D.: Shrinking thermokarst ponds and groundwater
dynamics in discontinuous permafrost near council, Alaska, Permafrost
Periglac. Proc., 14, 151–160, https://doi.org/10.1002/ppp.451,
2003.
a
Zabelina, S. A., Shirokova, L. S., Klimov, S. I., Chupakov, A. V., Lim, A. G.,
Polishchuk, Y. M., Polishchuk, V. Y., Bogdanov, A. N., Muratov, I. N.,
Guerin, F., Karlsson, J., and Pokrovsky, O. S.: Carbon emission from
thermokarst lakes in NE European tundra, Limnol. Oceanogr., 66,
216–230, https://doi.org/10.1002/lno.11560, 2020. a
Zhu, Y., Purdy, K. J., Eyice, Ö., Shen, L., Harpenslager, S. F.,
Yvon-Durocher, G., Dumbrell, A. J., and Trimmer, M.: Disproportionate
increase in freshwater methane emissions induced by experimental warming,
Nat. Clim. Change, 10, 685–690, https://doi.org/10.1038/s41558-020-0824-y, 2020. a, b
Zubrzycki, S., Kutzbach, L., Grosse, G., Desyatkin, A., and Pfeiffer, E.-M.: Organic carbon and total nitrogen stocks in soils of the Lena River Delta, Biogeosciences, 10, 3507–3524, https://doi.org/10.5194/bg-10-3507-2013, 2013. a, b, c, d
Short summary
We use a new model to investigate how methane emissions from Arctic ponds change with warming. We find that emissions increase substantially. Under annual temperatures 5 °C above present temperatures, pond methane emissions are more than 3 times higher than now. Most of this increase is caused by an increase in plant productivity as plants provide the substrate microbes used to produce methane. We conclude that vegetation changes need to be included in predictions of pond methane emissions.
We use a new model to investigate how methane emissions from Arctic ponds change with warming....
Altmetrics
Final-revised paper
Preprint