Articles | Volume 16, issue 1
https://doi.org/10.5194/tc-16-103-2022
© Author(s) 2022. 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-16-103-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Jan 2022
Research article |
| 13 Jan 2022
| 13 Jan 2022
An empirical algorithm to map perennial firn aquifers and ice slabs within the Greenland Ice Sheet using satellite L-band microwave radiometry
Julie Z. Miller
CORRESPONDING AUTHOR
Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
Earth Science and Observation Center, University of Colorado Boulder, Boulder, Colorado, USA
Riley Culberg
Department of Electrical Engineering, Stanford University, Stanford, California, USA
David G. Long
Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah, USA
Christopher A. Shuman
Joint Center for Earth Systems Technology at Code 615, Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, University of Maryland, Baltimore County, Greenbelt, Maryland, USA
Dustin M. Schroeder
Department of Electrical Engineering, Stanford University, Stanford, California, USA
Department of Geophysics, Stanford University, Stanford, CA, USA
Mary J. Brodzik
Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
National Snow and Ice Data Center, University of Colorado Boulder, Boulder, Colorado, USA
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Cited articles
Abdalati, W. and Steffen, K.: Snowmelt on the Greenland Ice Sheet as derived from passive microwave satellite data, J. Climate, 10, 165–175, https://doi.org/10.1175/1520-0442(1997)010<0165:SOTGIS>2.0.CO;2, 1997.
Alley, R. B., Dupont, T. K., Parizek, B. R., and Anandakrishnan, S.: Access of surface meltwater to beds of sub-freezing glaciers: Preliminary insights, Ann. Glaciol., 40, 8–14, https://doi.org/10.3189/172756405781813483, 2005.
Ashcraft, I. and Long, D.: Comparison of methods for melt detection over Greenland using active and passive microwave measurements, Int. J. Remote Sens., 27, 2469–2488, https://doi.org/10.1080/01431160500534465, 2006.
Benson, C. S.: Stratigraphic studies in the snow and firn of the Greenland Ice Sheet, PhD thesis, California Institute of Technology, 228 pp., 1960.
Brangers, I., Lievens, H., Miège, C., Demuzere, M., Brucker, L., and De Lannoy, G. J. M.: Sentinel-1 detects firn aquifers in the Greenland Ice Sheet, Geophys. Res. Lett., 47, e2019GL085192, https://doi.org/10.1029/2019GL085192, 2020.
Brodzik, M. J., Billingsley, B., Haran, T., Raup, B., and Savoie, M. H.: EASE-Grid 2.0: Incremental but significant improvements for Earth-gridded data sets, ISPRS Int. J. Geo-Inf., 1, 32–45, https://doi.org/10.3390/ijgi1010032, 2012.
Brodzik, M. J., Long, D. G., and Hardman, M. A.: SMAP Radiometer Twice-Daily rSIR-Enhanced EASE-Grid 2.0 Brightness Temperatures, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/QZ3WJNOUZLFK, 2019.
Chu, W., Schroeder, D. M., and Siegfried, M. R.: Retrieval of englacial firn aquifer thickness from ice-penetrating radar sounding in southeastern Greenland, Geophys. Res. Lett., 45, 11770–11778, https://doi.org/10.1029/2018GL079751, 2018.
Chudley, T. R., Christoffersen, P., Doyle, S. H., Bougamont, M., Schoonman, C. M., Hubbard, B., and James, M. R.: Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier, P. Natl. Acad. Sci. USA, 51, 25468–25477, https://doi.org/10.1073/pnas.1913685116, 2019.
Colgan, W., Rajaram, H., Abdalati, W., McCutchan, C., Mottram, R., Moussavi, M. S., and Grigsby, S.: Observations, models, and mass balance implications: Glacier crevasses, Rev. Geophys., 54, 119–161, https://doi.org/10.1002/2015RG000504, 2016.
CReSIS: CReSIS radar depth sounder data, Digital Media, http://data.cresis.ku.edu/ (last access: 1 April 2021), 2016.
