Article
Oceanography
Hailu Kong, Malte F. Jansen
Summary: The response of the Southern Ocean circulation to changes in surface wind stress remains uncertain, highlighting the importance of considering topography and parameterized eddies in coarse-resolution simulations. Topography plays a crucial role in modulating the response of the Southern Ocean circulation to changes in surface wind stress, emphasizing the need for further research on the interaction between mesoscale eddies and stationary meanders induced by topography.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Geosciences, Multidisciplinary
A. Solodoch, A. L. Stewart, A. McC. Hogg, A. K. Morrison, A. E. Kiss, A. F. Thompson, S. G. Purkey, L. Cimoli
Summary: This study uses a global high-resolution ocean/sea-ice simulation and passive tracer deployments to examine the export pathways of Antarctic Bottom Water (AABW). The results show that AABW from different source regions are blended during their export, with Weddell Sea- and Prydz Bay-sourced AABW mainly exported to the Atlantic and Indian Oceans, while Ross Sea- and Adelie Land-sourced AABW mainly exported to the Pacific Ocean. This has important implications for the three-dimensional structure of the global overturning circulation.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Fabio Boeira Dias, Catia M. Domingues, Simon J. Marsland, Stephen R. Rintoul, Petteri Uotila, Russell Fiedler, Mauricio M. Mata, Nathaniel L. Bindoff, Abhishek Savita
Summary: The study highlights the influence of surface wind perturbations on the response of the Antarctic subpolar Southern Ocean, leading to enhanced Antarctic Bottom Water formation and accelerated global Meridional Overturning Circulation. Open Water Polynya (OWP) events are triggered by upwelling warm waters and inhibition of sea ice growth, with their availability linked to deep ocean heat reservoirs.
JOURNAL OF CLIMATE
(2021)
Article
Geosciences, Multidisciplinary
J. Mak, D. P. Marshall, G. Madec, J. R. Maddison
Summary: The global ocean overturning circulation is crucial for climate evolution and is sensitive to the mesoscale eddy energy dissipation timescale. This study highlights the importance of constraining uncertainties associated with eddy energy dissipation for climate model projections over centennial timescales and paleoclimate simulations over millennial timescales.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Xiaoming Zhai, Zhibin Yang
Summary: It is found that eddies impinging on the western boundary excite boundary waves that propagate equatorward along the western boundary, leading to coherent meridional overturning circulation (MOC) anomalies equatorward of the incident eddy field. The magnitude and duration of eddy-induced MOC anomalies are variable and irregular, with implications for meridional heat transport variability across the latitudes.
Review
Meteorology & Atmospheric Sciences
Frank J. Pavia, C. Spencer Jones, Sophia K. Hines
Summary: This paper critically assesses the approaches used to determine the geometry of Atlantic circulation during the Last Glacial Maximum (LGM) and provides best practices for future research. The study highlights the complexity of interpreting geochemical proxies as water mass structure due to small-scale mixing processes in the ocean interior. It outlines promising paths for further ascertaining the LGM circulation structure.
JOURNAL OF CLIMATE
(2022)
Article
Geosciences, Multidisciplinary
Qianjiang Xing, Andreas Klocker, David Munday, Joanne Whittaker
Summary: This study demonstrates the crucial role of turbulent processes in setting the strength of the global ocean's deep-reaching Meridional Overturning Circulation (MOC) and explains the dynamics behind the changes in the lower cell of the MOC associated with the geological evolution of Southern Ocean gateways. The opening of a gateway leads to the abrupt onset of a vigorous, deep-reaching MOC, which decreases with further deepening of the gateway.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
D. J. Webb, P. Spence, R. M. Holmes, M. H. England
Summary: The study shows that anomalous changes in Southern Ocean wind patterns can lead to variations in the North Atlantic overturning circulation, with a more significant response observed in scenarios where the winds intensify poleward. The primary mechanism linking these changes is the propagation of baroclinic waves, with differences in the sign of the waves leading to contrasting impacts on the Atlantic Meridional Overturning Circulation (AMOC).
