Articles | Volume 17, issue 6
https://doi.org/10.5194/tc-17-2455-2023
© Author(s) 2023. 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-17-2455-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
22 Jun 2023
Research article |
| 22 Jun 2023
| 22 Jun 2023
Hydraulic suppression of basal glacier melt in sill fjords
Department of Meteorology, Stockholm University, 10691 Stockholm, Sweden
Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Eef van Dongen
Department of Meteorology, Stockholm University, 10691 Stockholm, Sweden
Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Martin Jakobsson
Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden
Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Matt O'Regan
Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden
Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Christian Stranne
Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden
Bolin Center for Climate Research, Stockholm University, 10691 Stockholm, Sweden
Related authors
Jonathan Wiskandt, Inga Monika Koszalka, and Johan Nilsson
The Cryosphere, 17, 2755–2777, https://doi.org/10.5194/tc-17-2755-2023, https://doi.org/10.5194/tc-17-2755-2023, 2023
Short summary
Short summary
Understanding ice–ocean interactions under floating ice tongues in Greenland and Antarctica is a major challenge in climate modelling and a source of uncertainty in future sea level projections. We use a high-resolution ocean model to investigate basal melting and melt-driven circulation under the floating tongue of Ryder Glacier, northwestern Greenland. We study the response to oceanic and atmospheric warming. Our results are universal and relevant for the development of climate models.
Matt O'Regan, Thomas M. Cronin, Brendan Reilly, Aage Kristian Olsen Alstrup, Laura Gemery, Anna Golub, Larry A. Mayer, Mathieu Morlighem, Matthias Moros, Ole L. Munk, Johan Nilsson, Christof Pearce, Henrieka Detlef, Christian Stranne, Flor Vermassen, Gabriel West, and Martin Jakobsson
The Cryosphere, 15, 4073–4097, https://doi.org/10.5194/tc-15-4073-2021, https://doi.org/10.5194/tc-15-4073-2021, 2021
Short summary
Short summary
Ryder Glacier is a marine-terminating glacier in north Greenland discharging ice into the Lincoln Sea. Here we use marine sediment cores to reconstruct its retreat and advance behavior through the Holocene. We show that while Sherard Osborn Fjord has a physiography conducive to glacier and ice tongue stability, Ryder still retreated more than 40 km inland from its current position by the Middle Holocene. This highlights the sensitivity of north Greenland's marine glaciers to climate change.
Sara Broomé, Léon Chafik, and Johan Nilsson
Ocean Sci., 16, 715–728, https://doi.org/10.5194/os-16-715-2020, https://doi.org/10.5194/os-16-715-2020, 2020
Short summary
Short summary
Observations in the Nordic Seas have shown a general warming and an increase in sea surface height over the last few decades. However, our results reveal that the sea surface heights and heat content in the decade following the mid-2000s have not risen much or even stagnated. This is most prominent in the eastern Nordic Seas, where waters of Atlantic origin dominate. We conclude that this stagnation is possibly a consequence of decreased heat transport from the subpolar North Atlantic.
Malin Ödalen, Jonas Nycander, Andy Ridgwell, Kevin I. C. Oliver, Carlye D. Peterson, and Johan Nilsson
Biogeosciences, 17, 2219–2244, https://doi.org/10.5194/bg-17-2219-2020, https://doi.org/10.5194/bg-17-2219-2020, 2020
Short summary
Short summary
In glacial periods, ocean uptake of carbon is likely a key player for achieving low atmospheric CO2. In climate models, ocean biological uptake of carbon (C) and phosphorus (P) are often assumed to occur in fixed proportions.
In this study, we allow the ratio of C : P to vary and simulate, to first approximation, the complex biological changes that occur in the ocean over long timescales. We show here that, for glacial–interglacial cycles, this complexity contributes to low atmospheric CO2.
Christian Stranne, Larry Mayer, Martin Jakobsson, Elizabeth Weidner, Kevin Jerram, Thomas C. Weber, Leif G. Anderson, Johan Nilsson, Göran Björk, and Katarina Gårdfeldt
Ocean Sci., 14, 503–514, https://doi.org/10.5194/os-14-503-2018, https://doi.org/10.5194/os-14-503-2018, 2018
Short summary
Short summary
The ocean surface mixed layer depth (MLD) is an important parameter within several research disciplines, as variations in the MLD influence air–sea CO2 exchange and ocean primary production. A new method is presented in which acoustic mapping of the MLD is done remotely by means of echo sounders. This method allows for observations of high-frequency variability in the MLD, as horizontal and temporal resolutions can be increased by orders of magnitude compared to traditional in situ measurements.
David K. Hutchinson, Agatha M. de Boer, Helen K. Coxall, Rodrigo Caballero, Johan Nilsson, and Michiel Baatsen
Clim. Past, 14, 789–810, https://doi.org/10.5194/cp-14-789-2018, https://doi.org/10.5194/cp-14-789-2018, 2018
Short summary
Short summary
The Eocene--Oligocene transition was a major cooling event 34 million years ago. Climate model studies of this transition have used low ocean resolution or topography that roughly approximates the time period. We present a new climate model simulation of the late Eocene, with higher ocean resolution and topography which is accurately designed for this time period. These features improve the ocean circulation and gateways which are thought to be important for this climate transition.
Göran Björk, Martin Jakobsson, Karen Assmann, Leif G. Andersson, Johan Nilsson, Christian Stranne, and Larry Mayer
Ocean Sci., 14, 1–13, https://doi.org/10.5194/os-14-1-2018, https://doi.org/10.5194/os-14-1-2018, 2018
Short summary
Short summary
This study presents detailed bathymetric data along with hydrographic data at two deep passages across the Lomonosov Ridge in the Arctic Ocean. The southern channel is relatively smooth with a sill depth close to 1700 m. Hydrographic data reveals an eastward flow in the southern part and opposite in the northern part. The northern passage is characterized by a narrow and steep ridge with a sill depth of 1470 m. Here, water exchange appears to occur in well-defined but irregular vertical layers.
Martin Jakobsson, Christof Pearce, Thomas M. Cronin, Jan Backman, Leif G. Anderson, Natalia Barrientos, Göran Björk, Helen Coxall, Agatha de Boer, Larry A. Mayer, Carl-Magnus Mörth, Johan Nilsson, Jayne E. Rattray, Christian Stranne, Igor Semiletov, and Matt O'Regan
Clim. Past, 13, 991–1005, https://doi.org/10.5194/cp-13-991-2017, https://doi.org/10.5194/cp-13-991-2017, 2017
Short summary
Short summary
The Arctic and Pacific oceans are connected by the presently ~53 m deep Bering Strait. During the last glacial period when the sea level was lower than today, the Bering Strait was exposed. Humans and animals could then migrate between Asia and North America across the formed land bridge. From analyses of sediment cores and geophysical mapping data from Herald Canyon north of the Bering Strait, we show that the land bridge was flooded about 11 000 years ago.
Johan Nilsson, Martin Jakobsson, Chris Borstad, Nina Kirchner, Göran Björk, Raymond T. Pierrehumbert, and Christian Stranne
The Cryosphere, 11, 1745–1765, https://doi.org/10.5194/tc-11-1745-2017, https://doi.org/10.5194/tc-11-1745-2017, 2017
Short summary
Short summary
Recent data suggest that a 1 km thick ice shelf extended over the glacial Arctic Ocean during MIS 6, about 140 000 years ago. Here, we theoretically analyse the development and equilibrium features of such an ice shelf. The ice shelf was effectively dammed by the Fram Strait and the mean ice-shelf thickness was controlled primarily by the horizontally integrated mass balance. Our results can aid in resolving some outstanding questions of the state of the glacial Arctic Ocean.
