Articles | Volume 13, issue 11
https://doi.org/10.5194/tc-13-2797-2019
© Author(s) 2019. 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-13-2797-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
04 Nov 2019
Research article |
| 04 Nov 2019
| 04 Nov 2019
Recent precipitation decrease across the western Greenland ice sheet percolation zone
Gabriel Lewis
CORRESPONDING AUTHOR
Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
Erich Osterberg
Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
Robert Hawley
Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
Hans Peter Marshall
Geosciences Department, Boise State University, Boise, ID, USA
Tate Meehan
Geosciences Department, Boise State University, Boise, ID, USA
Karina Graeter
Office of Sustainability, University of Maine, Orono, ME, USA
Forrest McCarthy
College of Fisheries and Ocean Sciences, University of Alaska
Fairbanks, Fairbanks, AK, USA
Thomas Overly
NASA Cryospheric Sciences Laboratory, NASA Goddard Space Flight
Center, Greenbelt, MD, USA
Earth System Science Interdisciplinary Center (ESSIC), University of
Maryland, College Park, MD, USA
Zayta Thundercloud
Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
David Ferris
Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
Related authors
Helle Astrid Kjær, Patrick Zens, Ross Edwards, Martin Olesen, Ruth Mottram, Gabriel Lewis, Christian Terkelsen Holme, Samuel Black, Kasper Holst Lund, Mikkel Schmidt, Dorthe Dahl-Jensen, Bo Vinther, Anders Svensson, Nanna Karlsson, Jason E. Box, Sepp Kipfstuhl, and Paul Vallelonga
The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-337, https://doi.org/10.5194/tc-2020-337, 2021
Manuscript not accepted for further review
Short summary
Short summary
We have reconstructed accumulation in 6 firn cores and 8 snow cores in Northern Greenland and compared with a regional Climate model over Greenland. We find the model underestimate precipitation especially in north-eastern part of the ice cap- an important finding if aiming to reconstruct surface mass balance.
Temperatures at 10 meters depth at 6 sites in Greenland were also determined and show a significant warming since the 1990's of 0.9 to 2.5 °C.
Alexandra Giese, Steven Arcone, Robert Hawley, Gabriel Lewis, and Patrick Wagnon
The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-60, https://doi.org/10.5194/tc-2019-60, 2019
Preprint withdrawn
Short summary
Short summary
This manuscript defines a novel method of determining the depth of debris on a debris-covered glacier using 960 MHz Ground-Penetrating Radar, under circumstances which prevent the detection of a coherent reflection at the debris-ice interface. Our method was verified using full-scale debris-analog experiments and uses internal scattering within the debris layer. We use this method to measure debris thickness on Changri Nup Glacier, in the Nepal Himalaya.
Gabriel Lewis, Erich Osterberg, Robert Hawley, Brian Whitmore, Hans Peter Marshall, and Jason Box
The Cryosphere, 11, 773–788, https://doi.org/10.5194/tc-11-773-2017, https://doi.org/10.5194/tc-11-773-2017, 2017
Short summary
Short summary
We analyze 25 flight lines from NASA's Operation IceBridge Accumulation Radar totaling to determine snow accumulation throughout the dry snow and percolation zone of the Greenland Ice Sheet. Our results indicate that regional differences between IceBridge and model accumulation are large enough to significantly alter the Greenland Ice Sheet surface mass balance, with implications for future global sea-level rise.
Derek James Pickell, Robert Lyman Hawley, and Adam LeWinter
EGUsphere, https://doi.org/10.5194/egusphere-2024-2898, https://doi.org/10.5194/egusphere-2024-2898, 2024
Short summary
Short summary
We use a low-cost GNSS network to measure surface accumulation and roughness in Greenland's interior. We find the technique is sensitive to areas 4–20 meters from the GNSS antenna, which sits 1–2 meters above the ground. Results highlight seasonal changes in surface roughness, influenced by wind and snow events, but suggest other factors also play a role. This method of measuring roughness provides an easy and novel way of obtaining these measurements autonomously in remote snowy regions.
Ursula A. Jongebloed, Jacob I. Chalif, Linia Tashmim, William C. Porter, Kelvin H. Bates, Qianjie Chen, Erich C. Osterberg, Bess G. Koffman, Jihong Cole-Dai, Dominic A. Winksi, David G. Ferris, Karl J. Kreutz, Cameron P. Wake, and Becky Alexander
EGUsphere, https://doi.org/10.5194/egusphere-2024-3026, https://doi.org/10.5194/egusphere-2024-3026, 2024
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Marine phytoplankton emit dimethyl sulfide (DMS), which forms methanesulfonic acid (MSA) and sulfate. MSA concentrations in ice cores decreased over the industrial era, which has been attributed to pollution-driven changes in DMS chemistry. We use a models to investigate DMS chemistry compared to observations of DMS, MSA, and sulfate. We find that modeled DMS, MSA, and sulfate are influenced by pollution-sensitive oxidant concentrations, characterization of DMS chemistry, and other variables.
Murat Aydin, Melinda R. Nicewonger, Gregory L. Britten, Dominic Winski, Mary Whelan, John D. Patterson, Erich Osterberg, Christopher F. Lee, Tara Harder, Kyle J. Callahan, David Ferris, and Eric S. Saltzman
Clim. Past, 20, 1885–1917, https://doi.org/10.5194/cp-20-1885-2024, https://doi.org/10.5194/cp-20-1885-2024, 2024
Short summary
Short summary
We present a new ice core carbonyl sulfide (COS) record from the South Pole, Antarctica, yielding a 52 000-year atmospheric record after correction for production in the ice sheet. The results display a large increase in atmospheric COS concurrent with the last deglaciation. The deglacial COS rise results from an overall strengthening of atmospheric COS sources, implying a large increase in ocean sulfur gas emissions. Atmospheric sulfur gases have negative climate feedbacks.
Randall Bonnell, Daniel McGrath, Jack Tarricone, Hans-Peter Marshall, Ella Bump, Caroline Duncan, Stephanie Kampf, Yunling Lou, Alex Olsen-Mikitowicz, Megan Sears, Keith Williams, Lucas Zeller, and Yang Zheng
The Cryosphere, 18, 3765–3785, https://doi.org/10.5194/tc-18-3765-2024, https://doi.org/10.5194/tc-18-3765-2024, 2024
Short summary
Short summary
Snow provides water for billions of people, but the amount of snow is difficult to detect remotely. During the 2020 and 2021 winters, a radar was flown over mountains in Colorado, USA, to measure the amount of snow on the ground, while our team collected ground observations to test the radar technique’s capabilities. The technique yielded accurate measurements of the snowpack that had good correlation with ground measurements, making it a promising application for the upcoming NISAR satellite.
Tate G. Meehan, Ahmad Hojatimalekshah, Hans-Peter Marshall, Elias J. Deeb, Shad O'Neel, Daniel McGrath, Ryan W. Webb, Randall Bonnell, Mark S. Raleigh, Christopher Hiemstra, and Kelly Elder
The Cryosphere, 18, 3253–3276, https://doi.org/10.5194/tc-18-3253-2024, https://doi.org/10.5194/tc-18-3253-2024, 2024
Short summary
Short summary
Snow water equivalent (SWE) is a critical parameter for yearly water supply forecasting and can be calculated by multiplying the snow depth by the snow density. We combined high-spatial-resolution snow depth information with ground-based radar measurements to solve for snow density. Extrapolated density estimates over our study area resolved detailed patterns that agree with the known interactions of snow with wind, terrain, and vegetation and were utilized in the calculation of SWE.
