Journal of Glaciology最新文献_第10页

Characterising the ice sheet surface in Northeast Greenland using Sentinel-1 SAR data 利用Sentinel-1 SAR数据表征格陵兰东北部冰盖表面

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-31 DOI: 10.1017/jog.2023.64

Qingying Shu, Rebecca Killick, A. Leeson, C. Nemeth, X. Fettweis, A. Hogg, David Leslie

{"title":"Characterising the ice sheet surface in Northeast Greenland using Sentinel-1 SAR data","authors":"Qingying Shu, Rebecca Killick, A. Leeson, C. Nemeth, X. Fettweis, A. Hogg, David Leslie","doi":"10.1017/jog.2023.64","DOIUrl":"https://doi.org/10.1017/jog.2023.64","url":null,"abstract":"\u0000 Over half of the recent mass loss from the Greenland ice sheet, and its associated contribution to global sea level rise, can be attributed to increased surface meltwater runoff, with the remainder a result of dynamical processes such as calving and ice discharge. It is therefore important to quantify the distribution of melting on the ice sheet if we are to adequately understand past ice sheet change and make predictions for the future. In this article, we present a novel semi-empirical approach for characterising ice sheet surface conditions using high-resolution synthetic aperture radar (SAR) backscatter data from the Sentinel-1 satellite. We apply a state-space model to nine sites within North-East Greenland to identify changes in SAR backscatter, and we attribute these to different surface types with reference to optical satellite imagery and meteorological data. A set of decision-making rules for labelling ice sheet melting states are determined based on this analysis and subsequently applied to previously unseen sites. We show that our method performs well in (1) recognising some of the ice sheet surface types such as snow and dark ice and (2) determining whether the surface is melting or not melting. Sentinel-1 SAR data are of high spatial resolution; thus, in developing a method to identify the state of the surface from these data, we improve our capability to understand the variation of ice sheet melting across time and space.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45804716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Remote sensing of glacier change (1965–2021) and identification of surge-type glaciers on Severnaya Zemlya, Russian High Arctic 俄罗斯高北极Severnaya Zemlya冰川变化遥感（1965–2021）和浪涌型冰川识别

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-17 DOI: 10.1017/jog.2023.60

Holly Wytiahlowsky, C. Stokes, D. Evans

{"title":"Remote sensing of glacier change (1965–2021) and identification of surge-type glaciers on Severnaya Zemlya, Russian High Arctic","authors":"Holly Wytiahlowsky, C. Stokes, D. Evans","doi":"10.1017/jog.2023.60","DOIUrl":"https://doi.org/10.1017/jog.2023.60","url":null,"abstract":"Glaciers in the Russian High Arctic have undergone accelerated mass loss due to atmospheric and oceanic warming in the Barents–Kara Sea region. Most studies have concentrated on the western Barents–Kara sector, despite evidence of accelerating mass loss as far east as Severnaya Zemlya. However, long-term trends in glacier change on Severnaya Zemlya are largely unknown and this record may be complicated by surge-type glaciers. Here, we present a long-term assessment of glacier change (1965–2021) on Severnaya Zemlya and a new inventory of surge-type glaciers using declassified spy-satellite photography (KH-7/9 Hexagon) and optical satellite imagery (ASTER, Sentinel-2A, Landsat-4/5 TM and 8 OLI). Glacier area reduced from 17 053 km2 in 1965 to 16 275 in 2021 (−5%; mean: −18%, max: −100%), with areal shrinkage most pronounced at land-terminating glaciers on southern Severnaya Zemlya, where there is a recent (post-2010s) increase in summer atmospheric temperatures. We find that surging may be more widespread than previously thought, with three glaciers classified confirmed as surge-type, eight as likely to have surged and nine as possible, comprising 11% of Severnaya Zemlya's 190 glaciers (37% by area). Under continued warming, we anticipate accelerated retreat and increased likelihood of surging as basal thermal regimes shift.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48841085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Calving, ice flow, and thickness of outlet glaciers controlled by land-fast sea ice in Lützow-Holm Bay, East Antarctica 南极洲东部吕措-霍尔姆湾陆地快速海冰控制的出口冰川的崩解、冰流和厚度

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-14 DOI: 10.1017/jog.2023.59

Ken Kondo, S. Sugiyama

{"title":"Calving, ice flow, and thickness of outlet glaciers controlled by land-fast sea ice in Lützow-Holm Bay, East Antarctica","authors":"Ken Kondo, S. Sugiyama","doi":"10.1017/jog.2023.59","DOIUrl":"https://doi.org/10.1017/jog.2023.59","url":null,"abstract":"\u0000 To investigate the mechanisms driving recent changes in outlet glaciers in Antarctica, we measured the glacier front position, flow velocity and surface elevation of five outlet glaciers flowing into Lützow-Holm Bay in East Antarctica. After a steady advance from 2008 to 2015, all the glaciers synchronously retreated by 0.4–6.0 km between 2016 and 2018. The initiation of the retreat coincided with the breakup of land-fast sea ice in Lützow-Holm Bay in 2016, which resulted in the largest sea-ice loss in the region since 1998. Similar flow variations and surface elevation changes were observed near the grounding line of Shirase, Skallen and Telen glaciers. The slowdown in 2011–15 (by 13%) and the speedup in 2016–18 (by 7%) coincided with the respective increase and decrease in surface elevation. Simultaneous retreat and acceleration after the land-fast sea-ice breakup implies that sea ice has a significant influence on glacier dynamics. Thickening/thinning observed near the grounding line was attributed to a reduced/enhanced stretching flow regime during the deceleration/acceleration period. Our results demonstrate that land-fast sea ice affects not only terminus positions, but also the flow speed and ice thickness of the Antarctic glaciers.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48231587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Amundsen Sea Embayment ice-sheet mass-loss predictions to 2050 calibrated using observations of velocity and elevation change 阿蒙森海海湾冰盖质量损失预测到2050年校准使用观测速度和海拔变化

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-14 DOI: 10.1017/jog.2023.57

S. Bevan, S. Cornford, Lin Gilbert, Inès N. Otosaka, Daniel F. Martin, Trystan Surawy-Stepney

引用次数: 1

Ocean wave blocking by periodic surface rolls fortifies Arctic ice shelves 周期性的海面翻滚阻挡了海浪，巩固了北极冰架

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-14 DOI: 10.1017/jog.2023.58

Peter Nekrasov, D. Macayeal

引用次数: 0

Antarctic iceberg melt rate variability and sensitivity to ocean thermal forcing 南极冰山融化速率的可变性和对海洋热强迫的敏感性

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-14 DOI: 10.1017/jog.2023.54

E. Enderlin, C. Moffat, Emily E. Miller, Adam Dickson, Caitlin Oliver, Mariama C. Dryák-Vallies, Rainey Aberle

{"title":"Antarctic iceberg melt rate variability and sensitivity to ocean thermal forcing","authors":"E. Enderlin, C. Moffat, Emily E. Miller, Adam Dickson, Caitlin Oliver, Mariama C. Dryák-Vallies, Rainey Aberle","doi":"10.1017/jog.2023.54","DOIUrl":"https://doi.org/10.1017/jog.2023.54","url":null,"abstract":"\u0000 Changes in iceberg calving fluxes and oceanographic conditions around Antarctica have likely influenced the spatial and temporal distribution of iceberg fresh water fluxes to the surrounding ocean basins. However, Antarctic iceberg melt rate estimates have been limited to very large icebergs in the open ocean. Here we use a remote-sensing approach to estimate iceberg melt rates from 2011 to 2022 for 15 study sites around Antarctica. Melt rates generally increase with iceberg draft and follow large-scale variations in ocean temperature: maximum melt rates for the western peninsula, western ice sheet, eastern ice sheet and eastern peninsula are ~50, ~40, ~5 and ~5 m a−1, respectively. Iceberg melt sensitivity to thermal forcing varies widely, with a best-estimate increase in melting of ~24 m a−1°C−1 and range from near-zero to ~100 m a−1°C−1. Variations in water shear likely contribute to the apparent spread in thermal forcing sensitivity across sites. Although the sensitivity of iceberg melt rates to water shear prevents the use of melt rates as a proxy to infer coastal water mass temperature variability, additional coastal iceberg melt observations will likely improve models of Southern Ocean fresh water fluxes and have potential for subglacial discharge plume mapping.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47849413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geothermal heat flow from borehole measurements at the margin of Princess Elizabeth Land (East Antarctic Ice Sheet) 伊丽莎白公主地（南极东部冰盖）边缘钻孔测量的地热流