M. Löfverström, R. Caballero, J. Nilsson, and J. Kleman
Clim. Past, 10, 1453–1471, https://doi.org/10.5194/cp-10-1453-2014, https://doi.org/10.5194/cp-10-1453-2014, 2014
M. Berger, J. Brandefelt, and J. Nilsson
Clim. Past, 9, 969–982, https://doi.org/10.5194/cp-9-969-2013, https://doi.org/10.5194/cp-9-969-2013, 2013
Allison P. Lepp, Lauren E. Miller, John B. Anderson, Matt O'Regan, Monica C. M. Winsborrow, James A. Smith, Claus-Dieter Hillenbrand, Julia S. Wellner, Lindsay O. Prothro, and Evgeny A. Podolskiy
The Cryosphere, 18, 2297–2319, https://doi.org/10.5194/tc-18-2297-2024, https://doi.org/10.5194/tc-18-2297-2024, 2024
Short summary
Short summary
Shape and surface texture of silt-sized grains are measured to connect marine sediment records with subglacial water flow. We find that grain shape alteration is greatest in glaciers where high-energy drainage events and abundant melting of surface ice are inferred and that the surfaces of silt-sized sediments preserve evidence of glacial transport. Our results suggest grain shape and texture may reveal whether glaciers previously experienced temperate conditions with more abundant meltwater.
Flor Vermassen, Clare Bird, Tirza M. Weitkamp, Kate F. Darling, Hanna Farnelid, Céline Heuzé, Allison Y. Hsiang, Salar Karam, Christian Stranne, Marcus Sundbom, and Helen K. Coxall
EGUsphere, https://doi.org/10.5194/egusphere-2024-1091, https://doi.org/10.5194/egusphere-2024-1091, 2024
Short summary
Short summary
We provide the first systematic survey of planktonic foraminifera in the high Arctic Ocean. Our results describe the abundance and species composition under summer sea-ice. They indicate that the polar specialist N. pachyderma is the only species present, with subpolar species absent. The dataset will be a valuable reference for continued monitoring of the state of planktonic foraminifera communities as they respond to the ongoing sea-ice decline and the ‘Atlantification’ of the Arctic Ocean.
Lara F. Pérez, Paul C. Knutz, John R. Hopper, Marit-Solveig Seidenkrantz, Matt O'Regan, and Stephen Jones
Sci. Dril., 33, 33–46, https://doi.org/10.5194/sd-33-33-2024, https://doi.org/10.5194/sd-33-33-2024, 2024
Short summary
Short summary
The Greenland ice sheet is highly sensitive to global warming and a major contributor to sea level rise. In Northeast Greenland, ice–ocean–tectonic interactions are readily observable today, but geological records that illuminate long-term trends are lacking. NorthGreen aims to promote scientific drilling proposals to resolve key scientific questions on past changes in the Northeast Greenland margin that further affected the broader Earth system.
Erik Gustafsson, Bo G. Gustafsson, Martijn Hermans, Christoph Humborg, and Christian Stranne
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-211, https://doi.org/10.5194/gmd-2023-211, 2024
Preprint under review for GMD
Short summary
Short summary
Methane (CH4) cycling in the Baltic Sea is studied through model simulations, allowing a first estimate of key CH4 fluxes. A preliminary budget identifies benthic CH4 release as the dominant source, and two main sinks: CH4 oxidation in the water (87 % of the sinks) and outgassing to the atmosphere (13 % of the sinks). This study addresses CH4 emissions from coastal seas and is a first step towards understanding the relative importance of open water outgassing compared to local coastal hotspots.
Julia Muchowski, Martin Jakobsson, Lars Umlauf, Lars Arneborg, Bo Gustafsson, Peter Holtermann, Christoph Humborg, and Christian Stranne
Ocean Sci., 19, 1809–1825, https://doi.org/10.5194/os-19-1809-2023, https://doi.org/10.5194/os-19-1809-2023, 2023
Short summary
Short summary
We show observational data of highly increased mixing and vertical salt flux rates in a sparsely sampled region of the northern Baltic Sea. Co-located acoustic observations complement our in situ measurements and visualize turbulent mixing with high spatial resolution. The observed mixing is generally not resolved in numerical models of the area but likely impacts the exchange of water between the adjacent basins as well as nutrient and oxygen conditions in the Bothnian Sea.
Jonathan Wiskandt, Inga Monika Koszalka, and Johan Nilsson
The Cryosphere, 17, 2755–2777, https://doi.org/10.5194/tc-17-2755-2023, https://doi.org/10.5194/tc-17-2755-2023, 2023
Short summary
Short summary
Understanding ice–ocean interactions under floating ice tongues in Greenland and Antarctica is a major challenge in climate modelling and a source of uncertainty in future sea level projections. We use a high-resolution ocean model to investigate basal melting and melt-driven circulation under the floating tongue of Ryder Glacier, northwestern Greenland. We study the response to oceanic and atmospheric warming. Our results are universal and relevant for the development of climate models.
Gabriel West, Darrell S. Kaufman, Martin Jakobsson, and Matt O'Regan
Geochronology, 5, 285–299, https://doi.org/10.5194/gchron-5-285-2023, https://doi.org/10.5194/gchron-5-285-2023, 2023
Short summary
Short summary
We report aspartic and glutamic acid racemization analyses on Neogloboquadrina pachyderma and Cibicidoides wuellerstorfi from the Arctic Ocean (AO). The rates of racemization in the species are compared. Calibrating the rate of racemization in C. wuellerstorfi for the past 400 ka allows the estimation of sample ages from the central AO. Estimated ages are older than existing age assignments (as previously observed for N. pachyderma), confirming that differences are not due to taxonomic effects.
Felicity A. Holmes, Eef van Dongen, Riko Noormets, Michał Pętlicki, and Nina Kirchner
The Cryosphere, 17, 1853–1872, https://doi.org/10.5194/tc-17-1853-2023, https://doi.org/10.5194/tc-17-1853-2023, 2023
Short summary
Short summary
Glaciers which end in bodies of water can lose mass through melting below the waterline, as well as by the breaking off of icebergs. We use a numerical model to simulate the breaking off of icebergs at Kronebreen, a glacier in Svalbard, and find that both melting below the waterline and tides are important for iceberg production. In addition, we compare the modelled glacier front to observations and show that melting below the waterline can lead to undercuts of up to around 25 m.
Jesse R. Farmer, Katherine J. Keller, Robert K. Poirier, Gary S. Dwyer, Morgan F. Schaller, Helen K. Coxall, Matt O'Regan, and Thomas M. Cronin
Clim. Past, 19, 555–578, https://doi.org/10.5194/cp-19-555-2023, https://doi.org/10.5194/cp-19-555-2023, 2023
Short summary
Short summary
Oxygen isotopes are used to date marine sediments via similar large-scale ocean patterns over glacial cycles. However, the Arctic Ocean exhibits a different isotope pattern, creating uncertainty in the timing of past Arctic climate change. We find that the Arctic Ocean experienced large local oxygen isotope changes over glacial cycles. We attribute this to a breakdown of stratification during ice ages that allowed for a unique low isotope value to characterize the ice age Arctic Ocean.
Raisa Alatarvas, Matt O'Regan, and Kari Strand
Clim. Past, 18, 1867–1881, https://doi.org/10.5194/cp-18-1867-2022, https://doi.org/10.5194/cp-18-1867-2022, 2022
Short summary
Short summary
This research contributes to efforts solving research questions related to the history of ice sheet decay in the Northern Hemisphere. The East Siberian continental margin sediments provide ideal material for identifying the mineralogical signature of ice sheet derived material. Heavy mineral analysis from marine glacial sediments from the De Long Trough and Lomonosov Ridge was used in interpreting the activity of the East Siberian Ice Sheet in the Arctic region.
Jaclyn Clement Kinney, Karen M. Assmann, Wieslaw Maslowski, Göran Björk, Martin Jakobsson, Sara Jutterström, Younjoo J. Lee, Robert Osinski, Igor Semiletov, Adam Ulfsbo, Irene Wåhlström, and Leif G. Anderson
Ocean Sci., 18, 29–49, https://doi.org/10.5194/os-18-29-2022, https://doi.org/10.5194/os-18-29-2022, 2022
Short summary
Short summary
We use data crossing Herald Canyon in the Chukchi Sea collected in 2008 and 2014 together with numerical modelling to investigate the circulation in the western Chukchi Sea. A large fraction of water from the Chukchi Sea enters the East Siberian Sea south of Wrangel Island and circulates in an anticyclonic direction around the island. To assess the differences between years, we use numerical modelling results, which show that high-frequency variability dominates the flow in Herald Canyon.
