A5019944689- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Climate variability and models
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Winter Sports Injuries and Performance
- Atmospheric and Environmental Gas Dynamics
- Landslides and related hazards
- Pleistocene-Era Hominins and Archaeology
- Geophysics and Gravity Measurements
- Geological Studies and Exploration
- Marine and fisheries research
- Astro and Planetary Science
- Hydrocarbon exploration and reservoir analysis
- Marine animal studies overview
- Polar Research and Ecology
- Marine and environmental studies
- Ocean Waves and Remote Sensing
- Scientific Research and Discoveries
- Ocean Acidification Effects and Responses
- Marine and coastal ecosystems
Japan Agency for Marine-Earth Science and Technology
2017-2025
Hokkaido University
2008-2024
The Graduate University for Advanced Studies, SOKENDAI
2024
University of Tasmania
2015-2020
Antarctic Climate and Ecosystems Cooperative Research Centre
2015-2020
The University of Tokyo
2008-2017
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
2014
Significance The Ross Sea is a major drainage basin for the Antarctic Ice Sheet and contains world’s largest ice shelf. Newly acquired swath bathymetry data sediment cores provide evidence two episodes of ice-shelf collapse. Two novel geochemical proxies, compound specific radiocarbon dating radiogenic beryllium ( 10 Be), constrain timing most recent widespread (∼280,000 km 2 ) breakup as having occurred in late Holocene. Three-dimensional ice-shelf/ocean modeling results comparison with...
We investigate basal melting of all Antarctic ice shelves by a circumpolar shelf‐sea ice‐ocean coupled model and estimate the total 770–944 Gt/yr under present‐day climate conditions. present comparison with previous observational modeling estimates for each shelf. Heat sources are largely different among shelves. Sensitivities to surface air warming enhanced westerly winds over Circumpolar Current investigated from series numerical experiments. In this strongly depends on but is hardly...
The Totten Glacier in East Antarctica, with an ice volume equivalent to >3.5 m of global sea-level rise, is grounded below sea level and, therefore, vulnerable ocean forcing. Here, we use bathymetric and oceanographic observations from previously unsampled parts the continental shelf reveal on-shelf warm water pathways defined by deep topographic features. Access Ice Shelf (TIS) cavity facilitated a break, broad depression on shelf, cyclonic circulation that carries inner troughs provide...
Using an ice‐ocean coupled model with fine horizontal resolution around East Antarctica, sea ice production and dense shelf water (DSW) formation in coastal polynyas are investigated. The reproduces well the locations of high there. DSW is formed over continental shelves under a number polynyas. A threshold density, beyond which net takes place, largely different among densest most vigorous occurs Cape Darnley Mertz‐Ninnis Glacier followed by somewhat less but still significant Prydz‐Barrier...
Abstract Warm Modified Circumpolar Deep Water (MCDW) from the Southern Ocean drives rapid basal melt of Totten Ice Shelf on Sabrina Coast (East Antarctica), affecting mass balance grounded Glacier. Recent observations show that MCDW intrudes onto continental shelf through a depression at break. Here we investigate such intrusions by combining (1) new oceanographic and bathymetric collected for two consecutive years profiling floats in south break, (2) measurements...
Ocean–cryosphere interactions along the Adélie and George V Land (AGVL) coast are investigated using a coupled ocean–sea ice–ice shelf model. The dominant feature of Mertz Glacier Tongue (MGT), located at approximately 145°E, was highly productive winter coastal polynya system, until its calving in February 2010 dramatically changed regional “icescape.” This study examines annual mean, seasonal, interannual variabilities sea ice production; basal melting MGT; shelves, large icebergs, fast...
Understanding ice shelf–ocean interaction is fundamental to projecting the Antarctic sheet response a warming climate. Numerical models are powerful tool for simulating this interaction, yet limited by inherent model weaknesses and scarce observations, leading parameterisations that unverified unvalidated below shelves. We explore how different simulate using 2nd Ice Shelf–Ocean Model Intercomparison Project (ISOMIP+) framework. Vertical discretisation resolution of ocean shown have...
Climate change alters the extent and structure of sea-ice environments, which affects how they function as a habitat for polar species. Identifying characteristics that serve indicators quality will be crucial to monitoring management climate impacts. In Southern Ocean, Antarctic krill is key prey species fishery target. Krill larvae depend upon habitats survive winter recruit population in spring. Existing observations lack sufficient spatiotemporal coverage quantify ones contribute...
