Article
Oceanography
S. J. Lentz
Summary: A remarkably consistent upwelling circulation driven by cross-shelf buoyancy gradients, rather than traditional wind forcing, is observed on the southern New England inner shelf. This circulation is strongest in summer and plays a crucial role in cooling the inner shelf and facilitating cross-shelf exchange.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Geosciences, Multidisciplinary
D. A. Slater, D. Carroll, H. Oliver, M. J. Hopwood, F. Straneo, M. Wood, J. K. Willis, M. Morlighem
Summary: The glacial fjords in Greenland play a crucial role in regulating the exchange of heat, freshwater, and nutrients between the ice sheet and the ocean. This study provides valuable insights into the dynamics of these fjords and quantifies the upwelling fluxes. It highlights the importance of considering fjord-scale processes in large-scale ice sheet and climate models.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Chuning Wang, Robert J. Chant, Rebecca H. Jackson
Summary: A new model framework, ROMS-ICEPLUME, has been developed to parameterize the rising and initial outflow stage of subglacial discharge plumes in tidewater glacier fjords. The framework shows improved performance in reproducing the plume structure compared to previous models without the parameterization algorithm.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Oceanography
Chuning Wang, Robert J. Chant, Rebecca H. Jackson
Summary: In this study, a new model framework is developed to parameterize the rising and initial outflowing stage of subglacial discharge plumes in tidewater glacier fjords. The new framework improves model performance and successfully reproduces the strong outflowing plume structure observed in-situ. This advancement in understanding the circulation in tidewater glacier fjords is crucial.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Oceanography
Robert Sanchez, Donald Slater, Fiammetta Straneo
Summary: Freshwater from the Greenland Ice Sheet is routed to the ocean through narrow fjords, impacting ecosystems and circulation. The timing of freshwater export is influenced by the residence time in glacial fjords. In Saqqarleq, a fjord in west Greenland, seasonal freshwater storage was observed, with a rapid freshening trend driven by surface mixing and stratification. A box model was constructed to understand the dynamics and found a month lag between subglacial meltwater discharge and net freshwater export. These findings highlight the importance of accounting for fjord-induced delays in large-scale models studying the impact of Greenland freshwater on the climate system.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Geosciences, Multidisciplinary
J. M. Cusack, R. H. Jackson, J. D. Nash, E. Skyllingstad, E. C. Pettit, D. A. Sutherland, R. J. Motyka, J. M. Amundson
Summary: Submarine melting contributes to the acceleration of marine-terminating glacier retreat globally. Subglacial discharge plumes, such as energetic ocean flows, are found to enhance submarine melting nearby. By studying observations and conducting large eddy simulation, it is discovered that discharge plumes produce high-frequency internal gravity waves that spread to distant areas of the glacier terminus, obtaining energy from turbulent motions within the plume and its surface outflow. Consideration of these waves' velocities near the terminus leads to a 70% increase in predicted melt rates, which may explain the observed discrepancies with theoretical predictions. As the dynamic elements of a buoyant plume rising through a stratified ocean are common in many tidewater glacier systems, these internal waves are likely to be widespread.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Alexander O. Hager, David A. Sutherland, Jason M. Amundson, Rebecca H. Jackson, Christian Kienholz, Roman J. Motyka, Jonathan D. Nash
Summary: This study reveals the importance of freshwater reflux in influencing circulation in glacial fjords, especially during the summer. The mixing and re-entrainment of glacial freshwater in the subglacial discharge plume play a significant role in altering the near-glacier water properties and transporting warm water to the glacier grounding line. This circulatory phenomenon is absent in the winter when there is minimal freshwater reflux.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Multidisciplinary Sciences
Philip Bertrand, Joel Bety, Nigel G. Yoccoz, Marie-Josee Fortin, Hallvard Strom, Harald Steen, Jack Kohler, Stephanie M. Harris, Samantha C. Patrick, Olivier Chastel, P. Blevin, Haakon Hop, Geir Moholdt, Josephine Maton, Sebastien Descamps
Summary: In Arctic marine predator colonies, individual movements and colonial segregation are influenced by seascape characteristics, with tidewater glacier fronts being important features. This study found that black-legged kittiwakes are more likely to forage near glacier fronts located closer to their colonies, creating fine-scale spatial segregation among adjacent colonies. Results suggest that spatially predictable foraging patches like glacier fronts can strongly impact predator movements and intercolonial spatial segregation.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
Carlo Cossu
Summary: In this study, the genesis of large-scale coherent rolls in turbulent wall-bounded flows was investigated through linear stability analysis, revealing the importance of modeling turbulent Reynolds stresses for consistent predictions. The onset of large-scale convection was found to be associated with a critical friction Richardson number.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
M. Taha, S. Zhao, A. Lamorlette, J. L. Consalvi, P. Boivin
Summary: The pressure-based hybrid lattice-Boltzmann method proposed by Farag et al. was evaluated for simulating buoyancy driven flows. Validation studies on different cases and comparison with experimental results showed good overall agreement in terms of mean and fluctuation quantities, as well as global entrainment.
