Articles | Volume 20, issue 2
https://doi.org/10.5194/tc-20-1001-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-20-1001-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Forest disturbances and their impact on ground surface temperatures in permafrost-underlain forest in central Mongolia
Department of Geosciences, University of Oslo, Oslo, 0371, Norway
Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo, 0371, Norway
Dashtseren Avirmed
Institute of Geography and Geoecology, Mongolian Academy of Sciences, Ulaanbaatar, 15170, Mongolia
UNESCO Chair of Environmental Sciences in Eastern Central Asia, Mongolian Academy of Sciences, Ulaanbaatar, 15170, Mongolia
Khurelbaatar Temuujin
Institute of Geography and Geoecology, Mongolian Academy of Sciences, Ulaanbaatar, 15170, Mongolia
Clare Webster
Department of Geosciences, University of Oslo, Oslo, 0371, Norway
Department of Geography, University of Zurich, 8057 Zürich, Switzerland
Hanna Lee
Department of Biology, Norwegian University of Science and Technology, Trondheim, 7419, Norway
Sebastian Westermann
Department of Geosciences, University of Oslo, Oslo, 0371, Norway
Centre for Biogeochemistry in the Anthropocene, University of Oslo, Oslo, 0371, Norway
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Ruben Van Daele, Hanna Lee, Inge Althuizen, and Martijn L. Vandegehuchte
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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
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Fang Li, Xiang Song, Sandy P. Harrison, Jennifer R. Marlon, Zhongda Lin, L. Ruby Leung, Jörg Schwinger, Virginie Marécal, Shiyu Wang, Daniel S. Ward, Xiao Dong, Hanna Lee, Lars Nieradzik, Sam S. Rabin, and Roland Séférian
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Robin Benjamin Zweigel, Avirmed Dashtseren, Khurelbaatar Temuujin, Anarmaa Sharkhuu, Clare Webster, Hanna Lee, and Sebastian Westermann
Biogeosciences, 21, 5059–5077, https://doi.org/10.5194/bg-21-5059-2024, https://doi.org/10.5194/bg-21-5059-2024, 2024
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Sigrid Trier Kjær, Sebastian Westermann, Nora Nedkvitne, and Peter Dörsch
Biogeosciences, 21, 4723–4737, https://doi.org/10.5194/bg-21-4723-2024, https://doi.org/10.5194/bg-21-4723-2024, 2024
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Juditha Aga, Livia Piermattei, Luc Girod, Kristoffer Aalstad, Trond Eiken, Andreas Kääb, and Sebastian Westermann
Earth Surf. Dynam., 12, 1049–1070, https://doi.org/10.5194/esurf-12-1049-2024, https://doi.org/10.5194/esurf-12-1049-2024, 2024
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Coastal rock cliffs on Svalbard are considered to be fairly stable; however, long-term trends in coastal-retreat rates remain unknown. This study examines changes in the coastline position along Brøggerhalvøya, Svalbard, using aerial images from 1970, 1990, 2010, and 2021. Our analysis shows that coastal-retreat rates accelerate during the period 2010–2021, which coincides with increasing storminess and retreating sea ice.
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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
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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.
Ali Asaadi, Jörg Schwinger, Hanna Lee, Jerry Tjiputra, Vivek Arora, Roland Séférian, Spencer Liddicoat, Tomohiro Hajima, Yeray Santana-Falcón, and Chris D. Jones
Biogeosciences, 21, 411–435, https://doi.org/10.5194/bg-21-411-2024, https://doi.org/10.5194/bg-21-411-2024, 2024
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Carbon cycle feedback metrics are employed to assess phases of positive and negative CO2 emissions. When emissions become negative, we find that the model disagreement in feedback metrics increases more strongly than expected from the assumption that the uncertainties accumulate linearly with time. The geographical patterns of such metrics over land highlight that differences in response between tropical/subtropical and temperate/boreal ecosystems are a major source of model disagreement.
Bernd Etzelmüller, Ketil Isaksen, Justyna Czekirda, Sebastian Westermann, Christin Hilbich, and Christian Hauck
The Cryosphere, 17, 5477–5497, https://doi.org/10.5194/tc-17-5477-2023, https://doi.org/10.5194/tc-17-5477-2023, 2023
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Permafrost (permanently frozen ground) is widespread in the mountains of Norway and Iceland. Several boreholes were drilled after 1999 for long-term permafrost monitoring. We document a strong warming of permafrost, including the development of unfrozen bodies in the permafrost. Warming and degradation of mountain permafrost may lead to more natural hazards.
Esteban Alonso-González, Kristoffer Aalstad, Norbert Pirk, Marco Mazzolini, Désirée Treichler, Paul Leclercq, Sebastian Westermann, Juan Ignacio López-Moreno, and Simon Gascoin
Hydrol. Earth Syst. Sci., 27, 4637–4659, https://doi.org/10.5194/hess-27-4637-2023, https://doi.org/10.5194/hess-27-4637-2023, 2023
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Here we explore how to improve hyper-resolution (5 m) distributed snowpack simulations using sparse observations, which do not provide information from all the areas of the simulation domain. We propose a new way of propagating information throughout the simulations adapted to the hyper-resolution, which could also be used to improve simulations of other nature. The method has been implemented in an open-source data assimilation tool that is readily accessible to everyone.
