Article
Environmental Sciences
Kaitlyn M. Strickfaden, Adrienne M. Marshall, Leona K. Svancara, David E. Ausband, Timothy E. Link
Summary: Knowledge of snow cover distribution and disappearance dates is crucial for understanding hydrological dynamics and wildlife habitat management. Identification of snow refugia is especially important as snow cover timing and duration change due to climate change. This study aimed to increase understanding of snow refugia in complex terrain by using remote cameras to monitor snowpack conditions. Linear models were used to relate snow disappearance dates to topoclimatic and canopy cover metrics. The models revealed that elevation, aspect, and canopy cover had significant effects on snow disappearance dates, with high-elevation, north-facing sites in cold-air pools showing the latest snow disappearance dates. In addition, in situ hydroclimate observations indicated that temperature and snow depth also influenced snow disappearance dates. This new understanding of factors influencing snow refugia can inform forest management actions and snow-dependent wildlife species management in complex terrain.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
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
Environmental Sciences
E. S. Miles, J. F. Steiner, P. Buri, W. W. Immerzeel, F. Pellicciotti
Summary: The study explores the impact of supraglacial debris, ice cliffs, and supraglacial ponds on glacier melt rates, highlighting the importance of considering these factors in global melt modeling. Results show that ice cliffs have a melt rate 2-3 times higher than clean glacier ice, with supraglacial ponds primarily influenced by latent heat exchange.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
T. D. L. Irvine-Fynn, A. Edwards, I. T. Stevens, A. C. Mitchell, P. Bunting, J. E. Box, K. A. Cameron, J. M. Cook, K. Naegeli, S. M. E. Rassner, J. C. Ryan, M. Stibal, C. J. Williamson, A. Hubbard
Summary: This study quantifies microbial abundance and cellular biomass flux in the western sector of the Greenland Ice Sheet, revealing slow interstitial water flow but high cell transport to supraglacial streams per square meter. The research suggests that cellular carbon accumulation in the weathering crust exceeds fluvial export, providing significant flux to support heterotrophs and methanogenesis at the bed.
NATURE COMMUNICATIONS
(2021)
Article
Geography, Physical
Tobias Zolles, Andreas Born
Summary: The study found that the sensitivity of the model towards individual parameters and parameterizations is uncertain in space and time, with the model being most sensitive to atmospheric emissivity and down-welling longwave radiation. During the Last Glacial Maximum period, turbulent latent heat flux dominates over the entire ice sheet, while having a smaller impact on the Greenland ice sheet in the modern climate.
Article
Geography, Physical
Tilly Woods, Ian J. Hewitt
Summary: Shortwave radiation beneath an ice-sheet surface forms a near-surface porous layer known as the weathering crust, which provides habitat to impurities and microbial life. We develop a mathematical model that incorporates thermodynamics and population dynamics to study the evolution of these layers. The model considers mass and energy conservation, radiation absorption, microbial growth mediated by melting ice nutrients, and potential feedbacks. Our findings reveal the importance of relative amounts of shortwave radiation and other heat fluxes in determining the structure of the weathering crust, explaining its formation and disappearance under different conditions, and suggesting potential changes in response to climate change.
Article
Geosciences, Multidisciplinary
Alex Winter-Billington, Ruzica Dadic, R. D. Moore, Gerald Flerchinger, Patrick Wagnon, Argha Banerjee
Summary: A new one-dimensional model of debris-covered ice ablation based on the Simultaneous Heat and Water transfer model is introduced. The study reveals that patchy snow cover in the ablation season may introduce uncertainty and deviate from the predicted relationship between ablation and debris thickness.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Environmental Sciences
Philippine Chambault, Philippe Gaspar, Florence Dell'Amico
Summary: Unusual environmental events can push marine animals outside their physiological tolerances, increasing the risk of stranding. Rescue centers play a crucial role in reporting distressed animals and tracking rehabilitated individuals. The study in the Bay of Biscay suggests that while larger sea turtles migrate to pelagic waters, smaller ones remain in the bay, crossing colder but more productive waters, potentially indicating a foraging ground for immature turtles.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Geography, Physical
Annelies Voordendag, Marion Reveillet, Shelley MacDonell, Stef Lhermitte
Summary: Physically based snow models play a crucial role in providing water availability projections by offering valuable insights into the evolution of snow cover. However, uncertainties in snow modelling persist due to differences in how snow physics and meteorological forcing are represented. This study compared two snow models, SNOWPACK and SnowModel, in a semi-arid region of the Andes in Chile, finding that sensitivity to parameters and forcing played a significant role in the results, while the choice between the two models had less impact.