Culberg, R.: Refrozen melt layer location, density, and connectivity records from airborne radar sounding, Greenland, NSF Arctic Data Center [data set], https://doi.org/10.18739/A2736M33W, 2021.
Culberg, R., Schroeder, D. M., and Chu, W.: Extreme melt season ice layers reduce firn permeability across Greenland, Nat. Commun., 12, 2336, https://doi.org/10.1038/s41467-021-22656-5, 2021.
Cullather, R. I., Andrews, L. C., Croteau, M. J., Digirolamo, N. E., Hall, D. K., Lim, Y., Loomis, B. D., Shuman, C. A., and Nowicki, S. M. J.: Anomalous circulation in July 2019 resulting in mass loss on the Greenland Ice Sheet, Geophys. Res. Lett., 47, e2020GL087263, https://doi.org/10.1029/2020GL087263, 2020.
Das, S. B., Joughin, I., Behn, M. D., Howat, I. M., King,
M. A., Lizarralde, D., and Bhatia, M. P.: Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage, Science, 320, 778–781, https://doi.org/10.1126/science.1153360, 2008.
Dunmire, D., Banwell, A. F., Wever, N., Lenaerts,
J. T. M., and Datta, R. T.: Contrasting regional variability of
buried meltwater extent over 2 years across the Greenland Ice Sheet,
The Cryosphere, 15, 2983–3005, https://doi.org/10.5194/tc-15-2983-2021, 2021.
Early, D. S. and Long, D. G.: Image reconstruction and enhanced-resolution imaging from irregular samples, IEEE T. Geosci. Remote, 39, 291–302, https://doi.org/10.1109/36.905237, 2001.
Echelmeyer, K., Clarke, T. S., and Harrison, W. D.: Surficial glaciology of Jakobshavn Isbræ, West Greenland, 1. Surface morphology, J. Glaciol., 37, 368–382, https://doi.org/10.1017/S0022143000005803, 1991.
Entekhabi, D., Johnson, J., Kimball, J., Piepmeier, J. R., Koster, R. D., Martin, N., McDonald, K. C., Moghaddam, M., Moran, S., Reichle, R., Shi, J. C., Njoku, E. G., Spencer, M. W., Thurman, S. W., Tsang, L., Van Zyl, J., O'Neill, P. E., Kellogg, K. H., Crow, W. T., Edelstein, W. N., Entin, J. K., Goodman, S. D., and Jackson, T. J.: The Soil Moisture Active Passive (SMAP) Mission, Proc. IEEE, 98, 704–716, https://doi.org/10.1109/JPROC.2010.2043918, 2010.
Forster, R. R., Box, J. E., Van Den Broeke, M. R., Miège, C., Burgess, E. W., Van Angelen, J. H., Lenaerts, J. T. M., Koenig, L. S., Paden, J., Lewis, C., Gogineni, S. P., Leuschen, C., and McConnell, J. R.: Extensive liquid meltwater storage in firn within the Greenland Ice Sheet, Nat. Geosci., 7, 95–98, https://doi.org/10.1038/ngeo2043, 2014.
Fountain, A. G. and Walder, J. S.: Water flow through temperate glaciers, Rev. Geophys., 36, 299–328, https://doi.org/10.1029/97RG03579, 1998.
Freilich, M. H., Long, D. G., and Spencer, M. W.: SeaWinds: A scanning scatterometer for ADEOS-II science overview, Proc. IEEE, 1994, 960–963, https://doi.org/10.1109/IGARSS.1994.399313, 1994.
Franco, B., Fettweis, X., and Erpicum, M.: Future projections of the Greenland ice sheet energy balance driving the surface melt, The Cryosphere, 7, 1–18, https://doi.org/10.5194/tc-7-1-2013, 2013.
Hall, D. K. and DiGirolamo, N.: Multilayer Greenland Ice Surface Temperature, Surface Albedo, and Water Vapor from MODIS, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/7THUWT9NMPDK, 2019.
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, https://doi.org/10.1175/JCLI-D-11-00365.1, 2012.
Haran, T., Bohlander J., Scambos T., Painter, T., and Fahnestock, M.: MEaSUREs MODIS Boulder, Colorado, USA, NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.5067/9ZO79PHOTYE5, 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.
Hicks, B. R. and Long, D. G.: Inferring Greenland melt and refreeze severity from SeaWinds scatterometer data, Int. J. Remote Sens., 32, 8053–8080, https://doi.org/10.1080/01431161.2010.532174, 2011.
Howat, I.: MEaSUREs Greenland Ice Mapping Project (GIMP) Land Ice and Ocean Classification Mask, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/B8X58MQBFUPA, 2017.
Howat, I. M., Negrete, A., and Smith, B. E.: The Greenland Ice Mapping Project (GIMP) land classification and surface elevation data sets, The Cryosphere, 8, 1509–1518, https://doi.org/10.5194/tc-8-1509-2014, 2014.
Howat, I., Negrete, A., and Smith, B.: MEaSUREs Greenland Ice Mapping Project (GIMP) Digital Elevation Model, Version 1, NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.5067/NV34YUIXLP9W, 2015.
Humphrey, N. F., Harper, J. T., and Pfeffer, W. T.: Thermal tracking of meltwater retention in Greenland's accumulation area, J. Geophys. Res.-Earth Surf., 117, https://doi.org/10.1029/2011JF002083, 2012.
Jezek, K. C., Gogineni, P., and Shanableh, M.: Radar measurements of melt zones on the Greenland Ice Sheet, Geophys. Res. Lett., 21, 33–36, https://doi.org/10.1029/93GL03377, 1994.
Jezek, K. C., Johnson, J. T., Drinkwater, M. R., Macelloni, G., Tsang, L., Aksoy, M., and Durand M.: Radiometric approach for estimating relative changes in intraglacier average temperature, IEEE T. Geosci. Remote, 53, 134–143, https://doi.org/10.1109/TGRS.2014.2319265, 2015.
Jezek, K. C., Johnson, J. T., Tan, S., Tsang, L., Andrews, M. J., Brogioni, M., Macelloni, G., Durand, M., Chen, C. C., Belgiovane, D. J., Duan, Y., Yardim, C., Li, H., Bringer, A., Leuski, V., and Aksoy, M.: 500–2000 MHz brightness temperature spectra of the northwestern Greenland Ice Sheet, IEEE T. Geosci. Remote, 56, 1485–1496, https://doi.org/10.1109/TGRS.2017.2764381, 2018.
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, https://doi.org/10.1126/science.1153288, 2008.
Joughin, I., Das, S. B., Flowers, G. E., Behn, M. D., Alley, R. B., King, M. A., Smith, B. E., Bamber, J. L., van den Broeke, M. R., and van Angelen, J. H.: Influence of ice-sheet geometry and supraglacial lakes on seasonal ice-flow variability, The Cryosphere, 7, 1185–1192, https://doi.org/10.5194/tc-7-1185-2013, 2013.
Kerr, Y. H., Waldteufel, P., Wigneron, J., Martinuzzi, J., Font, J., and Berger, M.: Soil moisture retrieval from space: The Soil Moisture and Ocean Salinity (SMOS) mission, IEEE T. Geosci. Remote, 39, 1729–1735, https://doi.org/10.1109/36.942551, 2001.
Koenig, L. S., Miège, C., Forster, R. R., and Brucker, L.: Initial in situ measurements of perennial meltwater storage in the Greenland firn aquifer, Geophys. Res. Lett., 41, 81–85, https://doi.org/10.1002/2013GL058083, 2014.
Koenig, L. S., Lampkin, D. J., Montgomery, L. N., Hamilton, S. L., Turrin, J. B., Joseph, C. A., Moutsafa, S. E., Panzer, B., Casey, K. A., Paden, J. D., Leuschen, C., and Gogineni, P.: Wintertime storage of water in buried supraglacial lakes across the Greenland Ice Sheet, The Cryosphere, 9, 1333–1342, https://doi.org/10.5194/tc-9-1333-2015, 2015.