Anatoly O. Sinitsyn, Sara Bazin, Rasmus Benestad, Bernd Etzelmüller, Ketil Isaksen, Hanne Kvitsand, Julia Lutz, Andrea L. Popp, Lena Rubensdotter, and Sebastian Westermann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2950, https://doi.org/10.5194/egusphere-2023-2950, 2023
Preprint archived
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This study looked at under the ground on Svalbard, an archipelago close to the North Pole. We found something very surprising – there is water under the all year around frozen soil. This was not known before. This water could be used for drinking if we manage it carefully. This is important because getting clean drinking water is very difficult in Svalbard, and other Arctic places. Also, because the climate is getting warmer, there might be even more water underground in the future.
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
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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
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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.
Matan Ben-Asher, Florence Magnin, Sebastian Westermann, Josué Bock, Emmanuel Malet, Johan Berthet, Ludovic Ravanel, and Philip Deline
Earth Surf. Dynam., 11, 899–915, https://doi.org/10.5194/esurf-11-899-2023, https://doi.org/10.5194/esurf-11-899-2023, 2023
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Quantitative knowledge of water availability on high mountain rock slopes is very limited. We use a numerical model and field measurements to estimate the water balance at a steep rock wall site. We show that snowmelt is the main source of water at elevations >3600 m and that snowpack hydrology and sublimation are key factors. The new information presented here can be used to improve the understanding of thermal, hydrogeological, and mechanical processes on steep mountain rock slopes.
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
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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.
Louise Steffensen Schmidt, Thomas Vikhamar Schuler, Erin Emily Thomas, and Sebastian Westermann
The Cryosphere, 17, 2941–2963, https://doi.org/10.5194/tc-17-2941-2023, https://doi.org/10.5194/tc-17-2941-2023, 2023
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Here, we present high-resolution simulations of glacier mass balance (the gain and loss of ice over a year) and runoff on Svalbard from 1991–2022, one of the fastest warming regions in the Arctic. The simulations are created using the CryoGrid community model. We find a small overall loss of mass over the simulation period of −0.08 m yr−1 but with no statistically significant trend. The average runoff was found to be 41 Gt yr−1, with a significant increasing trend of 6.3 Gt per decade.
Justyna Czekirda, Bernd Etzelmüller, Sebastian Westermann, Ketil Isaksen, and Florence Magnin
The Cryosphere, 17, 2725–2754, https://doi.org/10.5194/tc-17-2725-2023, https://doi.org/10.5194/tc-17-2725-2023, 2023
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We assess spatio-temporal permafrost variations in selected rock walls in Norway over the last 120 years. Ground temperature is modelled using the two-dimensional ground heat flux model CryoGrid 2D along nine profiles. Permafrost probably occurs at most sites. All simulations show increasing ground temperature from the 1980s. Our simulations show that rock wall permafrost with a temperature of −1 °C at 20 m depth could thaw at this depth within 50 years.
Norbert Pirk, Kristoffer Aalstad, Yeliz A. Yilmaz, Astrid Vatne, Andrea L. Popp, Peter Horvath, Anders Bryn, Ane Victoria Vollsnes, Sebastian Westermann, Terje Koren Berntsen, Frode Stordal, and Lena Merete Tallaksen
Biogeosciences, 20, 2031–2047, https://doi.org/10.5194/bg-20-2031-2023, https://doi.org/10.5194/bg-20-2031-2023, 2023
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We measured the land–atmosphere exchange of CO2 and water vapor in alpine Norway over 3 years. The extremely snow-rich conditions in 2020 reduced the total annual evapotranspiration to 50 % and reduced the growing-season carbon assimilation to turn the ecosystem from a moderate annual carbon sink to an even stronger source. Our analysis suggests that snow cover anomalies are driving the most consequential short-term responses in this ecosystem’s functioning.
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
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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.
Cas Renette, Kristoffer Aalstad, Juditha Aga, Robin Benjamin Zweigel, Bernd Etzelmüller, Karianne Staalesen Lilleøren, Ketil Isaksen, and Sebastian Westermann
Earth Surf. Dynam., 11, 33–50, https://doi.org/10.5194/esurf-11-33-2023, https://doi.org/10.5194/esurf-11-33-2023, 2023
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One of the reasons for lower ground temperatures in coarse, blocky terrain is a low or varying soil moisture content, which most permafrost modelling studies did not take into account. We used the CryoGrid community model to successfully simulate this effect and found markedly lower temperatures in well-drained, blocky deposits compared to other set-ups. The inclusion of this drainage effect is another step towards a better model representation of blocky mountain terrain in permafrost regions.
Norbert Pirk, Kristoffer Aalstad, Sebastian Westermann, Astrid Vatne, Alouette van Hove, Lena Merete Tallaksen, Massimo Cassiani, and Gabriel Katul
Atmos. Meas. Tech., 15, 7293–7314, https://doi.org/10.5194/amt-15-7293-2022, https://doi.org/10.5194/amt-15-7293-2022, 2022
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In this study, we show how sparse and noisy drone measurements can be combined with an ensemble of turbulence-resolving wind simulations to estimate uncertainty-aware surface energy exchange. We demonstrate the feasibility of this drone data assimilation framework in a series of synthetic and real-world experiments. This new framework can, in future, be applied to estimate energy and gas exchange in heterogeneous landscapes more representatively than conventional methods.
