Articles | Volume 14, issue 12
https://doi.org/10.5194/tc-14-4365-2020
© Author(s) 2020. 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-14-4365-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
02 Dec 2020
Research article |
| 02 Dec 2020
| 02 Dec 2020
Detecting seasonal ice dynamics in satellite images
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
Alex S. Gardner
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
Lauren C. Andrews
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Related authors
Alex S. Gardner, Chad A. Greene, Joseph H. Kennedy, Mark A. Fahnestock, Maria Liukis, Luis A. López, Yang Lei, Ted A. Scambos, and Amaury Dehecq
The Cryosphere, 19, 3517–3533, https://doi.org/10.5194/tc-19-3517-2025, https://doi.org/10.5194/tc-19-3517-2025, 2025
Short summary
Short summary
The NASA MEaSUREs Inter-mission Time Series of Land Ice Velocity and Elevation (ITS_LIVE) project provides glacier and ice sheet velocity products for the full Landsat, Sentinel-1, and Sentinel-2 satellite archives and will soon include data from the NISAR satellite. This paper describes the ITS_LIVE processing chain and gives guidance for working with the cloud-optimized glacier and ice sheet velocity products.
Fernando S. Paolo, Alex S. Gardner, Chad A. Greene, Johan Nilsson, Michael P. Schodlok, Nicole-Jeanne Schlegel, and Helen A. Fricker
The Cryosphere, 17, 3409–3433, https://doi.org/10.5194/tc-17-3409-2023, https://doi.org/10.5194/tc-17-3409-2023, 2023
Short summary
Short summary
We report on a slowdown in the rate of thinning and melting of West Antarctic ice shelves. We present a comprehensive assessment of the Antarctic ice shelves, where we analyze at a continental scale the changes in thickness, flow, and basal melt over the past 26 years. We also present a novel method to estimate ice shelf change from satellite altimetry and a time-dependent data set of ice shelf thickness and basal melt rates at an unprecedented resolution.
Alex S. Gardner, Chad A. Greene, Joseph H. Kennedy, Mark A. Fahnestock, Maria Liukis, Luis A. López, Yang Lei, Ted A. Scambos, and Amaury Dehecq
The Cryosphere, 19, 3517–3533, https://doi.org/10.5194/tc-19-3517-2025, https://doi.org/10.5194/tc-19-3517-2025, 2025
Short summary
Short summary
The NASA MEaSUREs Inter-mission Time Series of Land Ice Velocity and Elevation (ITS_LIVE) project provides glacier and ice sheet velocity products for the full Landsat, Sentinel-1, and Sentinel-2 satellite archives and will soon include data from the NISAR satellite. This paper describes the ITS_LIVE processing chain and gives guidance for working with the cloud-optimized glacier and ice sheet velocity products.
Alamgir Hossan, Andreas Colliander, Nicole-Jeanne Schlegel, Joel Harper, Lauren Andrews, Jana Kolassa, Julie Z. Miller, and Richard Cullather
EGUsphere, https://doi.org/10.5194/egusphere-2025-2681, https://doi.org/10.5194/egusphere-2025-2681, 2025
Short summary
Short summary
Microwave L-band radiometry offers a promising tool for estimating the total surface-to-subsurface liquid water amount (LWA) in the snow and firn in polar ice sheets. An accurate modelling of wet snow effective permittivity is a key to this. Here, we evaluated the performance of ten commonly used microwave dielectric mixing models for estimating LWA in the percolation zone of the Greenland Ice Sheet to help an appropriate choice of dielectric mixing model for LWA retrieval algorithms.
Johan Nilsson and Alex S. Gardner
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-311, https://doi.org/10.5194/essd-2024-311, 2024
Preprint under review for ESSD
Short summary
Short summary
Integrating data from multiple satellite altimetry missions, we analyzed Greenland’s peripheral glaciers and Ice Sheet (GrIS) from 1992–2023. Our methodology ensures consistent, reliable elevation change data, now publicly available via NASA's ITS_LIVE project. The GrIS lost an average of -173 ± 19 Gt a-1 and peripheral glaciers -23 ± 5 Gt a-1 from 1992–2022. The study highlights the importance of continued monitoring to understand climate change impacts on Earth's Cryosphere.