Isis Brangers, Hans-Peter Marshall, Gabrielle De Lannoy, Devon Dunmire, Christian Mätzler, and Hans Lievens
The Cryosphere, 18, 3177–3193, https://doi.org/10.5194/tc-18-3177-2024, https://doi.org/10.5194/tc-18-3177-2024, 2024
Short summary
Short summary
To better understand the interactions between C-band radar waves and snow, a tower-based experiment was set up in the Idaho Rocky Mountains. The reflections were collected in the time domain to measure the backscatter profile from the various snowpack and ground surface layers. The results demonstrate that C-band radar is sensitive to seasonal patterns in snow accumulation but that changes in microstructure, stratigraphy and snow wetness may complicate satellite-based snow depth retrievals.
Alexander Ronan, Robert Hawley, and Jonathan Chipman
EGUsphere, https://doi.org/10.5194/egusphere-2024-1152, https://doi.org/10.5194/egusphere-2024-1152, 2024
Short summary
Short summary
We generate a 2010–2021 time series of CryoSat-2 waveform shape metrics on the Greenland Ice Sheet, and compare it to CryoSat-2 elevation data, to investigate the reliability of two algorithms used to derive elevations from the SIRAL radar altimeter. Retracked elevations are found to depend on a waveform's leading-edge width in the dry snow zone. The study indicates that retracking algorithms must consider significant climate events and snow conditions when assessing elevation change.
Ian E. McDowell, Kaitlin M. Keegan, S. McKenzie Skiles, Christopher P. Donahue, Erich C. Osterberg, Robert L. Hawley, and Hans-Peter Marshall
The Cryosphere, 18, 1925–1946, https://doi.org/10.5194/tc-18-1925-2024, https://doi.org/10.5194/tc-18-1925-2024, 2024
Short summary
Short summary
Accurate knowledge of firn grain size is crucial for many ice sheet research applications. Unfortunately, collecting detailed measurements of firn grain size is difficult. We demonstrate that scanning firn cores with a near-infrared imager can quickly produce high-resolution maps of both grain size and ice layer distributions. We map grain size and ice layer stratigraphy in 14 firn cores from Greenland and document changes to grain size and ice layer content from the extreme melt summer of 2012.
Zachary Hoppinen, Ross T. Palomaki, George Brencher, Devon Dunmire, Eric Gagliano, Adrian Marziliano, Jack Tarricone, and Hans-Peter Marshall
EGUsphere, https://doi.org/10.5194/egusphere-2024-1018, https://doi.org/10.5194/egusphere-2024-1018, 2024
Short summary
Short summary
This study uses radar imagery from the Sentinel-1 satellite to derive snow depth from increases in the returning energy. These retrieved depths are then compared to nine lidar derived snow depths across the western United State to assess the ability of this technique to be used to monitor global snow distributions. We also qualitatively compare the changes in underlying Sentinel-1 amplitudes against both the total lidar snow depths and 9 automated snow monitoring stations.
Rainey Aberle, Ellyn Enderlin, Shad O'Neel, Caitlyn Florentine, Louis Sass, Adam Dickson, Hans-Peter Marshall, and Alejandro Flores
EGUsphere, https://doi.org/10.5194/egusphere-2024-548, https://doi.org/10.5194/egusphere-2024-548, 2024
Short summary
Short summary
Tracking seasonal snow on glaciers is critical for understanding glacier health. However, current snow detection methods struggle to distinguish seasonal snow from glacier ice. To address this, we developed a new automated workflow for tracking seasonal snow on glaciers using satellite imagery and machine learning. Applying this method can help provide insights into glacier health, water resources, and the effects of climate change on snow cover over broad spatial scales.
Shadi Oveisgharan, Robert Zinke, Zachary Hoppinen, and Hans Peter Marshall
The Cryosphere, 18, 559–574, https://doi.org/10.5194/tc-18-559-2024, https://doi.org/10.5194/tc-18-559-2024, 2024
Short summary
Short summary
The seasonal snowpack provides water resources to billions of people worldwide. Large-scale mapping of snow water equivalent (SWE) with high resolution is critical for many scientific and economics fields. In this work we used the radar remote sensing interferometric synthetic aperture radar (InSAR) to estimate the SWE change between 2 d. The error in the estimated SWE change is less than 2 cm for in situ stations. Additionally, the retrieved SWE using InSAR is correlated with lidar snow depth.
Zachary Hoppinen, Shadi Oveisgharan, Hans-Peter Marshall, Ross Mower, Kelly Elder, and Carrie Vuyovich
The Cryosphere, 18, 575–592, https://doi.org/10.5194/tc-18-575-2024, https://doi.org/10.5194/tc-18-575-2024, 2024
Short summary
Short summary
We used changes in radar echo travel time from multiple airborne flights to estimate changes in snow depths across Idaho for two winters. We compared our radar-derived retrievals to snow pits, weather stations, and a 100 m resolution numerical snow model. We had a strong Pearson correlation and root mean squared error of 10 cm relative to in situ measurements. Our retrievals also correlated well with our model, especially in regions of dry snow and low tree coverage.
Ling Fang, Theo M. Jenk, Dominic Winski, Karl Kreutz, Hanna L. Brooks, Emma Erwin, Erich Osterberg, Seth Campbell, Cameron Wake, and Margit Schwikowski
The Cryosphere, 17, 4007–4020, https://doi.org/10.5194/tc-17-4007-2023, https://doi.org/10.5194/tc-17-4007-2023, 2023
Short summary
Short summary
Understanding the behavior of ocean–atmosphere teleconnections in the North Pacific during warm intervals can aid in predicting future warming scenarios. However, majority ice core records from Alaska–Yukon region only provide data for the last few centuries. This study introduces a continuous chronology for Denali ice core from Begguya, Alaska, using multiple dating methods. The early-Holocene-origin Denali ice core will facilitate future investigations of hydroclimate in the North Pacific.
Jack Tarricone, Ryan W. Webb, Hans-Peter Marshall, Anne W. Nolin, and Franz J. Meyer
The Cryosphere, 17, 1997–2019, https://doi.org/10.5194/tc-17-1997-2023, https://doi.org/10.5194/tc-17-1997-2023, 2023
Short summary
Short summary
Mountain snowmelt provides water for billions of people across the globe. Despite its importance, we cannot currently measure the amount of water in mountain snowpacks from satellites. In this research, we test the ability of an experimental snow remote sensing technique from an airplane in preparation for the same sensor being launched on a future NASA satellite. We found that the method worked better than expected for estimating important snowpack properties.
Aaron Chesler, Dominic Winski, Karl Kreutz, Bess Koffman, Erich Osterberg, David Ferris, Zayta Thundercloud, Joseph Mohan, Jihong Cole-Dai, Mark Wells, Michael Handley, Aaron Putnam, Katherine Anderson, and Natalie Harmon
Clim. Past, 19, 477–492, https://doi.org/10.5194/cp-19-477-2023, https://doi.org/10.5194/cp-19-477-2023, 2023
Short summary
Short summary
Ice core microparticle data typically use geometry assumptions to calculate particle mass and flux. We use dynamic particle imaging, a novel technique for ice core dust analyses, combined with traditional laser particle counting and Coulter counter techniques to assess particle shape in the South Pole Ice Core (SPC14) spanning 50–16 ka. Our results suggest that particles are dominantly ellipsoidal in shape and that spherical assumptions overestimate particle mass and flux.