Jörg Schwinger, Ali Asaadi, Norman Julius Steinert, and Hanna Lee
Earth Syst. Dynam., 13, 1641–1665, https://doi.org/10.5194/esd-13-1641-2022, https://doi.org/10.5194/esd-13-1641-2022, 2022
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We test whether climate change can be partially reversed if CO2 is removed from the atmosphere to compensate for too large past and near-term emissions by using idealized model simulations of overshoot pathways. On a timescale of 100 years, we find a high degree of reversibility if the overshoot size remains small, and we do not find tipping points even for intense overshoots. We caution that current Earth system models are most likely not able to skilfully model tipping points in ecosystems.
Juri Palmtag, Jaroslav Obu, Peter Kuhry, Andreas Richter, Matthias B. Siewert, Niels Weiss, Sebastian Westermann, and Gustaf Hugelius
Earth Syst. Sci. Data, 14, 4095–4110, https://doi.org/10.5194/essd-14-4095-2022, https://doi.org/10.5194/essd-14-4095-2022, 2022
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The northern permafrost region covers 22 % of the Northern Hemisphere and holds almost twice as much carbon as the atmosphere. This paper presents data from 651 soil pedons encompassing more than 6500 samples from 16 different study areas across the northern permafrost region. We use this dataset together with ESA's global land cover dataset to estimate soil organic carbon and total nitrogen storage up to 300 cm soil depth, with estimated values of 813 Pg for carbon and 55 Pg for nitrogen.
Noah D. Smith, Eleanor J. Burke, Kjetil Schanke Aas, Inge H. J. Althuizen, Julia Boike, Casper Tai Christiansen, Bernd Etzelmüller, Thomas Friborg, Hanna Lee, Heather Rumbold, Rachael H. Turton, Sebastian Westermann, and Sarah E. Chadburn
Geosci. Model Dev., 15, 3603–3639, https://doi.org/10.5194/gmd-15-3603-2022, https://doi.org/10.5194/gmd-15-3603-2022, 2022
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The Arctic has large areas of small mounds that are caused by ice lifting up the soil. Snow blown by wind gathers in hollows next to these mounds, insulating them in winter. The hollows tend to be wetter, and thus the soil absorbs more heat in summer. The warm wet soil in the hollows decomposes, releasing methane. We have made a model of this, and we have tested how it behaves and whether it looks like sites in Scandinavia and Siberia. Sometimes we get more methane than a model without mounds.
Hannah Ming Siu Vickers, Priscilla Mooney, Eirik Malnes, and Hanna Lee
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-57, https://doi.org/10.5194/tc-2022-57, 2022
Manuscript not accepted for further review
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Rain-on-snow (ROS) events are becoming more frequent as a result of a warming climate, and can have significant impacts on nature and society. Accurate representation of ROS events is need to identify where impacts are greatest both now and in the future. We compare rain-on-snow climatologies from a climate model, ground and satellite radar observations and show how different methods can lead to contrasting conclusions and interpretation of the results should take into account their limitations.
Sarah E. Chadburn, Eleanor J. Burke, Angela V. Gallego-Sala, Noah D. Smith, M. Syndonia Bret-Harte, Dan J. Charman, Julia Drewer, Colin W. Edgar, Eugenie S. Euskirchen, Krzysztof Fortuniak, Yao Gao, Mahdi Nakhavali, Włodzimierz Pawlak, Edward A. G. Schuur, and Sebastian Westermann
Geosci. Model Dev., 15, 1633–1657, https://doi.org/10.5194/gmd-15-1633-2022, https://doi.org/10.5194/gmd-15-1633-2022, 2022
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We present a new method to include peatlands in an Earth system model (ESM). Peatlands store huge amounts of carbon that accumulates very slowly but that can be rapidly destabilised, emitting greenhouse gases. Our model captures the dynamic nature of peat by simulating the change in surface height and physical properties of the soil as carbon is added or decomposed. Thus, we model, for the first time in an ESM, peat dynamics and its threshold behaviours that can lead to destabilisation.
Bernd Etzelmüller, Justyna Czekirda, Florence Magnin, Pierre-Allain Duvillard, Ludovic Ravanel, Emanuelle Malet, Andreas Aspaas, Lene Kristensen, Ingrid Skrede, Gudrun D. Majala, Benjamin Jacobs, Johannes Leinauer, Christian Hauck, Christin Hilbich, Martina Böhme, Reginald Hermanns, Harald Ø. Eriksen, Tom Rune Lauknes, Michael Krautblatter, and Sebastian Westermann
Earth Surf. Dynam., 10, 97–129, https://doi.org/10.5194/esurf-10-97-2022, https://doi.org/10.5194/esurf-10-97-2022, 2022
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This paper is a multi-authored study documenting the possible existence of permafrost in permanently monitored rockslides in Norway for the first time by combining a multitude of field data, including geophysical surveys in rock walls. The paper discusses the possible role of thermal regime and rockslide movement, and it evaluates the possible impact of atmospheric warming on rockslide dynamics in Norwegian mountains.
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
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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
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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
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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.