Henrieka Detlef, Brendan Reilly, Anne Jennings, Mads Mørk Jensen, Matt O'Regan, Marianne Glasius, Jesper Olsen, Martin Jakobsson, and Christof Pearce
The Cryosphere, 15, 4357–4380, https://doi.org/10.5194/tc-15-4357-2021, https://doi.org/10.5194/tc-15-4357-2021, 2021
Short summary
Short summary
Here we examine the Nares Strait sea ice dynamics over the last 7000 years and their implications for the late Holocene readvance of the floating part of Petermann Glacier. We propose that the historically observed sea ice dynamics are a relatively recent feature, while most of the mid-Holocene was marked by variable sea ice conditions in Nares Strait. Nonetheless, major advances of the Petermann ice tongue were preceded by a shift towards harsher sea ice conditions in Nares Strait.
Matt O'Regan, Thomas M. Cronin, Brendan Reilly, Aage Kristian Olsen Alstrup, Laura Gemery, Anna Golub, Larry A. Mayer, Mathieu Morlighem, Matthias Moros, Ole L. Munk, Johan Nilsson, Christof Pearce, Henrieka Detlef, Christian Stranne, Flor Vermassen, Gabriel West, and Martin Jakobsson
The Cryosphere, 15, 4073–4097, https://doi.org/10.5194/tc-15-4073-2021, https://doi.org/10.5194/tc-15-4073-2021, 2021
Short summary
Short summary
Ryder Glacier is a marine-terminating glacier in north Greenland discharging ice into the Lincoln Sea. Here we use marine sediment cores to reconstruct its retreat and advance behavior through the Holocene. We show that while Sherard Osborn Fjord has a physiography conducive to glacier and ice tongue stability, Ryder still retreated more than 40 km inland from its current position by the Middle Holocene. This highlights the sensitivity of north Greenland's marine glaciers to climate change.
Colin Ware, Larry Mayer, Paul Johnson, Martin Jakobsson, and Vicki Ferrini
Geosci. Instrum. Method. Data Syst., 9, 375–384, https://doi.org/10.5194/gi-9-375-2020, https://doi.org/10.5194/gi-9-375-2020, 2020
Short summary
Short summary
Geographic coordinates (latitude and longitude) are widely used in geospatial applications, and terrains are often defined by regular grids in geographic coordinates. However, because of convergence of lines of longitude near the poles there is oversampling in the latitude (zonal) direction. Also, there is no standard way of defining a hierarchy of grids to consistently deal with data having different spatial resolutions. The proposed global geographic grid system solves both problems.
Sara Broomé, Léon Chafik, and Johan Nilsson
Ocean Sci., 16, 715–728, https://doi.org/10.5194/os-16-715-2020, https://doi.org/10.5194/os-16-715-2020, 2020
Short summary
Short summary
Observations in the Nordic Seas have shown a general warming and an increase in sea surface height over the last few decades. However, our results reveal that the sea surface heights and heat content in the decade following the mid-2000s have not risen much or even stagnated. This is most prominent in the eastern Nordic Seas, where waters of Atlantic origin dominate. We conclude that this stagnation is possibly a consequence of decreased heat transport from the subpolar North Atlantic.
Malin Ödalen, Jonas Nycander, Andy Ridgwell, Kevin I. C. Oliver, Carlye D. Peterson, and Johan Nilsson
Biogeosciences, 17, 2219–2244, https://doi.org/10.5194/bg-17-2219-2020, https://doi.org/10.5194/bg-17-2219-2020, 2020
Short summary
Short summary
In glacial periods, ocean uptake of carbon is likely a key player for achieving low atmospheric CO2. In climate models, ocean biological uptake of carbon (C) and phosphorus (P) are often assumed to occur in fixed proportions.
In this study, we allow the ratio of C : P to vary and simulate, to first approximation, the complex biological changes that occur in the ocean over long timescales. We show here that, for glacial–interglacial cycles, this complexity contributes to low atmospheric CO2.
Francesco Muschitiello, Matt O'Regan, Jannik Martens, Gabriel West, Örjan Gustafsson, and Martin Jakobsson
Geochronology, 2, 81–91, https://doi.org/10.5194/gchron-2-81-2020, https://doi.org/10.5194/gchron-2-81-2020, 2020
Short summary
Short summary
In this study we present a new marine chronology of the last ~30 000 years for a sediment core retrieved from the central Arctic Ocean. Our new chronology reveals substantially faster sedimentation rates during the end of the last glacial cycle, the Last Glacial Maximum, and deglaciation than previously reported, thus implying a substantial re-interpretation of paleoceanographic reconstructions from this sector of the Arctic Ocean.
Zhongshi Zhang, Qing Yan, Ran Zhang, Florence Colleoni, Gilles Ramstein, Gaowen Dai, Martin Jakobsson, Matt O'Regan, Stefan Liess, Denis-Didier Rousseau, Naiqing Wu, Elizabeth J. Farmer, Camille Contoux, Chuncheng Guo, Ning Tan, and Zhengtang Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2020-38, https://doi.org/10.5194/cp-2020-38, 2020
Manuscript not accepted for further review
Short summary
Short summary
Whether an ice sheet once grew over Northeast Siberia-Beringia has been debated for decades. By comparing climate modelling with paleoclimate and glacial records from around the North Pacific, this study shows that the Laurentide-Eurasia-only ice sheet configuration fails in explaining these records, while a scenario involving the ice sheet over Northeast Siberia-Beringia succeeds. It highlights the complexity in glacial climates and urges new investigations across Northeast Siberia-Beringia.
Kelly A. Hogan, Martin Jakobsson, Larry Mayer, Brendan T. Reilly, Anne E. Jennings, Joseph S. Stoner, Tove Nielsen, Katrine J. Andresen, Egon Nørmark, Katrien A. Heirman, Elina Kamla, Kevin Jerram, Christian Stranne, and Alan Mix
The Cryosphere, 14, 261–286, https://doi.org/10.5194/tc-14-261-2020, https://doi.org/10.5194/tc-14-261-2020, 2020
Short summary
Short summary
Glacial sediments in fjords hold a key record of environmental and ice dynamic changes during ice retreat. Here we use a comprehensive geophysical survey from the Petermann Fjord system in NW Greenland to map these sediments, identify depositional processes and calculate glacial erosion rates for the retreating palaeo-Petermann ice stream. Ice streaming is the dominant control on glacial erosion rates which vary by an order of magnitude during deglaciation and are in line with modern rates.
Martin Jakobsson, Matt O'Regan, Carl-Magnus Mörth, Christian Stranne, Elizabeth Weidner, Jim Hansson, Richard Gyllencreutz, Christoph Humborg, Tina Elfwing, Alf Norkko, Joanna Norkko, Björn Nilsson, and Arne Sjöström
Earth Surf. Dynam., 8, 1–15, https://doi.org/10.5194/esurf-8-1-2020, https://doi.org/10.5194/esurf-8-1-2020, 2020
Short summary
Short summary
We studied coastal sea floor terraces in parts of the Baltic Sea using various types of sonar data, sediment cores, and video. Terraces (~1 m high, > 100 m long) are widespread in depths < 15 m and are formed in glacial clay. Our study supports an origin from groundwater flow through silty layers, undermining overlying layers when discharged at the sea floor. Submarine groundwater discharge like this may be a significant source of freshwater to the Baltic Sea that needs to be studied further.
Gabriel West, Darrell S. Kaufman, Francesco Muschitiello, Matthias Forwick, Jens Matthiessen, Jutta Wollenburg, and Matt O'Regan
Geochronology, 1, 53–67, https://doi.org/10.5194/gchron-1-53-2019, https://doi.org/10.5194/gchron-1-53-2019, 2019
Short summary
Short summary
We report amino acid racemization analyses of foraminifera from well-dated sediment cores from the Yermak Plateau, Arctic Ocean. Sample ages are compared with model predictions, revealing that the rates of racemization generally conform to a global compilation of racemization rates at deep-sea sites. These results highlight the need for further studies to test and explain the origin of the purportedly high rate of racemization indicated by previous analyses of central Arctic sediments.
