Journal of Glaciology最新文献_第3页

Meteorological drivers of melt at two nearby glaciers in the McMurdo Dry Valleys of Antarctica 南极洲麦克默多干谷附近两个冰川融化的气象驱动因素

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-18 DOI: 10.1017/jog.2023.98

Marte G. Hofsteenge, Nicolas J. Cullen, Jonathan P. Conway, Carleen H. Reijmer, Michiel R. van den Broeke, Marwan Katurji

{"title":"Meteorological drivers of melt at two nearby glaciers in the McMurdo Dry Valleys of Antarctica","authors":"Marte G. Hofsteenge, Nicolas J. Cullen, Jonathan P. Conway, Carleen H. Reijmer, Michiel R. van den Broeke, Marwan Katurji","doi":"10.1017/jog.2023.98","DOIUrl":"https://doi.org/10.1017/jog.2023.98","url":null,"abstract":"<p>We study the meteorological drivers of melt at two glaciers in Taylor Valley, Antarctica, using 22 years of weather station observations and surface energy fluxes. The glaciers are located only 30 km apart, but have different local climates; Taylor Glacier is generally drier and windier than Commonwealth Glacier, which receives more snowfall due to its proximity to the coast. Commonwealth Glacier shows more inter-annual melt variability, explained by variable albedo due to summer snowfall events. A significant increase in surface melt at Commonwealth Glacier is associated with a decrease in summer minimum albedo. Inter-annual variability in melt at both glaciers is linked to degree-days above freezing during föhn events, occurring more frequently at Taylor Glacier. At Taylor Glacier melt occurs most often with positive air temperatures, but föhn conditions also favour sublimation, which cools the surface and prevents melt for the majority of the positive air temperatures. At Commonwealth Glacier, most of the melt instead occurs with sub-zero air temperatures, driven by strong solar radiative heating. Future melt at Taylor Glacier will likely be more sensitive to changes in föhn events, while Commonwealth Glacier will be impacted more by changes in near coastal weather, where moisture inputs can drive cloud cover, snowfall and change albedo.</p>","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"108 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138715827","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

Improved representation of laminar and turbulent sheet flow in subglacial drainage models 改进冰川下排水模型中层流和湍流片流的表示方法

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-12 DOI: 10.1017/jog.2023.103

Tim Hill, G. Flowers, Matthew J. Hoffman, Derek Bingham, M. Werder

引用次数: 0

Radar internal reflection horizons from multisystem data reflect ice dynamic and surface accumulation history along the Princess Ragnhild Coast, Dronning Maud Land, East Antarctica 来自多系统数据的雷达内部反射水平面反映了南极洲东部德龙宁毛德地拉格恩希尔德公主海岸的冰层动态和地表堆积历史

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-12 DOI: 10.1017/jog.2023.93

Inka Koch, Reinhard Drews, Steven Franke, Daniela Jansen, Falk Marius Oraschewski, Leah Sophie Muhle, Vjeran Višnjević, Kenichi Matsuoka, Frank Pattyn, Olaf Eisen

{"title":"Radar internal reflection horizons from multisystem data reflect ice dynamic and surface accumulation history along the Princess Ragnhild Coast, Dronning Maud Land, East Antarctica","authors":"Inka Koch, Reinhard Drews, Steven Franke, Daniela Jansen, Falk Marius Oraschewski, Leah Sophie Muhle, Vjeran Višnjević, Kenichi Matsuoka, Frank Pattyn, Olaf Eisen","doi":"10.1017/jog.2023.93","DOIUrl":"https://doi.org/10.1017/jog.2023.93","url":null,"abstract":"<p>Ice shelves, which regulate ice flow from the Antarctic ice sheet towards the ocean, are shaped by spatiotemporal patterns of surface accumulation, surface/basal melt and ice dynamics. Therefore, an ice dynamic and accumulation history are imprinted in the internal ice stratigraphy, which can be imaged by radar in the form of internal reflection horizons (IRHs). Here, IRHs were derived from radar data combined across radar platforms (airborne and ground-based) in coastal eastern Dronning Maud Land (East Antarctica), comprising three ice rises and adjacent two ice shelves. To facilitate interpretation of dominant spatiotemporal patterns of processes shaping the local IRH geometry, traced IRHs are classified into three different types (laterally continuous, discontinuous or absent/IRH-free). Near-surface laterally continuous IRHs reveal local accumulation patterns, reflecting the mean easterly wind direction, and correlate with surface slopes. Areas of current and past increased ice flow and internal deformation are marked by discontinuous or IRH-free zones, and can inform about paleo ice-stream dynamics. The established IRH datasets extend continent-wide mapping efforts of IRHs to an important and climatically sensitive ice marginal region of Antarctica and are ready for integration into ice-flow models to improve predictions of Antarctic ice drainage.</p>","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"23 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138574374","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