Daniele Peano, Deborah Hemming, Stefano Materia, Christine Delire, Yuanchao Fan, Emilie Joetzjer, Hanna Lee, Julia E. M. S. Nabel, Taejin Park, Philippe Peylin, David Wårlind, Andy Wiltshire, and Sönke Zaehle
Biogeosciences, 18, 2405–2428, https://doi.org/10.5194/bg-18-2405-2021, https://doi.org/10.5194/bg-18-2405-2021, 2021
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Global climate models are the scientist’s tools used for studying past, present, and future climate conditions. This work examines the ability of a group of our tools in reproducing and capturing the right timing and length of the season when plants show their green leaves. This season, indeed, is fundamental for CO2 exchanges between land, atmosphere, and climate. This work shows that discrepancies compared to observations remain, demanding further polishing of these tools.
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
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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.
Hanna Lee, Helene Muri, Altug Ekici, Jerry Tjiputra, and Jörg Schwinger
Earth Syst. Dynam., 12, 313–326, https://doi.org/10.5194/esd-12-313-2021, https://doi.org/10.5194/esd-12-313-2021, 2021
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We assess how three different geoengineering methods using aerosol affect land ecosystem carbon storage. Changes in temperature and precipitation play a large role in vegetation carbon uptake and storage, but our results show that increased levels of CO2 also play a considerable role. We show that there are unforeseen regional consequences under geoengineering applications, and these consequences should be taken into account in future climate policies before implementing them.
Cited articles
Angerer, J., Han, G., Fujisaki, I., and Havstad, K.: Climate Change and Ecosystems of Asia With Emphasis on Inner Mongolia and Mongolia, Rangelands, 30, 46–51, https://doi.org/0.2111/1551-501X(2008)30[46:CCAEOA]2.0.CO;2, 2008.
Bendavid, N. S., Alexander, H. D., Davydov, S. P., Kropp, H., Mack, M. C., Natali, S. M., Spawn-Lee, S. A., Zimov, N. S., and Loranty, M. M.: Shrubs Compensate for Tree Leaf Area Variation and Influence Vegetation Indices in Post-Fire Siberian Larch Forests, J. Geophys. Res.-Biogeo., 128, e2022JG007107, https://doi.org/10.1029/2022JG007107, 2023.
Beringer, J., Lynch, A. H., Chapin, F. S., Mack, M., and Bonan, G. B.: The Representation of Arctic Soils in the Land Surface Model: The Importance of Mosses, J. Climate, 14, 3324–3335, https://doi.org/10.1175/1520-0442(2001)014<3324:TROASI>2.0.CO;2, 2001.
Bonan, G.: Ecological Climatology: concepts and applications, 3rd edn., Cambridge University Press, https://doi.org/10.1017/CBO9781107339200, 2016.
Bonan, G. B. and Shugart, H. H.: Environmental Factors and Ecological Processes in Boreal Forests, Annu. Rev. Ecol. Syst., 20, 1–28, https://doi.org/10.1146/annurev.es.20.110189.000245, 1989.
Bréda, N. J. J.: Ground-based measurements of leaf area index: a review of methods, instruments and current controversies, J. Exp. Bot., 54, 2403–2417, https://doi.org/10.1093/jxb/erg263, 2003.
Chang, X., Jin, H., Zhang, Y., He, R., Luo, D., Wang, Y., Lü, L., and Zhang, Q.: Thermal Impacts of Boreal Forest Vegetation on Active Layer and Permafrost Soils in Northern da Xing'Anling (Hinggan) Mountains, Northeast China, Arct. Antarct. Alp. Res., 47, 267–279, https://doi.org/10.1657/aaar00c-14-016, 2015.
Chasmer, L., Quinton, W., Hopkinson, C., Petrone, R., and Whittington, P.: Vegetation Canopy and Radiation Controls on Permafrost Plateau Evolution within the Discontinuous Permafrost Zone, Northwest Territories, Canada, Permafr. Periglac. Process., 22, 199–213, https://doi.org/10.1002/ppp.724, 2011.
Chen, J. and Cihlar, J.: Quantifying the effect of canopy architecture on optical measurements of leaf area index using two gap size analysis methods, IEEE Trans. Geosci. Remote Sens., 33, 777–787, https://doi.org/10.1109/36.387593, 1995.
Chen, J., Black, T. A., and Adams, R. S.: Evaluation of hemispherical photography for determining plant area index and geometry of a forest stand, Agric. For. Meteorol., 56, 129–143, https://doi.org/10.1016/0168-1923(91)90108-3, 1991.
Dalai, S., Dambaravjaa, O., and Purevjav, G.: Water Challenges in Ulaanbaatar, Mongolia, in: Urban Drought: Emerging Water Challenges in Asia, edited by: Ray, B. and Shaw, R., Springer Singapore, Singapore, 347–361, https://doi.org/10.1007/978-981-10-8947-3_20, 2019.
Dashtseren, A., Ishikawa, M., Iijima, Y., and Jambaljav, Y.: Temperature regimes of the active layer and seasonally frozen ground under a forest-steppe mosaic, Mongolia, Permafr. Periglac. Process., 25, 295–306, https://doi.org/10.1002/ppp.1824, 2014.
