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Ice ridge evolution: Investigation in-situ and computer simulations
No full textThe article presents a two-dimensional three-layer non-stationary thermodynamic model allowing to calculate the annual variation (thermodynamic evolution) of the ice ridge using external meteorological and hydrological parameters as well as the information on the initial ice ridge porosity. For the test model simulation, the results of the study of morphometric characteristics of the ice ridge carried out in May-June 2011 and in April 2012 at « North Pole −38» and «North Pole −39» drifting stations were used. These studies were conducted using electric thermal drilling with computer recording of the penetration rate. Boreholes were drilled along the cross-section of the ridge crest at 0.5 m intervals. Cross-sectional profiles of ice ridge are illustrated. Applying the proposed model, it was possible to adequately reproduce the observed evolutionary changes in the main morphometric parameters (sail height, keel depth, thickness of the consolidated layer) of the investigated ice ridge.journal articl
Retrieving compressive sea ice strength in the Beaufort Sea using the inverse visco-plastic model
No full textWe apply a simplified 2d Visco-Plastic (VP) sea ice model with a spatially variable representation of the sea ice rheological parameters for retrieving maximum compressive sea ice strength from satellite and in situ observations. A set of Observing System Simulation Experiments (OSSEs) demonstrates feasibility of optimizing rheological parameter of the VP sea ice model through the variational data assimilation approach during the periods of strong sea ice convergence if accurate sea ice observations are available. Following this strategy, the developed variational data assimilation VP model was applied to the sea ice velocity (https://nsidc.org/data/nsidc-0116/v ersions/4), sea ice concentration (https://nsidc.org/data/) and CryoSat-2 sea ice thickness observations collected in the vicinity of three moorings in the Beaufort Sea during periods of intensive sea ice convergence. Ice velocities from moorings and atmospheric wind speed (NCEP-NCAR) were used as well. Our results show that conventional maximum compressive sea ice strength (Hibler, 1979) may depend on sea ice thickness or other parameters partly controlled by the sea ice thickness, which is driven by the seasonal cycle.journal articl
Report on the geological field survey in the regions of Lützow-Holm Bay, Prince Olav Coast and Enderby Land, 2023-2024(JARE-65)
Get PDF第65 次日本南極地域観測隊（JARE-65）では，2023-2024の夏期期間にリュツォ・ホルム湾，プリンスオラフ海岸及びエンダビーランドにおいて地質調査を行った．調査隊のメンバーは，地質研究者4 名で構成され，第65次夏期観測では，「しらせ」搭載ヘリコプターと共に観測隊チャーターの小型ヘリコプターによる野外調査の支援がなされた．本稿では，観測計画を実施するための主に設営面での計画，準備，そして行動経過について報告する．The 65th Japanese Antarctic Research Expedition (JARE-65) conducted geological field surveys in Lützow-Holm Bay, Prince Olav Coast and Enderby Land regions during the 2023-2024 austral summer season. The field party consisted of four geologists. A small helicopter in addition to Shirase's big helicopter were used to support field parties during the summer operations conducted by JARE-65. This report summarizes preparations for field operations and activities of the geological team.departmental bulletin pape
Silica minerals in eucrites: Implication for crystallization and metamorphic history of Vestan crust
Get PDFThe 15th Symposium on Polar Science/Ordinary sessions [OA] Antarctic Meteorite, Thu. 5 Dec. / 3F Conference room, The Institute of Statistical Mathematicsconference outpu
Magnetic signature of the four paired Miller Range nakhlites MIL 03346, MIL 090030, MIL 090032 and MIL 090136.
Get PDFThe 15th Symposium on Polar Science/Ordinary sessions [OA] Antarctic Meteorite, Thu. 5 Dec. / Entrance Hall (1st floor), National Institute of Polar Researchconference outpu
Recovering true size distribution of the chondrules from two-dimensional plane sections close to each other
Get PDFThe 15th Symposium on Polar Science/Ordinary sessions [OA] Antarctic Meteorite, Thu. 5 Dec. / Entrance Hall (1st floor), National Institute of Polar Researchconference outpu
Bi-directional Neural Network for Polar Weather Forecasting
Get PDFThe 15th Symposium on Polar Science/Interdisciplinary sessions [ID] Polar data science, Thu. 5 Dec. / 3F Conference room, National Institute of Polar Researchconference outpu
Highly active ice-nucleating particles increased with surface warming over Svalbard
Get PDFThe 15th Symposium on Polar Science/Ordinary sessions [OB] Polar biology, Wed. 4 Dec. / 3F Conference room, The Institute of Statistical Mathematicsconference outpu