JOURNAL OF CLIMATE
(2021)
Article
Geosciences, Multidisciplinary
M. D. Thomas, A. Fedorov, N. J. Burls, W. Liu
Summary: Research suggests that North Pacific deep water formation and a Pacific meridional overturning circulation (PMOC) may have been active during the Pliocene epoch, different from the modern-day climate conditions. Most subducted North Pacific deep water upwells in the Southern Ocean, but around 15% upwells in the tropical Indo-Pacific Oceans, distinguishing the PMOC from the present-day AMOC. The connection to the Indian Ocean is relatively fast at about 250 years, while the connection to the tropical Pacific is slower, taking around 800 years.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Oceanography
Jan-Erik Tesdal, Graeme A. MacGilchrist, Rebecca L. Beadling, Stephen M. Griffies, John P. Krasting, Paul J. Durack
Summary: Two different climate models have been used to study the impact of wind stress and Antarctic ice sheet melting on the Southern Ocean meridional overturning circulation (SO MOC). The study shows that the largest impact is found in the lower limb of the SO MOC, associated with the formation of Antarctic Bottom Water (AABW), which is enhanced by wind and weakened by AIS meltwater perturbations. Both models indicate a reduction in AABW transport due to AIS melting, however, the higher resolution simulation shows a greater volume deflation of AABW south of 30°S.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Meteorology & Atmospheric Sciences
Anais Bretones, Kerim H. Nisancioglu, Mari F. Jensen, Ailin Brakstad, Shuting Yang
Summary: While the retreat of Arctic sea ice has become widespread, the potential weakening of the Atlantic meridional overturning circulation (AMOC) in response to global warming is still being debated. A long simulation study using the EC-Earth-Parallel Ice Sheet Model (PISM) climate model investigated the link between changes in Arctic sea ice cover and AMOC strength. The results showed that as the winter sea ice edge retreated, the Arctic meridional overturning circulation (ArMOC) strengthened, but the mixing in the Labrador and Greenland Seas reduced, causing a weakening of the AMOC. The location of deep-water formation was found to play a decisive role in the structure and strength of the ArMOC.
JOURNAL OF CLIMATE
(2022)
Article
Oceanography
Nicholas P. Foukal, Robert S. Pickart
Summary: This study presents the first continuous mooring records of the West Greenland Coastal Current (WGCC), which is a conduit of fresh, buoyant outflow from the Arctic Ocean and the Greenland Ice Sheet. The results show that the WGCC on the southwest Greenland shelf is a distinct current with strong variability in its lateral position. Additionally, the study finds that the WGCC has a similar strength to the East Greenland Coastal Current (EGCC), but transports less liquid freshwater due to its higher salinity.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Oceanography
Ashwita Chouksey, Alexa Griesel, Manita Chouksey, Carsten Eden
Summary: We investigate the impact of variation in isopycnal diffusivity on ocean circulation using a non-eddy-resolving model. Our findings show that changes in diffusivity have a surprisingly large effect on the strength of the Atlantic residual overturning circulation and the Antarctic Circumpolar Current. This highlights the importance of accurately representing isopycnal diffusion in models.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Oceanography
Chiung-Yin Chang, Malte F. Jansen
Summary: The study reveals a disagreement between existing scaling theories, partly explained by the distinct measurements of overturning strengths in the channel and basin scales under different external parameters.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Oceanography
Zhi Li, Matthew H. England, Sjoerd Groeskamp, Ivana Cerovecki, Yiyong Luo
Summary: The seasonal evolution of Subantarctic Mode Water (SAMW) volume is analyzed using kinematic and thermodynamic estimates, showing that the variability of SAMW volume is dominated by changes in the mixed layer. The formation of SAMW volume in the mixed layer is mainly influenced by air-sea buoyancy fluxes, entrainment, and northward Ekman transport across the Subantarctic Front. In the interior, SAMW formation is controlled by exchanges between the mixed layer and interior, mainly occurring during August-October, with strong regional variability in subduction hotspots.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Environmental Sciences
Henri F. Drake, Geoffrey Henderson
Summary: The article discusses the importance of climate science in driving both mitigation and adaptation to climate change, calling on physical climate scientists to consider the pathways through which their research improves societal welfare.