Dozier, J. and Frew, J.: Rapid calculation of terrain parameters for radiation modeling from digital elevation data, IEEE T. Geosci. Remote, 28, 963–969, https://doi.org/10.1109/36.58986, 1990.
Dulamsuren, C., Hauck, M., Khishigjargal, M., Leuschner, H. H., and Leuschner, C.: Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica, Oecologia, 163, 1091–1102, https://doi.org/10.1007/s00442-010-1689-y, 2010.
Esri: World Imagery [Web map], Scale not given, Esri World Imagery, https://www.arcgis.com/home/webmap/viewer.html?webmap=50c23e4987a44de4ab163e1baeab4a46. (last access: 9 January 2026), 8 September 2022.
Fedorov, A. N., Iwahana, G., Konstantinov, P. Y., Machimura, T., Argunov, R. N., Efremov, P. V., Lopez, L. M. C., and Takakai, F.: Variability of Permafrost and Landscape Conditions Following Clear Cutting of Larch Forest in Central Yakutia, Permafr. Periglac. Process., 28, 331–338, https://doi.org/10.1002/ppp.1897, 2017.
Fernández-Giménez, M. E., Allington, G. R. H., Angerer, J., Reid, R. S., Jamsranjav, C., Ulambayar, T., Hondula, K., Baival, B., Batjav, B., Altanzul, T., and Baasandorj, Y.: Using an integrated social-ecological analysis to detect effects of household herding practices on indicators of rangeland resilience in Mongolia, Environ. Res. Lett., 13, 075010, https://doi.org/10.1088/1748-9326/aacf6f, 2018.
Fisher, J., Estop-Aragonés, C., Thierry, A., Charman, D. J., Wolfe, S. A., Hartley, I. P., Murton, J. B., Williams, M., and Phoenix, G. K.: The influence of vegetation and soil characteristics on active-layer thickness of permafrost soils in boreal forest, Glob. Change Biol., 22, 3127–3140, https://doi.org/10.1111/gcb.13248, 2016.
Ganbat, G. and Baik, J.-J.: Wintertime winds in and around the Ulaanbaatar metropolitan area in the presence of a temperature inversion, Asia-Pac, J. Atmospheric Sci., 52, 309–325, https://doi.org/10.1007/s13143-016-0007-y, 2016.
Gerelchuluun, B. and Ahn, J. B.: Air temperature distribution over Mongolia using dynamical downscaling and statistical correction, Int. J. Climatol., 34, 2464–2476, https://doi.org/10.1002/JOC.3853, 2014.
Glenn, E. P., Huete, A. R., Nagler, P. L., and Nelson, S. G.: Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape, Sensors, 8, 2136–2160, https://doi.org/10.3390/s8042136, 2008.
Hartmann, D. L.: Global Physical Climatology, 2nd edn., Elsevier, 485 pp., ISBN-13 978-01232853-1, 2016.
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., 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., 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.
Hiemstra, C. A., Liston, G. E., and Reiners, W. A.: Snow Redistribution by Wind and Interactions with Vegetation at Upper Treeline in the Medicine Bow Mountains, Wyoming, U.S.A., Arct. Antarct. Alp. Res., 34, 262–273, https://doi.org/10.1080/15230430.2002.12003493, 2002.
Hong, S.-H., Lkhamjav, J., Jin, H.-G., and Baik, J.-J.: Spatiotemporal variations of 100 m wind in Mongolia and implications for wind energy resources, Int. J. Climatol., 43, 3433–3452, https://doi.org/10.1002/joc.8037, 2023.
Iijima, Y., Ishikawa, M., and Jambaljav, Y.: Hydrological cycle in relation to permafrost environment in forest-grassland ecotone in Mongolia, J. Jpn. Assoc. Hydrol. Sci., 42, 119–130, https://doi.org/10.4145/jahs.42.119, 2012.
Ishikawa, M., Sharkhuu, N., Zhang, Y., Kadota, T., and Ohata, T.: Ground thermal and moisture conditions at the southern boundary of discontinuous permafrost, Mongolia, Permafr. Periglac. Process., 16, 209–216, https://doi.org/10.1002/PPP.483, 2005.
Ishikawa, M., Jamvaljav, Y., Dashtseren, A., Sharkhuu, N., Davaa, G., Iijima, Y., Baatarbileg, N., and Yoshikawa, K.: Thermal states, responsiveness and degradation of marginal permafrost in Mongolia, Permafr. Periglac. Process., 29, 271–282, https://doi.org/10.1002/PPP.1990, 2018.
Iwahana, G., Machimura, T., Kobayashi, Y., Fedorov, A. N., Konstantinov, P. Y., and Fukuda, M.: Influence of forest clear-cutting on the thermal and hydrological regime of the active layer near Yakutsk, eastern Siberia, J. Geophys. Res.-Biogeo., 110, https://doi.org/10.1029/2005JG000039, 2005.
Jafarov, E. E., Marchenko, S. S., and Romanovsky, V. E.: Numerical modeling of permafrost dynamics in Alaska using a high spatial resolution dataset, The Cryosphere, 6, 613–624, https://doi.org/10.5194/tc-6-613-2012, 2012.
