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1. A review of the scientific knowledge of the seascape off Dronning Maud Land, Antarctica

Author

Lowther, Andrew, von Quillfeldt, Cecilie, Assmy, Philipp, De Steur, Laura, Descamps, Sebastien, Divine, Dmitry, Elvevold, Synnøve, Forwick, Matthias, Fransson, Agneta, Fraser, Alexander, Gerland, Sebastian, Granskog, Mats, Hallanger, Ingeborg, Hattermann, Tore, Itkin, Mikhail, Hop, Haakon, Husum, Katrine, Kovacs, Kit, Lydersen, Christian, Matsuoka, Kenichi, Miettinen, Arto, Moholdt, Geir, Moreau, Sebastien, Myhre, Per Inge, Orme, Lisa, Pavlova, Olga, and Tandberg, Ann Helene

Published
2022
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2. Evidence of active subglacial lakes under a slowly moving coastal region of the Antarctic Ice Sheet.

Author

Arthur, Jennifer F., Shackleton, Calvin, Moholdt, Geir, Matsuoka, Kenichi, and van Oostveen, Jelte

Abstract

Active subglacial lakes beneath the Antarctic Ice Sheet provide insights into the dynamic subglacial environment, with implications for ice-sheet dynamics and mass balance. Most previously identified lakes have been found upstream (>100 km) of fast-flowing glaciers in West Antarctica, and none have been found in the coastal region of Dronning Maud Land (DML) in East Antarctica. The regional distribution and extent of lakes as well as their timescales and mechanisms of filling–draining activity remain poorly understood. We present local ice surface elevation changes in the coastal DML region that we interpret as unique evidence of seven active subglacial lakes located under slowly moving ice near the grounding line margin. Laser altimetry data from ICESat-2 and ICESat (Ice, Cloud, and Land Elevation Satellites) combined with multi-temporal Reference Digital Elevation Model of Antarctica (REMA) strips reveal that these lakes actively fill and drain over periods of several years. Stochastic analyses of subglacial water routing together with visible surface lineations on ice shelves indicate that these lakes discharge meltwater across the grounding line. Two lakes are within 15 km of the grounding line, while another three are within 54 km. Ice flows 17–172 m a−1 near these lakes, much slower than the mean ice flow speed near other active lakes within 100 km of the grounding line (303 m a−1). Our results improve knowledge of subglacial meltwater dynamics and evolution in this region of East Antarctica and provide new observational data to refine subglacial hydrological models. [ABSTRACT FROM AUTHOR]

Published
2025
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5. Quantarctica, an integrated mapping environment for Antarctica, the Southern Ocean, and sub-Antarctic islands

Author

Matsuoka, Kenichi, Skoglund, Anders, Roth, George, de Pomereu, Jean, Griffiths, Huw, Headland, Robert, Herried, Brad, Katsumata, Katsuro, Le Brocq, Anne, Licht, Kathy, Morgan, Fraser, Neff, Peter D., Ritz, Catherine, Scheinert, Mirko, Tamura, Takeshi, Van de Putte, Anton, van den Broeke, Michiel, von Deschwanden, Angela, Deschamps-Berger, César, Van Liefferinge, Brice, Tronstad, Stein, and Melvær, Yngve

Published
2021
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7. Sediment Freeze‐On and Transport Near the Onset of a Fast‐Flowing Glacier in East Antarctica

Author

Franke, Steven, Wolovick, Michael, Drews, Reinhard, Jansen, Daniela, Matsuoka, Kenichi, Bons, Paul D, Franke, Steven, Wolovick, Michael, Drews, Reinhard, Jansen, Daniela, Matsuoka, Kenichi, and Bons, Paul D

Abstract

Understanding the material properties and physical conditions of basal ice is crucial for a comprehensive understanding of Antarctic ice‐sheet dynamics. Yet, direct data are sparse and difficult to acquire. Here, we employ ultra‐wideband radar to map high‐backscatter zones near the glacier bed within East Antarctica's Jutulstraumen drainage basin. Our backscatter analysis reveals that the basal ice in an area of ∼10,000 km² is composed of along‐flow oriented sediment‐laden basal ice units connected to the basal substrate, extending up to several hundred meters thick. Three‐dimensional thermomechanical modeling supports that these units form via basal freeze‐on of subglacial water that originated from further upstream. Our findings suggest that basal freeze‐on, and the entrainment and transport of subglacial material play a significant role in an accurate representation of material, physical, and rheological properties of the Antarctic ice sheet's basal ice, ultimately enhancing the accuracy and reliability of ice‐sheet modeling.

Published
2024

8. Sediment-laden basal ice units near the onset of a fast-flowing glacier in East Antarctica

Author

Franke, Steven, Wolovick, Michael, Drews, Reinhard, Jansen, Daniela, Matsuoka, Kenichi, Bons, Paul D, Franke, Steven, Wolovick, Michael, Drews, Reinhard, Jansen, Daniela, Matsuoka, Kenichi, and Bons, Paul D

Abstract

Understanding the material properties and physical conditions of basal ice is crucial for a comprehensive understanding of Antarctic ice-sheet dynamics. Yet, direct data are sparse and difficult to acquire, necessitating geophysical data for analysis. We employed high-resolution ultra-wideband radar to map high-backscatter zones near the glacier bed within East Antarctica's Jutulstraumen drainage basin. In addition, we used radar forward modelling to constrain their material composition. Our results reveal along-flow oriented sediment-laden basal ice units connected to the basal substrate, extending to several hundred meters thick. Three-dimensional thermomechanical modelling suggests these units initially form via basal freeze-on of subglacial water originating upstream. We suggest that basal freeze-on and the entrainment and transport of subglacial material play a significant role in an accurate representation of the material, physical, and rheological properties of the Antarctic ice sheet's basal ice, ultimately enhancing the accuracy and reliability of ice-sheet modelling.

Published
2024

9. Gilteritinib as Post-Transplant Maintenance for Acute Myeloid Leukemia With Internal Tandem Duplication Mutation of FLT3