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-07 DOI: 10.1017/jog.2023.43

P. Talalay, D. Gong, Xiaopeng Fan, Yazhou Li, G. Leitchenkov, B. Li, Nan Zhang, Rusheng Wang, Yang Yang, Jialin Hong

引用次数: 0

A comparison of contemporaneous airborne altimetry and ice-thickness measurements of Antarctic ice shelves 南极冰架同时期空中测高和冰厚测量的比较

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-03 DOI: 10.1017/jog.2023.49

Allison M. Chartrand, I. Howat

{"title":"A comparison of contemporaneous airborne altimetry and ice-thickness measurements of Antarctic ice shelves","authors":"Allison M. Chartrand, I. Howat","doi":"10.1017/jog.2023.49","DOIUrl":"https://doi.org/10.1017/jog.2023.49","url":null,"abstract":"\u0000 Estimates of ice shelf mass loss are typically based on surface height measurements, assuming hydrostatic equilibrium and estimated firn thickness. Recent investigations, however, challenge the assumption that ice shelves are freely floating, particularly in proximity to narrow structures such as basal channels and shear margins. We compare contemporaneous measurements of Antarctic ice shelf thickness, from ice-penetrating radar, to freeboard height, from laser altimetry, acquired during multiple airborne surveys. On average, the hydrostatic thickness differs from observed thickness by at least ~17 ± 98 m, but this difference varies well beyond the propagated error within and among ice shelves, and depends on the corrections applied. We find that uncertainty in firn thickness can account for most, but not all, of the imbalance. Overall, errors in hydrostatic thickness do not significantly impact estimated basal melt rates. Our results indicate that localized approaches to estimating ice shelf thickness and rates of change are not applicable at large scales, and vice versa, and point to the need for more abundant and accurate firn and ice thickness measurements to improve estimates and predictions of ice shelf mass loss.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43532270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ice-flow perturbation analysis: a method to estimate ice-sheet bed topography and conditions from surface datasets 冰流摄动分析:一种从地表数据集估计冰盖床地形和条件的方法

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-03 DOI: 10.1017/jog.2023.50

Helen Ockenden, R. Bingham, Andrew Curtis, D. Goldberg

{"title":"Ice-flow perturbation analysis: a method to estimate ice-sheet bed topography and conditions from surface datasets","authors":"Helen Ockenden, R. Bingham, Andrew Curtis, D. Goldberg","doi":"10.1017/jog.2023.50","DOIUrl":"https://doi.org/10.1017/jog.2023.50","url":null,"abstract":"\u0000 One of the largest contributors to uncertainty in predictions of sea-level rise from ice-sheet models is a lack of knowledge about the bed topography beneath ice sheets. Bed topography maps are normally made by interpolating between linear radar surveys using methods that include kriging, mass conservation and flowline diffusion, all of which may miss influential mesoscale (2–30 km) bedforms. Previous works have explored an Ice-Flow Perturbation Analysis (IFPA) approach for estimating bed topography using the surface expression of these mesoscale bedforms. Using regions of Pine Island Glacier that have been intensively surveyed by ice-penetrating radar as test sites, and a refined IFPA methodology, we find that IFPA detects bedforms capable of influencing ice flow which are not represented in Bedmachine Antarctica and other interpolated bed products. We further explore the ability of IFPA to estimate relative bed slipperiness, finding higher slipperiness in the main trunk and tributaries. Alongside other methods which estimate ice thickness, bed topography maps from IFPA have the potential to constrain projections of future sea-level rise, especially where radar data are sparse.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41526673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

JOG volume 69 issue 276 Cover and Back matter JOG卷69期276封面和封底

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-07-28 DOI: 10.1017/jog.2023.56

引用次数: 0