Article
Oceanography
R. L. Beadling, J. P. Krasting, S. M. Griffies, W. J. Hurlin, B. Bronselaer, J. L. Russell, G. A. MacGilchrist, J. -E. Tesdal, M. Winton
Summary: This study uses two coupled climate models to investigate the physical response of the Southern Ocean to changes in surface wind stress and Antarctic meltwater. The results demonstrate the strong influence of Antarctic meltwater on governing changes in the Antarctic shelf, with the Antarctic Slope Current playing a crucial role in these dynamics.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Oceanography
Houssam Yassin, Stephen M. Griffies
Summary: The study demonstrates that surface geostrophic velocity in regions with mixed layer instability is mainly induced by surface buoyancy anomalies. By considering variable stratification, the study shows that buoyancy anomalies can generate different dynamical regimes depending on the vertical structure of stratification. The different stratification structures result in different velocity fields and surface kinetic energy spectra.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Multidisciplinary Sciences
Benjamin A. Storer, Michele Buzzicotti, Hemant Khatri, Stephen M. Griffies, Hussein Aluie
Summary: The development of satellite altimetry has led to increased attention on the presence of mesoscale eddies in the ocean. This study introduces a new method to analyze larger scales and reveals the Antarctic Circumpolar Current as the dominant feature of the global circulation. The study also shows seasonal variations in length scales, with different kinetic energy peaks in spring and late summer in both hemispheres.
NATURE COMMUNICATIONS
(2022)
Review
Physics, Fluids & Plasmas
Hussein Aluie, Shikhar Rai, Hao Yin, Aarne Lees, Dongxiao Zhao, Stephen M. Griffies, Alistair Adcroft, Jessica K. Shang
Summary: The paper highlights the different roles of vorticity and strain in the transport of coarse-grained scalars at large scales of turbulence. It introduces a new multiscale gradient expansion method, and emphasizes that the contribution of subscale vorticity is solely a conservative advection.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Geosciences, Multidisciplinary
Jiaxu Zhang, Wei Cheng, Michael Steele, Wilbert Weijer
Summary: Recent progress in understanding Beaufort Gyre dynamics highlights the role of ice-ocean stress in stabilizing freshwater content over seasonal to interannual timescales, but the response of stratification and freshwater content to surface forcing over decadal timescales remains unclear.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Engineering, Ocean
N. V. Zilberman, M. Scanderbeg, A. R. Gray, P. R. Oke
Summary: This study aims to provide observation-based estimates of large-scale subsurface ocean circulation. By exploiting the drift of autonomous profiling floats, the inferred circulation at the parking depth is carefully isolated and combined with observations from over 11,000 floats to deliver a new dataset with unprecedented accuracy. The new estimates of subsurface currents are suitable for assessing global models, reanalyses, and forecasts, as well as constraining ocean circulation in data-assimilating models.
JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
(2023)
Article
Statistics & Probability
Beomjo Park, Mikael Kuusela, Donata Giglio, Alison Gray
Summary: Statistical analysis of ocean heat transport is complex due to incomplete large-scale data, spatiotemporal dynamics, and potential model errors. We present a comprehensive statistical framework for interpolating global ocean heat transport using Argo float measurements. We use a latent local Gaussian process regression and a two-stage fitting procedure to address the statistical challenges. Our approach provides data-driven global ocean heat transport fields that vary in space and time and can help understand dynamic phenomena like El Nino & La Nina. The framework and Argo-based estimates are validated with satellite products, showing realistic subsurface ocean heat transport estimates.
ANNALS OF APPLIED STATISTICS
(2023)
Article
Meteorology & Atmospheric Sciences
Adele K. Morrison, Wilma G. C. Huneke, Julia Neme, Paul Spence, Andrew McC. Hogg, Matthew H. England, Stephen M. Griffies
Summary: Winds around the Antarctic continental margin play a significant role in the local ocean stratification and circulation. By using a high-resolution global ocean-sea ice model, this study investigates the impact of zonal and meridional surface winds on the formation of dense shelf water and the temperature of continental shelf waters. The zonal easterly winds drive a southward Ekman transport, cooling the continental shelf. On the other hand, the meridional winds strengthen the abyssal overturning circulation through a sea ice advection mechanism.