Author

Levis, M, Hamadani, M, Logan, B, Jones, R, Singh, A, Litzow, M, Wingard, J, Papadopoulos, E, Perl, A, Soiffer, R, Ustun, C, Ueda Oshima, M, Uy, G, Waller, E, Vasu, S, Solh, M, Mishra, A, Muffly, L, Kim, H, Mikesch, J, Najima, Y, Onozawa, M, Thomson, K, Nagler, A, Wei, A, Marcucci, G, Geller, N, Hasabou, N, Delgado, D, Rosales, M, Hill, J, Gill, S, Nuthethi, R, King, D, Wittsack, H, Mendizabal, A, Devine, S, Horowitz, M, Chen, Y, Agura, E, Altman, J, Anagnostopoulos, A, Anand, S, Artz, A, Aulitzky, W, Balderman, S, Ballen, K, Becker, M, Beguin, Y, Berkahn, L, Berneman, Z, Bhatt, V, Bilmon, I, Bonifazi, F, Briggs, A, Bruno, B, Brunstein, C, Byrne, M, Byrne, J, Cabrero, M, Cairoli, R, Carrum, G, Cerny, J, Cheong, J, Ciceri, F, Colorado, M, Cook, R, Couriel, D, Craddock, C, Damon, L, Deol, A, Desbrosses, Y, Di Grazia, C, Di Stasi, A, Dias, A, Dorritie, K, Essell, J, Eto, T, Farag, S, Forcade, E, Frankfurt, O, Fujiwara, S, Fukuda, T, Fukushima, K, Furst, S, Goto, T, Hall, A, Hatta, S, Hicheri, Y, Horwitz, M, Hou, H, How, J, Howard, D, Hsu, W, Huynh, A, Irvine, D, Ishikawa, T, Jamieson, K, Jedrzejczak, W, Jethava, Y, Jimenez, A, Jung, C, Kanda, J, Karakasis, D, Kato, J, Kekre, N, Khera, N, Klein, A, Kobbe, G, Kornblit, B, Kota, V, Lachance, S, Leber, B, Lee, C, Lee, J, Lin, T, Liu, T, Martelli, M, Martinez, C, Matsuoka, K, Mccarty, J, Mendez, L, Michelis, F, Mineishi, S, Mohty, M, Moors, I, Motyckova, G, Mueller, L, Nakamae, H, Nakano, N, Nathan, S, Nicholson, E, Norkin, M, Ogawa, Y, Olesen, G, Oluwole, O, Pantin, J, Paulson, K, Pemberton, L, Perera, T, Piatkowska-Jakubas, B, Poire, X, Protheroe, R, Rambaldi, A, Ritchie, D, Ross, K, Rubio, M, Santarone, S, Sanz Caballer, J, Sawa, M, Schaar, D, Scheid, C, Schriber, J, Seropian, S, Shah, N, Shore, T, Gil, J, Sobecks, R, Socie, G, Sprague, K, Spyridonidis, A, Stelljes, M, Stiff, P, Stuart, R, Tanaka, M, Tandra, A, Tholouli, E, Thomas, X, Tiribelli, M, Tomlinson, B, Tsirigotis, P, Tzachanis, D, Uchida, N, Ueda, M, Valcarcel Ferreiras, D, Wagner, E, Watson, A, Weisdorf, D, Wolschke, C, Wrobel, T, Yakoub-Agha, I, Yamauchi, T, Yared, J, Yeh, S, Yoon, S, Yoshihara, S, Null, N, Levis, Mark J., Hamadani, Mehdi, Logan, Brent, Jones, Richard J., Singh, Anurag K., Litzow, Mark, Wingard, John R., Papadopoulos, Esperanza B., Perl, Alexander E., Soiffer, Robert J., Ustun, Celalettin, Ueda Oshima, Masumi, Uy, Geoffrey L., Waller, Edmund K., Vasu, Sumithra, Solh, Melhem, Mishra, Asmita, Muffly, Lori, Kim, Hee-Je, Mikesch, Jan-Henrik, Najima, Yuho, Onozawa, Masahiro, Thomson, Kirsty, Nagler, Arnon, Wei, Andrew H., Marcucci, Guido, Geller, Nancy L., Hasabou, Nahla, Delgado, David, Rosales, Matt, Hill, Jason, Gill, Stanley C., Nuthethi, Rishita, King, Denise, Wittsack, Heather, Mendizabal, Adam, Devine, Steven M., Horowitz, Mary M., Chen, Yi-Bin, Agura, Ed, Altman, Jessica, Anagnostopoulos, Achiles, Anand, Sarah, Artz, Andrew, Aulitzky, Walter, Balderman, Sophia, Ballen, Karen, Becker, Michael, Beguin, Yves, Berkahn, Leanne, Berneman, Zwi, Bhatt, Vijaya, Bilmon, Ian, Bonifazi, Francesca, Briggs, Adrienne, Bruno, Benedetto, Brunstein, Claudio, Byrne, Michael, Byrne, Jenny, Cabrero, Monica, Cairoli, Roberto, Carrum, George, Cerny, Jan, Cheong, June-Won, Ciceri, Fabio, Colorado, Mercedes, Cook, Rachel, Couriel, Daniel, Craddock, Charles, Damon, Lloyd, Deol, Abhinav, Desbrosses, Yohan, Devine, Steve, Di Grazia, Carmela, Di Stasi, Antonio, Dias, Ajoy, Dorritie, Kathy, Essell, James, Eto, Tetsuya, Farag, Sherif, Forcade, Edouard, Frankfurt, Olga, Fujiwara, Shinichiro, Fukuda, Takahiro, Fukushima, Kentaro, Furst, Sabine, Goto, Tatsunori, Hall, Aric, Hatta, Shunsuke, Hicheri, Yosr, Horwitz, Mitchell, Hou, Hsin-An, How, Jonathan, Howard, Dianna, Hsu, Wei-Hsun (Blake), Huynh, Anne, Irvine, David, Ishikawa, Takayuki, Jamieson, Katarzyna, Jedrzejczak, Wieslaw, Jethava, Yogesh, Jimenez, Antonio, Jung, Chul Won, Kanda, Junya, Karakasis, Dimitrios, Kato, Jun, Kekre, Natasha, Khera, Nandita, Klein, Andreas, Kobbe, Guido, Kornblit, Brian, Kota, Vamsi, Lachance, Silvy, Leber, Brian, Lee, Catherine, Lee, Je Hwan, Lin, Tung-Liang, Liu, Ta-Chih, Martelli, Maurizio, Martinez, Carmen, Matsuoka, Kenichi, McCarty, John, Mendez, Lourdes, Michelis, Fotios, Mineishi, Shin, Mohty, Mohamad, Moors, Ine, Motyckova, Gabriela, Mueller, Lutz, Nakamae, Hirohisa, Nakano, Nobuaki, Nathan, Sunita, Nicholson, Emma, Norkin, Maxim, Ogawa, Yoshiaki, Olesen, Gitte, Oluwole, Olalekan, Pantin, Jeremy, Paulson, Kristjan, Pemberton, Lucy, Perera, Travis, Piatkowska-Jakubas, Beata, Poire, Xavier, Protheroe, Rachel, Rambaldi, Alessandro, Ritchie, David, Ross, Kelly, Rubio, Marie-Therese, Santarone, Stella, Sanz Caballer, Jaime, Sawa, Masashi, Schaar, Dale, Scheid, Christoph, Schriber, Jeffrey, Seropian, Stuart, Shah, Nilay, Shah, Nirav, Shore, Tsiporah, Gil, Jorge Sierra, Singh, Anurag, Sobecks, Ronald, Socie, Gerard, Soiffer, Robert, Sprague, Kellie, Spyridonidis, Alexandros, Stelljes, Matthias, Stiff, Patrick, Stuart, Robert, Tanaka, Masatsugu, Tandra, Anand, Tholouli, Eleni, Thomas, Xavier, Tiribelli, Mario, Tomlinson, Benjamin, Tsirigotis, Panagiotis, Tzachanis, Dimitrios, Uchida, Naoyuki, Ueda, Masumi, Valcarcel Ferreiras, David, Wagner, Eva, Watson, Anne-Marie, Weisdorf, Daniel, Wolschke, Christine, Wrobel, Tomasz, Yakoub-Agha, Ibrahim, Yamauchi, Takuji, Yared, Jean, Yeh, Su-Peng, Yoon, Sung-Soo, Yoshihara, Satoshi, null, null, Levis, M, Hamadani, M, Logan, B, Jones, R, Singh, A, Litzow, M, Wingard, J, Papadopoulos, E, Perl, A, Soiffer, R, Ustun, C, Ueda Oshima, M, Uy, G, Waller, E, Vasu, S, Solh, M, Mishra, A, Muffly, L, Kim, H, Mikesch, J, Najima, Y, Onozawa, M, Thomson, K, Nagler, A, Wei, A, Marcucci, G, Geller, N, Hasabou, N, Delgado, D, Rosales, M, Hill, J, Gill, S, Nuthethi, R, King, D, Wittsack, H, Mendizabal, A, Devine, S, Horowitz, M, Chen, Y, Agura, E, Altman, J, Anagnostopoulos, A, Anand, S, Artz, A, Aulitzky, W, Balderman, S, Ballen, K, Becker, M, Beguin, Y, Berkahn, L, Berneman, Z, Bhatt, V, Bilmon, I, Bonifazi, F, Briggs, A, Bruno, B, Brunstein, C, Byrne, M, Byrne, J, Cabrero, M, Cairoli, R, Carrum, G, Cerny, J, Cheong, J, Ciceri, F, Colorado, M, Cook, R, Couriel, D, Craddock, C, Damon, L, Deol, A, Desbrosses, Y, Di Grazia, C, Di Stasi, A, Dias, A, Dorritie, K, Essell, J, Eto, T, Farag, S, Forcade, E, Frankfurt, O, Fujiwara, S, Fukuda, T, Fukushima, K, Furst, S, Goto, T, Hall, A, Hatta, S, Hicheri, Y, Horwitz, M, Hou, H, How, J, Howard, D, Hsu, W, Huynh, A, Irvine, D, Ishikawa, T, Jamieson, K, Jedrzejczak, W, Jethava, Y, Jimenez, A, Jung, C, Kanda, J, Karakasis, D, Kato, J, Kekre, N, Khera, N, Klein, A, Kobbe, G, Kornblit, B, Kota, V, Lachance, S, Leber, B, Lee, C, Lee, J, Lin, T, Liu, T, Martelli, M, Martinez, C, Matsuoka, K, Mccarty, J, Mendez, L, Michelis, F, Mineishi, S, Mohty, M, Moors, I, Motyckova, G, Mueller, L, Nakamae, H, Nakano, N, Nathan, S, Nicholson, E, Norkin, M, Ogawa, Y, Olesen, G, Oluwole, O, Pantin, J, Paulson, K, Pemberton, L, Perera, T, Piatkowska-Jakubas, B, Poire, X, Protheroe, R, Rambaldi, A, Ritchie, D, Ross, K, Rubio, M, Santarone, S, Sanz Caballer, J, Sawa, M, Schaar, D, Scheid, C, Schriber, J, Seropian, S, Shah, N, Shore, T, Gil, J, Sobecks, R, Socie, G, Sprague, K, Spyridonidis, A, Stelljes, M, Stiff, P, Stuart, R, Tanaka, M, Tandra, A, Tholouli, E, Thomas, X, Tiribelli, M, Tomlinson, B, Tsirigotis, P, Tzachanis, D, Uchida, N, Ueda, M, Valcarcel Ferreiras, D, Wagner, E, Watson, A, Weisdorf, D, Wolschke, C, Wrobel, T, Yakoub-Agha, I, Yamauchi, T, Yared, J, Yeh, S, Yoon, S, Yoshihara, S, Null, N, Levis, Mark J., Hamadani, Mehdi, Logan, Brent, Jones, Richard J., Singh, Anurag K., Litzow, Mark, Wingard, John R., Papadopoulos, Esperanza B., Perl, Alexander E., Soiffer, Robert J., Ustun, Celalettin, Ueda Oshima, Masumi, Uy, Geoffrey L., Waller, Edmund K., Vasu, Sumithra, Solh, Melhem, Mishra, Asmita, Muffly, Lori, Kim, Hee-Je, Mikesch, Jan-Henrik, Najima, Yuho, Onozawa, Masahiro, Thomson, Kirsty, Nagler, Arnon, Wei, Andrew H., Marcucci, Guido, Geller, Nancy L., Hasabou, Nahla, Delgado, David, Rosales, Matt, Hill, Jason, Gill, Stanley C., Nuthethi, Rishita, King, Denise, Wittsack, Heather, Mendizabal, Adam, Devine, Steven M., Horowitz, Mary M., Chen, Yi-Bin, Agura, Ed, Altman, Jessica, Anagnostopoulos, Achiles, Anand, Sarah, Artz, Andrew, Aulitzky, Walter, Balderman, Sophia, Ballen, Karen, Becker, Michael, Beguin, Yves, Berkahn, Leanne, Berneman, Zwi, Bhatt, Vijaya, Bilmon, Ian, Bonifazi, Francesca, Briggs, Adrienne, Bruno, Benedetto, Brunstein, Claudio, Byrne, Michael, Byrne, Jenny, Cabrero, Monica, Cairoli, Roberto, Carrum, George, Cerny, Jan, Cheong, June-Won, Ciceri, Fabio, Colorado, Mercedes, Cook, Rachel, Couriel, Daniel, Craddock, Charles, Damon, Lloyd, Deol, Abhinav, Desbrosses, Yohan, Devine, Steve, Di Grazia, Carmela, Di Stasi, Antonio, Dias, Ajoy, Dorritie, Kathy, Essell, James, Eto, Tetsuya, Farag, Sherif, Forcade, Edouard, Frankfurt, Olga, Fujiwara, Shinichiro, Fukuda, Takahiro, Fukushima, Kentaro, Furst, Sabine, Goto, Tatsunori, Hall, Aric, Hatta, Shunsuke, Hicheri, Yosr, Horwitz, Mitchell, Hou, Hsin-An, How, Jonathan, Howard, Dianna, Hsu, Wei-Hsun (Blake), Huynh, Anne, Irvine, David, Ishikawa, Takayuki, Jamieson, Katarzyna, Jedrzejczak, Wieslaw, Jethava, Yogesh, Jimenez, Antonio, Jung, Chul Won, Kanda, Junya, Karakasis, Dimitrios, Kato, Jun, Kekre, Natasha, Khera, Nandita, Klein, Andreas, Kobbe, Guido, Kornblit, Brian, Kota, Vamsi, Lachance, Silvy, Leber, Brian, Lee, Catherine, Lee, Je Hwan, Lin, Tung-Liang, Liu, Ta-Chih, Martelli, Maurizio, Martinez, Carmen, Matsuoka, Kenichi, McCarty, John, Mendez, Lourdes, Michelis, Fotios, Mineishi, Shin, Mohty, Mohamad, Moors, Ine, Motyckova, Gabriela, Mueller, Lutz, Nakamae, Hirohisa, Nakano, Nobuaki, Nathan, Sunita, Nicholson, Emma, Norkin, Maxim, Ogawa, Yoshiaki, Olesen, Gitte, Oluwole, Olalekan, Pantin, Jeremy, Paulson, Kristjan, Pemberton, Lucy, Perera, Travis, Piatkowska-Jakubas, Beata, Poire, Xavier, Protheroe, Rachel, Rambaldi, Alessandro, Ritchie, David, Ross, Kelly, Rubio, Marie-Therese, Santarone, Stella, Sanz Caballer, Jaime, Sawa, Masashi, Schaar, Dale, Scheid, Christoph, Schriber, Jeffrey, Seropian, Stuart, Shah, Nilay, Shah, Nirav, Shore, Tsiporah, Gil, Jorge Sierra, Singh, Anurag, Sobecks, Ronald, Socie, Gerard, Soiffer, Robert, Sprague, Kellie, Spyridonidis, Alexandros, Stelljes, Matthias, Stiff, Patrick, Stuart, Robert, Tanaka, Masatsugu, Tandra, Anand, Tholouli, Eleni, Thomas, Xavier, Tiribelli, Mario, Tomlinson, Benjamin, Tsirigotis, Panagiotis, Tzachanis, Dimitrios, Uchida, Naoyuki, Ueda, Masumi, Valcarcel Ferreiras, David, Wagner, Eva, Watson, Anne-Marie, Weisdorf, Daniel, Wolschke, Christine, Wrobel, Tomasz, Yakoub-Agha, Ibrahim, Yamauchi, Takuji, Yared, Jean, Yeh, Su-Peng, Yoon, Sung-Soo, Yoshihara, Satoshi, and null, null