Leung Tsang, Michael Durand, Chris Derksen, Ana P. Barros, Do-Hyuk Kang, Hans Lievens, Hans-Peter Marshall, Jiyue Zhu, Joel Johnson, Joshua King, Juha Lemmetyinen, Melody Sandells, Nick Rutter, Paul Siqueira, Anne Nolin, Batu Osmanoglu, Carrie Vuyovich, Edward Kim, Drew Taylor, Ioanna Merkouriadi, Ludovic Brucker, Mahdi Navari, Marie Dumont, Richard Kelly, Rhae Sung Kim, Tien-Hao Liao, Firoz Borah, and Xiaolan Xu
The Cryosphere, 16, 3531–3573, https://doi.org/10.5194/tc-16-3531-2022, https://doi.org/10.5194/tc-16-3531-2022, 2022
Short summary
Short summary
Snow water equivalent (SWE) is of fundamental importance to water, energy, and geochemical cycles but is poorly observed globally. Synthetic aperture radar (SAR) measurements at X- and Ku-band can address this gap. This review serves to inform the broad snow research, monitoring, and application communities about the progress made in recent decades to move towards a new satellite mission capable of addressing the needs of the geoscience researchers and users.
Juha Lemmetyinen, Juval Cohen, Anna Kontu, Juho Vehviläinen, Henna-Reetta Hannula, Ioanna Merkouriadi, Stefan Scheiblauer, Helmut Rott, Thomas Nagler, Elisabeth Ripper, Kelly Elder, Hans-Peter Marshall, Reinhard Fromm, Marc Adams, Chris Derksen, Joshua King, Adriano Meta, Alex Coccia, Nick Rutter, Melody Sandells, Giovanni Macelloni, Emanuele Santi, Marion Leduc-Leballeur, Richard Essery, Cecile Menard, and Michael Kern
Earth Syst. Sci. Data, 14, 3915–3945, https://doi.org/10.5194/essd-14-3915-2022, https://doi.org/10.5194/essd-14-3915-2022, 2022
Short summary
Short summary
The manuscript describes airborne, dual-polarised X and Ku band synthetic aperture radar (SAR) data collected over several campaigns over snow-covered terrain in Finland, Austria and Canada. Colocated snow and meteorological observations are also presented. The data are meant for science users interested in investigating X/Ku band radar signatures from natural environments in winter conditions.
Hans Lievens, Isis Brangers, Hans-Peter Marshall, Tobias Jonas, Marc Olefs, and Gabriëlle De Lannoy
The Cryosphere, 16, 159–177, https://doi.org/10.5194/tc-16-159-2022, https://doi.org/10.5194/tc-16-159-2022, 2022
Short summary
Short summary
Snow depth observations at high spatial resolution from the Sentinel-1 satellite mission are presented over the European Alps. The novel observations can improve our knowledge of seasonal snow mass in areas with complex topography, where satellite-based estimates are currently lacking, and benefit a number of applications including water resource management, flood forecasting, and numerical weather prediction.
Ahmad Hojatimalekshah, Zachary Uhlmann, Nancy F. Glenn, Christopher A. Hiemstra, Christopher J. Tennant, Jake D. Graham, Lucas Spaete, Arthur Gelvin, Hans-Peter Marshall, James P. McNamara, and Josh Enterkine
The Cryosphere, 15, 2187–2209, https://doi.org/10.5194/tc-15-2187-2021, https://doi.org/10.5194/tc-15-2187-2021, 2021
Short summary
Short summary
We describe the relationships between snow depth, vegetation canopy, and local-scale processes during the snow accumulation period using terrestrial laser scanning (TLS). In addition to topography and wind, our findings suggest the importance of fine-scale tree structure, species type, and distributions on snow depth. Snow depth increases from the canopy edge toward the open areas, but wind and topographic controls may affect this trend. TLS data are complementary to wide-area lidar surveys.
Rhae Sung Kim, Sujay Kumar, Carrie Vuyovich, Paul Houser, Jessica Lundquist, Lawrence Mudryk, Michael Durand, Ana Barros, Edward J. Kim, Barton A. Forman, Ethan D. Gutmann, Melissa L. Wrzesien, Camille Garnaud, Melody Sandells, Hans-Peter Marshall, Nicoleta Cristea, Justin M. Pflug, Jeremy Johnston, Yueqian Cao, David Mocko, and Shugong Wang
The Cryosphere, 15, 771–791, https://doi.org/10.5194/tc-15-771-2021, https://doi.org/10.5194/tc-15-771-2021, 2021
Short summary
Short summary
High SWE uncertainty is observed in mountainous and forested regions, highlighting the need for high-resolution snow observations in these regions. Substantial uncertainty in snow water storage in Tundra regions and the dominance of water storage in these regions points to the need for high-accuracy snow estimation. Finally, snow measurements during the melt season are most needed at high latitudes, whereas observations at near peak snow accumulations are most beneficial over the midlatitudes.
Helle Astrid Kjær, Patrick Zens, Ross Edwards, Martin Olesen, Ruth Mottram, Gabriel Lewis, Christian Terkelsen Holme, Samuel Black, Kasper Holst Lund, Mikkel Schmidt, Dorthe Dahl-Jensen, Bo Vinther, Anders Svensson, Nanna Karlsson, Jason E. Box, Sepp Kipfstuhl, and Paul Vallelonga
The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-337, https://doi.org/10.5194/tc-2020-337, 2021
Manuscript not accepted for further review
Short summary
Short summary
We have reconstructed accumulation in 6 firn cores and 8 snow cores in Northern Greenland and compared with a regional Climate model over Greenland. We find the model underestimate precipitation especially in north-eastern part of the ice cap- an important finding if aiming to reconstruct surface mass balance.
Temperatures at 10 meters depth at 6 sites in Greenland were also determined and show a significant warming since the 1990's of 0.9 to 2.5 °C.
Jenna A. Epifanio, Edward J. Brook, Christo Buizert, Jon S. Edwards, Todd A. Sowers, Emma C. Kahle, Jeffrey P. Severinghaus, Eric J. Steig, Dominic A. Winski, Erich C. Osterberg, Tyler J. Fudge, Murat Aydin, Ekaterina Hood, Michael Kalk, Karl J. Kreutz, David G. Ferris, and Joshua A. Kennedy
Clim. Past, 16, 2431–2444, https://doi.org/10.5194/cp-16-2431-2020, https://doi.org/10.5194/cp-16-2431-2020, 2020
Short summary
Short summary
A new ice core drilled at the South Pole provides a 54 000-year paleo-environmental record including the composition of the past atmosphere. This paper describes the gas chronology for the South Pole ice core, based on a high-resolution methane record. The new gas chronology, in combination with the existing ice age scale from Winski et al. (2019), allows a model-independent reconstruction of the delta age record.
Miguel A. Aguayo, Alejandro N. Flores, James P. McNamara, Hans-Peter Marshall, and Jodi Mead
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2020-451, https://doi.org/10.5194/hess-2020-451, 2020
Manuscript not accepted for further review
Alexandra Giese, Aaron Boone, Patrick Wagnon, and Robert Hawley
The Cryosphere, 14, 1555–1577, https://doi.org/10.5194/tc-14-1555-2020, https://doi.org/10.5194/tc-14-1555-2020, 2020
Short summary
Short summary
Rocky debris on glacier surfaces is known to affect the melt of mountain glaciers. Debris can be dry or filled to varying extents with liquid water and ice; whether debris is dry, wet, and/or icy affects how efficiently heat is conducted through debris from its surface to the ice interface. Our paper presents a new energy balance model that simulates moisture phase, evolution, and location in debris. ISBA-DEB is applied to West Changri Nup glacier in Nepal to reveal important physical processes.