Kuipers Munneke, P. K., Ligtenberg, S. R. M., Van Den Broeke, M. R., Van Angelen, J. H., and Forster, R. R.: Explaining the presence of perennial liquid water bodies in the firn of the Greenland Ice Sheet, Geophys. Res. Lett., 41, 476–483, https://doi.org/10.1002/2013GL058389, 2014.
Le Vine, D. M., Lagerloef, G. S. E., Colomb, F. R., Yueh, S. H., and Pellerano, F. A.: Aquarius: An instrument to monitor sea surface salinity from space, IEEE T. Geosci. Remote, 45, 2040–2050, https://doi.org/10.1109/TGRS.2007.898092, 2007.
Lewis, C., Gogineni, S., Rodriguez-Morales, F., Panzer, B., Stumpf, T., Paden, J., and Leuschen, C.: Airborne fine-resolution UHF radar: An approach to the study of englacial reflections, firn compaction and ice attenuation rates, J. Glaciol., 61, 89–100, https://doi.org/10.3189/2015JoG14J089, 2015.
Long, D. G. and Brodzik, M. J.: Optimum image formation for spaceborne microwave radiometer products, IEEE T. Geosci. Remote, 54, 2763–2779, https://doi.org/10.1109/TGRS.2015.2505677, 2016.
Long, D. G. and Daum, D. L.: Spatial resolution enhancement of SSM/I data, IEEE T. Geosci. Remote, 36, 407–417, https://doi.org/10.1109/36.662726, 1998.
Long, D. G., Hardin, P. J., and Whiting, P. T.: Resolution enhancement of spaceborne scatterometer data, IEEE T. Geosci. Remote, 31, 700–715, https://doi.org/10.1109/36.225536, 1993.
Long, D. G., Brodzik, M. J., and Hardman M. A.: Enhanced-resolution SMAP brightness temperature image products, IEEE T. Geosci. Remote, 57, 4151–4163, https://doi.org/10.1109/TGRS.2018.2889427, 2019.
MacFerrin, M.: Greenland Ice Slabs Data, figshare [data set], https://doi.org/10.6084/m9.figshare.8309777.v1, 2019.
MacFerrin, M., Machguth, H., van As, D., Charalampidis, C., Stevens, C. M., Heilig, A., Vandecrux, B., Langen, P. L., Mottram, R., Fettweis, X., van den Broeke, M. R., Pfeffer, W. T., Moussavi, M. S., and Abdalati, W.: Rapid expansion of Greenland's low-permeability ice slabs, Nature, 573, 403–407, https://doi.org/10.1038/s41586-019-1550-3, 2019.
Machguth, H. MacFerrin, M., van As, D., Box, J. E., Charalampidis, C., Colgan., W., Fausto, R. S., Harro, A. J., Mosley-Thompson, E., and van de Wal, R. S. W.: Greenland meltwater storage in firn limited by near-surface ice formation, Nat. Clim. Change, 6, 390–393, https://doi.org/10.1038/nclimate2899, 2016.
Mätzler, C. and Hüppi, R.: Review of signature studies for microwave remote sensing of snowpacks, Adv. Space Res., 9, 253–265, https://doi.org/10.1016/0273-1177(89)90493-6, 1989.
Miège, C.: Spatial extent of Greenland firn aquifer detected by airborne radars, 2010–2014, Arctic Data Center [data set], https://doi.org/10.18739/A2985M, 2018.
Miège, C., Forster, R. R., Brucker, L., Koenig, L. S., Solomon, D. K., Paden, J. D., Box, J. E., Burgess, E. W., Miller, J. Z., McNerney, L., Brautigam, N., Fausto, R. S., and Gogineni, S.: Spatial extent and temporal variability of Greenland firn aquifers detected by ground and airborne radars, J. Geophys. Res.-Earth, 121, 2381–2398, https://doi.org/10.1002/2016JF003869, 2016.