Abstract

PURPOSEAllogeneic hematopoietic cell transplantation (HCT) improves outcomes for patients with AML harboring an internal tandem duplication mutation of FLT3 (FLT3-ITD) AML. These patients are routinely treated with a FLT3 inhibitor after HCT, but there is limited evidence to support this. Accordingly, we conducted a randomized trial of post-HCT maintenance with the FLT3 inhibitor gilteritinib (ClinicalTrials.gov identifier: NCT02997202) to determine if all such patients benefit or if detection of measurable residual disease (MRD) could identify those who might benefit.METHODSAdults with FLT3-ITD AML in first remission underwent HCT and were randomly assigned to placebo or 120 mg once daily gilteritinib for 24 months after HCT. The primary end point was relapse-free survival (RFS). Secondary end points included overall survival (OS) and the effect of MRD pre- and post-HCT on RFS and OS.RESULTSThree hundred fifty-six participants were randomly assigned post-HCT to receive gilteritinib or placebo. Although RFS was higher in the gilteritinib arm, the difference was not statistically significant (hazard ratio [HR], 0.679 [95% CI, 0.459 to 1.005]; two-sided P =.0518). However, 50.5% of participants had MRD detectable pre- or post-HCT, and, in a prespecified subgroup analysis, gilteritinib was beneficial in this population (HR, 0.515 [95% CI, 0.316 to 0.838]; P =.0065). Those without detectable MRD showed no benefit (HR, 1.213 [95% CI, 0.616 to 2.387]; P =.575).CONCLUSIONAlthough the overall improvement in RFS was not statistically significant, RFS was higher for participants with detectable FLT3-ITD MRD pre- or post-HCT who received gilteritinib treatment. To our knowledge, these data are among the first to support the effectiveness of MRD-based post-HCT therapy.