Brian Menounos, Alex Gardner, Caitlyn Florentine, and Andrew Fountain
The Cryosphere, 18, 889–894, https://doi.org/10.5194/tc-18-889-2024, https://doi.org/10.5194/tc-18-889-2024, 2024
Short summary
Short summary
Glaciers in western North American outside of Alaska are often overlooked in global studies because their potential to contribute to changes in sea level is small. Nonetheless, these glaciers represent important sources of freshwater, especially during times of drought. We show that these glaciers lost mass at a rate of about 12 Gt yr-1 for about the period 2013–2021; the rate of mass loss over the period 2018–2022 was similar.
Youngmin Choi, Helene Seroussi, Mathieu Morlighem, Nicole-Jeanne Schlegel, and Alex Gardner
The Cryosphere, 17, 5499–5517, https://doi.org/10.5194/tc-17-5499-2023, https://doi.org/10.5194/tc-17-5499-2023, 2023
Short summary
Short summary
Ice sheet models are often initialized using snapshot observations of present-day conditions, but this approach has limitations in capturing the transient evolution of the system. To more accurately represent the accelerating changes in glaciers, we employed time-dependent data assimilation. We found that models calibrated with the transient data better capture past trends and more accurately reproduce changes after the calibration period, even with limited observations.
Celia Trunz, Kristin Poinar, Lauren C. Andrews, Matthew D. Covington, Jessica Mejia, Jason Gulley, and Victoria Siegel
The Cryosphere, 17, 5075–5094, https://doi.org/10.5194/tc-17-5075-2023, https://doi.org/10.5194/tc-17-5075-2023, 2023
Short summary
Short summary
Models simulating water pressure variations at the bottom of glaciers must use large storage parameters to produce realistic results. Whether that storage occurs englacially (in moulins) or subglacially is a matter of debate. Here, we directly simulate moulin volume to constrain the storage there. We find it is not enough. Instead, subglacial processes, including basal melt and input from upstream moulins, must be responsible for stabilizing these water pressure fluctuations.
Fernando S. Paolo, Alex S. Gardner, Chad A. Greene, Johan Nilsson, Michael P. Schodlok, Nicole-Jeanne Schlegel, and Helen A. Fricker
The Cryosphere, 17, 3409–3433, https://doi.org/10.5194/tc-17-3409-2023, https://doi.org/10.5194/tc-17-3409-2023, 2023
Short summary
Short summary
We report on a slowdown in the rate of thinning and melting of West Antarctic ice shelves. We present a comprehensive assessment of the Antarctic ice shelves, where we analyze at a continental scale the changes in thickness, flow, and basal melt over the past 26 years. We also present a novel method to estimate ice shelf change from satellite altimetry and a time-dependent data set of ice shelf thickness and basal melt rates at an unprecedented resolution.
Alex S. Gardner, Nicole-Jeanne Schlegel, and Eric Larour
Geosci. Model Dev., 16, 2277–2302, https://doi.org/10.5194/gmd-16-2277-2023, https://doi.org/10.5194/gmd-16-2277-2023, 2023
Short summary
Short summary
This is the first description of the open-source Glacier Energy and Mass Balance (GEMB) model. GEMB models the ice sheet and glacier surface–atmospheric energy and mass exchange, as well as the firn state. The model is evaluated against the current state of the art and in situ observations and is shown to perform well.