Colin R. Meyer, Kaitlin M. Keegan, Ian Baker, and Robert L. Hawley
The Cryosphere, 14, 1449–1458, https://doi.org/10.5194/tc-14-1449-2020, https://doi.org/10.5194/tc-14-1449-2020, 2020
Short summary
Short summary
We describe snow compaction laboratory data with a new mathematical model. Using a compression device that is similar to a French press with snow instead of coffee grounds, Wang and Baker (2013) compacted numerous snow samples of different densities at a constant velocity to determine the force required for snow compaction. Our mathematical model for compaction includes airflow through snow and predicts the required force, in agreement with the experimental data.
Dominic A. Winski, Tyler J. Fudge, David G. Ferris, Erich C. Osterberg, John M. Fegyveresi, Jihong Cole-Dai, Zayta Thundercloud, Thomas S. Cox, Karl J. Kreutz, Nikolas Ortman, Christo Buizert, Jenna Epifanio, Edward J. Brook, Ross Beaudette, Jeffrey Severinghaus, Todd Sowers, Eric J. Steig, Emma C. Kahle, Tyler R. Jones, Valerie Morris, Murat Aydin, Melinda R. Nicewonger, Kimberly A. Casey, Richard B. Alley, Edwin D. Waddington, Nels A. Iverson, Nelia W. Dunbar, Ryan C. Bay, Joseph M. Souney, Michael Sigl, and Joseph R. McConnell
Clim. Past, 15, 1793–1808, https://doi.org/10.5194/cp-15-1793-2019, https://doi.org/10.5194/cp-15-1793-2019, 2019
Short summary
Short summary
A deep ice core was recently drilled at the South Pole to understand past variations in the Earth's climate. To understand the information contained within the ice, we present the relationship between the depth and age of the ice in the South Pole Ice Core. We found that the oldest ice in our record is from 54 302 ± 519 years ago. Our results show that, on average, 7.4 cm of snow falls at the South Pole each year.
Alexandra Giese, Steven Arcone, Robert Hawley, Gabriel Lewis, and Patrick Wagnon
The Cryosphere Discuss., https://doi.org/10.5194/tc-2019-60, https://doi.org/10.5194/tc-2019-60, 2019
Preprint withdrawn
Short summary
Short summary
This manuscript defines a novel method of determining the depth of debris on a debris-covered glacier using 960 MHz Ground-Penetrating Radar, under circumstances which prevent the detection of a coherent reflection at the debris-ice interface. Our method was verified using full-scale debris-analog experiments and uses internal scattering within the debris layer. We use this method to measure debris thickness on Changri Nup Glacier, in the Nepal Himalaya.
Daniel McGrath, Louis Sass, Shad O'Neel, Chris McNeil, Salvatore G. Candela, Emily H. Baker, and Hans-Peter Marshall
The Cryosphere, 12, 3617–3633, https://doi.org/10.5194/tc-12-3617-2018, https://doi.org/10.5194/tc-12-3617-2018, 2018
Short summary
Short summary
Measuring the amount and spatial pattern of snow on glaciers is essential for monitoring glacier mass balance and quantifying the water budget of glacierized basins. Using repeat radar surveys for 5 consecutive years, we found that the spatial pattern in snow distribution is stable over the majority of the glacier and scales with the glacier-wide average. Our findings support the use of sparse stake networks for effectively measuring interannual variability in winter balance on glaciers.
Nancy A. N. Bertler, Howard Conway, Dorthe Dahl-Jensen, Daniel B. Emanuelsson, Mai Winstrup, Paul T. Vallelonga, James E. Lee, Ed J. Brook, Jeffrey P. Severinghaus, Taylor J. Fudge, Elizabeth D. Keller, W. Troy Baisden, Richard C. A. Hindmarsh, Peter D. Neff, Thomas Blunier, Ross Edwards, Paul A. Mayewski, Sepp Kipfstuhl, Christo Buizert, Silvia Canessa, Ruzica Dadic, Helle A. Kjær, Andrei Kurbatov, Dongqi Zhang, Edwin D. Waddington, Giovanni Baccolo, Thomas Beers, Hannah J. Brightley, Lionel Carter, David Clemens-Sewall, Viorela G. Ciobanu, Barbara Delmonte, Lukas Eling, Aja Ellis, Shruthi Ganesh, Nicholas R. Golledge, Skylar Haines, Michael Handley, Robert L. Hawley, Chad M. Hogan, Katelyn M. Johnson, Elena Korotkikh, Daniel P. Lowry, Darcy Mandeno, Robert M. McKay, James A. Menking, Timothy R. Naish, Caroline Noerling, Agathe Ollive, Anaïs Orsi, Bernadette C. Proemse, Alexander R. Pyne, Rebecca L. Pyne, James Renwick, Reed P. Scherer, Stefanie Semper, Marius Simonsen, Sharon B. Sneed, Eric J. Steig, Andrea Tuohy, Abhijith Ulayottil Venugopal, Fernando Valero-Delgado, Janani Venkatesh, Feitang Wang, Shimeng Wang, Dominic A. Winski, V. Holly L. Winton, Arran Whiteford, Cunde Xiao, Jiao Yang, and Xin Zhang
Clim. Past, 14, 193–214, https://doi.org/10.5194/cp-14-193-2018, https://doi.org/10.5194/cp-14-193-2018, 2018
Short summary
Short summary
Temperature and snow accumulation records from the annually dated Roosevelt Island Climate Evolution (RICE) ice core show that for the past 2 700 years, the eastern Ross Sea warmed, while the western Ross Sea showed no trend and West Antarctica cooled. From the 17th century onwards, this dipole relationship changed. Now all three regions show concurrent warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea.
Gabriel Lewis, Erich Osterberg, Robert Hawley, Brian Whitmore, Hans Peter Marshall, and Jason Box
The Cryosphere, 11, 773–788, https://doi.org/10.5194/tc-11-773-2017, https://doi.org/10.5194/tc-11-773-2017, 2017
Short summary
Short summary
We analyze 25 flight lines from NASA's Operation IceBridge Accumulation Radar totaling to determine snow accumulation throughout the dry snow and percolation zone of the Greenland Ice Sheet. Our results indicate that regional differences between IceBridge and model accumulation are large enough to significantly alter the Greenland Ice Sheet surface mass balance, with implications for future global sea-level rise.
Kelly M. Brunt, Robert L. Hawley, Eric R. Lutz, Michael Studinger, John G. Sonntag, Michelle A. Hofton, Lauren C. Andrews, and Thomas A. Neumann
The Cryosphere, 11, 681–692, https://doi.org/10.5194/tc-11-681-2017, https://doi.org/10.5194/tc-11-681-2017, 2017
Short summary
Short summary
This manuscript presents an analysis of NASA airborne lidar data based on in situ GPS measurements from the interior of the Greenland Ice Sheet. Results show that for two airborne altimeters, surface elevation biases are less than 0.12 m and measurement precisions are 0.09 m or better. The study concludes that two NASA airborne lidars are sufficiently characterized to form part of a satellite data validation strategy, specifically for ICESat-2, scheduled to launch in 2018.
Thomas B. Overly, Robert L. Hawley, Veit Helm, Elizabeth M. Morris, and Rohan N. Chaudhary
The Cryosphere, 10, 1679–1694, https://doi.org/10.5194/tc-10-1679-2016, https://doi.org/10.5194/tc-10-1679-2016, 2016
Short summary
Short summary
We demonstrate that snow accumulation rates across the Greenland Ice Sheet, determined from RADAR layers and modeled snow density profiles, are identical to ground-based measurements of snow accumulation. Three regional climate models underestimate snow accumulation compared to RADAR layer estimates. Using RADAR increases spatial coverage and improves accuracy of snow accumulation estimates. Incorporating our results into climate models may reduce uncertainty of sea-level rise estimates.