Published
2024

10. Evolution of ice rises in the Fimbul Ice Shelf, Dronning Maud Land, over the last millennium

Author

Goel, Vikram, Martín, Carlos, Matsuoka, Kenichi, Goel, Vikram, Martín, Carlos, and Matsuoka, Kenichi

Abstract

We investigate two ice rises, Kupol Moskovskij and Kupol Ciolkovskogo, in the Fimbul Ice Shelf, East Antarctica, situated ~60 km from each other but differing in their glaciological settings. We apply a thermo-mechanically coupled Elmer/Ice model to profiles going across these ice rises and use it to investigate their past evolution covering present to several millennia ago. We constrain the model results using field measurements, including surface-velocity measurements, and surface mass balance estimated by isochronous radar stratigraphy dated with firn cores. We find that the ice rises are thickening at present (2012–2014), which started only in recent decades. Investigation of deeper radar reflectors suggests a stronger upwind-downwind contrast in surface mass balance in the past for both ice rises, with varying details. This result matches what was previously found on Blåskimen Island ice rise, which is also in the Fimbul Ice Shelf. Moreover, Kupol Moskovskij, situated at a shear margin, shows signs of recent changes in its ice-divide position, while Kupol Ciolkovskogo shows a more stable divide position. This study highlights the long-term influence of surface mass balance on ice rises, as well as the strong influence of local glaciological settings on their evolution.

Published
2024

12. Radar internal reflection horizons from multisystem data reflect ice dynamic and surface accumulation history along the Princess Ragnhild Coast, Dronning Maud Land, East Antarctica

Author

Koch, Inka, primary, Drews, Reinhard, additional, Franke, Steven, additional, Jansen, Daniela, additional, Oraschewski, Falk Marius, additional, Muhle, Leah Sophie, additional, Višnjević, Vjeran, additional, Matsuoka, Kenichi, additional, Pattyn, Frank, additional, and Eisen, Olaf, additional

Published
2023
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13. Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet

Author

Morlighem, Mathieu, Rignot, Eric, Binder, Tobias, Blankenship, Donald, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Ferraccioli, Fausto, Forsberg, René, Fretwell, Peter, Goel, Vikram, Greenbaum, Jamin S., Gudmundsson, Hilmar, Guo, Jingxue, Helm, Veit, Hofstede, Coen, Howat, Ian, Humbert, Angelika, Jokat, Wilfried, Karlsson, Nanna B., Lee, Won Sang, Matsuoka, Kenichi, Millan, Romain, Mouginot, Jeremie, Paden, John, Pattyn, Frank, Roberts, Jason, Rosier, Sebastian, Ruppel, Antonia, Seroussi, Helene, Smith, Emma C., Steinhage, Daniel, Sun, Bo, Broeke, Michiel R. van den, Ommen, Tas D. van, Wessem, Melchior van, and Young, Duncan A.

Published
2020
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17. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C., primary, Fretwell, Peter, additional, Bodart, Julien A., additional, Pritchard, Hamish D., additional, Aitken, Alan, additional, Bamber, Jonathan L., additional, Bell, Robin, additional, Bianchi, Cesidio, additional, Bingham, Robert G., additional, Blankenship, Donald D., additional, Casassa, Gino, additional, Catania, Ginny, additional, Christianson, Knut, additional, Conway, Howard, additional, Corr, Hugh F. J., additional, Cui, Xiangbin, additional, Damaske, Detlef, additional, Damm, Volkmar, additional, Drews, Reinhard, additional, Eagles, Graeme, additional, Eisen, Olaf, additional, Eisermann, Hannes, additional, Ferraccioli, Fausto, additional, Field, Elena, additional, Forsberg, René, additional, Franke, Steven, additional, Fujita, Shuji, additional, Gim, Yonggyu, additional, Goel, Vikram, additional, Gogineni, Siva Prasad, additional, Greenbaum, Jamin, additional, Hills, Benjamin, additional, Hindmarsh, Richard C. A., additional, Hoffman, Andrew O., additional, Holmlund, Per, additional, Holschuh, Nicholas, additional, Holt, John W., additional, Horlings, Annika N., additional, Humbert, Angelika, additional, Jacobel, Robert W., additional, Jansen, Daniela, additional, Jenkins, Adrian, additional, Jokat, Wilfried, additional, Jordan, Tom, additional, King, Edward, additional, Kohler, Jack, additional, Krabill, William, additional, Kusk Gillespie, Mette, additional, Langley, Kirsty, additional, Lee, Joohan, additional, Leitchenkov, German, additional, Leuschen, Carlton, additional, Luyendyk, Bruce, additional, MacGregor, Joseph, additional, MacKie, Emma, additional, Matsuoka, Kenichi, additional, Morlighem, Mathieu, additional, Mouginot, Jérémie, additional, Nitsche, Frank O., additional, Nogi, Yoshifumi, additional, Nost, Ole A., additional, Paden, John, additional, Pattyn, Frank, additional, Popov, Sergey V., additional, Rignot, Eric, additional, Rippin, David M., additional, Rivera, Andrés, additional, Roberts, Jason, additional, Ross, Neil, additional, Ruppel, Anotonia, additional, Schroeder, Dustin M., additional, Siegert, Martin J., additional, Smith, Andrew M., additional, Steinhage, Daniel, additional, Studinger, Michael, additional, Sun, Bo, additional, Tabacco, Ignazio, additional, Tinto, Kirsty, additional, Urbini, Stefano, additional, Vaughan, David, additional, Welch, Brian C., additional, Wilson, Douglas S., additional, Young, Duncan A., additional, and Zirizzotti, Achille, additional

Published
2023
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18. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C., Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesido, Bingham, Robert G., Blankenship, Donald D., Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F.J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard C.A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Anneka N., Humbert, Anglika, Jacobel, Robert W., Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O., Nogi, Yoshifumi, Nost, Ole A., Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David M., Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C., Wilson, Douglas S., Young, Duncan A., and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets.

Published
2023

19. Characterizing bedrock topography and basal conditions in critical coastal regions of the Antarctic ice sheet within the RINGS international effort

Author

Matsuoka, Kenichi, Ferraccioli, Fausto, Cui, Xiangbing, Forsberg, Rene, Jordan, Tom, McCormack, Felicity, and Tinto, Kirsty

Abstract

Comprenhending Antarctic coastal regions is fundamental to our understanding of the dynamic responses of the Antarctic ice sheet to ocean and climate warming.. These coastal regions contain multiple potential tipping points for the Antarctic Ice Sheet in a warming world, which must be better understood to predict the future magnitude and rates of global sea-level rise in a more robust fashion.The Antarctic Ice Sheet constitutes the largest uncertainty in future sea-level projections. 50 years of aereogeophysical observations have led to significant advances in our knowledge of bed topography and basal conditions and itheir influence on ice sheet dynamics. primarily in the interior of Antarctica Howevver, the critical coastal regions where the West and East Antarctic ice sheets meet the ocean and that are the sites of current and future change remain in many places insufficiently surveyed and understood.Here we present a new international initiative RINGS that aims to provide the first comprehensive pan-Antarctic wide coverage of the Antarctic coast mainly via new coordinated aerogeophysical campaigns. Together with an overview of the current multidisciplinary understanding of the Antarctic coastal regions, we present a new ensemble analysis of published datasets to present data coverage and knowledge gaps, and their regional distribution is discussed in the context of present ice-sheet dynamics and potential future change Finally, we identify outstanding science priorities and discuss protocols for new airborne surveys to develop a novel comprehensive dataset of Antarctic grounding zones (the main RING) and both landward and seaward RINGS all-around Antarctica., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

20. 250 years of snow accumulation and summertime melt in the coastal Dronning Maud Land, East Antarctica

Author

Dey, Rahul, Thamban, Meloth, Laluraj, Chavarukonam Madhavanpillai, and Matsuoka, Kenichi

Abstract

The mass balance of coastal Antarctica is significantly affected by warming in low-elevation areas. Summer melting in Antarctica can be a major concern in the warming climate scenario, but very few records exist for the coastal region. We present a 250-year ice core record of snow accumulation and summertime melting history from an ice core drilled at the summit of the Djupranen Ice Rise in coastal Dronning Maud Land, East Antarctica. Water-stable isotopes, visual stratigraphy, and major ion profiles were used to establish chronologies constrained by non-sea salt sulphate and tritium anomaly records. The melt index is calculated as the water-equivalent ratio of all melt layers in a year to total annual accumulation. The yearly average accumulation rate is 0.32 ± 0.14 m w.e. a-1, while the yearly mean melt rate is 1 ± 1.25 %. The ice core record shows a significant decrease in snow accumulation rates in recent decades. Accumulation rates show high variability, with a significant decline since the 1980s. Annual melt was surprisingly higher in the pre-industrial era (before 1850 CE), averaging 1.3 % compared to 0.9 % in the present. We observed melting events in 184 out of 248 years, with the lowest melting period being 1796–1809. There is no correlation between ERA5 2m temperature and annual melt or δ18O. In contrast, the ERA5 total precipitation trend is the opposite of annual snow accumulation from the ice core, suggesting a complex mechanism affecting the region's seasonal melting and snow accumulation rates., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

22. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C, Fretwell, Peter, Bodart, Julien A, Pritchard, Hamish D, Aitken, Alan, Bamber, Jonathan L, Bell, Robin, Bianchi, Cesidio, Bingham, Robert G, Blankenship, Donald D, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh FJ, Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard CA, Hoffman, Andrew O, Holmlund, Per, Holschuh, Nicholas, Holt, John W, Horlings, Annika N, Humbert, Angelika, Jacobel, Robert W, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Gillespie, Mette Kusk, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O, Nogi, Yoshifumi, Nost, Ole A, Paden, John, Pattyn, Frank, Popov, Sergey V, Rignot, Eric, Rippin, David M, Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M, Siegert, Martin J, Smith, Andrew M, Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C, Wilson, Douglas S, Young, Duncan A, Zirizzotti, Achille, Frémand, Alice C, Fretwell, Peter, Bodart, Julien A, Pritchard, Hamish D, Aitken, Alan, Bamber, Jonathan L, Bell, Robin, Bianchi, Cesidio, Bingham, Robert G, Blankenship, Donald D, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh FJ, Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard CA, Hoffman, Andrew O, Holmlund, Per, Holschuh, Nicholas, Holt, John W, Horlings, Annika N, Humbert, Angelika, Jacobel, Robert W, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Gillespie, Mette Kusk, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O, Nogi, Yoshifumi, Nost, Ole A, Paden, John, Pattyn, Frank, Popov, Sergey V, Rignot, Eric, Rippin, David M, Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M, Siegert, Martin J, Smith, Andrew M, Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C, Wilson, Douglas S, Young, Duncan A, and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023). See the Data availability section for the complete list of datasets.

Published
2023

23. Radar internal reflection horizons from multisystem data reflect ice dynamic and surface accumulation history along the Princess Ragnhild Coast, Dronning Maud Land, East Antarctica

Author

Koch, Inka, Drews, Reinhard, Franke, Steven, Jansen, Daniela, Oraschewski, Falk Marius, Muhle, Leah Sophie, Višnjević, Vjeran, Matsuoka, Kenichi, Pattyn, Frank, Eisen, Olaf, Koch, Inka, Drews, Reinhard, Franke, Steven, Jansen, Daniela, Oraschewski, Falk Marius, Muhle, Leah Sophie, Višnjević, Vjeran, Matsuoka, Kenichi, Pattyn, Frank, and Eisen, Olaf

Abstract

Ice shelves, which regulate ice flow from the Antarctic ice sheet towards the ocean, are shaped by spatiotemporal patterns of surface accumulation, surface/basal melt and ice dynamics. Therefore, an ice dynamic and accumulation history are imprinted in the internal ice stratigraphy, which can be imaged by radar in the form of internal reflection horizons (IRHs). Here, IRHs were derived from radar data combined across radar platforms (airborne and ground-based) in coastal eastern Dronning Maud Land (East Antarctica), comprising three ice rises and adjacent two ice shelves. To facilitate interpretation of dominant spatiotemporal patterns of processes shaping the local IRH geometry, traced IRHs are classified into three different types (laterally continuous, discontinuous or absent/IRH-free). Near-surface laterally continuous IRHs reveal local accumulation patterns, reflecting the mean easterly wind direction, and correlate with surface slopes. Areas of current and past increased ice flow and internal deformation are marked by discontinuous or IRH-free zones, and can inform about paleo ice-stream dynamics. The established IRH datasets extend continent-wide mapping efforts of IRHs to an important and climatically sensitive ice marginal region of Antarctica and are ready for integration into ice-flow models to improve predictions of Antarctic ice drainage.

Published
2023

24. Ice-ocean interactions at Riiser-Larsen Ice Shelf assessed by unveiling of seabed beneath it

Author

Eisermann, Hannes, Hattermann, Tore, Matsuoka, Kenichi, Franke, Steven, Steinhage, Daniel, Helm, Veit, Ruppel, Antonia, Läufer, Andreas, Leinen, Stefan, Johann, Felix, Eagles, Graeme, Eisermann, Hannes, Hattermann, Tore, Matsuoka, Kenichi, Franke, Steven, Steinhage, Daniel, Helm, Veit, Ruppel, Antonia, Läufer, Andreas, Leinen, Stefan, Johann, Felix, and Eagles, Graeme

Abstract

The Riiser-Larsen ice shelf is the fourth largest ice shelf on Earth. The detailed depth and shape of the seabed beneath the ice shelf is entirely unknown. Since bed topography beneath ice shelves generally poses the controlling factor of heat exchange between the open ocean and water cavities, this unknown factor inhibits proper assessment of ice-ocean interactions. In coastal Dronning Maud Land, the intrusion of Warm Deep Water – a warm intermediate water mass transported by the Weddell Gyre – into the ice shelf cavities is strongly dependent on seabed depth. We are addressing this shortcoming by generating a bathymetric model beneath the ice shelf based on the inversion of gravity data and complementary data sets of magnetic and ice penetrating radar data, all acquired during the joint AWI-BGR airborne campaign ‘RIISERBATHY’ in 2022/23. The resulting model will have a resolution of 5 to 10 km and is complemented offshore by shipborne hydroacoustic data. We present the first versions of the model here. Modelled depths can be compared to thermocline depths of available in-situ oceanographic data close to and at the calving fronts. In doing so, we will identify key regions of possible entry for Warm Deep Water into the cavity beneath the ice shelf.

Published
2023

25. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice, Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesidio, Bingham, Robert G., Blankenship, Donald, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F. J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin Stevens, Hills, Benjamin, Hindmarsh, Richard C. A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Annika, Humbert, Angelika, Jacobel, Robert, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Kusk Gillespie, Mette, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph A., MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jeremie, Nitsche, Frank, Nogi, Yoshifumi, Nost, Ole, Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David, Medina-Rivera, Alejandra, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian, Wilson, Douglas S., Young, Duncan A., Zirizzotti, Achille, Frémand, Alice, Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesidio, Bingham, Robert G., Blankenship, Donald, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F. J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin Stevens, Hills, Benjamin, Hindmarsh, Richard C. A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Annika, Humbert, Angelika, Jacobel, Robert, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Kusk Gillespie, Mette, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph A., MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jeremie, Nitsche, Frank, Nogi, Yoshifumi, Nost, Ole, Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David, Medina-Rivera, Alejandra, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian, Wilson, Douglas S., Young, Duncan A., and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss andthe ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce newgridded maps of ice thickness and bed topography for the internationalscientific community, but also to standardize and make available all thegeophysical survey data points used in producing the Bedmap griddedproducts. Here, we document the survey data used in the latest iteration,Bedmap3, incorporating and adding to all of the datasets previously used forBedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically,we describe the processes used to standardize and make these and futuresurveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal(https://bedmap.scar.org, last access: 1 March 2023) created to provideunprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data heldwithin it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets., info:eu-repo/semantics/published

Published
2023

26. Radar internal reflection horizons from multisystem data reflect ice dynamic and surface accumulation history along the Princess Ragnhild Coast, Dronning Maud Land, East Antarctica.