Christian Stranne, Matt O'Regan, Martin Jakobsson, Volker Brüchert, and Marcelo Ketzer
Solid Earth, 10, 1541–1554, https://doi.org/10.5194/se-10-1541-2019, https://doi.org/10.5194/se-10-1541-2019, 2019
Martin Jakobsson, Christian Stranne, Matt O'Regan, Sarah L. Greenwood, Bo Gustafsson, Christoph Humborg, and Elizabeth Weidner
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, https://doi.org/10.5194/os-15-905-2019, 2019
Short summary
Short summary
The bottom topography of the Baltic Sea is analysed using the digital depth model from the European Marine Observation and Data Network (EMODnet) published in 2018. Analyses include depth distribution vs. area and seafloor depth variation on a kilometre scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper.
Birgit Wild, Natalia Shakhova, Oleg Dudarev, Alexey Ruban, Denis Kosmach, Vladimir Tumskoy, Tommaso Tesi, Hanna Joß, Helena Alexanderson, Martin Jakobsson, Alexey Mazurov, Igor Semiletov, and Örjan Gustafsson
The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-229, https://doi.org/10.5194/tc-2018-229, 2018
Revised manuscript not accepted
Short summary
Short summary
The thaw and degradation of subsea permafrost on the Arctic Ocean shelves is one of the key uncertainties concerning natural greenhouse gas emissions since difficult access limits the availability of observational data. In this study, we describe sediment properties and age constraints of a unique set of three subsea permafrost cores from the East Siberian Arctic Shelf, as well as content, origin and degradation state of organic matter at the current thaw front.
Zhongshi Zhang, Qing Yan, Elizabeth J. Farmer, Camille Li, Gilles Ramstein, Terence Hughes, Martin Jakobsson, Matt O'Regan, Ran Zhang, Ning Tan, Camille Contoux, Christophe Dumas, and Chuncheng Guo
Clim. Past Discuss., https://doi.org/10.5194/cp-2018-79, https://doi.org/10.5194/cp-2018-79, 2018
Revised manuscript not accepted
Short summary
Short summary
Our study challenges the widely accepted idea that the Laurentide-Eurasian ice sheets gradually extended across North America and Northwest Eurasia, and suggests the growth of the NH ice sheets is much more complicated. We find climate feedbacks regulate the distribution of the NH ice sheets, producing swings between two distinct ice sheet configurations: the Laurentide-Eurasian and a circum-Arctic configuration, where large ice sheets existed over Northeast Siberia and the Canadian Rockies.
Christian Stranne, Larry Mayer, Martin Jakobsson, Elizabeth Weidner, Kevin Jerram, Thomas C. Weber, Leif G. Anderson, Johan Nilsson, Göran Björk, and Katarina Gårdfeldt
Ocean Sci., 14, 503–514, https://doi.org/10.5194/os-14-503-2018, https://doi.org/10.5194/os-14-503-2018, 2018
Short summary
Short summary
The ocean surface mixed layer depth (MLD) is an important parameter within several research disciplines, as variations in the MLD influence air–sea CO2 exchange and ocean primary production. A new method is presented in which acoustic mapping of the MLD is done remotely by means of echo sounders. This method allows for observations of high-frequency variability in the MLD, as horizontal and temporal resolutions can be increased by orders of magnitude compared to traditional in situ measurements.
David K. Hutchinson, Agatha M. de Boer, Helen K. Coxall, Rodrigo Caballero, Johan Nilsson, and Michiel Baatsen
Clim. Past, 14, 789–810, https://doi.org/10.5194/cp-14-789-2018, https://doi.org/10.5194/cp-14-789-2018, 2018
Short summary
Short summary
The Eocene--Oligocene transition was a major cooling event 34 million years ago. Climate model studies of this transition have used low ocean resolution or topography that roughly approximates the time period. We present a new climate model simulation of the late Eocene, with higher ocean resolution and topography which is accurately designed for this time period. These features improve the ocean circulation and gateways which are thought to be important for this climate transition.
Göran Björk, Martin Jakobsson, Karen Assmann, Leif G. Andersson, Johan Nilsson, Christian Stranne, and Larry Mayer
Ocean Sci., 14, 1–13, https://doi.org/10.5194/os-14-1-2018, https://doi.org/10.5194/os-14-1-2018, 2018
Short summary
Short summary
This study presents detailed bathymetric data along with hydrographic data at two deep passages across the Lomonosov Ridge in the Arctic Ocean. The southern channel is relatively smooth with a sill depth close to 1700 m. Hydrographic data reveals an eastward flow in the southern part and opposite in the northern part. The northern passage is characterized by a narrow and steep ridge with a sill depth of 1470 m. Here, water exchange appears to occur in well-defined but irregular vertical layers.
Laura Gemery, Thomas M. Cronin, Robert K. Poirier, Christof Pearce, Natalia Barrientos, Matt O'Regan, Carina Johansson, Andrey Koshurnikov, and Martin Jakobsson
Clim. Past, 13, 1473–1489, https://doi.org/10.5194/cp-13-1473-2017, https://doi.org/10.5194/cp-13-1473-2017, 2017
Short summary
Short summary
Continuous, highly abundant and well-preserved fossil ostracodes were studied from radiocarbon-dated sediment cores collected on the Lomonosov Ridge (Arctic Ocean) that indicate varying oceanographic conditions during the last ~50 kyr. Ostracode assemblages from cores taken during the SWERUS-C3 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions, including changes in sea-ice cover and Atlantic Water inflow into the Eurasian Basin.
Matt O'Regan, Jan Backman, Natalia Barrientos, Thomas M. Cronin, Laura Gemery, Nina Kirchner, Larry A. Mayer, Johan Nilsson, Riko Noormets, Christof Pearce, Igor Semiletov, Christian Stranne, and Martin Jakobsson
Clim. Past, 13, 1269–1284, https://doi.org/10.5194/cp-13-1269-2017, https://doi.org/10.5194/cp-13-1269-2017, 2017
Short summary
Short summary
Past glacial activity on the East Siberian continental margin is poorly known, partly due to the lack of geomorphological evidence. Here we present geophysical mapping and sediment coring data from the East Siberian shelf and slope revealing the presence of a glacially excavated cross-shelf trough reaching to the continental shelf edge north of the De Long Islands. The data provide direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum.
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov, and Martin Jakobsson
Clim. Past, 13, 1097–1110, https://doi.org/10.5194/cp-13-1097-2017, https://doi.org/10.5194/cp-13-1097-2017, 2017
Short summary
Short summary
Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Martin Jakobsson, Christof Pearce, Thomas M. Cronin, Jan Backman, Leif G. Anderson, Natalia Barrientos, Göran Björk, Helen Coxall, Agatha de Boer, Larry A. Mayer, Carl-Magnus Mörth, Johan Nilsson, Jayne E. Rattray, Christian Stranne, Igor Semiletov, and Matt O'Regan
Clim. Past, 13, 991–1005, https://doi.org/10.5194/cp-13-991-2017, https://doi.org/10.5194/cp-13-991-2017, 2017
Short summary
Short summary
The Arctic and Pacific oceans are connected by the presently ~53 m deep Bering Strait. During the last glacial period when the sea level was lower than today, the Bering Strait was exposed. Humans and animals could then migrate between Asia and North America across the formed land bridge. From analyses of sediment cores and geophysical mapping data from Herald Canyon north of the Bering Strait, we show that the land bridge was flooded about 11 000 years ago.
Johan Nilsson, Martin Jakobsson, Chris Borstad, Nina Kirchner, Göran Björk, Raymond T. Pierrehumbert, and Christian Stranne
The Cryosphere, 11, 1745–1765, https://doi.org/10.5194/tc-11-1745-2017, https://doi.org/10.5194/tc-11-1745-2017, 2017
Short summary
Short summary
Recent data suggest that a 1 km thick ice shelf extended over the glacial Arctic Ocean during MIS 6, about 140 000 years ago. Here, we theoretically analyse the development and equilibrium features of such an ice shelf. The ice shelf was effectively dammed by the Fram Strait and the mean ice-shelf thickness was controlled primarily by the horizontally integrated mass balance. Our results can aid in resolving some outstanding questions of the state of the glacial Arctic Ocean.