Michael Sigl, Tyler J. Fudge, Mai Winstrup, Jihong Cole-Dai, David Ferris, Joseph R. McConnell, Ken C. Taylor, Kees C. Welten, Thomas E. Woodruff, Florian Adolphi, Marion Bisiaux, Edward J. Brook, Christo Buizert, Marc W. Caffee, Nelia W. Dunbar, Ross Edwards, Lei Geng, Nels Iverson, Bess Koffman, Lawrence Layman, Olivia J. Maselli, Kenneth McGwire, Raimund Muscheler, Kunihiko Nishiizumi, Daniel R. Pasteris, Rachael H. Rhodes, and Todd A. Sowers
Clim. Past, 12, 769–786, https://doi.org/10.5194/cp-12-769-2016, https://doi.org/10.5194/cp-12-769-2016, 2016
Short summary
Short summary
Here we present a chronology (WD2014) for the upper part (0–2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide ice core, which is based on layer counting of distinctive annual cycles preserved in the elemental, chemical and electrical conductivity records. We validated the chronology by comparing it to independent high-accuracy, absolutely dated chronologies. Given its demonstrated high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere.
M. P. Lüthi, C. Ryser, L. C. Andrews, G. A. Catania, M. Funk, R. L. Hawley, M. J. Hoffman, and T. A. Neumann
The Cryosphere, 9, 245–253, https://doi.org/10.5194/tc-9-245-2015, https://doi.org/10.5194/tc-9-245-2015, 2015
Short summary
Short summary
We analyze the thermal structure of the Greenland Ice Sheet with a heat flow model. New borehole measurements indicate that more heat is stored within the ice than would be expected from heat diffusion alone. We conclude that temperate paleo-firn and cyro-hydrologic warming are essential processes that explain the measurements.
L. Gray, D. Burgess, L. Copland, R. Cullen, N. Galin, R. Hawley, and V. Helm
The Cryosphere, 7, 1857–1867, https://doi.org/10.5194/tc-7-1857-2013, https://doi.org/10.5194/tc-7-1857-2013, 2013
B. F. Morriss, R. L. Hawley, J. W. Chipman, L. C. Andrews, G. A. Catania, M. J. Hoffman, M. P. Lüthi, and T. A. Neumann
The Cryosphere, 7, 1869–1877, https://doi.org/10.5194/tc-7-1869-2013, https://doi.org/10.5194/tc-7-1869-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Mass Balance Obs
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study
Globally consistent estimates of high-resolution Antarctic ice mass balance and spatially resolved glacial isostatic adjustment
On the importance of the humidity flux for the surface mass balance in the accumulation zone of the Greenland Ice Sheet
Combined GNSS reflectometry–refractometry for automated and continuous in situ surface mass balance estimation on an Antarctic ice shelf
Evaluating Greenland surface-mass-balance and firn-densification data using ICESat-2 altimetry
The regional-scale surface mass balance of Pine Island Glacier, West Antarctica, over the period 2005–2014, derived from airborne radar soundings and neutron probe measurements
Sensitivity of inverse glacial isostatic adjustment estimates over Antarctica
How does the ice sheet surface mass balance relate to snowfall? Insights from a ground-based precipitation radar in East Antarctica
Spatial and temporal distributions of surface mass balance between Concordia and Vostok stations, Antarctica, from combined radar and ice core data: first results and detailed error analysis
Natasha Valencic, Linda Pan, Konstantin Latychev, Natalya Gomez, Evelyn Powell, and Jerry X. Mitrovica
The Cryosphere, 18, 2969–2978, https://doi.org/10.5194/tc-18-2969-2024, https://doi.org/10.5194/tc-18-2969-2024, 2024
Short summary
Short summary
We quantify the effect of ongoing Antarctic bedrock uplift due to Ice Age or modern ice mass changes on estimates of ice thickness changes obtained from satellite-based ice height measurements. We find that variations in the Ice Age signal introduce an uncertainty in estimates of total Antarctic ice change of up to ~10%. Moreover, the usual assumption that the mapping between modern ice height and thickness changes is uniform systematically underestimates net Antarctic ice volume changes.
Matthias O. Willen, Martin Horwath, Eric Buchta, Mirko Scheinert, Veit Helm, Bernd Uebbing, and Jürgen Kusche
The Cryosphere, 18, 775–790, https://doi.org/10.5194/tc-18-775-2024, https://doi.org/10.5194/tc-18-775-2024, 2024
Short summary
Short summary
Shrinkage of the Antarctic ice sheet (AIS) leads to sea level rise. Satellite gravimetry measures AIS mass changes. We apply a new method that overcomes two limitations: low spatial resolution and large uncertainties due to the Earth's interior mass changes. To do so, we additionally include data from satellite altimetry and climate and firn modelling, which are evaluated in a globally consistent way with thoroughly characterized errors. The results are in better agreement with independent data.
Laura J. Dietrich, Hans Christian Steen-Larsen, Sonja Wahl, Anne-Katrine Faber, and Xavier Fettweis
The Cryosphere, 18, 289–305, https://doi.org/10.5194/tc-18-289-2024, https://doi.org/10.5194/tc-18-289-2024, 2024
Short summary
Short summary
The contribution of the humidity flux to the surface mass balance in the accumulation zone of the Greenland Ice Sheet is uncertain. Here, we evaluate the regional climate model MAR using a multi-annual dataset of eddy covariance measurements and bulk estimates of the humidity flux. The humidity flux largely contributes to the summer surface mass balance (SMB) in the accumulation zone, indicating its potential importance for the annual SMB in a warming climate.
Ladina Steiner, Holger Schmithüsen, Jens Wickert, and Olaf Eisen
The Cryosphere, 17, 4903–4916, https://doi.org/10.5194/tc-17-4903-2023, https://doi.org/10.5194/tc-17-4903-2023, 2023
Short summary
Short summary
The present study illustrates the potential of a combined Global Navigation Satellite System reflectometry and refractometry (GNSS-RR) method for accurate, simultaneous, and continuous estimation of in situ snow accumulation, snow water equivalent, and snow density time series. The combined GNSS-RR method was successfully applied on a fast-moving, polar ice shelf. The combined GNSS-RR approach could be highly advantageous for a continuous quantification of ice sheet surface mass balances.
Benjamin E. Smith, Brooke Medley, Xavier Fettweis, Tyler Sutterley, Patrick Alexander, David Porter, and Marco Tedesco
The Cryosphere, 17, 789–808, https://doi.org/10.5194/tc-17-789-2023, https://doi.org/10.5194/tc-17-789-2023, 2023
Short summary
Short summary
We use repeated satellite measurements of the height of the Greenland ice sheet to learn about how three computational models of snowfall, melt, and snow compaction represent actual changes in the ice sheet. We find that the models do a good job of estimating how the parts of the ice sheet near the coast have changed but that two of the models have trouble representing surface melt for the highest part of the ice sheet. This work provides suggestions for how to better model snowmelt.
Stefan Kowalewski, Veit Helm, Elizabeth Mary Morris, and Olaf Eisen
The Cryosphere, 15, 1285–1305, https://doi.org/10.5194/tc-15-1285-2021, https://doi.org/10.5194/tc-15-1285-2021, 2021
Short summary
Short summary
This study presents estimates of total mass input for the Pine Island Glacier (PIG) over the period 2005–2014 from airborne radar measurements. Our analysis reveals a total mass input similar to an earlier estimate for the period 1985–2009 and same area. This suggests a stationary total mass input contrary to the accelerated mass loss of PIG over the past decades. However, we also find that its uncertainty is highly sensitive to the geostatistical assumptions required for its calculation.