Author

Koch, Inka, Drews, Reinhard, Franke, Steven, Jansen, Daniela, Oraschewski, Falk Marius, Muhle, Leah Sophie, Višnjević, Vjeran, Matsuoka, Kenichi, Pattyn, Frank, and Eisen, Olaf

Subjects
GROUND penetrating radar, ANTARCTIC ice, SPATIOTEMPORAL processes, ICE sheets, ICE shelves, GLACIOLOGY, MELTWATER
Abstract

Ice shelves, which regulate ice flow from the Antarctic ice sheet towards the ocean, are shaped by spatiotemporal patterns of surface accumulation, surface/basal melt and ice dynamics. Therefore, an ice dynamic and accumulation history are imprinted in the internal ice stratigraphy, which can be imaged by radar in the form of internal reflection horizons (IRHs). Here, IRHs were derived from radar data combined across radar platforms (airborne and ground-based) in coastal eastern Dronning Maud Land (East Antarctica), comprising three ice rises and adjacent two ice shelves. To facilitate interpretation of dominant spatiotemporal patterns of processes shaping the local IRH geometry, traced IRHs are classified into three different types (laterally continuous, discontinuous or absent/IRH-free). Near-surface laterally continuous IRHs reveal local accumulation patterns, reflecting the mean easterly wind direction, and correlate with surface slopes. Areas of current and past increased ice flow and internal deformation are marked by discontinuous or IRH-free zones, and can inform about paleo ice-stream dynamics. The established IRH datasets extend continent-wide mapping efforts of IRHs to an important and climatically sensitive ice marginal region of Antarctica and are ready for integration into ice-flow models to improve predictions of Antarctic ice drainage. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Recent Ice sheet surface warming events over coastal Dronning Maud Land, East Antarctica: Causes and Implications.

Author

Gayathri, Eledath M., Laluraj, Chavarukonam M., Satheesan, Karathazhiyath, Matsuoka, Kenichi, and Thamban, Meloth

Subjects
ICE sheets, ANTARCTIC ice, ICE cores, TURBULENT mixing, SNOW accumulation, BOREHOLES
Abstract

Sudden short-term warming events over the ice sheet surface (hereafter Ice Sheet Surface Warming (ISSW) events) can affect mass balance by sublimation and on rare occasions melting when the temperature rises above 0 °C. On the one hand, the knowledge of the frequency and duration of these warming events is essential, while on the other hand, a process-level understanding of them is crucial for incorporating in climate models and tracing their behaviour in future climate scenarios. Here, we examined the ISSW events over coastal Dronning Maud Land (cDML) in East Antarctica using the borehole temperature record of an ice core covering a period of 2014–18 CE. The borehole surface thermistor record provided accurate estimation of year-round ISST and subsurface heat flux in the region. In total, 71 warming events (> 2 ºC for > 3 days) with a maximum warming of 11 °C were recorded during the period. They mostly occurred during spring (24) and winter (23), followed by autumn (15) and least in summer (9). The general meteorological setting during these events was the occurrence of strong winds. It was found that 84 % of ISSW events occurred during strong easterly winds with high snow accumulation, while 16 % occurred during strong southeasterly winds (katabatic) without any precipitation. The study suggests that for the first case, intense downward longwave radiation associated with warm air advection (with moisture from the surrounding ocean) heated the ice sheet's surface and led to snowfall. For the second case, turbulent mixing due to strong and dry winds from the interior of the continent (katabatic) led to ISSW. Furthermore, the synoptic conditions during ISSW events differed by changes in the relative positions of low pressure and high pressure over the southern ocean. Considering the drastic drop in accumulation in cDML since 1906 CE, a simultaneous increase in ISSW events (via their sublimation and melting rates), appears to have greater implications on the mass balance and stability of coastal Antarctic ice sheets in the long term. [ABSTRACT FROM AUTHOR]

Published
2023
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28. Supplementary material to "Investigating the spatial representativeness of Antarctic ice cores: A comparison of ice core and radar-derived surface mass balance"

Author

Cavitte, Marie G. P., primary, Goosse, Hugues, additional, Matsuoka, Kenichi, additional, Wauthy, Sarah, additional, Goel, Vikram, additional, Dey, Rahul, additional, Pratap, Bhanu, additional, Van Liefferinge, Brice, additional, Meloth, Thamban, additional, and Tison, Jean-Louis, additional

Published
2023
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31. Antarctic ice rises and rumples: Their properties and significance for ice-sheet dynamics and evolution

Author

Matsuoka, Kenichi, Hindmarsh, Richard C.A., Moholdt, Geir, Bentley, Michael J., Pritchard, Hamish D., Brown, Joel, Conway, Howard, Drews, Reinhard, Durand, Gaël, Goldberg, Daniel, Hattermann, Tore, Kingslake, Jonathan, Lenaerts, Jan T.M., Martín, Carlos, Mulvaney, Robert, Nicholls, Keith W., Pattyn, Frank, Ross, Neil, Scambos, Ted, and Whitehouse, Pippa L.

Published
2015
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32. International collaboration is urgently needed for airborne surveys in Enderby Land to fill the largest RINGS data gap

Author

Matsuoka, Kenichi, Clifton, Robb, Blankenship, Don, Cui, Xiangbin, Eagles, Graeme, Eisen, Olaf, Goel, Vikram, Greenbaum, Jamin, Guldahl, John, Hubert, Alain, Jong, Lenneke, Lidstrom, Sven, Minowa, Masahiro, Moholdt, Geir, Pattyn, Frank, Ray, Yogesh, Roberts, Jason, Steinhage, Daniel, Sugiyama, Shin, Sun, Bo, Tamura, Takeshi, and Young, Duncan

Abstract

This is a preliminary planning and scoping paper that seeks to identify potential plans and solutions to support the RINGS project in Enderby Land, East Antarctica. Enderby Land is the largest data gap of bed topography in the coastal regions of the Antarctic Ice Sheet and it must be urgenly filled. The plan presented in this paper does not reflect any commitment or undertaking by National Antarctic Programs or those named in the paper. More detailed planning and collaborative discussions will be needed to then seek agreement on resource allocations and contributions.

Published
2023
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33. Investigating the spatial representativeness of East Antarctic ice cores: a comparison of ice core and radar-derived surface mass balance over coastal ice rises and Dome Fuji.

Author

Cavitte, Marie G. P., Goosse, Hugues, Matsuoka, Kenichi, Wauthy, Sarah, Goel, Vikram, Dey, Rahul, Pratap, Bhanu, Van Liefferinge, Brice, Meloth, Thamban, and Tison, Jean-Louis

Subjects
ICE cores, ANTARCTIC ice, ICE shelves, ICE, ICE sheets, ABSOLUTE sea level change
Abstract

Surface mass balance (SMB) of the Antarctic Ice Sheet must be better understood to document the current Antarctic contribution to sea-level rise. In situ point data using snow stakes and ice cores are often used to evaluate the state of the ice sheet's mass balance, as well as to assess SMB derived from regional climate models, which are then used to produce future climate projections. However, spatial representativeness of individual point data remains largely unknown, particularly in the coastal regions of Antarctica with highly variable terrain. Here, we compare ice core data collected at the summit of eight ice rises along the coast of Dronning Maud Land, as well as at the Dome Fuji site, and shallow ice-penetrating radar data over these regions. Shallow radar data have the advantage of being spatially extensive, with a temporal resolution that varies between a yearly and multi-year resolution, from which we can derive a SMB record over the entire radar survey. This comparison therefore allows us to evaluate the spatial variability of SMB and the spatial representativeness of ice-core-derived SMB. We found that ice core mean SMB is very local, and the difference with radar-derived SMB increases in a logarithmic fashion as the surface covered by the radar data increases, with a plateau ∼ 1–2 km away from the ice crest for most ice rises, where there are strong wind–topography interactions, and ∼ 10 km where the ice shelves begin. The relative uncertainty in measuring SMB also increases rapidly as we move away from the ice core sites. Five of our ice rise sites show a strong spatial representativeness in terms of temporal variability, while the other three sites show that it is limited to a surface area between 20–120 km 2. The Dome Fuji site, on the other hand, shows a small difference between pointwise and area mean SMB, as well as a strong spatial representativeness in terms of temporal variability. We found no simple parameterization that could represent the spatial variability observed at all the sites. However, these data clearly indicate that local spatial SMB variability must be considered when assessing mass balance, as well as comparing modeled SMB values to point field data, and therefore must be included in the estimate of the uncertainty of the observations. [ABSTRACT FROM AUTHOR]

Published
2023
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34. Antarctic Bedmap data: FAIR sharing of 60 years of ice bed, surface and thickness data