Article
Geography, Physical
Basile de Fleurian, Richard Davy, Petra M. Langebroek
Summary: Record highs of meltwater production on the Greenland ice sheet have been observed in recent decades, with direct impacts on surface mass balance and sea level rise. The meltwater also affects ice dynamics through a lubrication feedback. Modeling simulations demonstrate that a longer melt season leads to faster glacier velocities for a given runoff value, while an increase in melt intensity tends to reduce glacier velocities.
Article
Geography, Physical
Joel Harper, Toby Meierbachtol, Neil Humphrey, Jun Saito, Aidan Stansberry
Summary: The study investigates the generation and fate of basal meltwater in the ablation zone of Isunnguata Sermia basin in western Greenland, finding that despite slow ice flow speeds in winter, the generation of basal meltwater remains significant, with the potential for an increase in generation rate due to winter ice flow acceleration. Additionally, analysis of basal cavity dynamics suggests that cavity expansion associated with flow acceleration may only accommodate a portion of the basal meltwater.
Article
Geography, Physical
Thomas E. Shaw, Wei Yang, Alvaro Ayala, Claudio Bravo, Chuanxi Zhao, Francesca Pellicciotti
Summary: The study compared the temperature changes on Tibetan glaciers with ambient temperatures and found that smaller glaciers are highly sensitive to external temperature changes, with the terminus being affected by warm-air processes. Local effects play a strong role in modulating temperature sensitivity near the glacier terminus.
Article
Geography, Physical
Neil F. Humphrey, Joel T. Harper, Toby W. Meierbachtol
Summary: Experiments in Greenland show that meltwater infiltration into cold firn is limited by thermal and density conditions, leading to the formation of perched aquifers rather than filling all available pore space. The results indicate that deep infiltration does not have access to all firn pore space.
JOURNAL OF GLACIOLOGY
(2021)
Article
Geography, Physical
Jonathan P. Conway, Jakob Abermann, Liss M. Andreassen, Mohd Farooq Azam, Nicolas J. Cullen, Noel Fitzpatrick, Rianne H. Giesen, Kirsty Langley, Shelley MacDonell, Thomas Moelg, Valentina Radic, Carleen H. Reijmer, Jean-Emmanuel Sicart
Summary: Clouds play a crucial role in the climate system and their impact on glacier melt varies in different climates. By analyzing datasets from 16 mountain glaciers around the world, this study reveals the complex relationships between clouds, meteorology, radiation, and surface energy balance. The results highlight the importance of considering the effect of clouds on net radiation when assessing glacier response to climate change.
Article
Geography, Physical
Horst Machguth, Andrew J. Tedstone, Enrico Mattea
Summary: The marginal areas of the Greenland ice sheet develop streams and lakes each summer, indicating the important role of surface runoff in the ice-sheet mass balance. This study maps the extent of surface runoff using MODIS data from 2000 to 2021 and finds an increasing trend in maximum slush limits until 2012. The data also suggest that the upward migration of surface runoff in 2012 stopped early due to thick ice layers near the surface.
JOURNAL OF GLACIOLOGY
(2023)
Article
Geography, Physical
Thomas E. Shaw, Genesis Ulloa, David Farias-Barahona, Rodrigo Fernandez, Jose M. Lattus, James McPhee
Summary: Glacier albedo in the central Chilean Andes exhibits high inter-annual variability, primarily influenced by snow cover and precipitation of preceding hydrological years. During the 2010-2020 'Mega Drought' period, there was an average decrease of 0.05 in glacier albedo, with a greater reduction observed at higher elevations. In 2020, the average decrease relative to 1986-2009 was 0.14 due to the lack of late summer snow cover and significantly reduced precipitation.
JOURNAL OF GLACIOLOGY
(2021)
Article
Environmental Sciences
Francisco Jara, Miguel Lagos-Zuniga, Rodrigo Fuster, Cristian Mattar, James McPhee
Summary: Seasonal snow and glaciers in arid mountain regions play a crucial role in sustaining human populations, economic activity, and ecosystems as reservoirs, but they are threatened by global warming. This study found that under warmer climates, the snowpack will be insensitive in high elevations, while liquid precipitation will increase at lower heights.