Matthias O. Willen, Martin Horwath, Ludwig Schröder, Andreas Groh, Stefan R. M. Ligtenberg, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 14, 349–366, https://doi.org/10.5194/tc-14-349-2020, https://doi.org/10.5194/tc-14-349-2020, 2020
Niels Souverijns, Alexandra Gossart, Irina V. Gorodetskaya, Stef Lhermitte, Alexander Mangold, Quentin Laffineur, Andy Delcloo, and Nicole P. M. van Lipzig
The Cryosphere, 12, 1987–2003, https://doi.org/10.5194/tc-12-1987-2018, https://doi.org/10.5194/tc-12-1987-2018, 2018
Short summary
Short summary
This work is the first to gain insight into the local surface mass balance over Antarctica using accurate long-term snowfall observations. A non-linear relationship between accumulation and snowfall is discovered, indicating that total surface mass balance measurements are not a good proxy for snowfall over Antarctica. Furthermore, the meteorological drivers causing changes in the local SMB are identified.
Emmanuel Le Meur, Olivier Magand, Laurent Arnaud, Michel Fily, Massimo Frezzotti, Marie Cavitte, Robert Mulvaney, and Stefano Urbini
The Cryosphere, 12, 1831–1850, https://doi.org/10.5194/tc-12-1831-2018, https://doi.org/10.5194/tc-12-1831-2018, 2018
Short summary
Short summary
This paper presents surface mass balance measurements from both GPR and ice core data collected during a traverse in a so-far-unexplored area between the DC and Vostok stations. Results presented here will contribute to a better knowledge of the global mass balance of the Antarctic ice sheet and thus help in constraining its contribution to sea level rise. Another novelty of the paper resides in the comprehensive error budget proposed for the method used for inferring accumulation rates.
Cited articles
Auger, J. D., Birkel, S. D., Maasch, K. A., Mayewski, P. A., and Schuenemann,
K. C.: Examination of precipitation variability in southern Greenland, J.
Geophys. Res., 122, 6202–6216, https://doi.org/10.1002/2016JD026377, 2017.
Bales, R. C., Guo, Q., Shen, D., McConnell, J. R., Du, G., Burkhart, J. F.,
Spikes, V. B., Hanna, E., and Cappelen, J.: Annual accumulation for Greenland
updated using ice core data developed during 2000–2006 and analysis of daily
coastal meteorological data, J. Geophys. Res.-Atmos., 114, D06116,
https://doi.org/10.1029/2008JD011208, 2009.
Ballinger, T. J., Hanna, E., Hall, R. J., Cropper, T. E., Miller, J.,
Ribergaard, M. H., Overland, J. E., and Høyer, J. L.: Anomalous blocking
over Greenland preceded the 2013 extreme early melt of local sea ice, Ann.
Glaciol., 2013, 1–10, https://doi.org/10.1017/aog.2017.30, 2017.
Benson, C. S.: Stratigraphic studies in the snow and firn of the Greenland
Ice Sheet, Folia Geogr. Danica, 9, 13–37, 1962.
Bevington, P. R. and Robinson, D. K.: Data Reduction and Error Analysis for
the Physical Sciences, 2nd Edn., McGraw-Hill, 1992.
Bintanja, R. and Selten, F. M.: Future increases in Arctic precipitation
linked to local evaporation and sea-ice retreat, Nature, 509,
479–482, https://doi.org/10.1038/nature13259, 2014.
Box, J. E., Bromwich, D. H., Veenhuis, B. A., Bai, L. S., Stroeve, J. C.,
Rogers, J. C., Steffen, K., Haran, T., and Wang, S. H.: Greenland Ice Sheet
Surface Mass Balance Variability (1988–2004) from Calibrated Polar MM5
Output, J. Climate, 19, 2783–2801, https://doi.org/10.1175/JCLI3738.1,
2006.
Box, J. E., Cressie, N., Bromwich, D. H., Jung, J. H., van den Broeke, M.
R., van Angelen, J. H., Forster, R. R., Miège, C., Mosley-Thompson, E.,
Vinther, B., and Mcconnell, J. R.: Greenland ice sheet mass balance
reconstruction. Part I: Net snow accumulation (1600–2009), J. Climate, 26,
3919–3934, https://doi.org/10.1175/JCLI-D-12-00373.1, 2013.
Brown, J., Harper, J., Pfeffer, W. T., Humphrey, N., and Bradford, J.:
High-resolution study of layering within the percolation and soaked facies
of the Greenland ice sheet, Ann. Glaciol., 52, 35–42,
https://doi.org/10.3189/172756411799096286, 2011.
Brown, J., Bradford, J., Harper, J., Pfeffer, W. T., Humphrey, N., and
Mosley-Thompson, E.: Georadar-derived estimates of firn density in the
percolation zone, western Greenland ice sheet, J. Geophys. Res.-Earth,
117, 1–14, https://doi.org/10.1029/2011JF002089, 2012.
Buchardt, S. L., Clausen, H. B., Vinther, B. M., and Dahl-Jensen, D.: Investigating the past and recent δ18O-accumulation relationship seen in Greenland ice cores, Clim. Past, 8, 2053–2059, https://doi.org/10.5194/cp-8-2053-2012, 2012.
Burgess, E. W., Forster, R. R., Box, J. E., Mosley-Thompson, E., Bromwich,
D. H., Bales, R. C., and Smith, L. C.: A spatially calibrated model of annual
accumulation rate on the Greenland Ice Sheet (1958–2007), J. Geophys. Res.-Earth, 115, 1–14, https://doi.org/10.1029/2009JF001293, 2010.
de la Peña, S., Howat, I. M., Nienow, P. W., van den Broeke, M. R., Mosley-Thompson, E., Price, S. F., Mair, D., Noël, B., and Sole, A. J.: Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming, The Cryosphere, 9, 1203–1211, https://doi.org/10.5194/tc-9-1203-2015, 2015.
Fettweis, X., Box, J. E., Agosta, C., Amory, C., Kittel, C., Lang, C., van As, D., Machguth, H., and Gallée, H.: Reconstructions of the 1900–2015 Greenland ice sheet surface mass balance using the regional climate MAR model, The Cryosphere, 11, 1015–1033, https://doi.org/10.5194/tc-11-1015-2017, 2017.
Gerlitz, K., Knoll, M., Cross, G., Luzitano, R., and Knight, R.: Processing
Ground Penetrating Radar Data to Improve Resolution of Near-Surface Targets,
in: Symposium on the Application of Geophysics to Engineering and
Environmental Problems 1993, Environment and Engineering
Geophysical Society, 561–574, 1993.
Graeter, K. A., Osterberg, E. C., Ferris, D., Hawley, R. L., Marshall, H. P.,
and Lewis, G.: Ice Core Records of West Greenland Surface Melt and Climate
Forcing, Geophys. Res. Lett., 45, 3164–3172, https://doi.org/10.1002/2017GL076641, 2018.
Hall, D. K., Comiso, J. C., DiGirolamo, N. E., Shuman, C. A., Key, J. R., and
Koenig, L. S.: A satellite-derived climate-quality data record of the
clear-sky surface temperature of the Greenland ice sheet, J. Climate, 25,
4785–4798, 2012.
Hall, D. K., Comiso, J. C., DiGirolamo, N. E., Shuman, C. A., Box, J. E., and
Koenig, L. S.: Variability in the surface temperature and melt extent of the
Greenland ice sheet from MODIS, Geophys. Res. Lett., 40, 2114–2120,
https://doi.org/10.1002/grl.50240, 2013.