Janse, R. J., Hoekstra, T., Jager, K. J., Zoccali, C., Tripepi, G., Dekker, F. W., and van Diepen, M.: Conducting correlation analysis: important limitations and pitfalls, Clin. Kidney J., 14, 2332–2337, https://doi.org/10.1093/ckj/sfab085, 2021.
Jonas, T., Webster, C., Mazzotti, G., and Malle, J.: HPEval: A canopy shortwave radiation transmission model using high-resolution hemispherical images, Agric. For. Meteorol., 284, 107903, https://doi.org/10.1016/j.agrformet.2020.107903, 2020.
Karthe, D., Malsy, M., Kopp, S., Minderlein, S., and Hülsmann, L.: Assessing water availability and its drivers in the context of an integrated water resources management (IWRM): a case study from the Kharaa River Basin, Mongolia, GeoÖko, 34, 5–26, 2013.
Kasischke, E. S. and Johnstone, J. F.: Variation in postfire organic layer thickness in a black spruce forest complex in interior Alaska and its effects on soil temperature and moisture, Can. J. For. Res., 35, 2164–2177, https://doi.org/10.1139/x05-159, 2005.
Klinge, M., Dulamsuren, C., Erasmi, S., Karger, D. N., and Hauck, M.: Climate effects on vegetation vitality at the treeline of boreal forests of Mongolia, Biogeosciences, 15, 1319–1333, https://doi.org/10.5194/bg-15-1319-2018, 2018.
Klinge, M., Schneider, F., Dulamsuren, C., Arndt, K., Bayarsaikhan, U., and Sauer, D.: Interrelations between relief, vegetation, disturbances, and permafrost in the forest-steppe of central Mongolia, Earth Surf. Process. Landf., 46, 1766–1782, https://doi.org/10.1002/esp.5116, 2021.
Kopp, B., Minderlein, S., and Menzel, L.: Soil moisture dynamics in a mountainous headwater area in the discontinuous permafrost zone of northern Mongolia, Arct. Antarct. Alp. Res., 46, 459–470, https://doi.org/10.1657/1938-4246-46.2.459, 2014.
Koutantou, K., Mazzotti, G., Brunner, P., Webster, C., and Jonas, T.: Exploring snow distribution dynamics in steep forested slopes with UAV-borne LiDAR, Cold Reg. Sci. Technol., 200, 103587, https://doi.org/10.1016/j.coldregions.2022.103587, 2022.
Lang, A. R. G.: Simplified estimate of leaf area index from transmittance of the sun's beam, Agric. For. Meteorol., 41, 179–186, https://doi.org/10.1016/0168-1923(87)90078-5, 1987.
Lange, J., Kopp, B. J., Bents, M., and Menzel, L.: Tracing variability of run-off generation in mountainous permafrost of semi-arid north-eastern Mongolia, Hydrol. Process., 29, 1046–1055, https://doi.org/10.1002/HYP.10218, 2015.
Li, X., Jin, H.-J., Wang, H.-W., Marchenko, S. S., Shan, W., Luo, D.-L., He, R.-X., Spektor, V., Huang, Y.-D., Li, X.-Y., and Jia, N.: Influences of forest fires on the permafrost environment: A review, Spec. Top. Degrading Permafr. Its Impacts, 12, 48–65, https://doi.org/10.1016/j.accre.2021.01.001, 2021.
Liu, J., Li, L., Akerblom, M., Wang, T., Skidmore, A., Zhu, X., and Heurich, M.: Comparative Evaluation of Algorithms for Leaf Area Index Estimation from Digital Hemispherical Photography through Virtual Forests, Remote Sens., 13, https://doi.org/10.3390/rs13163325, 2021.
Lkhagvadorj, D., Hauck, M., Dulamsuren, Ch., and Tsogtbaatar, J.: Pastoral nomadism in the forest-steppe of the Mongolian Altai under a changing economy and a warming climate, J. Arid Environ., 88, 82–89, https://doi.org/10.1016/j.jaridenv.2012.07.019, 2013a.
Lkhagvadorj, D., Hauck, M., Dulamsuren, C., and Tsogtbaatar, J.: Twenty Years After Decollectivization: Mobile Livestock Husbandry and Its Ecological Impact in the Mongolian Forest-Steppe, Hum. Ecol., 41, 725–735, https://doi.org/10.1007/s10745-013-9599-3, 2013b.
Loranty, M. M., Davydov, S. P., Kropp, H., Alexander, H. D., Mack, M. C., Natali, S. M., and Zimov, N. S.: Vegetation Indices Do Not Capture Forest Cover Variation in Upland Siberian Larch Forests, Remote Sens., 10, https://doi.org/10.3390/rs10111686, 2018.
Lundberg, A. and Koivusalo, H.: Estimating winter evaporation in boreal forests with operational snow course data, Hydrol. Process., 17, 1479–1493, https://doi.org/10.1002/hyp.1179, 2003.
Mahat, V. and Tarboton, D. G.: Canopy radiation transmission for an energy balance snowmelt model, Water Resour. Res., 48, https://doi.org/10.1029/2011WR010438, 2012.
Maxim Integrated: DS1922L/DS1922T iButton Temperature Loggers with 8KB Datalog Memory Data Sheet (Rev. 13), Maxim Integrated, 2015.
