Article
Meteorology & Atmospheric Sciences
Weigang Liu, Xingguo Yang, Michiel R. van den Broeke, Baojuan Huai, Diyi Yang, Dongqi Zhang, Xiang Qin, Ping Yue, Heling Wang, Minghu Ding
Summary: This study presents the cold-season glacier surface energy balance (SEB) result at high altitudes on Mt. Qomolangma based on in-situ observation from October 2007 to January 2008. The results show that strong winds and deficient clouds during the observational period led to a substantial sensible heat transport toward the glacier surface and an increase in longwave radiative loss. The clouds' shading effect surpassed its greenhouse effect and resulted in a decrease in incident solar radiation.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Meteorology & Atmospheric Sciences
Weigang Liu, Dongqi Zhang, Xiang Qin, Michiel R. van den Broeke, Youyan Jiang, Diyi Yang, Minghu Ding
Summary: The study investigated the atmospheric controls of the summertime glacier surface energy balance in the Himalayas using in situ meteorological data collected at 6,523 m above sea level. Cloud cover was found to play a crucial role in the surface energy balance, influencing the incoming longwave radiation more than the incident solar radiation during the active period of the South Asian Summer Monsoon. Furthermore, the comparison of glacier surface energy balances on the Tibetan Plateau revealed significant spatial variability in glacial sensitivity to different climatic conditions.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Geography, Physical
Wei Yang, Huabiao Zhao, Baiqing Xu, Jiule Li, Weicai Wang, Guangjian Wu, Zhongyan Wang, Tandong Yao
Summary: This article reports on the ground-penetrating radar survey of snow depth along the north slope of Mount Everest in May 2022. The results show that the updated snow depth on Mount Everest is much deeper than previously reported values (0.9-3.5 m), with an average depth of 9.5 m.
Article
Engineering, Environmental
Xuejun Sun, Qianggong Zhang, Guoshuai Zhang, Mingyue Li, Shengnan Li, Junming Guo, Huike Dong, Yunqiao Zhou, Shichang Kang, Xiaoping Wang, Jianbo Shi
Summary: Glaciers in the Himalayan region are receding rapidly and releasing legacy pollutants, such as mercury. This study conducted continuous monitoring and sampling in the Rongbuk Glacier-fed basin and found that mercury concentrations were mainly influenced by suspended particulate matter and showed diurnal variations. The annual export fluxes of total mercury and methyl mercury were estimated, and it was noted that the export of mercury from meltwater runoff in the Himalayas may increase in the future.
Article
Environmental Sciences
Mauri Pelto, Prajjwal Panday, Tom Matthews, Jon Maurer, L. Baker Perry
Summary: Recent observations of significant ablation on Himalayan glaciers in the Nepal-China region of Mount Everest in post-monsoon and early winter periods, as well as the installation of real-time weather stations by the Rolex National Geographic Perpetual Planet expedition, provide a unique opportunity to study the impact of warm and dry conditions on glaciers in the Mount Everest region. The unprecedented high temperatures and freezing levels recorded in the 2020/2021 winter highlight the urgency of understanding and addressing the effects of climate change on the fragile Himalayan glaciers.
Article
Engineering, Environmental
Mingyue Li, Guitao Shi, Yilan Li, Xiao Yan, Xuejun Sun, Deji Yangzong, Shengnan Li, Huike Dong, Yunqiao Zhou, Xiaoping Wang, Shichang Kang, Qianggong Zhang
Summary: Glacier melting exports a significant amount of nitrate to downstream aquatic ecosystems. Glacial lakes and glacier-fed rivers play a critical role in receiving and distributing glacier-derived nitrate. The concentration of nitrate is low and is minimally influenced by human activities. The nitrate concentration decreases in glacial lakes due to sedimentation and gradually increases from upstream to downstream in rivers.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Studies
Yujie Sun, Teiji Watanabe
Summary: The increase in tourist numbers and transformation of facilities were found to be key factors driving changes in mountain regions, but also leading to imbalanced development and unequal benefits. Diversification of trekking routes and improvement of facility and service quality could help mitigate these issues for sustainable mountain development.
