A5103180893- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Polar Research and Ecology
- Atmospheric aerosols and clouds
- Geology and Paleoclimatology Research
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Landslides and related hazards
- Methane Hydrates and Related Phenomena
- Spaceflight effects on biology
- Climate variability and models
- Smart Materials for Construction
- Remote Sensing and Land Use
- Aerospace Engineering and Energy Systems
- Spacecraft and Cryogenic Technologies
- Impact of AI and Big Data on Business and Society
- Algorithms and Data Compression
- Solar Radiation and Photovoltaics
- Marine and Coastal Research
- Soil Moisture and Remote Sensing
- Thermal Analysis in Power Transmission
Japan Aerospace Exploration Agency
2016-2025
National Centre for Earth Observation
2018-2019
Meteorological Research Institute
2018
Chiba University
2014-2016
Tokyo Institute of Technology
2001
Tokushima University
1983
Areas of dark ice have appeared on the Greenland sheet every summer in recent years. These are likely to a great impact mass balance because their low albedo. We report annual and geographical variations bare areas that Ice Sheet from 2000 2014 by using MODIS satellite images. The July monthly mean extent showed positive trend over these 15 years, large variability ranging 89,975 km2 279,075 km2, 5% 16% entire sheet, respectively. also varied annually, 3,575 26,975 4% 10% extent....
Abstract Cryoconite holes are water-filled cylindrical formed on ablation ice surfaces and commonly observed glaciers worldwide. Temporal changes of cryoconite characteristically <5 cm in diameter were monitored with a time-lapse interval camera over 15 d during the melting season Qaanaaq Glacier northwest Greenland. The drastically changed their dimensions synchronously collapsed twice study period. When collapsed, coverage surface increased from 1.0 to 3.5% field view camera, then...
Spatial variations in impurities (cryoconite) on the glacier surface were investigated Qaanaaq Ice Cap and Tugto Glacier northwest Greenland melting season of 2012. Abundance ranged from 0.36 to 119 g m-2 (dry weight, mean:18.8 m-2) bare ice 0.01 8.7 (mean:3.6 snow at study sites. On (an outlet Cap) impurity abundance was greatest mid-elevations, with fewer upper lower Surface reflectivity lowest mid-elevation area, suggesting that substantially reduce albedo mid-elevations surfaces. Organic...
Abstract. To improve surface mass balance (SMB) estimates for the Greenland Ice Sheet (GrIS), we developed a 5 km resolution regional climate model combining Japan Meteorological Agency Non-Hydrostatic atmospheric Model and Snow Metamorphism Albedo Process (NHM–SMAP) with an output interval of 1 h, forced by Japanese 55-year reanalysis (JRA-55). We used in situ data to evaluate NHM–SMAP GrIS during 2011–2014 years. investigated two options lower boundary conditions atmosphere: offline...
Global Observing Satellite for Greenhouse gases and Water cycle (GOSAT-GW) is a polar-orbiting satellite carrying two mission instruments, Total Anthropogenic Natural emissions mapping SpectrOmeter-3 (TANSO-3) Advanced Microwave Scanning Radiometer 3 (AMSR3). TANSO-3 developed by Ministry of the Environment follow-on Greenhouse-gas Observation 2 (GOSAT-2) launched in 2018. AMSR3 Japan Aerospace Exploration Agency (JAXA) Change Mission-Water (GCOM-W) to keep continuity passive microwave...
The detection of thin-ice thickness using satellite microwave radiometers is a strong tool for estimating sea-ice production in coastal polynyas, which leads to dense water formation driving ocean thermohaline circulation. Thin-ice areas are classified into two ice types: active frazil, comprising frazil and open water, thin solid ice, relatively uniform ice. A algorithm AMSR-E has been developed classify these types estimate <20 cm. In this study, we validate the applicability successor,...
The accelerated melting of the Greenland ice sheet, driven by recent global warming, has attracted significant attention regarding long-term variations in its mass balance. While several analyses have utilized snow indicators derived from microwave brightness temperatures observed through satellites, there is a lack studies examining diurnal behavior these during season. Advanced Microwave Satellite Radiometer 2 (AMSR2) aboard Global Change Observation Mission &#8211; Water (GCOM-W)...
This paper presents a new snow parameter retrieval (SPR) algorithm for the Global Change Observation Mission-Climate/Second Generation Imager (GCOM-C/SGLI) instrument (2018-present). combines accurate radiative transfer model (RTM) simulations and Scientific Machine Learning (SciML) methods, Multi-Layer Neural-Network (MLNN) techniques in particular. It provides pixel-by-pixel optically equivalent grain size two layers (i.e., thin surface layer deep layer), impurity concentration broadband...