Inès N. Otosaka, Andrew Shepherd, Erik R. Ivins, Nicole-Jeanne Schlegel, Charles Amory, Michiel R. van den Broeke, Martin Horwath, Ian Joughin, Michalea D. King, Gerhard Krinner, Sophie Nowicki, Anthony J. Payne, Eric Rignot, Ted Scambos, Karen M. Simon, Benjamin E. Smith, Louise S. Sørensen, Isabella Velicogna, Pippa L. Whitehouse, Geruo A, Cécile Agosta, Andreas P. Ahlstrøm, Alejandro Blazquez, William Colgan, Marcus E. Engdahl, Xavier Fettweis, Rene Forsberg, Hubert Gallée, Alex Gardner, Lin Gilbert, Noel Gourmelen, Andreas Groh, Brian C. Gunter, Christopher Harig, Veit Helm, Shfaqat Abbas Khan, Christoph Kittel, Hannes Konrad, Peter L. Langen, Benoit S. Lecavalier, Chia-Chun Liang, Bryant D. Loomis, Malcolm McMillan, Daniele Melini, Sebastian H. Mernild, Ruth Mottram, Jeremie Mouginot, Johan Nilsson, Brice Noël, Mark E. Pattle, William R. Peltier, Nadege Pie, Mònica Roca, Ingo Sasgen, Himanshu V. Save, Ki-Weon Seo, Bernd Scheuchl, Ernst J. O. Schrama, Ludwig Schröder, Sebastian B. Simonsen, Thomas Slater, Giorgio Spada, Tyler C. Sutterley, Bramha Dutt Vishwakarma, Jan Melchior van Wessem, David Wiese, Wouter van der Wal, and Bert Wouters
Earth Syst. Sci. Data, 15, 1597–1616, https://doi.org/10.5194/essd-15-1597-2023, https://doi.org/10.5194/essd-15-1597-2023, 2023
Short summary
Short summary
By measuring changes in the volume, gravitational attraction, and ice flow of Greenland and Antarctica from space, we can monitor their mass gain and loss over time. Here, we present a new record of the Earth’s polar ice sheet mass balance produced by aggregating 50 satellite-based estimates of ice sheet mass change. This new assessment shows that the ice sheets have lost (7.5 x 1012) t of ice between 1992 and 2020, contributing 21 mm to sea level rise.
Elias C. Massoud, Lauren Andrews, Rolf Reichle, Andrea Molod, Jongmin Park, Sophie Ruehr, and Manuela Girotto
Earth Syst. Dynam., 14, 147–171, https://doi.org/10.5194/esd-14-147-2023, https://doi.org/10.5194/esd-14-147-2023, 2023
Short summary
Short summary
In this study, we benchmark the forecast skill of the NASA’s Goddard Earth Observing System subseasonal-to-seasonal (GEOS-S2S version 2) hydrometeorological forecasts in the High Mountain Asia (HMA) region. Hydrometeorological forecast skill is dependent on the forecast lead time, the memory of the variable within the physical system, and the validation dataset used. Overall, these results benchmark the GEOS-S2S system’s ability to forecast HMA hydrometeorology on the seasonal timescale.
Yang Lei, Alex S. Gardner, and Piyush Agram
Earth Syst. Sci. Data, 14, 5111–5137, https://doi.org/10.5194/essd-14-5111-2022, https://doi.org/10.5194/essd-14-5111-2022, 2022
Short summary
Short summary
This work describes NASA MEaSUREs ITS_LIVE project's Version 2 Sentinel-1 image-pair ice velocity product and processing methodology. We show the refined offset tracking algorithm, autoRIFT, calibration for Sentinel-1 geolocation biases and correction of the ionosphere streaking problems. Validation was performed over three typical test sites covering the globe by comparing with other similar global and regional products.
Sophie Goliber, Taryn Black, Ginny Catania, James M. Lea, Helene Olsen, Daniel Cheng, Suzanne Bevan, Anders Bjørk, Charlie Bunce, Stephen Brough, J. Rachel Carr, Tom Cowton, Alex Gardner, Dominik Fahrner, Emily Hill, Ian Joughin, Niels J. Korsgaard, Adrian Luckman, Twila Moon, Tavi Murray, Andrew Sole, Michael Wood, and Enze Zhang
The Cryosphere, 16, 3215–3233, https://doi.org/10.5194/tc-16-3215-2022, https://doi.org/10.5194/tc-16-3215-2022, 2022
Short summary
Short summary
Terminus traces have been used to understand how Greenland's glaciers have changed over time; however, manual digitization is time-intensive, and a lack of coordination leads to duplication of efforts. We have compiled a dataset of over 39 000 terminus traces for 278 glaciers for scientific and machine learning applications. We also provide an overview of an updated version of the Google Earth Engine Digitization Tool (GEEDiT), which has been developed specifically for the Greenland Ice Sheet.