Clint M. Miller, Gerald R. Dickens, Martin Jakobsson, Carina Johansson, Andrey Koshurnikov, Matt O'Regan, Francesco Muschitiello, Christian Stranne, and Carl-Magnus Mörth
Biogeosciences, 14, 2929–2953, https://doi.org/10.5194/bg-14-2929-2017, https://doi.org/10.5194/bg-14-2929-2017, 2017
Short summary
Short summary
Continental slopes north of the East Siberian Sea are assumed to hold large amounts of methane. We present pore water chemistry from the 2014 SWERUS-C3 expedition. These are among the first results generated from this vast climatically sensitive region, and they imply that abundant methane, including gas hydrates, do not characterize the East Siberian Sea slope or rise. This contradicts previous modeling and discussions, which due to the lack of data are almost entirely based assumption.
Leif G. Anderson, Göran Björk, Ola Holby, Sara Jutterström, Carl Magnus Mörth, Matt O'Regan, Christof Pearce, Igor Semiletov, Christian Stranne, Tim Stöven, Toste Tanhua, Adam Ulfsbo, and Martin Jakobsson
Ocean Sci., 13, 349–363, https://doi.org/10.5194/os-13-349-2017, https://doi.org/10.5194/os-13-349-2017, 2017
Short summary
Short summary
We use data collected in 2014 to show that the outflow of nutrient-rich water occurs much further to the west than has been reported in the past. We suggest that this is due to much less summer sea-ice coverage in the northwestern East Siberian Sea than in the past decades. Further, our data support a more complicated flow pattern in the region where the Mendeleev Ridge reaches the shelf compared to the general cyclonic circulation within the individual basins as suggested historically.
Christof Pearce, Aron Varhelyi, Stefan Wastegård, Francesco Muschitiello, Natalia Barrientos, Matt O'Regan, Thomas M. Cronin, Laura Gemery, Igor Semiletov, Jan Backman, and Martin Jakobsson
Clim. Past, 13, 303–316, https://doi.org/10.5194/cp-13-303-2017, https://doi.org/10.5194/cp-13-303-2017, 2017
Short summary
Short summary
The eruption of the Alaskan Aniakchak volcano of 3.6 thousand years ago was one of the largest Holocene eruptions worldwide. The resulting ash is found in several Alaskan sites and as far as Newfoundland and Greenland. In this study, we found ash from the Aniakchak eruption in a marine sediment core from the western Chukchi Sea in the Arctic Ocean. Combined with radiocarbon dates on mollusks, the volcanic age marker is used to calculate the marine radiocarbon reservoir age at that time.
Erik Gustafsson, Christoph Humborg, Göran Björk, Christian Stranne, Leif G. Anderson, Marc C. Geibel, Carl-Magnus Mörth, Marcus Sundbom, Igor P. Semiletov, Brett F. Thornton, and Bo G. Gustafsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-115, https://doi.org/10.5194/bg-2017-115, 2017
Preprint withdrawn
Short summary
Short summary
In this study we quantify key carbon cycling processes on the East Siberian Arctic Shelf. A specific aim is to determine the pathways of terrestrial organic carbon (OC) supplied by rivers and coastline erosion – and particularly to what extent degradation of terrestrial OC contributes to air-sea CO2 exchange. We estimate that the shelf is a weak CO2 sink, although this sink is considerably reduced mainly by degradation of eroded OC and to a lesser extent by degradation of riverine OC.
M. Löfverström, R. Caballero, J. Nilsson, and J. Kleman
Clim. Past, 10, 1453–1471, https://doi.org/10.5194/cp-10-1453-2014, https://doi.org/10.5194/cp-10-1453-2014, 2014
M. Berger, J. Brandefelt, and J. Nilsson
Clim. Past, 9, 969–982, https://doi.org/10.5194/cp-9-969-2013, https://doi.org/10.5194/cp-9-969-2013, 2013
F. O. Nitsche, K. Gohl, R. D. Larter, C.-D. Hillenbrand, G. Kuhn, J. A. Smith, S. Jacobs, J. B. Anderson, and M. Jakobsson
The Cryosphere, 7, 249–262, https://doi.org/10.5194/tc-7-249-2013, https://doi.org/10.5194/tc-7-249-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Arctic (e.g. Greenland)
Recent warming trends of the Greenland ice sheet documented by historical firn and ice temperature observations and machine learning
Spatially heterogeneous effect of climate warming on the Arctic land ice
Uncertainties in forecast surface mass balance outweigh uncertainties in basal sliding descriptions for 21st Century mass loss from three major Greenland outlet glaciers
Improving modelled albedo over the Greenland ice sheet through parameter optimisation and MODIS snow albedo retrievals
Direct measurement of warm Atlantic Intermediate Water close to the grounding line of Nioghalvfjerdsfjorden (79° N) Glacier, northeast Greenland
Brief communication: Preliminary ICESat-2 (Ice, Cloud and land Elevation Satellite-2) measurements of outlet glaciers reveal heterogeneous patterns of seasonal dynamic thickness change
Uncertainties in projected surface mass balance over the polar ice sheets from dynamically downscaled EC-Earth models
Comment on “Exceptionally high heat flux needed to sustain the Northeast Greenland Ice Stream” by Smith-Johnsen et al. (2020)
Thinning leads to calving-style changes at Bowdoin Glacier, Greenland
Possible impacts of a 1000 km long hypothetical subglacial river valley towards Petermann Glacier in northern Greenland
Greenland Ice Sheet late-season melt: investigating multiscale drivers of K-transect events
In situ observed relationships between snow and ice surface skin temperatures and 2 m air temperatures in the Arctic
Baptiste Vandecrux, Robert S. Fausto, Jason E. Box, Federico Covi, Regine Hock, Åsa K. Rennermalm, Achim Heilig, Jakob Abermann, Dirk van As, Elisa Bjerre, Xavier Fettweis, Paul C. J. P. Smeets, Peter Kuipers Munneke, Michiel R. van den Broeke, Max Brils, Peter L. Langen, Ruth Mottram, and Andreas P. Ahlstrøm
The Cryosphere, 18, 609–631, https://doi.org/10.5194/tc-18-609-2024, https://doi.org/10.5194/tc-18-609-2024, 2024
Short summary
Short summary
How fast is the Greenland ice sheet warming? In this study, we compiled 4500+ temperature measurements at 10 m below the ice sheet surface (T10m) from 1912 to 2022. We trained a machine learning model on these data and reconstructed T10m for the ice sheet during 1950–2022. After a slight cooling during 1950–1985, the ice sheet warmed at a rate of 0.7 °C per decade until 2022. Climate models showed mixed results compared to our observations and underestimated the warming in key regions.
Damien Maure, Christoph Kittel, Clara Lambin, Alison Delhasse, and Xavier Fettweis
The Cryosphere, 17, 4645–4659, https://doi.org/10.5194/tc-17-4645-2023, https://doi.org/10.5194/tc-17-4645-2023, 2023
Short summary
Short summary
The Arctic is warming faster than the rest of the Earth. Studies have already shown that Greenland and the Canadian Arctic are experiencing a record increase in melting rates, while Svalbard has been relatively less impacted. Looking at those regions but also extending the study to Iceland and the Russian Arctic archipelagoes, we see a heterogeneity in the melting-rate response to the Arctic warming, with the Russian archipelagoes experiencing lower melting rates than other regions.
J. Rachel Carr, Emily A. Hill, and G. Hilmar Gudmundsson
EGUsphere, https://doi.org/10.5194/egusphere-2023-1759, https://doi.org/10.5194/egusphere-2023-1759, 2023
Short summary
Short summary
The Greenland ice sheet is one of the world's largest glaciers and is melting quickly, in response to climate change. It contains fast-flowing channels of ice that move ice from Greenland's centre to its coasts and allow Greenland to react quickly to climate warming. As a result, we want to predict how these glaciers will behave in the future, but there are lots of uncertainties. Here we asses the impacts of two main sources of uncertainties in glacier models.