Abstract Melting ice shelves around Antarctica control the massive input of freshwater into ocean and play an intricate role in global heat redistribution. The Amery Ice Shelf regulates wintertime sea-ice growth dense shelf water formation. We investigated warm Antarctic Surface Water melting its impact on water. Here we show that coastal summer 2016/17 was almost free, leading to higher surface temperatures. glacial meltwater fraction highest record, hypothesised be attributable anomalous...
Abstract We investigate spreading pathways of basal meltwater released from all Antarctic ice shelves using a circumpolar coupled shelf‐sea ice‐ocean model that reproduces major features the Southern Ocean circulation, including Circumpolar Current (ACC). Several independent virtual tracers are used to identify detailed meltwaters. The depend on formation sites, because meltwaters transported by local ambient ocean circulation. Meltwaters in Weddell and Amundsen‐Bellingshausen Seas...
Abstract. Societal adaptation to rising sea levels requires robust projections of the Antarctic Ice Sheet’s retreat, particularly due ocean-driven basal melting its fringing ice shelves. Recent advances in ocean models that simulate ice-shelf offer an opportunity reduce uncertainties ice–ocean interactions. Here, we compare several community-contributed, circum-Antarctic simulations highlight inter-model differences, evaluate agreement with satellite-derived melt rates, and examine...
Recent observations and model simulations show that the inflow of warm Circumpolar Deep Water (CDW) causes rapid significant melting thinning ice shelves West Antarctic Ice Sheet, contributing to ongoing increase in discharge grounded ice. This process is also thought contribute deglaciation Sheet after Last Glacial Maximum (LGM). However, role CDW a potential large-scale ice-mass loss East Antarctica largely unknown. In this study, we present new, well-dated sedimentary core records sheet...
Abstract Ocean circulation around the Antarctic coastal margins plays a critical role in heat delivery to Antarctica, melting ice shelves. However, until recently, satellite‐based sea‐level observations have been limited by presence of sea ice. With improved algorithms, it is now possible monitor fluctuations over most Southern Ocean, including ice‐covered areas. We identified several clockwise gyres along East satellite‐derived dynamic ocean topography (DOT). Singular value decomposition...
Abstract The spreading of dense shelf water (DSW) from Antarctic coastal margins to lower latitudes plays a vital role in the ocean thermohaline circulation and global climate system. Through enhanced localized sea ice production polynyas, cold saline DSW is formed over continental regions as precursor Bottom Water (AABW). However, detailed fate Southern Ocean still unclear. Here we conduct extensive passive tracer experiments using circumpolar ocean‐sea ice‐ice model investigate pathways...
Overall Antarctic sea ice extent in the 2016 spring attained a record minimum for satellite period , presenting an abrupt departure from maxima previous years and slight upward trend since 1979.In atmospheric conditions over Southern Ocean changed dramatically prevailing cold westerly anomalies summer to warm easterly spring.We conducted numerical experiments with ocean-sea model quantify major factors responsible unanticipated change 2016.Our successfully reproduces longterm increasing...
Abstract Much attention has been paid to ocean–cryosphere interactions over the Southern Ocean. Basal melting of Antarctic ice shelves reported be primary ablation process for sheets. Warm waters on continental shelf, such as Circumpolar Deep Water (CDW) and Surface (AASW), play a critical role in active shelf basal melting. However, temporal evolution mechanisms warm water intrusions throughout twentieth century early twenty-first have not rigorously examined are fully understood. Here, we...
Abstract Basal melting of the Antarctic ice shelves is an important factor in determining stability sheet. This study used climatic outputs atmosphere–ocean general circulation model to force a circumpolar ocean that resolves shelf cavity investigate response different conditions (i.e., doubling CO2 and Last Glacial Maximum conditions). Sensitivity experiments were also conducted roles both surface atmospheric change changes oceanic lateral boundary conditions. It was found rate basal melt...
Abstract Oceanic changes before and after the relocation of iceberg B9B calving Mertz Glacier Tongue (MGT) in February 2010 are examined on continental shelf off Adélie Land/George V Land coast, East Antarctica. Summer hydrographic observations, including stable oxygen isotope ratio (δ 18 O), 2001/2008 2011/2015 results a numerical model used. Along western flank MGT, temperature decreased between 2001 2015 for most water column Depression. δ O generally decreased, especially at MGT draft...
Abstract We estimate the sea-ice extent and basal melt of Antarctic ice shelves at Last Glacial Maximum (LGM) using a coupled ice-shelf-sea-ice-ocean model. The shape shelves, ocean conditions atmospheric surface LGM are different from those in present day; these derived an ice-shelf-ice-sheet model, sea-ice-ocean model climate for glacial simulations, respectively. winter sea is shown to extend up ∼7° latitude further equatorward than day. For summer, shows extensive cover Atlantic sector...