Article
Engineering, Civil
Alba Sanmiguel-Vallelado, James McPhee, Paula Esmeralda Ojeda Carreno, Enrique Moran-Tejeda, J. Julio Camarero, Juan Ignacio Lopez-Moreno
Summary: This study analyzes the response of forest-snow interactions to temperature and precipitation changes in four forests near the Spanish Pyrenees. Through simulations and sensitivity analysis, it was found that forest cover exhibits topographic variability in its sensitivity to climate change.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Raul R. Cordero, Edgardo Sepulveda, Sarah Feron, Chenghao Wang, Alessandro Damiani, Francisco Fernandoy, Steven Neshyba, Penny M. Rowe, Valentina Asencio, Jorge Carrasco, Juan A. Alfonso, Shelley MacDonell, Gunther Seckmeyer, Juan M. Carrera, Jose Jorquera, Pedro Llanillo, Jacob Dana, Alia L. Khan, Gino Casassa
Summary: The Andean snowpack is a crucial water source for communities but is sensitive to black carbon (BC) deposition, which accelerates melting. Measurements show BC concentrations ranging from 2 to 15 ng g(-1), with heavily impacted areas experiencing seasonal snowpack shrinking up to 241 mm water equivalent.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Arno C. Hammann, Shelley MacDonell
Summary: This study designs and compares several methods to estimate the impact of singular disruptive events on meteorological variables at the earth's surface, using observational data from individual meteorological surface stations. The study focuses on the effect of the total solar eclipse of July 2nd, 2019, in the Coquimbo Region of Chile, on near-surface air temperatures and winds. The results show that most stations registered a temperature drop of 1-2 degrees C, with some experiencing a drop of over 6 degrees C.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
Ivan Vergara, Rene Garreaud, Alvaro Ayala
Summary: This study investigates the variability of extreme turbidity events (ETE) in the glacierized Maipo River basin in the Andes, finding a significant increase in frequency and annual number of these events over the past three decades. The increase is likely influenced by glacier melt and regional warming and drying trends.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Geosciences, Multidisciplinary
Simone Schauwecker, Gabriel Palma, Shelley MacDonell, Alvaro Ayala, Maximiliano Viale
Summary: Understanding the variability of the snowline and the 0 degrees C isotherm during infrequent precipitation events in the dry Andes in Chile is crucial for precipitation, snow cover, and discharge predictions. By gathering snowline photographs and validating them with observed data and reanalysis data, the study reveals a mesoscale lowering of the 0 degrees C isotherm over the windward slopes and the presence of a near-freezing isothermal layer during precipitation events.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Environmental Sciences
Octavio Murillo, Pablo A. Mendoza, Nicolas Vasquez, Naoki Mizukami, Alvaro Ayala
Summary: The implementation of elevation bands has implications for snowpack modeling, particularly in terms of precipitation distribution, snowmelt, sublimation, and snow water equivalent. These implications may vary with climate conditions and vertical discretization.
WATER RESOURCES RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Thomas E. Shaw, Pascal Buri, Michael McCarthy, Evan S. Miles, Alvaro Ayala, Francesca Pellicciotti
Summary: The presence of a developed boundary layer decouples a glacier's response from ambient conditions, suggesting that sensitivity to climate change is increased by glacier retreat. To test this hypothesis, six years of distributed meteorological data on a small Swiss glacier in the period 2001-2022 were analyzed. The results show that there has been a significant reduction in glacier area (-35% change up to 2022) accompanied by frontal retreat, a switch in wind patterns, and increased sensitivity of on-glacier temperature to off-glacier temperature. These findings indicate that as the climate continues to warm and extreme summers become more frequent, the demise of the glacier is sealed due to the absence of density-driven katabatic winds.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geography, Physical
Shelley Macdonell, Paloma Nunez Farias, Valentina Aliste, Alvaro Ayala, Camilo Guzman, Patricio Jofre Diaz, Nicole Schaffer, Simone Schauwecker, Eric A. Sproles, Eduardo Yanez San Francisco
Summary: This paper discusses the importance of community engagement and explores how such engagement can strengthen cryospheric science research and empower local communities.
ANNALS OF GLACIOLOGY
(2022)
Article
Geography, Physical
Nicole Schaffer, Shelley MacDonell
Summary: The importance of Andean glaciers as water resources has been recognized in the past two decades. Laws have been enacted in Chile and Argentina to protect the glaciers, but they are limited in their effectiveness. The authors propose a classification system based on the sensitivity of glaciers to environmental changes, which can be adapted to meet the specific needs of different regions and evolve over time. The classification system can facilitate the evaluation and management of water resources.
Article
Geography, Physical
Giulia de Pasquale, Remi Valois, Nicole Schaffer, Shelley MacDonell
Summary: This study presents the geophysical measurements and interpretations of two contrasting rock glaciers in the Chilean Andes. The results confirm significant differences in hydrological roles between intact and relict rock glaciers, and propose a diagnostic model to differentiate between them.
Article
Geography, Physical
Benjamin Aubrey Robson, Shelley MacDonell, Alvaro Ayala, Tobias Bolch, Pal Ringkjob Nielsen, Sebastian Vivero
Summary: Glaciers and rock glaciers in the semi-arid northern Chile have shown different responses to climate change. Most glaciers in the region have rapidly lost mass over the last few decades, while the changes in rock glaciers are less understood. Climatological analyses indicate a general increase in air temperature, decrease in humidity, and variable precipitation since the 1980s. Severe droughts since 2010 have led to negative mass balances for both glaciers and rock glaciers in the area.