NASA JPL: NASA Shuttle Radar Topography Mission (SRTM): Shuttle Radar Topography Mission (SRTM) Global 1 arc second, OpenTopography [data set], https://doi.org/10.5069/G9445JDF (last access: 9 January 2026), 2013.
Obu, J., Westermann, S., Bartsch, A., Berdnikov, N., Christiansen, H. H., Dashtseren, A., Delaloye, R., Elberling, B., Etzelmüller, B., Kholodov, A., Khomutov, A., Kääb, A., Leibman, M. O., Lewkowicz, A. G., Panda, S. K., Romanovsky, V., Way, R. G., Westergaard-Nielsen, A., Wu, T., Yamkhin, J., and Zou, D.: Northern Hemisphere permafrost map based on TTOP modelling for 2000–2016 at 1 km2 scale, Earth-Sci. Rev., 193, 299–316, https://doi.org/10.1016/j.earscirev.2019.04.023, 2019.
Roy, D. and Zhang, H.: NASA Global Web-Enabled Landsat Data Monthly Global 30 m V031, Earth Data [data set], https://doi.org/10.5067/MEASURES/GWELD/GWELDMO.031, 2019.
Schleppi, P., Conedera, M., Sedivy, I., and Thimonier, A.: Correcting non-linearity and slope effects in the estimation of the leaf area index of forests from hemispherical photographs, Agric. For. Meteorol., 144, 236–242, https://doi.org/10.1016/j.agrformet.2007.02.004, 2007.
Schlütz, F., Dulamsuren, C., Wieckowska, M., Mühlenberg, M., and Hauck, M.: Late Holocene vegetation history suggests natural origin of steppes in the northern Mongolian mountain taiga, Palaeogeogr. Palaeoclimatol. Palaeoecol., 261, 203–217, https://doi.org/10.1016/j.palaeo.2007.12.012, 2008.
Schmidt, J. U., Etzelmüller, B., Schuler, T. V., Magnin, F., Boike, J., Langer, M., and Westermann, S.: Surface temperatures and their influence on the permafrost thermal regime in high-Arctic rock walls on Svalbard, The Cryosphere, 15, 2491–2509, https://doi.org/10.5194/tc-15-2491-2021, 2021.
Smith, M. and Riseborough, D. W.: Permafrost monitoring and detection of climate change, Permafr. Periglac. Process., 7, 301–309, https://doi.org/10.1002/(SICI)1099-1530(199610)7:4<301::AID-PPP231>3.0.CO;2-R, 1996.
Smith, M. and Riseborough, D. W.: Climate and the limits of permafrost: a zonal analysis, Permafr. Periglac. Process., 13, 1–15, https://doi.org/10.1002/ppp.410, 2002.
Stuenzi, S. M., Boike, J., Cable, W., Herzschuh, U., Kruse, S., Pestryakova, L. A., Schneider von Deimling, T., Westermann, S., Zakharov, E. S., and Langer, M.: Variability of the surface energy balance in permafrost-underlain boreal forest, Biogeosciences, 18, 343–365, https://doi.org/10.5194/bg-18-343-2021, 2021a.
Stuenzi, S. M., Boike, J., Gädeke, A., Herzschuh, U., Kruse, S., Pestryakova, L. A., Westermann, S., and Langer, M.: Sensitivity of ecosystem-protected permafrost under changing boreal forest structures, Environ. Res. Lett., 16, 084045, https://doi.org/10.1088/1748-9326/ac153d, 2021b.
Stuenzi, S. M., Kruse, S., Boike, J., Herzschuh, U., Oehme, A., Pestryakova, L. A., Westermann, S., and Langer, M.: Thermohydrological Impact of Forest Disturbances on Ecosystem-Protected Permafrost, J. Geophys. Res.-Biogeo., 127, e2021JG006630, https://doi.org/10.1029/2021JG006630, 2022.
Sturm, M., Holmgren, J., McFadden, J. P., Liston, G. E., Chapin, F. S., and Racine, C. H.: Snow–Shrub Interactions in Arctic Tundra: A Hypothesis with Climatic Implications, J. Climate, 14, 336–344, https://doi.org/10.1175/1520-0442(2001)014<0336:SSIIAT>2.0.CO;2, 2001.
Sugimoto, A., Yanagisawa, N., Naito, D., Fujita, N., and Maximov, T. C.: Importance of permafrost as a source of water for plants in east Siberian taiga, Ecol. Res., 17, 493–503, https://doi.org/10.1046/j.1440-1703.2002.00506.x, 2002.
Sumiya, E., Dorligjav, S., Purevtseren, M., Gombodorj, G., Byamba-Ochir, M., Dugerjav, O., Sugar, M., Batsuuri, B., and Tsegmid, B.: Climate Patterns Affecting Cold Season Air Pollution of Ulaanbaatar City, Mongolia, Climate, 11, https://doi.org/10.3390/cli11010004, 2023.
Temuujin, K., Dashtseren, A., Etzelmüller, B., Undrakhtsetseg, T., Aalstad, K., and Westermann, S.: Spatial variability of near-surface ground temperatures in a discontinuous permafrost area in Mongolia, Front. Earth Sci., 12, https://doi.org/10.3389/feart.2024.1456012, 2024.
