A5011293520- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Polar Research and Ecology
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Marine and coastal ecosystems
- Winter Sports Injuries and Performance
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Seismic Waves and Analysis
- Landslides and related hazards
- Geological Studies and Exploration
- Ocean Waves and Remote Sensing
- Indigenous Studies and Ecology
- Mercury impact and mitigation studies
- Marine and environmental studies
- Isotope Analysis in Ecology
- Heavy metals in environment
- Underwater Acoustics Research
- Seismology and Earthquake Studies
- Seismic Imaging and Inversion Techniques
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Ocean Acidification Effects and Responses
- Environmental DNA in Biodiversity Studies
The University of Tokyo
2020-2024
Hokkaido University
2014-2022
Sphere Institute
2021-2022
Arctic Research Centre
2017-2020
Abstract In Greenland, tidewater glaciers discharge turbid subglacial freshwater into fjords, forming a plume near the calving front. To elucidate effects of this on nutrient and dissolved inorganic carbon transport to surface in these we conducted observational studies Bowdoin Glacier its fjord northwestern Greenland during summer 2016. Our results provide evidence macronutrient from deep front glacier. This is driven by formation resulting subsequent upwelling along glacier The water...
Abstract Glacial fjords in Greenland show high productivity owing to the runoff of meltwater from glaciers. Macronutrient dynamics (of nitrate, phosphate, and silicate) associated with subglacial discharge plumes front marine‐terminating glaciers are widely cited as important drivers summer phytoplankton blooms fjords. However, iron (Fe), an essential micronutrient for primary production, remain largely unstudied glacial To investigate role Fe supply processes fjords, a comprehensive survey...
Abstract An increasing body of work has shown the potential impacts subglacial discharge from marine‐terminating glaciers on marine environment around Greenland. Upwelling nutrients associated with rising buoyant plumes near front plays a key role in maintaining high productivity connected fjords. The response protist communities to discharges into fjords nevertheless remains poorly understood. Here we show data water properties, nutrients, and during two summers 2018 2019 Greenlandic fjord...
Abstract. The Arctic Laptev and East Siberian seas (LESS) have high biogeochemical activity. Nutrient inputs associated with river runoff shelf sediment–water exchange processes are vital for supporting primary production in the LESS. Relative to macronutrients, data on dissolved iron (dFe) manganese (dMn), which essential micronutrients producers, historically been sparse Some dFe dMn reportedly carried central by Transpolar Drift, a major current that directly transports Eurasian water,...
Abstract In Greenland, tidewater glaciers discharge turbid subglacial freshwater into fjords, forming plumes near the calving fronts, and these areas serve as an important foraging habitat for seabirds. To investigate effect of on assemblages surface feeders divers in a glacial fjord, we conducted boat-based seabird surveys, near-surface zooplankton samplings, hydrographic measurements at Bowdoin Fjord, northwestern Greenland July. Foraging (black-legged kittiwake Rissa tridactyla, glaucous...
Abstract Antarctic sea ice is an important temporal reservoir of iron which can boost primary production in the marginal zone during seasonal melt. While studies have reported that fast bears high concentrations due to proximity coastal sources, less clear are biogeochemical changes this pool undergoes late spring. Here we describe a 3‐week time series physical and data, including iron, from first‐year sampled near Davis Station (Prydz Bay, East Antarctica) austral spring 2015. Our study...
Measurements of underwater sound are still scarce in the rapidly changing Arctic. Tele-seismically detectable glacial earthquakes caused by iceberg calving have been known for nearly two decades but their levels remain undocumented. Here, we present near-source records from a kilometer-scale associated with earthquake. Records were obtained using an ocean-bottom lander deployed near front Greenlandic tidewater Bowdoin Glacier July 2019. An underwater-detonation-like signal overall duration...