Article
Mechanics
Xin Chen, Ao Xu, Ke-Qing Xia, Heng-Dong Xi
Summary: We experimentally studied the effect of cell tilting on the temperature oscillation in turbulent Rayleigh-Benard convection. We found that the temperature oscillation intensity measured in-fluid is much stronger than that measured in-wall. The azimuthal profiles of the oscillation intensity measured by in-fluid and in-wall share similar spatial distribution.
Review
Multidisciplinary Sciences
Harry L. Bryden
Summary: Continuous observations of ocean circulation at 26 degrees N in the subtropical Atlantic Ocean since April 2004 revealed the complexity of the Atlantic Meridional overturning circulation (AMOC) with contributions from wind-driven and buoyancy-driven components. In 2009, there was a sharp reduction in the southward flow of deep waters below 1100 m depth, indicating variability in the buoyancy-driven circulation. Over the 14-year observational period from 2004 to 2018, the AMOC declined by 2.4 Sv.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Environmental Sciences
Jan Kavan, Iwo Wieczorek, Guy D. Tallentire, Mihail Demidionov, Jakub Uher, Mateusz C. Strzelecki
Summary: Glacier-fed hydrological systems in high latitude regions show seasonal variation in meltwater runoff, with peak runoff coinciding with high air temperatures. Monitoring these processes requires complex fieldwork, but this study demonstrates the use of remote sensing data to analyze the dynamics of sediment in lakes and plumes. The study proposes a new SSL index for quantifying sediment influx to the marine environment.
Article
Geosciences, Multidisciplinary
Miles M. P. Couchman, Bethan Wynne-Cattanach, Matthew H. Alford, Colm-cille P. Caulfield, Rich R. Kerswell, Jennifer A. MacKinnon, Gunnar Voet
Summary: Understanding how ocean turbulence transports heat is crucial for global circulation models. A new data-driven approach using unsupervised machine learning was presented for identifying distinct regions of turbulent mixing within a microstructure dataset. Applied to data collected near the Velasco Reef in Palau, the algorithm revealed spatial and temporal correlations between mixing characteristics and various environmental factors. Unsupervised machine learning has the potential to advance community understanding of turbulent mixing patterns globally.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geography, Physical
Kristin Poinar, Lauren C. Andrews
Summary: This study used remote-sensing data to analyze the relationship between strain rates and lake drainages in western Greenland. The study found that moulins associated with fast-draining lakes have significantly higher extensional background strain rates. However, the current ice sheet velocity products cannot accurately resolve the transient strain rates that drive fast lake drainages.
Article
Environmental Sciences
E. F. Eidam, D. A. Sutherland, D. K. Ralston, T. Conroy, J. Schmitt, P. Ruggiero, J. Wood
Summary: This article examines the impact of development activities such as dredging and shoreline reclamation on estuarine tidal and salt dynamics, using the Coos Estuary as an example. The study finds that over the past 150 years, the deepening of the primary navigation channel in the estuary has resulted in a decrease in estuary area and an increase in volume. A hydrodynamic model was used to evaluate the present and future impacts, and it was found that a proposed channel-depth increase would have negligible effects. The results highlight the importance of curating high-resolution bathymetric datasets for coastal management applications.
ESTUARIES AND COASTS
(2022)
Article
Geosciences, Multidisciplinary
Denis Felikson, Ginny A. Catania, Timothy C. Bartholomaus, Mathieu Morlighem, Brice P. Y. Noel
Summary: This study identifies knickpoints as the main factors limiting the diffusion of thinning of outlet glaciers, typically found in regions with steep bedrock topography. In contrast, in regions with gentle topography, these knickpoints may not exist or have a less steep slope, allowing thinning to spread far into the ice sheet interior.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Sarah F. Child, Leigh A. Stearns, Luc Girod, Henry H. Brecher
Summary: Researchers used structure-from-motion photogrammetry techniques to generate elevation data from historical Antarctic aerial imagery, overcoming limitations of traditional methods. Through this approach, they successfully estimated that the surface elevation of Byrd Glacier has remained constant for approximately 40 years.
Article
Oceanography
E. F. Eidam, D. A. Sutherland, D. K. Ralston, T. Conroy, B. Dye
Summary: Estuaries worldwide have undergone modifications over centuries, impacting sediment dynamics. The Coos Bay Estuary in Oregon, a small estuary with complex geometry, has experienced significant changes since 1865, leading to alterations in tidal amplitudes, salinity intrusion, and estuarine flow. These changes have resulted in reduced current magnitudes, increased stratification, and the formation of an estuarine turbidity maximum supplying sediment to proximal embayments.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
Sarah F. Child, Leigh A. Stearns, C. J. van der Veen, Pedro Elosegui
Summary: Research on Byrd Glacier reveals that short-lived flow accelerations can lead to abnormally large basal crevasses near the grounding line. Airborne radar measurements and particle tracking help understand the height and formation process of these crevasses, which have an impact on both Byrd Glacier and the Ross Ice Shelf.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geography, Physical
Sierra M. Melton, Richard B. Alley, Sridhar Anandakrishnan, Byron R. Parizek, Michael G. Shahin, Leigh A. Stearns, Adam L. LeWinter, David C. Finnegan
Summary: Meltwater drainage systems play a role in influencing the timing of calving at the Helheim Glacier in East Greenland. A buoyant subglacial discharge plume consistently appears at the central terminus, separate from the occurrence of full-thickness calving, indicating an inverse relationship between the two.
JOURNAL OF GLACIOLOGY
(2022)
Article
Geosciences, Multidisciplinary
D. A. Slater, D. Carroll, H. Oliver, M. J. Hopwood, F. Straneo, M. Wood, J. K. Willis, M. Morlighem
Summary: The glacial fjords in Greenland play a crucial role in regulating the exchange of heat, freshwater, and nutrients between the ice sheet and the ocean. This study provides valuable insights into the dynamics of these fjords and quantifies the upwelling fluxes. It highlights the importance of considering fjord-scale processes in large-scale ice sheet and climate models.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Dustin Carroll, Dimitris Menemenlis, Stephanie Dutkiewicz, Jonathan M. Lauderdale, Jess F. Adkins, Kevin W. Bowman, Holger Brix, Ian Fenty, Michelle M. Gierach, Chris Hill, Oliver Jahn, Peter Landschuetzer, Manfredi Manizza, Matt R. Mazloff, Charles E. Miller, David S. Schimel, Ariane Verdy, Daniel B. Whitt, Hong Zhang
Summary: The inventory and variability of oceanic dissolved inorganic carbon (DIC) are influenced by physical, chemical, and biological processes. Understanding the spatiotemporal variability of these processes is crucial for understanding the ocean carbon sink and its future trajectory.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Tom van der Stocken, Bram Vanschoenwinkel, Dustin Carroll, Kyle C. Cavanaugh, Nico Koedam
Summary: The distribution of mangrove forests will be impacted by climate change, especially in the Indo West Pacific region, due to changes in sea surface temperature and density. The dispersal of mangrove propagules may be altered, potentially reducing the resilience of mangrove forests in the future.