Article
Geography, Physical
Vincent Jomelli, Patrick Wagnon, Didier Swingedouw, Joanna Charton, Regis Braucher, Adele Hue, Fanny Brun, Christophe Colin, Stephanie Gairoard, Dibas Shrestha
Summary: The current research on the Mera and South Khare glaciers in Nepal indicates that Asian monsoon precipitation plays a dominant role in the interannual mass balance variability, while temperature affects the altitude of the snow-rain threshold. The study also suggests that the long-term evolution of the glaciers does not perfectly align with changes in Indian monsoon precipitation and temperature as simulated by climate models, indicating the need for further research and improved simulations to better understand glacier and climate dynamics.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Geography, Physical
Ann V. Rowan, Lindsey I. Nicholson, Duncan J. Quincey, Morgan J. Gibson, Tristram D. L. Irvine-Fynn, C. Scott Watson, Patrick Wagnon, David R. Rounce, Sarah S. Thompson, Philip R. Porter, Neil F. Glasser
Summary: The study found that supraglacial debris has a stable impact on the temperature of the underlying ice surface and melt, which can be estimated from near-surface temperature. This has the potential to greatly improve the representation of ablation in calculations of debris-covered glacier mass balance and projections of their response to climate change.
JOURNAL OF GLACIOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Pratima Pandey, Debangshu Banerjee, Prashant K. Champati Ray
Summary: The Shunkalpa Glacier in the Central Indian Himalaya is one of the largest glaciers formed by the union of the Kalabaland Glacier (10 km long) and the Yankchar Glacier (9 km long), with snout records dating back to 1886. The glacier's snout has been receding at a rate of 16 m/yr from 1990 to 2016. Satellite-derived surface velocity and ice thickness vary spatially, with the mean velocity of the Shunkalpa Glacier being 22 m/yr and the mean ice thickness being 109 m. The Kalabaland Glacier is more dynamic in terms of velocity compared to the Yankchar Glacier.
JOURNAL OF EARTH SYSTEM SCIENCE
(2021)
Article
Environmental Sciences
Daan Li, Liming Jiang, Ronggang Huang
Summary: By using remote sensing observations and an ice-flow model, a comprehensive investigation was conducted on hydrological and kinematic precursors before the calving event of Petermann Glacier in northern Greenland on 26 July 2017. The study found that prior to the calving, there was a rapid increase in ice flow speed, decrease in sea ice extent, and expansion of melt ponds on the glacier surface.
Article
Geosciences, Multidisciplinary
Sebastian B. Simonsen, Valentina R. Barletta, William T. Colgan, Louise Sandberg Sorensen
Summary: The study presents the first record of Greenland Ice Sheet mass balance from 1992 to 2020 using multisatellite Ku-band altimetry. It shows that the majority of the ice sheet contribution occurred after 2003, and that 2017 was the first year in the 21st century when the GrIS was in balance within uncertainties. The 28-year radar-derived mass balance record highlights the potential of the method to provide operational mass balance estimates using multisatellite Ku-band altimetry.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
William Colgan, Joseph A. MacGregor, Kenneth D. Mankoff, Ryan Haagenson, Harihar Rajaram, Yasmina M. Martos, Mathieu Morlighem, Mark A. Fahnestock, Kristian K. Kjeldsen
Summary: A new approach was presented to account for the influence of subglacial topography on geothermal heat flux beneath the Greenland and Antarctic ice sheets, establishing a simple empirical proportionality between local geothermal flux and topographic relief. This empirical method avoids limitations of existing analytic and numerical models, producing results consistent with both approaches and indicating the importance of topography on geothermal heat flux. The study suggests that the effect of local topography on geothermal heat flux can be as significant as the choice of regional geothermal heat flux field, particularly in regions where subglacial topography is well resolved.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2021)
Article
Geosciences, Multidisciplinary
Baptiste Vandecrux, William Colgan, Anne M. Solgaard, Jorgen Peder Steffensen, Nanna B. Karlsson
Summary: The research simulated the firn density and temperature changes at Camp Century over the next 80 years using climate models, indicating continued coverage of the debris field and increased depth by 2100. Firn temperatures are projected to rise, while a warm bias in air temperature simulations was identified, necessitating correction when using the models.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