Nina Raoult, Sylvie Charbit, Christophe Dumas, Fabienne Maignan, Catherine Ottlé, and Vladislav Bastrikov
The Cryosphere, 17, 2705–2724, https://doi.org/10.5194/tc-17-2705-2023, https://doi.org/10.5194/tc-17-2705-2023, 2023
Short summary
Short summary
Greenland ice sheet melting due to global warming could significantly impact global sea-level rise. The ice sheet's albedo, i.e. how reflective the surface is, affects the melting speed. The ORCHIDEE computer model is used to simulate albedo and snowmelt to make predictions. However, the albedo in ORCHIDEE is lower than that observed using satellites. To correct this, we change model parameters (e.g. the rate of snow decay) to reduce the difference between simulated and observed values.
Michael J. Bentley, James A. Smith, Stewart S. R. Jamieson, Margaret R. Lindeman, Brice R. Rea, Angelika Humbert, Timothy P. Lane, Christopher M. Darvill, Jeremy M. Lloyd, Fiamma Straneo, Veit Helm, and David H. Roberts
The Cryosphere, 17, 1821–1837, https://doi.org/10.5194/tc-17-1821-2023, https://doi.org/10.5194/tc-17-1821-2023, 2023
Short summary
Short summary
The Northeast Greenland Ice Stream is a major outlet of the Greenland Ice Sheet. Some of its outlet glaciers and ice shelves have been breaking up and retreating, with inflows of warm ocean water identified as the likely reason. Here we report direct measurements of warm ocean water in an unusual lake that is connected to the ocean beneath the ice shelf in front of the 79° N Glacier. This glacier has not yet shown much retreat, but the presence of warm water makes future retreat more likely.
Christian J. Taubenberger, Denis Felikson, and Thomas Neumann
The Cryosphere, 16, 1341–1348, https://doi.org/10.5194/tc-16-1341-2022, https://doi.org/10.5194/tc-16-1341-2022, 2022
Short summary
Short summary
Outlet glaciers are projected to account for half of the total ice loss from the Greenland Ice Sheet over the 21st century. We classify patterns of seasonal dynamic thickness changes of outlet glaciers using new observations from the Ice, Cloud and land Elevation Satellite-2 (ICESat-2). Our results reveal seven distinct patterns that differ across glaciers even within the same region. Future work can use our results to improve our understanding of processes that drive seasonal ice sheet changes.
Fredrik Boberg, Ruth Mottram, Nicolaj Hansen, Shuting Yang, and Peter L. Langen
The Cryosphere, 16, 17–33, https://doi.org/10.5194/tc-16-17-2022, https://doi.org/10.5194/tc-16-17-2022, 2022
Short summary
Short summary
Using the regional climate model HIRHAM5, we compare two versions (v2 and v3) of the global climate model EC-Earth for the Greenland and Antarctica ice sheets. We are interested in the surface mass balance of the ice sheets due to its importance when making estimates of future sea level rise. We find that the end-of-century change in the surface mass balance for Antarctica is 420 Gt yr−1 (v2) and 80 Gt yr−1 (v3), and for Greenland it is −290 Gt yr−1 (v2) and −1640 Gt yr−1 (v3).
Paul D. Bons, Tamara de Riese, Steven Franke, Maria-Gema Llorens, Till Sachau, Nicolas Stoll, Ilka Weikusat, Julien Westhoff, and Yu Zhang
The Cryosphere, 15, 2251–2254, https://doi.org/10.5194/tc-15-2251-2021, https://doi.org/10.5194/tc-15-2251-2021, 2021
Short summary
Short summary
The modelling of Smith-Johnson et al. (The Cryosphere, 14, 841–854, 2020) suggests that a very large heat flux of more than 10 times the usual geothermal heat flux is required to have initiated or to control the huge Northeast Greenland Ice Stream. Our comparison with known hotspots, such as Iceland and Yellowstone, shows that such an exceptional heat flux would be unique in the world and is incompatible with known geological processes that can raise the heat flux.
Eef C. H. van Dongen, Guillaume Jouvet, Shin Sugiyama, Evgeny A. Podolskiy, Martin Funk, Douglas I. Benn, Fabian Lindner, Andreas Bauder, Julien Seguinot, Silvan Leinss, and Fabian Walter
The Cryosphere, 15, 485–500, https://doi.org/10.5194/tc-15-485-2021, https://doi.org/10.5194/tc-15-485-2021, 2021
Short summary
Short summary
The dynamic mass loss of tidewater glaciers is strongly linked to glacier calving. We study calving mechanisms under a thinning regime, based on 5 years of field and remote-sensing data of Bowdoin Glacier. Our data suggest that Bowdoin Glacier ungrounded recently, and its calving behaviour changed from calving due to surface crevasses to buoyancy-induced calving resulting from basal crevasses. This change may be a precursor to glacier retreat.
Christopher Chambers, Ralf Greve, Bas Altena, and Pierre-Marie Lefeuvre
The Cryosphere, 14, 3747–3759, https://doi.org/10.5194/tc-14-3747-2020, https://doi.org/10.5194/tc-14-3747-2020, 2020
Short summary
Short summary
The topography of the rock below the Greenland ice sheet is not well known. One long valley appears as a line of dips because of incomplete data. So we use ice model simulations that unblock this valley, and these create a watercourse that may represent a form of river over 1000 km long under the ice. When we melt ice at the bottom of the ice sheet only in the deep interior, water can flow down the valley only when the valley is unblocked. It may have developed while an ice sheet was present.
Thomas J. Ballinger, Thomas L. Mote, Kyle Mattingly, Angela C. Bliss, Edward Hanna, Dirk van As, Melissa Prieto, Saeideh Gharehchahi, Xavier Fettweis, Brice Noël, Paul C. J. P. Smeets, Carleen H. Reijmer, Mads H. Ribergaard, and John Cappelen
The Cryosphere, 13, 2241–2257, https://doi.org/10.5194/tc-13-2241-2019, https://doi.org/10.5194/tc-13-2241-2019, 2019
Short summary
Short summary
Arctic sea ice and the Greenland Ice Sheet (GrIS) are melting later in the year due to a warming climate. Through analyses of weather station, climate model, and reanalysis data, physical links are evaluated between Baffin Bay open water duration and western GrIS melt conditions. We show that sub-Arctic air mass movement across this portion of the GrIS strongly influences late summer and autumn melt, while near-surface, off-ice winds inhibit westerly atmospheric heat transfer from Baffin Bay.
Pia Nielsen-Englyst, Jacob L. Høyer, Kristine S. Madsen, Rasmus Tonboe, Gorm Dybkjær, and Emy Alerskans
The Cryosphere, 13, 1005–1024, https://doi.org/10.5194/tc-13-1005-2019, https://doi.org/10.5194/tc-13-1005-2019, 2019
Short summary
Short summary
The paper facilitates the construction of a satellite-derived 2 m air temperature (T2m) product for Arctic snow/ice areas. The relationship between skin temperature (Tskin) and T2m is analysed using weather stations. The main factors influencing the relationship are seasonal variations, wind speed and clouds. A clear-sky bias is estimated to assess the effect of cloud-limited satellite observations. The results are valuable when validating satellite Tskin or estimating T2m from satellite Tskin.