Miles, K. E., Willis, I. C., Benedek, C. L., Williamson, A. G., and Tedesco, M.: Toward monitoring surface and subsurface lakes on the Greenland Ice Sheet Using Sentinel-1 SAR and Landsat-8 OLI imagery, Front. Earth Sci., 5, 58, https://doi.org/10.3389/feart.2017.00058, 2017.
Miller, J. Z.: Mapping Greenland's firn aquifers from space using active and passive satellite microwave remote sensing, PhD thesis, Department of Geography, University of Utah, 135 pp., 2019.
Miller, J. Z.: SMAP-derived Perennial Firn Aquifer and Ice Slab Extents 2015–2019 Version 0, Zenodo [data set], https://doi.org/10.5281/zenodo.5745983, 2021.
Miller, J. Z., Long, D. G., Jezek, K. C., Johnson, J. T., Brodzik, M. J., Shuman, C. A., Koenig, L. S., and Scambos, T. A.: Brief communication: Mapping Greenland's perennial firn aquifers using enhanced-resolution L-band brightness temperature image time series, The Cryosphere, 14, 2809–2817, https://doi.org/10.5194/tc-14-2809-2020, 2020.
Miller, O. L., Solomon, D. K., Miège, C., Koenig, L. S., Forster, R. R., Montgomery, L. N., Schmerr, N., Ligtenberg, S. R. M., Legchenko, A., and Brucker, L.: Hydraulic conductivity of a firn aquifer in southeast Greenland, Front. Earth Sci., 5, https://doi.org/10.3389/feart.2017.00038, 2017.
Montgomery, L. N., Schmerr, N., Burdick, S., Forster, R. R., Koenig, L., Legchenko, A., Ligtenberg, S., Miège, C., Miller, O. L., and Solomon, D. K.: Investigation of firn aquifer structure in southeastern Greenland using active source seismology, Front. Earth Sci., 5, https://doi.org/10.3389/feart.2017.00010, 2017.
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.
Mote, T. L. and Andersen, M. R.: Variations in snowpack melt on the Greenland Ice Sheet based on passive microwave measurements, J. Glaciol., 41, 51–60, https://doi.org/10.1017/S0022143000017755, 1995.
Müller, F.: Zonation in the Accumulation Area of the Glaciers of Axel Heiberg Island, N. W. T., Canada, J. Glaciol., 4, 302–311, 1962.
Nghiem, S. V., Steffen, K., Neumann, G. A., and Huff, R: Mapping of ice layer extent and snow accumulation in the percolation zone of the Greenland ice sheet, J. Geophys. Res., 110, F02017, https://doi.org/10.1029/2004JF000234, 2005.
Nghiem, S. V., Hall, D. K., Mote, T. L., Tedesco, M., Albert, M. R., Keegan, K., Shuman, C. A., DiGirolamo, N. E., and Neumann, G.: The extreme melt across the Greenland Ice Sheet in 2012, Geophys. Res. Lett., 39, L20502, https://doi.org/10.1029/2012GL053611, 2012.
Noël, B., van de Berg, W. J., Lhermitte, S. L. M., and van den Broeke, M. R.: Rapid ablation zone expansion amplifies north Greenland mass loss, Sci. Adv., 5, eaaw0123, https://doi.org/10.1126/sciadv.aaw0123, 2019.
Noël, B., van Kampenhout, L., Lenaerts, J. T. M., van de Berg, W. J., and van den Broeke, M. R.: A 21st century warming threshold for sustained Greenland Ice Sheet mass loss, Geophys. Res. Lett., 48, https://doi.org/10.1029/2020GL090471, 2021.
Paden, J., Li, J., Leuschen, C., Rodriguez-Morales, F., and Hale, R.: IceBridge Accumulation Radar L1B Geolocated Radar Echo Strength Profiles, Version 2, NASA National Snow and Ice Data Center Distributed Active Archive Center [data set], https://doi.org/10.5067/0ZY1XYHNIQNY, 2014 (updated 2018).
