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Over the past two decades, ice loss from the Greenland ice sheet (GrIS) has increased owing to enhanced surface melting and ice discharge to the ocean1-5. Whether continuing increased ice loss will accelerate further, and by how much, remains contentious6-9. A main contributor to future ice loss is the Northeast Greenland Ice Stream (NEGIS), Greenland's largest basin and a prominent feature of fast-flowing ice that reaches the interior of the GrIS10-12. Owing to its topographic setting, this sector is vulnerable to rapid retreat, leading to unstable conditions similar to those in the marine-based setting of ice streams in Antarctica13-20. Here we show that extensive speed-up and thinning triggered by frontal changes in 2012 have already propagated more than 200 km inland. We use unique global navigation satellite system (GNSS) observations, combined with surface elevation changes and surface speeds obtained from satellite data, to select the correct basal conditions to be used in ice flow numerical models, which we then use for future simulations. Our model results indicate that this marine-based sector alone will contribute 13.5-15.5 mm sea-level rise by 2100 (equivalent to the contribution of the entire ice sheet over the past 50 years) and will cause precipitous changes in the coming century. This study shows that measurements of subtle changes in the ice speed and elevation inland help to constrain numerical models of the future mass balance and higher-end projections show better agreement with observations.

The land ice contribution to global mean sea level rise has not yet been predicted1 using ice sheet and glacier models for the latest set of socio-economic scenarios, nor using coordinated exploration of uncertainties arising from the various computer models involved. Two recent international projects generated a large suite of projections using multiple models2-8, but primarily used previous-generation scenarios9 and climate models10, and could not fully explore known uncertainties. Here we estimate probability distributions for these projections under the new scenarios11,12 using statistical emulation of the ice sheet and glacier models. We find that limiting global warming to 1.5 degrees Celsius would halve the land ice contribution to twenty-first-century sea level rise, relative to current emissions pledges. The median decreases from 25 to 13 centimetres sea level equivalent (SLE) by 2100, with glaciers responsible for half the sea level contribution. The projected Antarctic contribution does not show a clear response to the emissions scenario, owing to uncertainties in the competing processes of increasing ice loss and snowfall accumulation in a warming climate. However, under risk-averse (pessimistic) assumptions, Antarctic ice loss could be five times higher, increasing the median land ice contribution to 42 centimetres SLE under current policies and pledges, with the 95th percentile projection exceeding half a metre even under 1.5 degrees Celsius warming. This would severely limit the possibility of mitigating future coastal flooding. Given this large range (between 13 centimetres SLE using the main projections under 1.5 degrees Celsius warming and 42 centimetres SLE using risk-averse projections under current pledges), adaptation planning for twenty-first-century sea level rise must account for a factor-of-three uncertainty in the land ice contribution until climate policies and the Antarctic response are further constrained.

The Northeast Greenland Ice Stream (NEGIS) has experienced substantial dynamic thinning in recent years. Here, we examine the evolving behavior of NEGIS, with focus on summer speedup at Zachariae Isstrøm, one of the NEGIS outlet glaciers, which has exhibited rapid retreat and acceleration, indicative of its vulnerability to changing climate conditions. Through a combination of Sentinel‐1 data, in‐situ GPS observations, and numerical ice flow modeling from 2007, we investigate the mechanisms driving short‐term changes. Our analysis reveals a summer speedup in ice flow both near the terminus and inland, with satellite data detecting changes up to 60 km inland, while GPS data capture changes up to 190 km inland along the glacier center line. We attribute this summer speedup to variations in subglacial hydrology, where surface meltwater runoff influences basal friction over the melt season. Incorporating subglacial hydrology into numerical models makes it possible to replicate observed ice velocity patterns. Plain Language Summary: The Northeast Greenland Ice Stream (NEGIS), a crucial part of the Greenland Ice Sheet, has been experiencing significant dynamic thinning recently. This study focuses on the summer speedup of Zachariae Isstrøm (ZI), one of NEGIS's outlet glaciers, which is rapidly retreating and accelerating, highlighting its sensitivity to climate change. Utilizing Sentinel‐1 satellite data, in‐situ GPS observations, and numerical ice flow modeling, we explore the mechanisms behind short‐term dynamic changes. We find that satellite data reveals short‐term summer (June to August) fluctuations in ice flow speed near the glacier terminus and up to 50–70 km inland. However, GPS data shows that this speedup extends further inland, up to at least 190 km along the main flow line. Only GPS data can detect the smaller‐scale summer speedups in these inland regions, providing critical observations for validating ice flow models. We determine that the seasonal acceleration of ice velocity at Zachariae Isstrøm is due to variations in subglacial hydrology, where surface meltwater runoff reduces basal friction by altering the subglacial hydrologic system during the melt season. Additionally, our study highlights that these findings are applicable beyond NEGIS, with similar speedup patterns observed in other Greenland glaciers. Key Points: GPS data reveal summer speed up at least 190 km inland along the main flowline of Zachariae IsstrømSubglacial hydrology is the main driver of the summer speedup near the terminus and deep inlandRecord high warming in 2019 led to a more intense and longer duration of the summer speedup [ABSTRACT FROM AUTHOR]

This study aims to propose a method for constructing basic digital twin data in South Korea by adhering to international standards and by utilizing publicly available data. Specifically, the study focuses on designing and proposing a digital twin data model for buildings, as building-related digital twin data are the most applicable among the basic digital twin data. To achieve this, the first section provides essential background information, introduces concepts and requirements related to basic digital twin data, and offers a brief overview of City Geography Markup Language (CityGML). The second section explains the methodology and the data used in this study. The third section presents the main findings: the selection of public data (building data) for constructing basic digital twin data, the mapping process using CityGML, and the creation of Unified Modeling Language (UML) diagrams. The fourth section discusses these findings. Finally, the conclusion and recommendations for future research are provided. This approach enhances the accuracy of building-related digital twin data and supports the use of digital twin services in both public and private sectors by enabling various spatial analyses. [ABSTRACT FROM AUTHOR]

In this study, the determination of iodine in 123 different types of foods was conducted. Iodine-selective electrode, microwave digestion/inductively coupled plasma mass spectrometry and tetramethylammonium hydroxide extraction/ inductively coupled plasma mass spectrometry (TMAH/ICP-MS) methods were tested to achieve the highest recoveries for the determination of iodine. Among them, TMAH/ICP-MS method was the most effective with respect to analytical recoveries (90-99%), limits of detection (0.013 [micro]g/kg) and quantification (0.04 [micro]g/kg) values. The intra- and inter-day relative standard deviations for iodine SRM were, Author(s): Jinbong Hwang [sup.1], Ji-Su Park [sup.1], So Young Kim [sup.1], Nho-Eul Song [sup.1], Miyoung Yoo [sup.1], Youngmin Choi [sup.2], Jin-Sik Nam [sup.3], Dongwon Seo [sup.1] Author Affiliations: (1) grid.418974.7, [...]