Journal of Glaciology最新文献_第7页

Fifty years of instrumental surface mass balance observations at Vostok Station, central Antarctica 南极中部沃斯托克站50年地表物质平衡仪器观测

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-09-04 DOI: 10.1017/jog.2023.53

A. Ekaykin, V. Lipenkov, N. Tebenkova

{"title":"Fifty years of instrumental surface mass balance observations at Vostok Station, central Antarctica","authors":"A. Ekaykin, V. Lipenkov, N. Tebenkova","doi":"10.1017/jog.2023.53","DOIUrl":"https://doi.org/10.1017/jog.2023.53","url":null,"abstract":"\u0000 We present the surface mass balance (SMB) dataset from Vostok Station's accumulation stake farms which provide the longest instrumental record of its kind obtained with a uniform technique in central Antarctica over the last 53 years. The snow build-up values at individual stakes demonstrate a strong random scatter related to the interaction of wind-driven snow with snow micro-relief. Because of this depositional noise, the signal-to-noise ratio (SNR) in individual SMB time series derived at single points (from stakes, snow pits or firn cores) is as low as 0.045. Averaging the data over the whole stake farm increases the SNR to 2.3 and thus allows us to investigate reliably the climatic variability of the SMB. Since 1970, the average snow accumulation rate at Vostok has been 22.5 ± 1.3 kg m−2 yr−1. Our data suggest an overall increase of the SMB during the observation period accompanied by a significant decadal variability. The main driver of this variability is local air temperature with an SMB temperature sensitivity of 2.4 ± 0.2 kg m−2 yr−1 K−1 (11 ± 2% K−1). A covariation between the Vostok SMB and the Southern Oscillation Index is also observed.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56961787","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

Bayesian parameter estimation in glacier mass-balance modelling using observations with distinct temporal resolutions and uncertainties 利用不同时间分辨率和不确定性观测资料进行冰川质量平衡模拟中的贝叶斯参数估计

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-31 DOI: 10.1017/jog.2023.62

Kamilla H. Sjursen, T. Dunse, Antoine Tambue, T. Schuler, L. Andreassen

{"title":"Bayesian parameter estimation in glacier mass-balance modelling using observations with distinct temporal resolutions and uncertainties","authors":"Kamilla H. Sjursen, T. Dunse, Antoine Tambue, T. Schuler, L. Andreassen","doi":"10.1017/jog.2023.62","DOIUrl":"https://doi.org/10.1017/jog.2023.62","url":null,"abstract":"\u0000 Empirical glacier mass-balance models are commonly used in assessments of glacier and runoff evolution. Recent satellite-borne geodetic mass-balance observations of global coverage facilitate large-scale model calibration that previously relied on sparse in situ observations of glacier mass change. Geodetic observations constitute temporally aggregated mass-balance signals with significant uncertainty, raising questions about the role of observations with different temporal resolutions and uncertainties in constraining model parameters. We employ a Bayesian approach and demonstrate the sensitivity of parameter values to commonly used mass-balance observations of seasonal, annual and decadal resolution with uncertainties characteristic to in situ and satellite-borne observations. For glaciers along a continentality gradient in Norway, the use of annual mass balances results in around 20% lower magnitude of modelled ablation and accumulation (1960–2020), compared to employing seasonal balances. Decadal mass balance also underestimates magnitudes of ablation and accumulation, but parameter values are strongly influenced by the prior distribution. The datasets yield similar estimates of annual mass balance with different margins of uncertainty. Decadal observations are afflicted with considerable uncertainty in mass-balance sensitivity due to high parameter uncertainty. Our results highlight the importance of seasonal observations when model applications require accurate magnitudes of ablation, e.g. to estimate meltwater runoff.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42240944","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

Surge-type glaciers in Kalaallit Nunaat (Greenland): distribution, temporal patterns and climatic controls Kalaallit Nunaat(格陵兰)的涌浪型冰川:分布、时间模式和气候控制

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-08-31 DOI: 10.1017/jog.2023.61

H. Lovell, J. Carrivick, O. King, J. Sutherland, J. Yde, C. M. Boston, Jakub Małecki

{"title":"Surge-type glaciers in Kalaallit Nunaat (Greenland): distribution, temporal patterns and climatic controls","authors":"H. Lovell, J. Carrivick, O. King, J. Sutherland, J. Yde, C. M. Boston, Jakub Małecki","doi":"10.1017/jog.2023.61","DOIUrl":"https://doi.org/10.1017/jog.2023.61","url":null,"abstract":"\u0000 We present the first systematic inventory of surge-type glaciers for the whole of Greenland compiled from published datasets and multitemporal satellite images and digital elevation models. The inventory allows us to define the spatial and climatic distribution of surge-type glaciers and to analyse the timing of surges from 1985 to 2019. We identified 274 surge-type glaciers, an increase of 37% compared to previous work. Mapping surge-type glacier distribution by temperature and precipitation variables derived from ERA5-Land reanalysis data shows that the west and east clusters occur in well-defined climatic envelopes. Analysis of the timing of surge active phases during the periods ~1985 to 2000 (T1) and ~2000 to 2019 (T2) suggests that overall surge activity is similar in T1 and T2, but there appears to be a reduction in surging in the west cluster in T2. Our climate analysis shows a coincident increase in mean annual and mean winter air temperature between T1 and T2. We suggest that as glaciers thin under current warming, some surge-type glaciers in the west cluster may be being prevented from surging due to (1) their inability to build-up sufficient mass and (2) a switch from a polythermal to a largely cold-based thermal regime.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47776439","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

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":" ","pages":""},"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":" ","pages":""},"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":" ","pages":""},"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":" ","pages":""},"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