Hanna, E., Mernild, S. H., Cappelen, J., and Steffen, K.: Recent warming in
Greenland in a long-term instrumental (1881–2012) climatic context: I.
Evaluation of surface air temperature records, Environ. Res. Lett., 7,
045404, https://doi.org/10.1088/1748-9326/7/4/045404, 2012.
Hanna, E., Jones, J. M., Cappelen, J., Mernild, S. H., Wood, L., Steffen, K.,
and Huybrechts, P.: The influence of North Atlantic atmospheric and oceanic
forcing effects on 1900–2010 Greenland summer climate and ice melt/runoff,
Int. J. Climatol., 33, 862–880, https://doi.org/10.1002/joc.3475, 2013.
Hanna, E., Cropper, T. E., Hall, R. J. and Cappelen, J.: Greenland Blocking
Index 1851–2015: a regional climate change signal, Int. J. Climatol.,
36, 4847–4861, https://doi.org/10.1002/joc.4673, 2016.
Hanna, E., Fettweis, X., and Hall, R. J.: Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models, The Cryosphere, 12, 3287–3292, https://doi.org/10.5194/tc-12-3287-2018, 2018.
Harper, J., Humphrey, N., Pfeffer, W. T., Brown, J., and Fettweis, X.:
Greenland ice-sheet contribution to sea-level rise buffered by meltwater
storage in firn, Nature, 491, 240–243, https://doi.org/10.1038/nature11566, 2012.
Hawley, R. L., Courville, Z. R., Kehrl, L. M., Lutz, E. R., Osterberg, E.
C., Overly, T. B., and Wong, G. J.: Recent accumulation variability in
northwest Greenland from ground-penetrating radar and shallow cores along
the Greenland Inland Traverse, J. Glaciol., 60, 375–382,
https://doi.org/10.3189/2014JoG13J141, 2014.
Herron, M. M. and Langway, C. C.: Firn densification: an empirical model,
J. Glaciol., 25, 373–385, https://doi.org/10.3189/S0022143000015239, 1980.
Hofer, S., Bamber, J., Tedstone, A., and Fettweis, X.: Decreasing clouds
drive mass loss on the Greenland Ice Sheet, EGU General Assembly Conference Abstract,
EGU General Assembly, Vienna, 19, 5086, 2017.
Karlöf, L., Isaksson, E., Winther, J. G., Gundestrup, N. S., Meijer, H.
A. J., Mulvaney, R., Pourchet, M., Hofstede, C., Lappegard, G., Petterson,
R., van den Broeke, M. R., and Van De Wal, R. S. W.: Accumulation variability
over a small area in east Dronning Maud Land, Antarctic, as determined from
shallow firn cores and snow pits: Some implications for ice-core records, J.
Glaciol., 51, 343–352, https://doi.org/10.3189/172756505781829232, 2005.
Kobayashi, S., Ota, Y., Harada, Y., Ebita, A., Moriya, M., Onoda, H., Onogi,
K., Kamahori, H., Kobayashi, C., Endo, H., Miyaoka, K., and Takahashi, K.:
The JRA-55 Reanalysis: General Specifications and Basic Characteristics, J.
Meteorol. Soc. Jpn. Ser. II, 93, 5–48, https://doi.org/10.2151/jmsj.2015-001,
2015.
Koenig, L. S., Ivanoff, A., Alexander, P. M., MacGregor, J. A., Fettweis, X., Panzer, B., Paden, J. D., Forster, R. R., Das, I., McConnell, J. R., Tedesco, M., Leuschen, C., and Gogineni, P.: Annual Greenland accumulation rates (2009–2012) from airborne snow radar, The Cryosphere, 10, 1739–1752, https://doi.org/10.5194/tc-10-1739-2016, 2016.
Kovacs, A., Gow, A. J., and Morey, R. M.: The in-situ dielectric constant of
polar firn revisited, Cold Reg. Sci. Technol., 23, 245–256,
https://doi.org/10.1016/0165-232X(94)00016-Q, 1995.
Lavielle, M.: Using penalized contrasts for the change-point problem, Signal
Process., 85, 1501–1510, https://doi.org/10.1016/j.sigpro.2005.01.012, 2005.
Lewis, G.: In-situ snow accumulation, melt, and firn density records using ground penetrating radar and firn cores, western Greenland, 1955–2017, Arctic Data Center, https://doi.org/10.18739/A2ZK55M55, 2019.
Lewis, G., Osterberg, E., Hawley, R., Whitmore, B., Marshall, H. P., and Box, J.: Regional Greenland accumulation variability from Operation IceBridge airborne accumulation radar, The Cryosphere, 11, 773–788, https://doi.org/10.5194/tc-11-773-2017, 2017.
McLeod, J. T. and Mote, T. L.: Linking interannual variability in extreme
Greenland blocking episodes to the recent increase in summer melting across
the Greenland ice sheet, Int. J. Climatol., 36, 1484–1499,
https://doi.org/10.1002/joc.4440, 2016.
Medley, B., Joughin, I., Das, S. B., Steig, E. J., Conway, H., Gogineni, S.
P., Criscitiello, A. S., McConnell, J. R., Smith, B. E., van den Broeke, M.
R., Lenaerts, J. T. M., Bromwich, D. H., and Nicolas, J. P.: Airborne-radar
and ice-core observations of annual snow accumulation over Thwaites Glacier,
West Antarctica confirm the spatiotemporal variability of global and
regional atmospheric models, Geophys. Res. Lett., 40, 3649–3654,
https://doi.org/10.1002/grl.50706, 2013.
Mernild, S. H., Hanna, E., Mcconnell, J. R., Sigl, M., Beckerman, A. P.,
Yde, J. C., Cappelen, J., Malmros, J. K., and Steffen, K.: Greenland
precipitation trends in a long-term instrumental climate context
(1890–2012): Evaluation of coastal and ice core records, Int. J. Climatol., 35, 303–320,
https://doi.org/10.1002/joc.3986, 2014.
Meyer, C. R. and Hewitt, I. J.: A continuum model for meltwater flow through compacting snow, The Cryosphere, 11, 2799–2813, https://doi.org/10.5194/tc-11-2799-2017, 2017.
Morlighem, M., Rignot, E. J., Mouginot, J., Seroussi, H., and Larour, E.:
Deeply incised submarine glacial valleys beneath the Greenland ice sheet,
Nat. Geosci., 7, 18–22, https://doi.org/10.1038/ngeo2167, 2014.
Morris, E. M. and Wingham, D. J.: Densification of polar snow: Measurements,
modeling, and implications for altimetry, J. Geophys. Res.-Earth,
119, 349–365, https://doi.org/10.1002/2013JF002898, 2014.
Mosley-Thompson, E., McConnell, J. R., Bales, R. C., Li, Z., Lin, P.-N.,
Steffen, K., Thompson, L. G., Edwards, R., and Bathke, D.: Local to
regional-scale variability of annual net accumulation on the Greenland ice
sheet from PARCA cores, J. Geophys. Res., 106, 33839,
https://doi.org/10.1029/2001JD900067, 2001.
Mouginot, J., Rignot, E., Bjørk, A. A., van den Broeke, M., Millan, R.,
Morlighem, M., Noël, B., Scheuchl, B., and Wood, M.: Forty-six years of
Greenland Ice Sheet mass balance from 1972 to 2018, P. Natl. Acad. Sci. USA,
116, 9239 LP – 9244, https://doi.org/10.1073/pnas.1904242116, 2019.
Nghiem, S. V., Steffen, K., Neumann, G., and Huf, R.: Mapping of ice layer
extent and snow accumulation in the percolation zone of the Greenland ice
sheet, J. Geophys. Res.-Earth, 110, 1–13,
https://doi.org/10.1029/2004JF000234, 2005.