Pfeffer, W. T., Meier, M. F., and Illangasekare, T. H.: Retention of Greenland runoff by refreezing: Implications for projected future sea level change, J. Geophys. Res.-Oceans, 96, 22117–22124, https://doi.org/10.1029/91JC02502, 1991.
Pfeffer, W. T. and Humphrey, N. F.: Determination of timing and location of water movement and ice-layer formation by temperature measurements in sub-freezing snow, J. Glaciol., 42, 292–304, https://doi.org/10.1017/S0022143000004159, 1996.
Piepmeier, J. R., Focardi, P., Horgan, K. A., Knuble, J., Ehsan, N., Lucey, J., Brambora, C., Brown, P. R., Hoffman, P. J., French, R. T., Mikhaylov, R. L., Kwack, E., Slimko, E. M., Dawson, D. E., Hudson, D., Peng, J., Mohammed, P. N., De Amici, G., Freedman, A. P., Medeiros, J., Sacks, F., Estep, R., Spencer, M. W., Chen, C. W., Wheeler, K. B., Edelstein, W. N., O'Neill, P. E., and Njoku, E. G.: SMAP L-band microwave radiometer: Instrument design and first year on orbit, IEEE T. Geosci. Remote, 55, 1954–1966, https://doi.org/10.1109/TGRS.2016.2631978, 2017.
Poinar, K., Joughin, I., Lilien, D., Brucker, L., Kehrl, L., and Nowicki, S.: Drainage of southeast Greenland firn aquifer water through crevasses to the bed, Front. Earth Sci., https://doi.org/10.3389/feart.2017.00005, 2017.
Poinar, K., Dow, C. F., and Andrews, L. C.: Long-term support of an active subglacial hydrologic system in southeast Greenland by firn aquifers, Geophys. Res. Lett., 46, 4772–4781, https://doi.org/10.1029/2019GL082786, 2019.
Rignot, E.: Backscatter model for the unusual radar properties of the Greenland Ice Sheet, J. Geophys. Res.-Planet., 100, 9389–9400, https://doi.org/10.1029/95JE00485, 1995.
Rignot, E. J., Ostro, S. J., Van Zyl, J., and Jezek, K. C.: Unusual radar echoes from the Greenland Ice Sheet, Science, 261, 1710–1713, https://doi.org/10.1126/science.261.5129.1710, 1993.
Rodriguez-Morales, F., Byers, K., Crowe, R., Player, K., Hale, R. D., Arnold, E. J., Smith, L., Gifford, C. M., Braaten, D., Panton, C., Gogineni, S., Leuschen, C. J., Paden, J. D., Li, J., Lewis, C. C., Panzer, B., Gomez-Garcia Alvestegui, D., and Patel, A.: Advanced multi-frequency radar instrumentation for polar research, IEEE T. Geosci. Remote, 52, 2824–2842, https://doi.org/10.1109/TGRS.2013.2266415, 2014.
Schröder, L., Neckel, N., Zindler, R., and Humbert, A.: Perennial supraglacial lakes in northeast Greenland observed by polarimetric SAR, Remote Sens., 12, 2798, https://doi.org/10.3390/rs12172798, 2020.
Shuman, C. A., Hall, D. K., DiGirolamo, N. E., Mefford, T. K., and Schnaubelt, M. J.: Comparison of near-surface air temperatures and MODIS ice-surface temperatures at Summit, Greenland (2008–2013), J. Appl. Meteorol. Clim., 53, 2171–2180, https://doi.org/10.1175/JAMC-D-14-0023.1, 2014.
Steffen, K., Nghiem, S. V., Huff, R., and Neumann, G.: The melt anomaly of 2002 on the Greenland Ice Sheet from active and passive microwave satellite observations, Geophys. Res. Lett., 31, L2040, https://doi.org/10.1029/2004GL020444, 2004.
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.