Environments along the coast of Greenland are rapidly changing under influence a warming climate in Arctic. To better understand changes coastal environments, we performed researches Qaanaaq region northwestern as part ArCS (Arctic Challenge for Sustainability) Project. Mass loss ice caps and marine-terminating outlet glaciers were quantified by field satellite observations. Measurements sampling fjords revealed important role glacial meltwater discharge marine ecosystems. Flooding stream...
Abstract Subglacial discharge from marine-terminating glaciers in Greenland injects large volumes of freshwater and suspended sediment into adjacent fjord environments. Although the itself is nutrient poor, formation meltwater plumes can enhance marine biological production by stimulating upwelling nutrient-rich water. Despite importance to ecosystems, little known quantitative impact processes on phytoplankton growth, including effects local plumes, fjord-wide stirring mixing, sediments net...
A prototype OpenMetBuoy (OMB) was deployed alongside a commercial buoy in the central Arctic Ocean, north of Laptev Sea, where there are historically no wave observations available. The inter-buoy comparison showed that OMB measured heights and periods accurately, so data were used to study predictability wave–ice model. first event we studied when both buoys observed sudden decrease significant Hm0, which caused by change wind directions from along ice edge off-ice wind. Ocean Wave Analysis...
Abstract In the Arctic, subglacial discharge plumes have been recently recognised as a key driver of fjord-scale circulation. However, owing to danger that accompanies prolonged observations at plumes, no time-series data are available. Here, we present results showing chaotic and irregular dynamics plume revealed by continuous subsurface monitoring directly on calving front Greenlandic glacier. We found intense fluctuations in current scalars (temperature salinity), shallow deep tidal...
Abstract Shearing along subduction zones, laboratory experiments on analogue faults, and sliding glacier beds are all associated with aseismic co-seismic slip. In this study, an ocean-bottom seismometer is deployed near the terminus of a Greenlandic tidewater glacier, effectively insulating signal from extremely noisy surface seismic wavefield. Continuous, tide-modulated tremor related to ice speed recorded at bed glacier. When noise interference (for example, due strong winds) low, also...
An atmosphere-sea ice-ocean interaction study was conducted at the Saroma-ko Lagoon, Hokkaido, Japan from 27 February to 9 March 2021. Air-sea ice CO2 flux measurements were by eddy covariance and chamber methods together with meteorological observations. Sea cores collected understand between atmosphere under-ice water respect fluxes of heat biogeochemical components. Physical parameters such as temperature, salinity, structure, environmental DNA, concentrations gases, nutrients, trace...
Iron (Fe) in seawater is essential for marine phytoplankton. The bioavailability of Fe to phytoplankton largely depends on its chemical form seawater. Fe(II) an important component surface water because photochemical reduction processes are related the acquisition mechanism However, biogeochemical have not been thoroughly investigated. This study applied luminol chemiluminescence method directly determine acidified Kuroshio area, subarctic Pacific, and Bering Sea. We successfully obtained...
Abstract. Subglacial discharge has significant impacts on water circulation, material transport, and biological productivity in proglacial fjords of Greenland. To help clarify the fjord properties effect subglacial discharge, we investigated vertical mass profiles Bowdoin Fjord northwestern Greenland based summer hydrographic observations, including turbidity, 2014 2016. We estimated fraction from observational data interpreted observed differences plume behavior between two seasons with...
To evaluate the effects of meltwater discharge from marine-terminating glaciers on a fjord protist community in northwestern Greenland during summer, we investigated distribution, abundance and biomass their relationships with hydrographic parameters. In standing stock protists, dinoflagellates (46.4%) oligotrich ciliates (39.5%) were dominant throughout study region. With respect to vertical abundant surface layer, mainly due suitable food conditions (abundance diatom nanoflagellates). Near...
Abstract About 70% of Earth’s surface is covered by ocean, for which seismic observations are challenging. Seafloor seismology overcame this fundamental difficulty and radically transformed the earth sciences, as it expanded coverage networks revealed otherwise inaccessible features. At same time, there has been a recent increase in number studies on cryoseismology. These have yielded multiple discoveries but limited primarily to land ice-surface receivers. Near ice calving fronts, such...