Nghiem, S. V., Hall, D. K., Mote, T. L., Tedesco, M., Albert, M. R., Keegan,
K. M., Shuman, C. A., DiGirolamo, N. E., and Neumann, G.: The extreme melt
across the Greenland ice sheet in 2012, Geophys. Res. Lett., 39, 6–11,
https://doi.org/10.1029/2012GL053611, 2012.
Noël, B., van de Berg, W. J., van Wessem, J. M., van Meijgaard, E., van As, D., Lenaerts, J. T. M., Lhermitte, S., Kuipers Munneke, P., Smeets, C. J. P. P., van Ulft, L. H., van de Wal, R. S. W., and van den Broeke, M. R.: Modelling the climate and surface mass balance of polar ice sheets using RACMO2 – Part 1: Greenland (1958–2016), The Cryosphere, 12, 811–831, https://doi.org/10.5194/tc-12-811-2018, 2018.
Nye, J. F.: Correction factor for accumulation measured by the thickness of
the annual layers in an ice sheet, J. Glaciol., 4, 785–788, 1963.
Osterberg, E. C., Handley, M. J., Sneed, S. B., Mayewski, P. A., and Kreutz,
K. J.: Continuous ice core melter system with discrete sampling for major
ion, trace element, and stable isotope analyses, Environ. Sci. Technol.,
40, 3355–3361, https://doi.org/10.1021/es052536w, 2006.
Osterberg, E. C., Hawley, R. L., Wong, G. J., Kopec, B., Ferris, D., and
Howley, J.: Coastal ice-core record of recent northwest Greenland
temperature and sea-ice concentration, J. Glaciol., 61, 1137–1146,
https://doi.org/10.3189/2015JoG15J054, 2015.
Overly, T. B., Hawley, R. L., Helm, V., Morris, E. M., and Chaudhary, R. N.: Greenland annual accumulation along the EGIG line, 1959–2004, from ASIRAS airborne radar and neutron-probe density measurements, The Cryosphere, 10, 1679–1694, https://doi.org/10.5194/tc-10-1679-2016, 2016.
Reeves Eyre, J. E. J. and Zeng, X.: Evaluation of Greenland near surface air temperature datasets, The Cryosphere, 11, 1591–1605, https://doi.org/10.5194/tc-11-1591-2017, 2017.
Rennermalm, A. K., Moustafa, S. E., Mioduszewski, J., Chu, V. W., Forster,
R. R., Hagedorn, B., Harper, J. T., Mote, T. L., Robinson, D. A., Shuman, C.
A., Smith, L. C., and Tedesco, M.: Understanding Greenland ice sheet
hydrology using an integrated multi-scale approach, Environ. Res. Lett.,
8, 015017, https://doi.org/10.1088/1748-9326/8/1/015017, 2013.
Rodriguez-Morales, F., Gogineni, S. P., Leuschen, C. J., Paden, J. D., Li,
J., Lewis, C. C., Panzer, B., Gomez-Garcia Alvestegui, D., Patel, A., Byers,
K., Crowe, R., Player, K., Hale, R. D., Arnold, E. J., Smith, L., Gifford,
C. M., Braaten, D., and Panton, C.: Advanced multifrequency radar
instrumentation for polar Research, IEEE T. Geosci. Remote, 52,
2824–2842, https://doi.org/10.1109/TGRS.2013.2266415, 2014.
Sasgen, I., van den Broeke, M. R., Bamber, J. L., Rignot, E. J., Sorensen,
L. S., Wouters, B., Martinec, Z., Velicogna, I., and Simonsen, S. B.: Timing
and origin of recent regional ice-mass loss in Greenland, Earth Planet. Sc.
Lett., 333–334, 293–303, https://doi.org/10.1016/j.epsl.2012.03.033, 2012.
Selesnick, I. W. and Sidney Burrus, C.: Generalized digital butterworth
filter design, IEEE T. Signal Proces., 46, 1688–1694,
https://doi.org/10.1109/78.678493, 1998.
Serreze, M.: Northern Hemisphere cyclone locations and characteristics from
NCEP/NCAR reanalysis data, Verison 1, Natl. Snow Ice Data Center, Boulder,
CO, Digit. media, available at: http://nsidc.org/data/nsidc-0423.html (last access: 3 January 2019),
2009.
Spikes, V. B., Hamilton, G. S., Arcone, S. A., Kaspari, S., and Mayewski, P.
A.: Variability in accumulation rates from GPR profiling on the West
Antarctic plateau, Ann. Glaciol., 39, 238–244,
https://doi.org/10.3189/172756404781814393, 2004.
Trusel, L. D., Das, S. B., Osman, M. B., Evans, M. J., Smith, B. E.,
Fettweis, X., McConnell, J. R., Noël, B., and van den Broeke, M. R.:
Nonlinear rise in Greenland runoff in response to post-industrial Arctic
warming, Nature, 564, 104–108, https://doi.org/10.1038/s41586-018-0752-4, 2018.
Vandecrux, B., Fausto, R. S., Langen, P. L., Van As, D., MacFerrin, M.,
Colgan, W., Ingeman-Nielsen, T., Steffen, K., Jensen, N. S., Møller, M.
T., and Box, J. E.: Drivers of Firn Density on the Greenland Ice Sheet
Revealed by Weather Station Observations and Modelling, J. Geophys. Res.-Earth, 123, 2563–2576, https://doi.org/10.1029/2017JF004597, 2018.
van den Broeke, M. R., Bamber, J. L., Ettema, J., Rignot, E. J., Schrama,
E., van de Berg, W. J., van Meijgaard, E., Velicogna, I., and Wouters, B.:
Partitioning recent Greenland mass loss., Science, 326, 984–986,
https://doi.org/10.1126/science.1178176, 2009.
van den Broeke, M. R., Enderlin, E. M., Howat, I. M., Kuipers Munneke, P., Noël, B. P. Y., van de Berg, W. J., van Meijgaard, E., and Wouters, B.: On the recent contribution of the Greenland ice sheet to sea level change, The Cryosphere, 10, 1933–1946, https://doi.org/10.5194/tc-10-1933-2016, 2016.
Vernon, C. L., Bamber, J. L., Box, J. E., van den Broeke, M. R., Fettweis, X., Hanna, E., and Huybrechts, P.: Surface mass balance model intercomparison for the Greenland ice sheet, The Cryosphere, 7, 599–614, https://doi.org/10.5194/tc-7-599-2013, 2013.
Wong, G. J., Hawley, R. L., Lutz, E. R., and Osterberg, E. C.: Trace-element
and physical response to melt percolation in Summit (Greenland) snow, Ann.
Glaciol., 54, 52–62, https://doi.org/10.3189/2013aog63a602, 2013.
Yilmaz, Ö.: Seismic data analysis: Processing, inversion, and interpretation of seismic data, Society of exploration geophysicists, 2001.
Zumberge, J. F., Heflin, M. B., Jefferson, D. C., Watkins, M. M., and Webb,
F. H.: Precise point positioning for the efficient and robust analysis of
GPS data from large networks, J. Geophys. Res.-Sol. Ea., 102,
5005–5017, https://doi.org/10.1029/96JB03860, 1997.
Short summary
We present accumulation records from sixteen 22–32 m long firn cores and 4436 km of ground-penetrating radar, covering the past 20–60 years of accumulation, collected across the western Greenland Ice Sheet percolation zone. Trends from both radar and firn cores, as well as commonly used regional climate models, show decreasing accumulation over the 1996–2016 period.
We present accumulation records from sixteen 22–32 m long firn cores and 4436 km of...