M. Niwano, J. E. Box, A. Wehrle, B. Vandecrux, W. T. Colgan, J. Cappelen
Summary: Research shows that rainfall on the Greenland ice sheet is expected to increase as the climate warms, with the northwest part of the ice sheet experiencing a fourfold increase in annual rainfall over the past 40 years. In September, both the amount and intensity of ice sheet-wide rainfall have also significantly increased.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Shfaqat A. Khan, Jonathan L. Bamber, Eric Rignot, Veit Helm, Andy Aschwanden, David M. Holland, Michiel van den Broeke, Michalea King, Brice Noel, Martin Truffer, Angelika Humbert, William Colgan, Saurabh Vijay, Peter Kuipers Munneke
Summary: We used satellite and airborne altimetry to estimate annual mass changes of the Greenland Ice Sheet. The study revealed that Greenland has experienced substantial ice loss, resulting in a sea-level rise of 6.9 mm from 2011 to 2020. The researchers also observed contrasting patterns of mass loss in different regions of the ice sheet, suggesting the potential use of these trends for validating ice sheet models.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Geosciences, Multidisciplinary
Shfaqat A. Khan, William Colgan, Thomas A. Neumann, Michiel R. van den Broeke, Kelly M. Brunt, Brice Noel, Jonathan L. Bamber, Javed Hassan, Anders A. Bjork
Summary: In recent decades, the peripheral glaciers in Greenland have experienced significant mass loss, contributing substantially to rising sea levels. Despite their small coverage area (4% of Greenland's ice), their mass loss is disproportionately large compared to the Greenland ice sheet. Satellite data shows that the mass loss from Greenland's peripheral glaciers has increased, with a fourfold increase observed in North Greenland. While mass loss from peripheral glaciers is widespread, there is also a complex regional pattern where increased precipitation at higher altitudes partially offsets increased melting at lower altitudes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geography, Physical
Ole Bennike, William Colgan, Lars Hedenas, Oliver Heiri, Geoffrey Lemdahl, Peter Wiberg-Larsen, Sofia Ribeiro, Roberto Pronzato, Renata Manconi, Anders A. Bjork
Summary: An organic-rich deposit was discovered at an elevation of 480 m above sea level at the Pingorsuit Glacier in North-West Greenland. The sediments contained remains of vascular plants, mosses, beetles, caddisflies, midges, bryozoans, sponges and other invertebrates. The fossils were deposited in a boreal environment with a mean July air temperature that was at least 9 degrees C higher than at present.
Article
Environmental Sciences
Jason E. Box, Alun Hubbard, David B. Bahr, William T. Colgan, Xavier Fettweis, Kenneth D. Mankoff, Adrien Wehrle, Brice Noel, Michiel R. van den Broeke, Bert Wouters, Anders A. Bjork, Robert S. Fausto
Summary: The melting of the Greenland ice sheet has become a significant contributor to sea-level rise, and the imbalance between recent climate and the ice sheet has resulted in substantial volume loss.
NATURE CLIMATE CHANGE
(2022)
Article
Geology
William Colgan, Hans Jorgen Henriksen, Ole Bennike, Sofia Riberio, Marie Keiding, Ida Karlsson Seidenfaden, Morten Graversgaard, Anne Gravsholt Busck, Mikkel Fruergaard, Michael Helt Knudsen, John Hopper, Torben Sonnenborg, Maria Rebekka Skjerbaek, Anders Anker Bjork, Holger Steffen, Lev Tarasov, R. Steven Nerem, Kristian K. Kjeldsen
Summary: This study presents the latest sea-level rise projections for four Danish cities based on the Intergovernmental Panel on Climate Change Sixth Assessment Report. The projections show significant increases in sea-level that will impact Danish harbors and the recurrence of extreme climate events. However, there is considerable uncertainty in these projections, highlighting the need for a national sea-level adaptation plan to ensure local planning aligns with risk and action standards.
Article
Geography, Physical
William Colgan, Jakob Jakobsen, Anne Solgaard, Anja Lokkegaard, Jakob Abermann, Shfaqat A. Khan, Beata Csatho, Joseph A. MacGregor, Robert S. Fausto, Nanna Karlsson, Allan O. Pedersen, Signe B. Andersen, John Sonntag, Christine S. Hvidberg, Andreas P. Ahlstrom
Summary: This study provides further measurements of the magnitude and azimuth of horizontal ice flow at Camp Century, Greenland. The results suggest a stable ice flow pattern with a thickening trend over time. However, the reasons for the migration of the ice flow divide are still unclear.