In order to better understand the source of minerals on dark-colored ice, located in Greenland ice sheet ablation zone, we analyzed Sr and Nd isotopic ratios cryoconite, which were collected from glaciers northwest southwest Greenland. We focused following: (i) comparison isotopes cyroconite with those sediments local distant areas, (ii) regional variations western Greenland, (iii) spatial across an individual a glacier. The mineral components cryoconite showed variable (87Sr/86Sr: 0.711335...
The mineralogical composition of cryoconite on a glacial surface was investigated six glaciers in northwest Greenland (Qaanaaq, Qaqortaq, Tugto, Bowdoin, Sun, and Scarlet Heart). X-ray diffraction analysis showed that the cryoconites mainly contained seven silicate minerals: hornblende, quartz, potassium feldspar, plagioclase, illite, kaolinite, chlorite. Semi-quantitative mineral Qaanaaq Glacier little variation among samples collected from five different elevations. This indicates minerals...
Abstract We developed a Handheld Integrating Sphere Snow Grain Sizer (HISSGraS) for field use to measure the specific surface area (SSA) of snow. In addition snow samples, HISSGraS can directly surfaces and pit walls. The basic measurement principle is same as that IceCube SSA instrument. retrieval algorithm from reflectance employs two conversion equations formulated using spherical nonspherical grain shape models. observed SSAs HISSGraS, gas adsorption method in snowfield Hokkaido, Japan....
Abstract Ocean phytoplankton are an important source of dimethyl sulfide, which influences marine cloud formation. Model studies suggest that declines in Arctic sea ice may lead to increased sulfide emissions, however observational support is lacking. Here, we present a 55-year high-resolution core record methane sulfonic acid flux, oxidation product from the southeast Greenland Ice Sheet. We infer temporal variations ocean emissions and find springtime (April–June) fluxes correlate well...
Accurate radiative transfer simulations of signals received by sensors deployed on satellite platforms for remote sensing purposes can be computationally demanding depending channel width and the spectral variation atmospheric surface optical properties. Therefore, methods that speed up such are desirable. While it is common practice to use "window" channels minimize influence gaseous absorption, impact underlying as well clouds aerosols has less attention. To reduce number monochromatic...
This paper presents a practical method for constructing more compact matrix structure of the precedence information used in new weak parsing. The parsing algorithm differs from conventional that relation .> signals sequence reduce actions, not just one. can be any grammars without degrading good error detection capability traditional parsers. It is shown by empirical results obtained matrices are very reasonable size and presented efficient.
We have been investigating the current imbalance problem comparing calculated result obtained by measurement of inductance distribution in multi-strand superconducting cable conductor using high accuracy LCR meter and measured actual it. So far, that had carried out at 1 kHz few Hz, respectively. As a result, experimental did not agree well with one. It was estimated discrepancy between both results due to error measurement. So, this time, we more precisely 100 and, also wider frequency...
Abstract. To improve surface mass balance (SMB) estimates for the Greenland Ice Sheet (GrIS), we developed a 5 km resolution regional climate model combining Japan Meteorological Agency Non-Hydrostatic atmospheric Model and Snow Metamorphism Albedo Process (NHM-SMAP) with an output interval of 1 h, forced by Japanese 55year Reanalysis (JRA-55). We used in situ data to evaluate NHM-SMAP GrIS during 2011–2014 years. investigated two options lower boundary conditions atmosphere, "off-line"...
北極域で現在急激に進行している温暖化は,海面上昇や大気の遠隔影響を通じて地球規模の環境変動をもたらすと考えられる.グリーンランド氷床の表面融解は様々な不確定性を含み,正確な将来予測を行う上で解明すべき課題となっている.地球温暖化のもとでグリーンランド氷床の大気,雪氷,雪氷微生物がどのように氷床変動に影響するかを明らかにするため,2011 年度から2019 年度にかけてSIGMA 及びSIGMA-II プロジェクトが実施された.また,平行してGRENE,ArCS といった大型の北極研究プロジェクトも実施され,日本のグリーンランド研究が一気に加速される状況になった.本稿ではSIGMA・SIGMA-II プロジェクト及び関連研究課題の成果について(1)大気・雪氷・雪氷微生物の現地観測,(2)アイスコア掘削,(3)衛星観測,(4)数値モデリングのカテゴリーに分けて解説する.さらに,これらの分野における現状の課題,最近開始されたArCS II雪氷課題へのつながり及び人材育成の重要性について述べる.