Johan Nilsson, Alex S. Gardner, and Fernando S. Paolo
Earth Syst. Sci. Data, 14, 3573–3598, https://doi.org/10.5194/essd-14-3573-2022, https://doi.org/10.5194/essd-14-3573-2022, 2022
Short summary
Short summary
The longest observational record available to study the mass balance of the Earth’s ice sheets comes from satellite altimeters. This record consists of multiple satellite missions with different measurements and quality, and it must be cross-calibrated and integrated into a consistent record for scientific use. Here, we present a novel approach for generating such a record providing a seamless record of elevation change for the Antarctic Ice Sheet that spans the period 1985 to 2020.
Lauren C. Andrews, Kristin Poinar, and Celia Trunz
The Cryosphere, 16, 2421–2448, https://doi.org/10.5194/tc-16-2421-2022, https://doi.org/10.5194/tc-16-2421-2022, 2022
Short summary
Short summary
We introduce a model for moulin geometry motivated by the wide range of sizes and shapes of explored moulins. Moulins comprise 10–14 % of the Greenland englacial–subglacial hydrologic system and act as time-varying water storage reservoirs. Moulin geometry can vary approximately 10 % daily and over 100 % seasonally. Moulin shape modulates the efficiency of the subglacial system that controls ice flow and should thus be included in hydrologic models.
Chloe A. Whicker, Mark G. Flanner, Cheng Dang, Charles S. Zender, Joseph M. Cook, and Alex S. Gardner
The Cryosphere, 16, 1197–1220, https://doi.org/10.5194/tc-16-1197-2022, https://doi.org/10.5194/tc-16-1197-2022, 2022
Short summary
Short summary
Snow and ice surfaces are important to the global climate. Current climate models use measurements to determine the reflectivity of ice. This model uses physical properties to determine the reflectivity of snow, ice, and darkly pigmented impurities that reside within the snow and ice. Therefore, the modeled reflectivity is more accurate for snow/ice columns under varying climate conditions. This model paves the way for improvements in the portrayal of snow and ice within global climate models.
Kristin Poinar and Lauren C. Andrews
The Cryosphere, 15, 1455–1483, https://doi.org/10.5194/tc-15-1455-2021, https://doi.org/10.5194/tc-15-1455-2021, 2021
Short summary
Short summary
This study addresses Greenland supraglacial lake drainages. We analyze ice deformation associated with lake drainages over 18 summers to assess whether
precursorstrain-rate events consistently precede lake drainages. We find that currently available remote sensing data products cannot resolve these events, and thus we cannot predict future lake drainages. Thus, future avenues for evaluating this hypothesis will require major field-based GPS or photogrammetry efforts.
Zachary Fair, Mark Flanner, Kelly M. Brunt, Helen Amanda Fricker, and Alex Gardner
The Cryosphere, 14, 4253–4263, https://doi.org/10.5194/tc-14-4253-2020, https://doi.org/10.5194/tc-14-4253-2020, 2020
Short summary
Short summary
Ice on glaciers and ice sheets may melt and pond on ice surfaces in summer months. Detection and observation of these meltwater ponds is important for understanding glaciers and ice sheets, and satellite imagery has been used in previous work. However, image-based methods struggle with deep water, so we used data from the Ice, Clouds, and land Elevation Satellite-2 (ICESat-2) and the Airborne Topographic Mapper (ATM) to demonstrate the potential for lidar depth monitoring.
Cited articles
Anandakrishnan, S., Voigt, D. E., Alley, R. B., and King, M.: Ice stream D flow speed is strongly modulated by the tide beneath the Ross Ice Shelf,
Geophys. Res. Lett., 30, 1361, https://doi.org/10.1029/2002GL016329, 2003. a
Andrews, L. C., Catania, G. A., Hoffman, M. J., Gulley, J. D., Lüthi,
M. P., Ryser, C., Hawley, R. L., and Neumann, T. A.: Direct observations of
evolving subglacial drainage beneath the Greenland Ice Sheet, Nature, 514,
80–83, https://doi.org/10.1038/nature13796, 2014. a
Armstrong, W. H., Anderson, R. S., and Fahnestock, M. A.: Spatial patterns of
summer speedup on south central Alaska glaciers, Geophys. Res. Lett., 44, 9379–9388, https://doi.org/10.1002/2017GL074370, 2017. a
Bartholomew, I., Nienow, P., Mair, D., Hubbard, A., King, M. A., and Sole, A.: Seasonal evolution of subglacial drainage and acceleration in a Greenland outlet glacier, Nat. Geosci., 3, 408–411, 2010. a
Burgess, E. W., Larsen, C. F., and Forster, R. R.: Summer melt regulates winter glacier flow speeds throughout Alaska, Geophys. Res. Lett., 40,
6160–6164, https://doi.org/10.1002/2013GL058228, 2013. a
Christianson, K., Bushuk, M., Dutrieux, P., Parizek, B. R., Joughin, I. R.,
Alley, R. B., Shean, D. E., Abrahamsen, E. P., Anandakrishnan, S., Heywood,
K. J., and Kim, T. W.: Sensitivity of Pine Island Glacier to observed ocean
forcing, Geophys. Res. Lett., 43, 10817–10825, https://doi.org/10.1002/2016GL070500, 2016. a
Dehecq, A., Gourmelen, N., Gardner, A. S., Brun, F., Goldberg, D., Nienow,
P. W., Berthier, E., Vincent, C., Wagnon, P., and Trouvé, E.:
Twenty-first century glacier slowdown driven by mass loss in High Mountain
Asia, Nat. Geosci., 12, 22–27, https://doi.org/10.1038/s41561-018-0271-9, 2019. a
Fahnestock, M., Scambos, T., Moon, T., Gardner, A., Haran, T., and Klinger, M.: Rapid large-area mapping of ice flow using Landsat 8, Remote Sens. Environ., 185, 84–94, https://doi.org/10.1016/j.rse.2015.11.023, 2016. a
Fausto, R. S. and van As, D.: Programme for monitoring of the Greenland ice sheet (PROMICE): Automatic weather station data, Version: v03,Geological Survey of Denmark and Greenland, https://doi.org/10.22008/promice/data/aws, 2019. a
Gardner, A. S., Moholdt, G., Scambos, T., Fahnstock, M., Ligtenberg, S., van den Broeke, M., and Nilsson, J.: Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years, The Cryosphere, 12, 521–547, https://doi.org/10.5194/tc-12-521-2018, 2018. a
Gardner, A. S., Fahnestock, M. A., and Scambos, T. A.: ITS_LIVE Regional
Glacier and Ice Sheet Surface Velocities,
National Snow and Ice Data Center (NSIDC), https://doi.org/10.5067/6II6VW8LLWJ7, 2019. a, b, c
Greene, C. A., Blankenship, D. D., Gwyther, D. E., Silvano, A., and van Wijk,
E.: Wind causes Totten Ice Shelf melt and acceleration, Sci. Adv.,
3, e1701681, https://doi.org/10.1126/sciadv.1701681, 2017a. a
Greene, C. A., Gwyther, D. E., and Blankenship, D. D.: Antarctic Mapping Tools
for Matlab, Comput. Geosci., 104, 151–157,
https://doi.org/10.1016/j.cageo.2016.08.003, 2017b. a
Greene, C. A., Young, D. A., Gwyther, D. E., Galton-Fenzi, B. K., and Blankenship, D. D.: Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing, The Cryosphere, 12, 2869–2882, https://doi.org/10.5194/tc-12-2869-2018, 2018. a
Greene, C. A., Thirumalai, K., Kearney, K. A., Delgado, J. M., Schwanghart, W., Wolfenbarger, N. S., Thyng, K. M., Gwyther, D. E., Gardner, A. S., and
Blankenship, D. D.: The Climate Data Toolbox for MATLAB, Geochem.
Geophy. Geosy., 20, 3774–3781, https://doi.org/10.1029/2019GC008392, 2019. a, b
Hetland, E., Musé, P., Simons, M., Lin, Y., Agram, P., and DiCaprio, C.:
Multiscale InSAR time series (MInTS) analysis of surface deformation, J. Geophys. Res.-Sol. Ea., 117, B02404, https://doi.org/10.1029/2011JB008731, 2012. a
Howat, I. M., Box, J. E., Ahn, Y., Herrington, A., and McFadden, E. M.:
Seasonal variability in the dynamics of marine-terminating outlet glaciers
in Greenland, J. Glaciol., 56, 601–613, 2010. a
Joughin, I.: MEaSUREs Greenland Annual Ice Sheet Velocity Mosaics from SAR and Landsat, NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.5067/OBXCG75U7540, 2017. a
Joughin, I., Das, S. B., King, M. A., Smith, B. E., Howat, I. M., and Moon, T.: Seasonal speedup along the western flank of the Greenland Ice Sheet,
Science, 320, 781–783, 2008. a
King, M. D., Howat, I. M., Jeong, S., Noh, M. J., Wouters, B., Noël, B., and van den Broeke, M. R.: Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet, The Cryosphere, 12, 3813–3825, https://doi.org/10.5194/tc-12-3813-2018, 2018. a
Kraaijenbrink, P., Meijer, S. W., Shea, J. M., Pellicciotti, F., De Jong,
S. M., and Immerzeel, W. W.: Seasonal surface velocities of a Himalayan
glacier derived by automated correlation of unmanned aerial vehicle imagery,
Ann. Glaciol., 57, 103–113, https://doi.org/10.3189/2016AoG71A072, 2016. a
Milillo, P., Minchew, B., Simons, M., Agram, P., and Riel, B.: Geodetic imaging
of time-dependent three-component surface deformation: Application to
tidal-timescale ice flow of Rutford ice stream, West Antarctica, IEEE
T. Geosci. Remote, 55, 5515–5524,
https://doi.org/10.1109/TGRS.2017.2709783, 2017. a
Minchew, B., Simons, M., Riel, B., and Milillo, P.: Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations, J. Geophys. Res.-Ea. Surf., 122, 167–190, https://doi.org/10.1002/2016JF003971, 2017. a, b
Moon, T., Joughin, I., Smith, B., and Howat, I.: 21st-century evolution of
Greenland outlet glacier velocities, Science, 336, 576–578,
https://doi.org/10.1126/science.1219985, 2012. a
Moon, T., Joughin, I., Smith, B., Broeke, M. R., Berg, W. J., Noël, B., and Usher, M.: Distinct patterns of seasonal Greenland glacier velocity,
Geophys. Res. Lett., 41, 7209–7216, https://doi.org/10.1002/2014GL061836,
2014. a
Moon, T., Joughin, I., and Smith, B.: Seasonal to multiyear variability of
glacier surface velocity, terminus position, and sea ice/ice mélange in
northwest Greenland, J. Geophys. Res.-Ea. Surf., 120,
818–833, https://doi.org/10.1002/2015JF003494, 2015. a
Mouginot, J., Rignot, E., and Scheuchl, B.: Sustained increase in ice
discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to
2013, Geophys. Res. Lett., 41, 1576–1584, 2014. a
Mouginot, J., Rignot, E., Scheuchl, B., and Millan, R.: Comprehensive Annual
Ice Sheet Velocity Mapping Using Landsat-8, Sentinel-1, and RADARSAT-2 Data,
Remote Sensing, 9, 364, https://doi.org/10.3390/rs9040364, 2017. a
Nakamura, K., Doi, K., and Shibuya, K.: Fluctuations in the flow velocity of
the Antarctic Shirase Glacier over an 11-year period, Polar Sci., 4,
443–455, https://doi.org/10.1016/j.polar.2010.04.010, 2010. a
Rignot, E., Mouginot, J., and Scheuchl, B.: MEaSUREs InSAR-Based Antarctica
Ice Velocity Map, NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.5067/D7GK8F5J8M8R,
2011.