Swift, C. T., Hayes, P. S., Herd, J. S., Jones, W. L., and Delnore, V. E.: Airborne microwave measurements of the southern Greenland Ice Sheet, J. Geophys. Res.-Sol. Ea., 90, 1983–1994, https://doi.org/10.1029/JB090iB02p01983, 1985.
Tedesco, M. and Fettweis, X.: Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet, The Cryosphere, 14, 1209–1223, https://doi.org/10.5194/tc-14-1209-2020, 2020.
Tedesco, M., Serreze, M., and Fettweis, X.: Diagnosing the extreme surface melt event over southwestern Greenland in 2007, The Cryosphere, 2, 159–166, https://doi.org/10.5194/tc-2-159-2008, 2008.
Tedesco, M., Fettweis, X., van den Broeke, M. R., van de Wal, R. S. W., Smeets, C. J. P. P., van de Berg, W. J., Serreze, M. C., and Box, J. E.: The role of albedo and accumulation in the 2010 melting record in Greenland, Environ. Res. Lett, 6, 014005, https://doi.org/10.1088/1748-9326/6/1/014005, 2011.
Tedesco, M., Mote, T., Fettweis, X., Hanna, E.,
Jeyaratnam, J., Booth, J. F., Datta, R., and Briggs, K.: Arctic
cut-off high drives the poleward shift of a new Greenland melting
record, Nat. Commun., 7, 11723–11723, https://doi.org/10.1038/ncomms11723, 2016.
Tiuri, M. E., Sihvola, A. H., Nyfors, E. G., and Hallikaiken, M. T.: The complex dielectric constant of snow at microwave frequencies, IEEE J. Oceanic Eng., 9, 377–382, https://doi.org/10.1109/JOE.1984.1145645, 1984.
Tsai, W., Nghiem, S. V., and Van Zyl, J. J.: SeaWinds scatterometer on QuikSCAT mission and the emerging land and ocean applications, Proc. SPIE, 4152, 89–99, https://doi.org/10.1117/12.410586, 2000.
Turton, J. V., Hochreuther, P., Reimann, N., and Blau,
M. T.: The distribution and evolution of supraglacial lakes on
79∘ N Glacier (north-eastern Greenland) and interannual climatic
controls, The Cryosphere, 15, 3877–3896,
https://doi.org/10.5194/tc-15-3877-2021, 2021.
Ulaby, F. T., Long, D. G., Blackwell, W. J., Elachi, C., Fung, A. K., Ruf, C., Sarabandi, C., Zebker, H. A., and Van Zyl, J.: Microwave radar and radiometric remote sensing, University of Michigan Press, Ann Arbor, 2014.
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.
van der Veen, C. J.: Fracture propagation as means of rapidly transferring surface meltwater to the base of glaciers, Geophys. Res. Lett., 34, L01501, https://doi.org/10.1029/2006GL028385, 2007.
Wessel, P. and Smith, W. H. F.: A global, self-consistent, hierarchical, high-resolution shoreline database, J. Geophys. Res., 101, 8741–8743, https://doi.org/10.1029/96JB00104, 1996.
Zwally, H. J., Abdalati, W., Herring, T., Larson, K., Saba, J., and Steffen, K.: Surface melt-induced acceleration of Greenland Ice Sheet flow, Science, 297, 218–222, https://doi.org/10.1126/science.1072708, 2002.
Zwally, J. H.: Microwave emissivity and accumulation rate of polar firn, J. Glaciol., 18, 195–215, https://doi.org/10.1017/S0022143000021304, 1977.
Short summary
We use L-band brightness temperature imagery from NASA's Soil Moisture Active Passive (SMAP) satellite to map the extent of perennial firn aquifer and ice slab areas within the Greenland Ice Sheet. As Greenland's climate continues to warm and seasonal surface melting increases in extent, intensity, and duration, quantifying the possible rapid expansion of perennial firn aquifers and ice slab areas has significant implications for understanding the stability of the Greenland Ice Sheet.
We use L-band brightness temperature imagery from NASA's Soil Moisture Active Passive (SMAP)...