JOURNAL OF CLIMATE
(2023)
Article
Multidisciplinary Sciences
Qian Li, Matthew H. England, Andrew McC. Hogg, Stephen R. Rintoul, Adele K. Morrison
Summary: The abyssal ocean circulation plays a crucial role in the global meridional overturning circulation, enabling the redistribution of heat, carbon, oxygen, and nutrients throughout the world ocean. Recent observations indicate that the abyssal ocean is experiencing warming at high southern latitudes, but the drivers and implications of this warming remain unclear. This study uses a high-resolution model to show that under a high-emissions scenario, Antarctic meltwater contributes to the contraction of Antarctic Bottom Water, leading to increased warming and aging of the abyssal ocean over the next 30 years. The results highlight the importance of Antarctic meltwater in shaping abyssal ocean circulation and emphasize the potential long-term impacts on global ocean biogeochemistry and climate.
Article
Oceanography
Jan-Erik Tesdal, Graeme A. MacGilchrist, Rebecca L. Beadling, Stephen M. Griffies, John P. Krasting, Paul J. Durack
Summary: Two different climate models have been used to study the impact of wind stress and Antarctic ice sheet melting on the Southern Ocean meridional overturning circulation (SO MOC). The study shows that the largest impact is found in the lower limb of the SO MOC, associated with the formation of Antarctic Bottom Water (AABW), which is enhanced by wind and weakened by AIS meltwater perturbations. Both models indicate a reduction in AABW transport due to AIS melting, however, the higher resolution simulation shows a greater volume deflation of AABW south of 30°S.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Oceanography
Christina Schmidt, Adele K. Morrison, Matthew H. England
Summary: Antarctic Bottom Water (AABW), a crucial part of global overturning circulation, has experienced both warming and freshening in recent decades, with significant interannual variability. The causes of this variability remain unclear due to limited measurements of ocean and air-sea-ice flux in the region. This study uses a global ocean-sea-ice model to simulate AABW formation and export from 1958 to 2018, showing strong interannual variability that is not consistent across different formation regions. The study highlights the importance of easterly winds in controlling AABW formation, emphasizing the need for longer and more comprehensive observational data to interpret trends accurately.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Geosciences, Multidisciplinary
Wilton Aguiar, Sang-Ki Lee, Hosmay Lopez, Shenfu Dong, Helene Seroussi, Dani C. Jones, Adele K. Morrison
Summary: Melting of the ice sheet in the Southern Ocean has implications for the formation and properties of the Antarctic Bottom Water (AABW). Models have been used to examine the effects of different spatial distributions and magnitudes of meltwater fluxes on AABW. The study finds that a realistic and spatially varying meltwater flux can sustain AABW with higher salinities compared to uniform meltwater flux simulations. Furthermore, the increasing meltwater discharge from the Antarctic ice sheet can contribute to the observed freshening of AABW.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Xiangdong Zhang, Han Tang, Jing Zhang, John E. Walsh, Erika L. Roesler, Benjamin Hillman, Thomas J. Ballinger, Wilbert Weijer
Summary: Intense cyclones in the Arctic have been observed more frequently in recent years, causing significant environmental and socioeconomic impacts. This study analyzed multiple reanalysis datasets and found an intensification of Arctic cyclone activity over the past seven decades. The study also identified various factors driving the increase in strong cyclones, including enhanced lower troposphere baroclinicity and amplified winter jet stream waves.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Joseph Schoonover, Wilbert Weijer, Jiaxu Zhang
Summary: In this paper, we present a new offline calculation software framework called FEOTS for tracer transport in the ocean. FEOTS is a set of tools that efficiently calculates tracer distributions using transport operators diagnosed from an ocean model. This paper demonstrates the transient modeling capabilities of FEOTS in the Argentine Basin, highlighting the challenges of capturing tracer transports using a non-linear advection scheme with impulse response functions. Future work will focus on improving computational efficiency, implementing a steady-state solver, and applying FEOTS to a model with unstructured grids.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