JOURNAL OF GLACIOLOGY
(2023)
Article
Geosciences, Multidisciplinary
William Colgan, Christopher Shields, Pavel Talalay, Xiaopeng Fan, Austin P. Lines, Joshua Elliott, Harihar Rajaram, Kenneth Mankoff, Morten Jensen, Mira Backes, Yunchen Liu, Xianzhe Wei, Nanna B. Karlsson, Henrik Spanggard, Allan O. Pedersen
Summary: We present an electrothermal ice-drilling system with a simple and low-cost melt tip designed to insert a temperature sensor cable into ice. The most innovative elements of the system are the melt tip and the winch, and the hardware and electrical designs of these components are available as open-access. Laboratory tests show that the melt tip has an efficiency of about 35% for converting electrical energy into forward melting heat, with a theoretical maximum penetration rate of approximately 12 mh(-1) at a maximum power of 6.0 kW. Field testing suggests the melt tip has an efficiency of around 15% and a theoretical maximum penetration rate of about 6 mh(-1). The primary depth-limiting factor is umbilical freeze-in due to borehole refreezing, with a theoretical depth limit of up to approximately 200 m depending on various factors.
GEOSCIENTIFIC INSTRUMENTATION METHODS AND DATA SYSTEMS
(2023)
Article
Geography, Physical
Joseph A. MacGregor, Winnie Chu, William T. Colgan, Mark A. Fahnestock, Denis Felikson, Nanna B. Karlsson, Sophie M. J. Nowicki, Michael Studinger
Summary: The basal thermal state (frozen or thawed) of the Greenland Ice Sheet is important for interpreting modern changes in ice flow. A new synthesis indicates that 33% of the ice sheet's bed is likely thawed, 40% likely frozen, and the remainder uncertain. The pattern suggests more of northern Greenland is likely thawed while more of southern Greenland is likely frozen, affecting interpretations of subglacial hydrology and future evolution models.
Article
Geography, Physical
Mimmi Oksman, Anna Bang Kvorning, Signe Hillerup Larsen, Kristian Kjellerup Kjeldsen, Kenneth David Mankoff, William Colgan, Thorbjorn Joest Andersen, Niels Norgaard-Pedersen, Marit-Solveig Seidenkrantz, Naja Mikkelsen, Sofia Ribeiro
Summary: Climate warming and freshwater discharge from the Greenland Ice Sheet are impacting Arctic marine coastal ecosystems, affecting their biological productivity. Using paleo-records, researchers have estimated runoff in a sub-Arctic fjord system in southwest Greenland since the late 19th century. The study reveals that increased freshwater runoff has led to higher marine productivity and changes in diatom assemblages and spring blooms.
Article
Geosciences, Multidisciplinary
William Colgan, Agnes Wansing, Kenneth Mankoff, Mareen Losing, John Hopper, Keith Louden, Jorg Ebbing, Flemming G. Christiansen, Thomas Ingeman-Nielsen, Lillemor Claesson Liljedahl, Joseph A. MacGregor, Arni Hjartarson, Stefan Bernstein, Nanna B. Karlsson, Sven Fuchs, Juha Hartikainen, Johan Liakka, Robert S. Fausto, Dorthe Dahl-Jensen, Anders Bjork, Jens-Ove Naslund, Finn Mork, Yasmina Martos, Niels Balling, Thomas Funck, Kristian K. Kjeldsen, Dorthe Petersen, Ulrik Gregersen, Gregers Dam, Tove Nielsen, Shfaqat A. Khan, Anja Lokkegaard
Summary: This article compiles and analyzes geothermal heat flow measurements in and around Greenland, creating a new database and spatial map. Using machine learning, the in situ measurements are synthesized into a consistent geothermal heat flow model. The model has the lowest mean heat flow in Greenland onshore areas and shows distinct spatial features.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Geosciences, Multidisciplinary
Kenneth D. Mankoff, Xavier Fettweis, Peter L. Langen, Martin Stendel, Kristian K. Kjeldsen, Nanna B. Karlsson, Brice Noel, Michiel R. van den Broeke, Anne Solgaard, William Colgan, Jason E. Box, Sebastian B. Simonsen, Michalea D. King, Andreas P. Ahlstrom, Signe Bech Andersen, Robert S. Fausto
Summary: The mass of the Greenland ice sheet is declining due to factors such as surface meltwater runoff, marine-terminating glacier calving, submarine melting, and basal melting. Different climate models and estimation methods have been used to analyze the mass balance changes from the past to the future.
EARTH SYSTEM SCIENCE DATA
(2021)