Oscillatory response of Larsen C Ice Shelf flow to the calving of iceberg A-68 拉森 C 冰架水流对冰山 A-68 破裂的振荡响应

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-11 DOI: 10.1017/jog.2023.102

Katherine A. Deakin, Frazer D. W. Christie, Karla Boxall, Ian C. Willis

引用次数: 0

Controls on calving at a large Greenland tidewater glacier: stress regime, self-organised criticality and the crevasse-depth calving law 格陵兰大潮汐冰川崩解的控制:应力状态、自组织临界和裂缝深度崩解规律

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-05 DOI: 10.1017/jog.2023.81

Douglas I. Benn, Joe Todd, Adrian Luckman, Suzanne Bevan, Thomas R. Chudley, Jan Åström, Thomas Zwinger, Samuel Cook, Poul Christoffersen

{"title":"Controls on calving at a large Greenland tidewater glacier: stress regime, self-organised criticality and the crevasse-depth calving law","authors":"Douglas I. Benn, Joe Todd, Adrian Luckman, Suzanne Bevan, Thomas R. Chudley, Jan Åström, Thomas Zwinger, Samuel Cook, Poul Christoffersen","doi":"10.1017/jog.2023.81","DOIUrl":"https://doi.org/10.1017/jog.2023.81","url":null,"abstract":"We investigate the physical basis of the crevasse-depth (CD) calving law by analysing relationships between glaciological stresses and calving behaviour at Sermeq Kujalleq (Store Glacier), Greenland. Our observations and model simulations show that the glacier has a stable position defined by a compressive arch between lateral pinning points. Ice advance beyond the arch results in calving back to the stable position; conversely, if melt-undercutting forces the ice front behind the stable position, it readvances because ice velocities exceed subaqueous melt rates. This behaviour is typical of self-organising criticality, in which the stable ice-front position acts as an attractor between unstable super-critical and sub-critical regimes. This perspective provides strong support for a ‘position-law’ approach to modelling calving at Sermeq Kujalleq, because any calving ‘rate’ is simply a by-product of how quickly ice is delivered to the critical point. The CD calving law predicts ice-front position from the penetration of surface and basal crevasse fields, and accurately simulates super-critical calving back to the compressive arch and melt-driven calving into the sub-critical zone. The CD calving law reflects the glaciological controls on calving at Sermeq Kujalleq and exhibits considerable skill in simulating its mean position and seasonal fluctuations.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"1 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138508996","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

The relationship between the permeability and liquid water content of polycrystalline temperate ice 多晶温带冰渗透率与液态水含量的关系

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-12-04 DOI: 10.1017/jog.2023.91

Jacob R. Fowler, Neal R. Iverson

{"title":"The relationship between the permeability and liquid water content of polycrystalline temperate ice","authors":"Jacob R. Fowler, Neal R. Iverson","doi":"10.1017/jog.2023.91","DOIUrl":"https://doi.org/10.1017/jog.2023.91","url":null,"abstract":"To better constrain meltwater transport and ice viscosity in temperate glaciers, particularly in ice stream shear margins, we use a custom permeameter to study the untested model relationship between the permeability of temperate ice and its liquid water content. The permeability of lab-made ice of two mean grain diameters (1.8 and 4.2 mm) is measured, and water content is controlled with the ice salinity and measured calorimetrically. Fluorescein dye is added to through-flowing, chilled water to highlight flow pathways through the ice after experiments. As predicted by a simple model, permeability increases with approximately the square of the water content and by about three orders of magnitude across water contents of 0.1–4.4%. However, permeability values are less than those of the model by average factors of 2.6 and 4.1 for the finer and coarser ice, respectively. This discrepancy is likely due to tortuous, truncated or air-clogged veins. The order-of-magnitude agreement between measured and modeled values may indicate that reduced permeability from these factors is nearly compensated by preferential flow in oversized veins that are isolated or arborescent. Both kinds of preferred flow pathways are observed but the latter only in fine-grained ice at water contents > 2%.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"19 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138508971","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

Observing glacier dynamics with low-cost, multi-GNSS positioning in Victoria Land, Antarctica 在南极洲维多利亚地利用低成本多全球导航卫星系统定位观测冰川动态

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-11-30 DOI: 10.1017/jog.2023.101

Holly Still, R. Odolinski, M. H. Bowman, Christina Hulbe, David J. Prior

引用次数: 0

Exceptional thinning through the entire altitudinal range of Mont-Blanc glaciers during the 2021/22 mass balance year 在 2021/22 质量平衡年期间，整个勃朗峰冰川高度范围内的冰川异常稀薄

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2023-11-29 DOI: 10.1017/jog.2023.100

Etienne Berthier, