両極の国際連携：研究データの管理公開と利活用－Polar Data Journal の紹介－

令和4年度ROIS-DS-JOINT2022共同研究集会「オープンサイエンス時代の重力観測・データの流通と利活用」日時：2022年12月19日（月）13:25〜12月20日（火）12:30場所：情報・システム研究機構データサイエンス共同利用基盤施設DS棟1F，大会議室H108-1，オンライン主催：情報・システム研究機構データサイエンス共同利用基盤施設極域環境データサイエンスセンタ

Assessment of the Greenland ice sheet change (2011–2021) derived from CryoSat-2

The Greenland ice sheet melting status is critical for global sea level rise and climate change. Based on the CryoSat-2 altimetry data from 2011 to 2021, the 5 km × 5 km DEMs of the Greenland ice sheet were derived by adopting the kriging interpolation method. Then the changes in elevation and volume of the ice sheet were calculated by using the intersection method. The changes in the ice sheet were analysed, and the results show that: (1) The accuracy of the Greenland DEMs obtained based on satellite altimetry data is region-dependent, with better accuracy in inland areas and higher elevation errors in marginal areas. (2) The inland area elevation remains unchanged basically or even shows an increasing trend, and there is an apparent melting trend in the marginal area, especially on the west coast. The contribution of the ice sheet melting mainly comes from elevations below 2000 m. (3) The main body of the Greenland ice sheet is melting with an elevation change rate of −13.27 ± 0.86 cm·a−1 and a volume change rate of −202.47 ± 14.8 km³·a−1. The rate of the Greenland ice sheet thinning has slowed down compared with the changes from 2003 to 2009

ADSの概要と日本の北極研究プロジェクト及び南極地域観測隊との連携

令和4年度ROIS-DS-JOINT2022共同研究集会「オープンサイエンス時代の重力観測・データの流通と利活用」日時：2022年12月19日（月）13:25〜12月20日（火）12:30場所：情報・システム研究機構データサイエンス共同利用基盤施設DS棟1F，大会議室H108-1，オンライン主催：情報・システム研究機構データサイエンス共同利用基盤施設極域環境データサイエンスセンタ

昭和基地におけるローカル5G実証実験について

第19回南極設営シンポジウム2023年5月16日（火）Zoomウェビナーによるオンライン開催主催：国立極地研究

Interannual variability of surface bio-optical characteristics in the frontal zones of the Indian sector of the Southern Ocean during austral summer

Surface bio-optical constituents (Chl-a, light-absorption coefficient of phytoplankton (aph (443)), detritus (ad(443)), coloured dissolved organic matter (aCDOM(443))), and hydrographic variables were studied across the fronts along 57.5°E during 2011, 2013 and 2015 in the Indian sector of Southern Ocean to understand their interannual variability and phytoplankton pigment package effect. Latitudinal increases of Chl-a, aph(443), and aCDOM(443) were observed in 2011 and 2013. Mean Chl-a was higher in 2013 than in 2015 and 2011. The Chl-a specific absorption (a*ph(443)) latitudinally decreased implying ‘pigment package effect’ with increasing latitude. Interannually increase of aph blue (443)/red (675) ratio suggested higher non-photosynthetic absorption during 2013 and 2015 than in 2011. The relative contributions of bio-optical constituents to total absorption (at) showed interannual decrease in aph(443) and increase in aCDOM(443) and ad(443) inferring phytoplankton growth and decay phases. The robust aph(443)-Chl-a relationship during 2011 was used to derive aph(443) for other years, which holds good for in situ and satellite-derived counterparts. aCDOM(443) positively correlated with Chl-a and negatively with CDOM-spectral slope (S300-500), suggesting autochthonous sources. Satellite-retrieved Chl-a, aph(443) showed significant correlation (p < 0.001) with in situ data. This study provides baseline bio-optical data for understanding phytoplankton size-class, and improvement of bio-optical algorithms in this relatively inaccessible polar region

PCB containment using geosynthetics in Canada\u27s Arctic

Two funnel-and-gate permeable reactive barriers (PRBs) with settling ponds comprised of a composite liner (geomembrane and geosynthetic clay liners (GCL)) were installed at Resolution Island (BAF-5), Nunavut to contain residual polychlorinated biphenyls (PCBs) moving with the sediment and annual snowmelt. The long-term performance of the geosynthetics used in the PRB funnels is studied for physical integrity and diffusive barrier properties after nine years of operation. Exhumed geomembrane specimens are compared with virgin material by index testing: diffusive resistance to benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds, as well as puncture, burst, and tensile strength. Exhumed GCLs are evaluated concerning hydraulic conductivity, the mass of bentonite per unit area, and swell index. The migration of PCBs through the composite liner system by diffusion is modelled and the diffusive and sorptive properties of the geomembrane (Dg = 1.7 × 10−14 m2/s, Sgf = 160,000) and GCL (De = 3.1 × 10−10 m2/s, bentonite plus fibers layer Kd = 15 mL/g, cover geotextile Kd = 12,000 mL/g, and carrier geotextile Kd = 16,000 mL/g) were calculated. Modelling results estimate that the composite liner was successfully containing PCBs. This was confirmed by downgradient monitoring. The challenges of the location and terrain, PRB design, construction, and maintenance are discussed along with recommendations for designing PRBs in other remote and cold region environments

南極上空大気重力波の気球実験におけるイリジウム衛星通信データの解析システムの構築

極域データサイエンスに関する研究集会日時：2023年2月20日（月）11:00〜18:00場所：情報・システム研究機構データサイエンス共同利用基盤施設DS棟1F（大会議室H108），オンライン主催：情報・システム研究機構データサイエンス共同利用基盤施設極域環境データサイエンスセンタ

国土地理院におけるデータ共有に関する現状

令和4年度ROIS-DS-JOINT2022共同研究集会「オープンサイエンス時代の重力観測・データの流通と利活用」日時：2022年12月19日（月）13:25〜12月20日（火）12:30場所：情報・システム研究機構データサイエンス共同利用基盤施設DS棟1F，大会議室H108-1，オンライン主催：情報・システム研究機構データサイエンス共同利用基盤施設極域環境データサイエンスセンタ