a
Robel, A. A., Tsai, V. C., Minchew, B., and Simons, M.: Tidal modulation of ice shelf buttressing stresses, Ann. Glaciol., 58, 12–20,
https://doi.org/10.1017/aog.2017.22, 2017. a
Rosier, S. H. and Gudmundsson, G. H.: Tidal controls on the flow of ice
streams, Geophys. Res. Lett., 43, 4433–4440,
https://doi.org/10.1002/2016GL068220, 2016. a
Scambos, T., Fahnestock, M., Gardner, A., and Klinger, M.: Global Land Ice
Velocity Extraction from Landsat 8 (GoLIVE), Version 1.1, NSIDC: National Snow and Ice Data Center,
https://doi.org/10.7265/N5ZP442B, 2016. a
Scambos, T. A., Dutkiewicz, M. J., Wilson, J. C., and Bindschadler, R. A.:
Application of image cross-correlation to the measurement of glacier velocity
using satellite image data, Remote Sens. Environ., 42, 177–186,
1992. a
Schoof, C.: Ice-sheet acceleration driven by melt supply variability, Nature,
468, 803–806, https://doi.org/10.1038/nature09618, 2010. a
Sole, A., Nienow, P., Bartholomew, I., Mair, D., Cowton, T., Tedstone, A., and King, M. A.: Winter motion mediates dynamic response of the Greenland Ice
Sheet to warmer summers, Geophys. Res. Lett., 40, 3940–3944,
https://doi.org/10.1002/grl.50764, 2013. a
Stevens, L. A., Behn, M. D., McGuire, J. J., Das, S. B., Joughin, I., Herring,
T., Shean, D. E., and King, M. A.: Greenland supraglacial lake drainages
triggered by hydrologically induced basal slip, Nature, 522, 73–76,
https://doi.org/10.1038/nature14480, 2015. a
Van As, D.: Warming, glacier melt and surface energy budget from weather
station observations in the Melville Bay region of northwest Greenland,
J. Glaciol., 57, 208–220, https://doi.org/10.3189/002214311796405898, 2011. a, b
van de Wal, R. S. W., Smeets, C. J. P. P., Boot, W., Stoffelen, M., van Kampen, R., Doyle, S. H., Wilhelms, F., van den Broeke, M. R., Reijmer, C. H., Oerlemans, J., and Hubbard, A.: Self-regulation of ice flow varies across the ablation area in south-west Greenland, The Cryosphere, 9, 603–611, https://doi.org/10.5194/tc-9-603-2015, 2015. a, b, c
Vijay, S., Khan, S. A., Kusk, A., Solgaard, A. M., Moon, T., and Bjørk,
A. A.: Resolving seasonal ice velocity of 45 Greenlandic glaciers with very
high temporal details, Geophys. Res. Lett., 46, 1485–1495,
https://doi.org/10.1029/2018GL081503, 2019. a
Walter, J. I., Box, J. E., Tulaczyk, S., Brodsky, E. E., Howat, I. M., Ahn, Y., and Brown, A.: Oceanic mechanical forcing of a marine-terminating Greenland glacier, Ann. Glaciol., 53, 181–192, 2012. a
Yasuda, T. and Furuya, M.: Dynamics of surge-type glaciers in West Kunlun Shan,
Northwestern Tibet, J. Geophys. Res.-Ea. Surf., 120,
2393–2405, https://doi.org/10.1002/2015JF003511, 2015. a
Zhou, C., Zhou, Y., Deng, F., Songtao, A., Wang, Z., and Dongchen, E.: Seasonal
and interannual ice velocity changes of Polar Record Glacier, East
Antarctica, Ann. Glaciol., 55, 45–51, https://doi.org/10.3189/2014AoG66A185,
2014. a
Short summary
Seasonal variability is a fundamental characteristic of any Earth surface system, but we do not fully understand which of the world's glaciers speed up and slow down on an annual cycle. Such short-timescale accelerations may offer clues about how individual glaciers will respond to longer-term changes in climate, but understanding any behavior requires an ability to observe it. We describe how to use satellite image feature tracking to determine the magnitude and timing of seasonal ice dynamics.
Seasonal variability is a fundamental characteristic of any Earth surface system, but we do not...