NATURE CLIMATE CHANGE
(2022)
Article
Multidisciplinary Sciences
Lizz Ultee, Denis Felikson, Brent Minchew, Leigh A. Stearns, Bryan Riel
Summary: This study assesses the ice flow variability of one of the largest Greenland outlet glaciers, Helheim Glacier, from 2009 to 2017 using dense observations, climate model output, and time series analysis tools. The study finds that ice speed is most strongly correlated with catchment-integrated runoff at seasonal to interannual scales, while multi-annual flow variability is most strongly correlated with multi-annual terminus variability.
NATURE COMMUNICATIONS
(2022)
Article
Plant Sciences
Jacqueline L. Raw, Tom Van der Stocken, Dustin Carroll, Linda R. Harris, Anusha Rajkaran, Lara Van Niekerk, Janine B. Adams
Summary: This study shows that dispersal limits the distribution of mangroves at the southern African range limit. Under future climate scenarios, 30% of estuaries currently supporting mangroves are predicted to become unsuitable, while six new estuaries beyond the current distribution are predicted to become suitable. There is limited connectivity between these new sites and established forests.
JOURNAL OF ECOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Hilde Oliver, Donald Slater, Dustin Carroll, Michael Wood, Mathieu Morlighem, Mark J. Hopwood
Summary: Subglacial discharge from Greenland's marine-terminating glaciers drives nutrient supply and stimulates phytoplankton growth. The nitrate fluxes are concentrated in a few critical systems, with 14% of glaciers accounting for half of the total flux anomaly. The largest flux occurs at Jakobshavn Isbr AE in Disko Bay, where subglacial discharge is highest. Subglacial discharge and nitrate flux anomaly also contribute to temporal variability in summer satellite chlorophyll a (Chl) near Greenland's coast.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
C. Bertin, D. Carroll, D. Menemenlis, S. Dutkiewicz, H. Zhang, A. Matsuoka, S. Tank, M. Manizza, C. E. Miller, M. Babin, A. Mangin, V. Le Fouest
Summary: Arctic warming changes the fluxes of nutrients and organic matter from land to sea, affecting air-sea carbon exchange. Using a biogeochemical model, this study examines the role of Mackenzie River discharge in modulating air-sea CO2 fluxes in the southeastern Beaufort Sea from 2000 to 2019. The discharge of six chemical constituents leads to a net CO2 outgassing of 0.13 TgC yr(-1) and a decrease in the coastal carbon sink due to riverine dissolved organic and inorganic carbon. The results indicate that the Mackenzie River influences the capacity of the southeastern Beaufort Sea to act as a sink or source of atmospheric CO2. Accurate representation of land-to-sea biogeochemical coupling is crucial for understanding the Arctic coastal ocean response to the rapidly changing environment.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Manfredi Manizza, Dustin Carroll, Dimitris Menemenlis, Hong Zhang, Charles E. Miller
Summary: In recent decades, changes in sea-ice seasonality in the Arctic Ocean (AO) have had significant impacts on the phenology of phytoplankton blooms. Early sea-ice melt triggers earlier blooms, while delayed formation of sea ice leads to second fall blooms. These changes could have important consequences for Arctic marine ecosystems in a warmer and changing climate.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Environmental Sciences
Tim Devries, Kana Yamamoto, Rik Wanninkhof, Nicolas Gruber, Judith Hauck, Jens Daniel Mueller, Laurent Bopp, Dustin Carroll, Brendan Carter, Thi-Tuyet-Trang Chau, Scott C. Doney, Marion Gehlen, Lucas Gloege, Luke Gregor, Stephanie Henson, Ji Hyun Kim, Yosuke Iida, Tatiana Ilyina, Peter Landschuetzer, Corinne Le Quere, David Munro, Cara Nissen, Lavinia Patara, Fiz F. Perez, Laure Resplandy, Keith B. Rodgers, Joerg Schwinger, Roland Seferian, Valentina Sicardi, Jens Terhaar, Joaquin Trinanes, Hiroyuki Tsujino, Andrew Watson, Sayaka Yasunaka, Jiye Zeng
Summary: This contribution analyzes the processes that determine the global ocean carbon sink and its trends and variability over the period 1985-2018 using models and observation-based products. The study finds that anthropogenic CO2 dominates the ocean CO2 sink, while climate-driven variability is potentially large but highly uncertain.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)