Cited articles
Armi, L.: The hydraulics of two flowing layers with different densities,
J. Fluid Mech., 163, 27–58, https://doi.org/10.1017/S0022112086002197,
1986. a
Aschwanden, A., Fahnestock, M. A., Truffer, M., Brinkerhoff, D. J., Hock, R.,
Khroulev, C., Mottram, R., and Khan, S. A.: Contribution of the Greenland Ice
Sheet to sea level over the next millennium, Science Advances, 5, eaav9396,
https://doi.org/10.1126/sciadv.aav9396, 2019. a, b
Bao, W. and Moffat, C.: Impact of shallow sills on heat transport and stratification regimes in proglacial fjords, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2023-32, in review, 2023. a, b, c
Cai, C., Rignot, E., Menemenlis, D., and Nakayama, Y.: Observations and
modeling of ocean-induced melt beneath Petermann Glacier Ice Shelf in
northwestern Greenland, Geophys. Res. Lett., 44, 8396–8403,
https://doi.org/10.1002/2017GL073711, 2017. a, b, c
Calder, B., Eriksson, B., Jerram, K., Weidner, E., Holmes, F., Muchowski, J., Prakash, A., Handl, T., Ståhl, E., Mayer, L., and Jakobsson, M.: High-resolution bathymetry from the Ryder 2019 expedition to Northwest Greenland. Dataset version 1, Bolin Centre Database [data set], https://doi.org/10.17043/oden-ryder-2019-bathymetry-1, 2020. a
De Andrés, E., Slater, D. A., Straneo, F., Otero, J., Das, S., and Navarro, F.: Surface emergence of glacial plumes determined by fjord stratification, The Cryosphere, 14, 1951–1969, https://doi.org/10.5194/tc-14-1951-2020, 2020. a
Favier, L., Jourdain, N. C., Jenkins, A., Merino, N., Durand, G., Gagliardini, O., Gillet-Chaulet, F., and Mathiot, P.: Assessment of sub-shelf melting parameterisations using the ocean–ice-sheet coupled model NEMO(v3.6)–Elmer/Ice(v8.3) , Geosci. Model Dev., 12, 2255–2283, https://doi.org/10.5194/gmd-12-2255-2019, 2019. a, b, c
Gade, H.: Melting of ice in sea water: a primitive model with application to
the Antarctic Shelf Ice and icebergs, J. Phys. Oceanogr., 9, 189–198,
https://doi.org/10.1175/1520-0485(1979)009<0189:MOIISW>2.0.CO;2, 1979. a, b
Gudmundsson, G. H.: Ice-shelf buttressing and the stability of marine ice sheets, The Cryosphere, 7, 647–655, https://doi.org/10.5194/tc-7-647-2013, 2013. a
Hager, A. O., Sutherland, D. A., Amundson, J. M., Jackson, R. H., Kienholz, C.,
Motyka, R. J., and Nash, J. D.: Subglacial Discharge Reflux and Buoyancy
Forcing Drive Seasonality in a Silled Glacial Fjord, J. Geophys.
Res.-Oceans, 127, e2021JC018355, https://doi.org/10.1029/2021JC018355, 2022. a, b
Hattermann, T., Smedsrud, L. H., Nøst, O. A., Lilly, J. M., and
Galton-Fenzi, B.: Eddy-resolving simulations of the Fimbul Ice Shelf cavity
circulation: Basal melting and exchange with open ocean, Ocean Model., 82,
28–44, 2014. a
Hill, E. A., Carr, J. R., Stokes, C. R., and Gudmundsson, G. H.: Dynamic changes in outlet glaciers in northern Greenland from 1948 to 2015, The Cryosphere, 12, 3243–3263, https://doi.org/10.5194/tc-12-3243-2018, 2018. a, b, c, d
Holland, D. M. and Jenkins, A.: Modeling Thermodynamic Ice–Ocean Interactions
at the Base of an Ice Shelf, J. Phys. Oceanogr., 29, 1787–1800,
https://doi.org/10.1175/1520-0485(1999)029<1787:MTIOIA>2.0.CO;2, 1999. a, b
Jackson, R. H. and Straneo, F.: Heat, Salt, and Freshwater Budgets for a
Glacial Fjord in Greenland, J. Phys. Oceanogr., 46, 2735–2768, https://doi.org/10.1175/JPO-D-15-0134.1, 2016. a, b, c
Jackson, R. H., Lentz, S. J., and Straneo, F.: The Dynamics of Shelf Forcing in
Greenlandic Fjords, J. Phys. Oceanogr., 48, 2799–2827,
https://doi.org/10.1175/JPO-D-18-0057.1, 2018. a
Jakobsson, M., Mayer, L. A., Nilsson, J., Stranne, C., Calder, B., O'Regan, M.,
Farrell, J. W., Cronin, T. M., Brüchert, V., Chawarski, J., Eriksson,
B., Fredriksson, J., Gemery, L., Glueder, A., Holmes, F. A., Jerram, K.,
Kirchner, N., Mix, A., Muchowski, J., Prakash, A., Reilly, B., Thornton, B.,
Ulfsbo, A., Weidner, E., Åkesson, H., Handl, T., Ståhl, E., Boze,
L.-G., Reed, S., West, G., and Padman, J.: Ryder Glacier in northwest
Greenland is shielded from warm Atlantic water by a bathymetric sill,
Communications Earth & Environment, 1, 45, https://doi.org/10.1038/s43247-020-00043-0,
2020. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r
Jenkins, A.: A one-dimensional model of ice shelf-ocean interaction, J.
Geophys. Res.-Oceans, 96, 20671–20677, https://doi.org/10.1029/91JC01842,
1991. a, b
Jenkins, A.: The Impact of Melting Ice on Ocean Waters, J. Phys.
Oceanogr., 29, 2370–2381,
https://doi.org/10.1175/1520-0485(1999)029<2370:TIOMIO>2.0.CO;2, 1999. a
Johannessen, O. M., Babiker, M., and Miles, M. W.: Unprecedented retreat in a
50-year observational record for Petermann Glacier, North Greenland,
Atmospheric and Oceanic Science Letters, 6, 259–265,
https://doi.org/10.3878/j.issn.1674-2834.13.0021, 2013. a, b
Johnson, H. L., Münchow, A., Falkner, K. K., and Melling, H.: Ocean
circulation and properties in Petermann Fjord, Greenland, J. Geophys. Res.-Oceans, 116, C01003, https://doi.org/10.1029/2010JC006519, 2011. a, b, c
Khazendar, A., Fenty, I. G., Carroll, D., Gardner, A., Lee, C. M., Fukumori, I., Wang,
I., Zhang, H., Seroussi, H., Moller, D., Noël, B. P. Y., van den Broeke, M. R.,Dinardo,
S., and Willis, J.: Interruption of two decades of
Jakobshavn Isbrae acceleration and thinning as regional ocean cools,
Nat. Geosci., 12, 277–283, 2019. a
Lazeroms, W. M. J., Jenkins, A., Gudmundsson, G. H., and van de Wal, R. S. W.: Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes, The Cryosphere, 12, 49–70, https://doi.org/10.5194/tc-12-49-2018, 2018. a, b
Lazeroms, W. M. J., Jenkins, A., Rienstra, S. W., and van de Wal, R. S. W.: An
Analytical Derivation of Ice-Shelf Basal Melt Based on the Dynamics of
Meltwater Plumes, J. Phys. Oceanogr., 49, 917–939,
https://doi.org/10.1175/JPO-D-18-0131.1, 2019. a
Lewis, E. L. and Perkin, R. G.: Ice pumps and their rates, J. Geophys. Res.,
91, 11756–11762, https://doi.org/10.1029/JC091iC10p11756, 1986. a
Lindeman, M. R., Straneo, F., Wilson, N. J., Toole, J. M., Krishfield, R. A.,
Beaird, N. L., Kanzow, T., and Schaffer, J.: Ocean Circulation and
Variability Beneath Nioghalvfjerdsbræ (79 North Glacier) Ice Tongue,
J. Geophys. Res.-Oceans, 125, e2020JC016091,
https://doi.org/10.1029/2020JC016091, 2020. a
Little, C. M., Gnanadesikan, A., and Hallberg, R.: Large-Scale Oceanographic
Constraints on the Distribution of Melting and Freezing under Ice Shelves, J.
Phys. Oceanogr., 38, 2242–2255, https://doi.org/10.1175/2008JPO3928.1, 2008. a
Little, C. M., Gnanadesikan, A., and Oppenheimer, M.: How ice shelf morphology
controls basal melting, J. Geophys. Res., 114, C12007, https://doi.org/10.1029/2008JC005197,
2009. a, b, c
Morlighem, M., Williams, C. N., Rignot, E., An, L., Arndt, J. E., Bamber, J. L.,
Catania, G., Chauché, N., Dowdeswell, J. A., Dorschel, B., Fenty, I., Hogan, K.,
Howat, I., Hubbard, A., Jakobsson, A., Jordan, T. M., Kjeldsen, K. K., Millan, R.,
Mayer, L, Mouginot, J., Noël, B. P. Y., O'Cofaigh, C., Palmer, S., Rysgaard, S.,
Seroussi, H., Siegert, M. J., Slabon, P., Straneo, F., van den Broeke, M. R.,
Weinrebe, W., Wood, M., and Zinglersen, K. B.: BedMachine v3: Complete Bed
Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo
Sounding Combined With Mass Conservation, Geophys. Res. Lett., 44,
11051–11061, https://doi.org/10.1002/2017GL074954, 2017. a
Mouginot, J., Rignot, E., Bjørk, A. A., van den Broeke, M., Millan, R.,
Morlighem, M., Noël, B., Scheuchl, B., and Wood, M.: Forty-six years of
Greenland Ice Sheet mass balance from 1972 to 2018, P.