Author

Frémand, Alice C., primary, Fretwell, Peter, additional, Bodart, Julien, additional, Pritchard, Hamish D., additional, Aitken, Alan, additional, Bamber, Jonathan L., additional, Bell, Robin, additional, Bianchi, Cesido, additional, Bingham, Robert G., additional, Blankenship, Donald D., additional, Casassa, Gino, additional, Catania, Ginny, additional, Christianson, Knut, additional, Conway, Howard, additional, Corr, Hugh F. J., additional, Cui, Xiangbin, additional, Damaske, Daniel, additional, Damm, Volkmar, additional, Drews, Reinhard, additional, Eagles, Graeme, additional, Eisen, Olaf, additional, Eisermann, Hannes, additional, Ferraccioli, Fausto, additional, Field, Elena, additional, Forsberg, René, additional, Franke, Steven, additional, Fujita, Shuji, additional, Gim, Yonggyu, additional, Goel, Vikram, additional, Gogineni, Siva Prasad, additional, Greenbaum, Jamin, additional, Hills, Benjamin, additional, Hindmarsh, Richard C. A., additional, Holmlund, Per, additional, Holschuh, Nicholas, additional, Holt, John W., additional, Humbert, Angelika, additional, Jacobel, Robert W., additional, Jansen, Daniela, additional, Jenkins, Adrian, additional, Jokat, Wilfried, additional, Jordan, Tom, additional, King, Edward, additional, Kohler, Jack, additional, Krabill, William, additional, Langley, Kirsty, additional, Lee, Joohan, additional, Leitchenkov, German, additional, Leuschen, Carlton, additional, Luyendyk, Bruce, additional, MacGregor, Joseph, additional, MacKie, Emma, additional, Matsuoka, Kenichi, additional, Morlinghem, Mathieu, additional, Mouginot, Jeremie, additional, Nitsche, Frank O., additional, Nogi, Yoshifumi, additional, Nost, Ole A., additional, Paden, John, additional, Pattyn, Frank, additional, Popov, Sergey V., additional, Riger-Kusk, Mette, additional, Rignot, Eric, additional, Rippin, David M., additional, Rivera, Andres, additional, Roberts, Jason, additional, Ross, Neil, additional, Ruppel, Antonia, additional, Schroeder, Dustin M., additional, Siegert, Martin J., additional, Smith, Andrew M., additional, Steinhage, Daniel, additional, Studinger, Michael, additional, Sun, Bo, additional, Tabacco, Ignazio, additional, Tinto, Kirsty, additional, Urbini, Stefano, additional, Vaughan, David, additional, Welch, Brian C., additional, Wilson, Douglas S., additional, Young, Duncan A., additional, and Zirizzotti, Achille, additional

Published
2022
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35. Supplementary material to "Antarctic Bedmap data: FAIR sharing of 60 years of ice bed, surface and thickness data"

Author

Frémand, Alice C., primary, Fretwell, Peter, additional, Bodart, Julien, additional, Pritchard, Hamish D., additional, Aitken, Alan, additional, Bamber, Jonathan L., additional, Bell, Robin, additional, Bianchi, Cesido, additional, Bingham, Robert G., additional, Blankenship, Donald D., additional, Casassa, Gino, additional, Catania, Ginny, additional, Christianson, Knut, additional, Conway, Howard, additional, Corr, Hugh F. J., additional, Cui, Xiangbin, additional, Damaske, Daniel, additional, Damm, Volkmar, additional, Drews, Reinhard, additional, Eagles, Graeme, additional, Eisen, Olaf, additional, Eisermann, Hannes, additional, Ferraccioli, Fausto, additional, Field, Elena, additional, Forsberg, René, additional, Franke, Steven, additional, Fujita, Shuji, additional, Gim, Yonggyu, additional, Goel, Vikram, additional, Gogineni, Siva Prasad, additional, Greenbaum, Jamin, additional, Hills, Benjamin, additional, Hindmarsh, Richard C. A., additional, Holmlund, Per, additional, Holschuh, Nicholas, additional, Holt, John W., additional, Humbert, Angelika, additional, Jacobel, Robert W., additional, Jansen, Daniela, additional, Jenkins, Adrian, additional, Jokat, Wilfried, additional, Jordan, Tom, additional, King, Edward, additional, Kohler, Jack, additional, Krabill, William, additional, Langley, Kirsty, additional, Lee, Joohan, additional, Leitchenkov, German, additional, Leuschen, Carlton, additional, Luyendyk, Bruce, additional, MacGregor, Joseph, additional, MacKie, Emma, additional, Matsuoka, Kenichi, additional, Morlinghem, Mathieu, additional, Mouginot, Jeremie, additional, Nitsche, Frank O., additional, Nogi, Yoshifumi, additional, Nost, Ole A., additional, Paden, John, additional, Pattyn, Frank, additional, Popov, Sergey V., additional, Riger-Kusk, Mette, additional, Rignot, Eric, additional, Rippin, David M., additional, Rivera, Andres, additional, Roberts, Jason, additional, Ross, Neil, additional, Ruppel, Antonia, additional, Schroeder, Dustin M., additional, Siegert, Martin J., additional, Smith, Andrew M., additional, Steinhage, Daniel, additional, Studinger, Michael, additional, Sun, Bo, additional, Tabacco, Ignazio, additional, Tinto, Kirsty, additional, Urbini, Stefano, additional, Vaughan, David, additional, Welch, Brian C., additional, Wilson, Douglas S., additional, Young, Duncan A., additional, and Zirizzotti, Achille, additional

Published
2022
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40. Investigating the spatial representativeness of Antarctic ice cores: A comparison of ice core and radar-derived surface mass balance.

Author

Cavitte, Marie G. P., Goosse, Hugues, Matsuoka, Kenichi, Wauthy, Sarah, Goel, Vikram, Dey, Rahul, Pratap, Bhanu, Van Liefferinge, Brice, Meloth, Thamban, and Tison, Jean-Louis

Abstract

Surface mass balance (SMB) over the Antarctic Ice Sheet must be better understood to document current Antarctic contribution to sea-level rise. Field point data using snow stakes and ice cores are often used to evaluate the state of the ice sheet's mass balance as well as to validate SMB derived from regional climate models, which are then used to produce future climate projections. However, spatial representativeness of individual point data remains largely unknown, particularly in the coastal regions 5 of Antarctica with highly variable terrains. Here, we compare ice core data collected at the summit of eight ice rises along the coast of Dronning Maud Land, as well as at the Dome Fuji site, and shallow ice-penetrating radar data over these regions. Shallow radar data has the advantage of being spatially extensive with a temporal resolution that varies between annual and sub-decadal resolution from which we can derive a SMB record over the entire radar survey. This comparison allows us therefore to evaluate the spatial variability of SMB and the spatial representativeness of ice-core derived 10 SMB. We found that ice core mean SMB is very local and the difference with radar-derived SMB increases in a logarithmicfashion as the surface covered by the radar data increases, with for most ice rises a plateau ~1-2 km away from the ice crest where there are strong wind-topography interactions, and ~10 km where the ice shelves begin. The relative uncertainty in measuring SMB also increases rapidly as we move away from the ice core sites. Five of our ice rise sites show a strong spatial representativeness in terms of temporal variability, while the other three sites show it is limited to a surface areas between 15 20-120 km2. The Dome Fuji site on the other hand shows a small difference between pointwise and area mean SMB, as well as a strong spatial representativeness in terms of temporal variability. We found no simple parameterization that could represent the spatial variability observed at all the sites. However, these data clearly indicate that local spatial SMB variability must be considered when assessing mass balance as well as comparing modeled SMB values to point field data. [ABSTRACT FROM AUTHOR]

Published
2023
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41. Surface Mass Balance Controlled by Local Surface Slope in Inland Antarctica: Implications for Ice‐Sheet Mass Balance and Oldest Ice Delineation in Dome Fuji

Author

Van Liefferinge, Brice, primary, Taylor, Drew, additional, Tsutaki, Shun, additional, Fujita, Shuji, additional, Gogineni, Prasad, additional, Kawamura, Kenji, additional, Matsuoka, Kenichi, additional, Moholdt, Geir, additional, Oyabu, Ikumi, additional, Abe‐Ouchi, Ayako, additional, Awasthi, Abhishek, additional, Buizert, Christo, additional, Gallet, Jean‐Charles, additional, Isaksson, Elisabeth, additional, Motoyama, Hideaki, additional, Nakazawa, Fumio, additional, Ohno, Hiroshi, additional, O’Neill, Charles, additional, Pattyn, Frank, additional, and Sugiura, Konosuke, additional

Published
2021
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42. Application of visual stratigraphy from line-scan images to constrain chronology and melt features of a firn core from coastal Antarctica.