Thimonier, A., Sedivy, I., and Schleppi, P.: Estimating leaf area index in different types of mature forest stands in Switzerland: a comparison of methods, Eur. J. For. Res., 129, 543–562, https://doi.org/10.1007/s10342-009-0353-8, 2010.
Tsogtbaatar, J.: Deforestation and reforestation needs in Mongolia, Restor. Res. Degraded For. Ecosyst., 201, 57–63, https://doi.org/10.1016/j.foreco.2004.06.011, 2004.
Undrakhbayar, E., Avirmed, D., Khurelbaatar, T., and Ariunbold, M.: Relationship between near ground surface temperature and land cover types of eastern lake Khuvsgul, Mong. J. Geogr. Geoecology, 61, 18–30, https://doi.org/10.5564/mjgg.v61i45.3343, 2024.
Walvoord, M. A. and Kurylyk, B. L.: Hydrologic Impacts of Thawing Permafrost-A Review, Vadose Zone J., 15, vzj2016.01.0010-vzj2016.01.0010, https://doi.org/10.2136/vzj2016.01.0010, 2016.
Webster, C., Rutter, N., Zahner, F., and Jonas, T.: Modeling subcanopy incoming longwave radiation to seasonal snow using air and tree trunk temperatures, J. Geophys. Res.-Atmos., 121, 1220–1235, https://doi.org/10.1002/2015JD024099, 2015.
Westermann, S., Østby, T. I., Gisnås, K., Schuler, T. V., and Etzelmüller, B.: A ground temperature map of the North Atlantic permafrost region based on remote sensing and reanalysis data, The Cryosphere, 9, 1303–1319, https://doi.org/10.5194/tc-9-1303-2015, 2015.
Yi, S., Woo, M., and Arain, M. A.: Impacts of peat and vegetation on permafrost degradation under climate warming, Geophys. Res. Lett., 34, https://doi.org/10.1029/2007GL030550, 2007.
Yoshikawa, K., Bolton, W. R., Romanovsky, V. E., Fukuda, M., and Hinzman, L. D.: Impacts of wildfire on the permafrost in the boreal forests of Interior Alaska, J. Geophys. Res., 108, https://doi.org/10.1029/2001jd000438, 2002.
Zamba, B.: THIRD NATIONAL COMMUNICATION OF MONGOLIA, Ministry of Environment and Tourism, Mongolia, Ulaanbaatar, Mongolia, 2018.
Zhang, T.: Influence of the seasonal snow cover on the ground thermal regime: An overview, Rev. Geophys., 43, RG4002–RG4002, https://doi.org/10.1029/2004RG000157, 2005.
Zhang, T., Osterkamp, T. E., and Stamnes, K.: Effects of Climate on the Active Layer and Permafrost on the North Slope of Alaska, U.S.A., Permafr. Periglac. Process., 8, 45–67, https://doi.org/10.1002/(SICI)1099-1530(199701)8:1<45::AID-PPP240>3.0.CO;2-K, 1997.
Zhang, Y., Chen, J. M., and Miller, J. R.: Determining digital hemispherical photograph exposure for leaf area index estimation, Agric. For. Meteorol., 133, 166–181, https://doi.org/10.1016/j.agrformet.2005.09.009, 2005.
Zhao, Y.-Y., Li, Z.-T., Xu, T., and Lou, A.: Leaf litter decomposition characteristics and controlling factors across two contrasting forest types, J. Plant Ecol., 15, 1285–1301, https://doi.org/10.1093/jpe/rtac073, 2022.
Zweigel, R. B.: Research data for egusphere-2025-2366, Zenodo [data set], https://doi.org/10.5281/zenodo.15470689, 2025.
Zweigel, R. B., Westermann, S., Nitzbon, J., Langer, M., Boike, J., Etzelmüller, B., and Vikhamar Schuler, T.: Simulating Snow Redistribution and its Effect on Ground Surface Temperature at a High-Arctic Site on Svalbard, J. Geophys. Res.-Earth Surf., 126, e2020JF005673, https://doi.org/10.1029/2020JF005673, 2021.
Zweigel, R. B., Dashtseren, A., Temuujin, K., Aalstad, K., Webster, C., Stuenzi, S. M., Aas, K. S., Lee, H., and Westermann, S.: Simulating the Thermal Regime and Surface Energy Balance of a Permafrost-Underlain Forest in Mongolia, J. Geophys. Res.-Earth Surf., 129, e2023JF007609, https://doi.org/10.1029/2023JF007609, 2024a.
Zweigel, R. B., Dashtseren, A., Temuujin, K., Sharkhuu, A., Webster, C., Lee, H., and Westermann, S.: Impact of livestock activity on near-surface ground temperatures in central Mongolian grasslands, Biogeosciences, 21, 5059–5077, https://doi.org/10.5194/bg-21-5059-2024, 2024b.
Short summary
Two years of data along a forest disturbance gradient in Mongolia show a larger annual ground surface temperature range in dead and logged forests than intact forest, while the range is dampened in stands of young regrowth. Compared to intact forest, mean annual ground surface temperatures are 0.5 °C colder in dead and logged forest and dense stands of young regrowth. This is linked to differences in vegetation and surface cover due to the disturbance and patterns in livestock activity.
Two years of data along a forest disturbance gradient in Mongolia show a larger annual ground...