Natl. Acad. Sci. USA, 116, 9239–9244, https://doi.org/10.1073/pnas.1904242116,
2019. a, b
Nick, F. M., Vieli, A., Andersen, M. L., Joughin, I., Payne, A., Edwards, T. L., Pattyn,
F., and van de Wal, R. S. W.: Future sea-level rise from
Greenland's main outlet glaciers in a warming climate, Nature, 497,
235–238, https://doi.org/10.1038/nature12068, 2013. a
Nycander, J., Hogg, A. M., and Frankcombe, L. M.: Open boundary conditions for
nonlinear channel flow, Ocean Model., 24, 108–121,
https://doi.org/10.1016/j.ocemod.2008.06.003, 2008. a
O'Regan, M., Cronin, T. M., Reilly, B., Alstrup, A. K. O., Gemery, L., Golub, A., Mayer, L. A., Morlighem, M., Moros, M., Munk, O. L., Nilsson, J., Pearce, C., Detlef, H., Stranne, C., Vermassen, F., West, G., and Jakobsson, M.: The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland, The Cryosphere, 15, 4073–4097, https://doi.org/10.5194/tc-15-4073-2021, 2021. a
Polyakov, I. V., Alekseev, G. V., Timokhov, L. A., Bhatt, U. S., Colony, R. L.,
Simmons, H. L., Walsh, D., Walsh, J. E., and Zakharov, V. F.: Variability of
the Intermediate Atlantic Water of the Arctic Ocean over the Last 100
Years, J. Climate, 17, 4485–4497, https://doi.org/10.1175/JCLI-3224.1, 2004. a
Price, J. F. and O'Neil Baringer, M.: Outflows and deep water production by
marginal seas, Prog. Oceanogr., 33, 161–200,
https://doi.org/10.1016/0079-6611(94)90027-2, 1994. a, b, c
Schoof, C.: Ice sheet grounding line dynamics: Steady states, stability, and
hysteresis, J. Geophys. Res., 112, F03S28, https://doi.org/10.1029/2006JF000664, f03S28, 2007. a
Schoof, C., Davis, A. D., and Popa, T. V.: Boundary layer models for calving marine outlet glaciers, The Cryosphere, 11, 2283–2303, https://doi.org/10.5194/tc-11-2283-2017, 2017. a
Shroyer, E. L., Padman, L., Samelson, R. M., Münchow, A., and Stearns,
L. A.: Seasonal control of Petermann Gletscher ice-shelf melt by the
ocean's response to sea-ice cover in Nares Strait, J. Glaciol.,
63, 324–330, https://doi.org/10.1017/jog.2016.140, 2017. a
Slater, D. A. and Straneo, F.: Submarine melting of glaciers in Greenland
amplified by atmospheric warming, Nat. Geosci., 15, 794–799,
https://doi.org/10.1038/s41561-022-01035-9, 2022. a, b
Stommel, H. and Farmer, H. G.: Control of salinity in an estuary by a
transition, J. Mar. Res, 12, 13–20, 1953. a
Straneo, F. and Heimbach, P.: North Atlantic warming and the retreat of
Greenland's outlet glaciers, Nature, 504, 36–43,
https://doi.org/10.1038/nature12854, 2013. a, b, c, d
Straneo, F., Sutherland, D., Holland, D., Gladish, C., Hamilton, G., Johnson,
H., and Koppes, M.: Characteristics of ocean waters reaching Greenland's
glaciers, Ann. Glaciol., 53, 202–210,
https://doi.org/10.3189/2012AoG60A059, 2012. a
Stranne, C., Nilsson, J., and Muchowski, J.: Oceanographic LADCP data from the Ryder 2019 expedition, Bolin Centre Database [data set], https://doi.org/10.17043/oden-ryder-2019-ladcp-1, 2020a. a
Stranne, C., Nilsson, J., Muchowski, J., and Chawarski, J.: Oceanographic CTD data from the Ryder 2019 expedition, Dataset version 1, Bolin Centre Database [data set], https://doi.org/10.17043/oden-ryder-2019-ctd-1, 2020b. a
Stranne, C., Nilsson, J., Ulfsbo, A., O'Regan, M., Coxall, H. K., Meire, L.,
Muchowski, J., Mayer, L. A., Brüchert, V., Fredriksson, J., Thornton,
B., Chawarski, J., West, G., Weidner, E., and Jakobsson, M.: The climate
sensitivity of northern Greenland fjords is amplified through sea-ice
damming, Communications Earth & Environment, 2, 70,
https://doi.org/10.1038/s43247-021-00140-8, 2021. a, b
Timmermans, M.-L.: Hydraulic Control and Mixing in a Semi-Enclosed Reservoir,
Tech. rep., Geophys. Fluid Dyn. Summer Study Program Tech. Rep. WHOI-98-09,
1998. a
Truffer, M. and Motyka, R. J.: Where glaciers meet water: Subaqueous melt and
its relevance to glaciers in various settings, Rev. Geophys., 54,
220–239, https://doi.org/10.1002/2015RG000494, 2016. a, b, c
Washam, P., Nicholls, K. W., Münchow, A., and Padman, L.: Summer surface
melt thins Petermann Gletscher Ice Shelf by enhancing channelized basal
melt, J. Glaciol., 65, 662–674, https://doi.org/10.1017/jog.2019.43, 2019. a
Wilson, N., Straneo, F., and Heimbach, P.: Satellite-derived submarine melt rates and mass balance (2011–2015) for Greenland's largest remaining ice tongues, The Cryosphere, 11, 2773–2782, https://doi.org/10.5194/tc-11-2773-2017, 2017. a, b, c
Wood, M., Rignot, E., Fenty, I., An, L., Bjørk, A., van den Broeke, M., Cai,
C., Kane, E., Menemenlis, D., Millan, R., Morlighem, M., Mouginot, J.,
Noël, B., Scheuchl, B., Velicogna, I., Willis, J. K., and Zhang, H.:
Ocean forcing drives glacier retreat in Greenland, Science Advances, 7, eaba7282,
https://doi.org/10.1126/sciadv.aba7282, 2021. a, b, c, d, e
Xu, Y., Rignot, E., Fenty, I., Menemenlis, D., and Flexas, M. M.: Subaqueous
melting of Store Glacier, west Greenland from three-dimensional,
high-resolution numerical modeling and ocean observations, Geophys.
Res. Lett., 40, 4648–4653, https://doi.org/10.1002/grl.50825, 2013. a, b, c, d
Zhao, K. X., Stewart, A. L., and McWilliams, J. C.: Sill-Influenced Exchange
Flows in Ice Shelf Cavities, J. Phys. Oceanogr., 49, 163–191,
https://doi.org/10.1175/JPO-D-18-0076.1, 2019.
a
Zhao, K. X., Stewart, A. L., and McWilliams, J. C.: Geometric Constraints on
Glacial Fjord–Shelf Exchange, J. Phys. Oceanogr., 51, 1223–1246, https://doi.org/10.1175/JPO-D-20-0091.1, 2021. a, b
Short summary
We investigate how topographical sills suppress basal glacier melt in Greenlandic fjords. The basal melt drives an exchange flow over the sill, but there is an upper flow limit set by the Atlantic Water features outside the fjord. If this limit is reached, the flow enters a new regime where the melt is suppressed and its sensitivity to the Atlantic Water temperature is reduced.
We investigate how topographical sills suppress basal glacier melt in Greenlandic fjords. The...