Author

Dey, Rahul, Thamban, Meloth, Laluraj, Chavarukonam Madhavanpillai, Mahalinganathan, Kanthanathan, Redkar, Bhikaji Laxman, Kumar, Sudhir, and Matsuoka, Kenichi

Subjects
SNOW accumulation, ICE cores, MELTING, STABLE isotopes, ACCELERATOR mass spectrometry
Abstract

Establishing an accurate chronology is crucial for interpretation of ice core-based climatic records. While high snow accumulation rates characterise coastal Antarctica, thus enabling recovery of highly resolved climatic records, summertime melting at such low-elevation sites offers challenges in establishing a reliable chronological framework through traditional approaches using the seasonality of stable water isotope and ionic proxy records. Here, we assess visual stratigraphy (VS) obtained from line-scan images as a proxy for annual layer counting in firn section (top 50 m) of the IND-36/B9 ice core (dated 1919–2016 CE) from the Djupranen Ice Rise in central Dronning Maud Land, East Antarctica. We also used these images to obtain melt history for the site and found that traditional thickness-based quantification of melt proportion results in significant overestimations. Since density has dominant control on VS profile over the firn section, we first used circulant single-spectrum analysis to remove the secular trend and then we extracted the seasonal VS signals attributed to dust and sea-salt inclusions. We find that melt layers do not significantly alter the VS records if masked during pre-processing. The age–depth model based on the reconstructed VS profile revealed an excellent match with identified time-markers within an uncertainty of ±2 years. [ABSTRACT FROM AUTHOR]

Published
2023
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43. Effects of birefringence within ice sheets on obliquely propagating radio waves

Author

Matsuoka, Kenichi, Wilen, Larry, Hurley, Shawn P., and Raymond, Charles F.

Subjects
Ice -- Properties, Remote sensing -- Methods, Wave propagation -- Methods, Polar regions -- Discovery and exploration, Polariscope -- Usage, Business, Earth sciences, Electronics and electrical industries
Abstract

In this paper, effects of birefringence on radio waves obliquely propagating though polar ice sheets are examined to facilitate interpretations of bistatic and side-looking radar data. A formalism applicable for arbitrary radar configurations is developed to predict the returned power from within and beneath the ice sheets that have arbitrary alignments of ice crystals (ice fabrics). We applied this formalism to a range of ice fabrics found in ice cores and assessed the effects of birefringence in terms of ray-path configurations, ice fabrics, and radar frequency. Predicted frequency dependence of the bed return power replicates prominent features observed at Greenland NGRIP ice-core site. Results show that birefringence in ice of 1 km or more thickness with strong (weak) fabric can reduce the power returned from the bed 2 dB or more at frequencies higher than 200 MHz (20 MHz) as compared to isotropic ice. This suggests that quantitative interpretation of the power returned from the bed requires careful assessment of birefringence almost everywhere over the ice sheets. Application of this formalism also suggests a radar-frequency range usable for attenuation measurements, possible effects of fabric on synthetic aperture radar processing, and a feasibility of remote sensing of ice fabric. Index Terms--Arctic regions, birefringence, ice, radar polarimetry.

Published
2009

45. Quantarctica, an integrated mapping environment for Antarctica, the Southern Ocean, and sub-Antarctic islands

Author

Sub Dynamics Meteorology, Marine and Atmospheric Research, Matsuoka, Kenichi, Skoglund, Anders, Roth, George, de Pomereu, Jean, Griffiths, Huw, Headland, Robert, Herried, Brad, Katsumata, Katsuro, Le Brocq, Anne, Licht, Kathy, Morgan, Fraser, Neff, Peter D., Ritz, Catherine, Scheinert, Mirko, Tamura, Takeshi, Van de Putte, Anton, van den Broeke, Michiel, von Deschwanden, Angela, Deschamps-Berger, César, Van Liefferinge, Brice, Tronstad, Stein, Melvær, Yngve, Sub Dynamics Meteorology, Marine and Atmospheric Research, Matsuoka, Kenichi, Skoglund, Anders, Roth, George, de Pomereu, Jean, Griffiths, Huw, Headland, Robert, Herried, Brad, Katsumata, Katsuro, Le Brocq, Anne, Licht, Kathy, Morgan, Fraser, Neff, Peter D., Ritz, Catherine, Scheinert, Mirko, Tamura, Takeshi, Van de Putte, Anton, van den Broeke, Michiel, von Deschwanden, Angela, Deschamps-Berger, César, Van Liefferinge, Brice, Tronstad, Stein, and Melvær, Yngve

Published
2021

46. Surface Mass Balance Controlled by Local Surface Slope in Inland Antarctica: Implications for Ice-Sheet Mass Balance and Oldest Ice Delineation in Dome Fuji

Author

Van Liefferinge, Brice, Taylor, Drew, Tsutaki, Shun, Fujita, Shuji, Gogineni, Prasad, Kawamura, Kenji, Matsuoka, Kenichi, Moholdt, Geir, Oyabu, Ikumi, Abe-Ouchi, Ayako, Awasthi, Abhishek, Buizert, Christo, Gallet, Jean‐Charles, Isaksson, Elisabeth, Motoyama, Hideaki, Nakazawa, Fumio, Ohno, Hiroshi, O’Neill, Charles, Pattyn, Frank, Sugiura, Konosuke, Van Liefferinge, Brice, Taylor, Drew, Tsutaki, Shun, Fujita, Shuji, Gogineni, Prasad, Kawamura, Kenji, Matsuoka, Kenichi, Moholdt, Geir, Oyabu, Ikumi, Abe-Ouchi, Ayako, Awasthi, Abhishek, Buizert, Christo, Gallet, Jean‐Charles, Isaksson, Elisabeth, Motoyama, Hideaki, Nakazawa, Fumio, Ohno, Hiroshi, O’Neill, Charles, Pattyn, Frank, and Sugiura, Konosuke

Abstract

The limited number of surface mass balance (SMB) observations in the Antarctic inland hampers estimates of ice-sheet contribution to global sea level and locations with million-year-old ice. We present finely resolved SMB over the past three centuries in a low-accumulation region with significant depth hoar formation on Dome Fuji derived from ∼1,100 km of microwave radar stratigraphy dated with a firn core. The regional-mean SMB over the past 264 years is estimated to ∼22.5 ± 3.3 kg m−2 a−1, but with large local variability of up to 30%. We found that local SMB is negatively correlated with surface slope at scales of a few hundred meters, resulting in anomalous zones of low SMB which represent as much as 8–10% of the total SMB on the inland plateau if the SMB-slope relationship is more widely valid. This impact should be investigated further to improve estimates of Antarctic mass balance and sea-level contribution., SCOPUS: le.j, info:eu-repo/semantics/published

Published
2021

50. Bed diagnosis in the Dome Fuji region, East Antarctica, using airborneradar data and englacial attenuation estimates

Author

Matsuoka, Kenichi, Van Liefferinge, Brice, Binder, Tobias, Eisen, Olaf, Helm, Veit, Karlsson, Nanna, Pattyn, Frank, and Steinhage, Daniel

Abstract

Radar reflectivity of the ice-sheet bed has been used as a diagnostic measure of the basal conditions. Such bed diagnosis could lead to constrain magnitude and spatial pattern of geothermal flux which remains poorly known under the Antarctic Ice Sheet. Radar reflectivity can be estimated from the radar-observed bed returned power by extracting englacial attenuation. Attenuation exponentially depends on ice temperature, and can vary larger than the difference in the bed reflectivity for thawed and dry beds. In the 2016-17 austral summer, Alfred Wegener Institute carried out 150-MHz airborne radar survey for∼19,000 line kilometers in a 400-km by 400-km area including Dome Fuji, East Antarctica, where the Oldest Ice is predicted to present. Bed topography, roughness, and subglacial hydraulic potential were analyzed and subglacial lakes were preliminary mapped. We extend that study by rigorous analysis of bed returned power. We hypothesize that model-predicted thawed area is consistent with high bed reflectivity area derived from the radar data, when englacial attenuation/temperature is derived for the correct geothermal flux. We carried out attenuation and radar reflectivity estimates for a range of geothermalflux and mapped spatial variations in the attenuation and bed reflectivity.

Published
2019

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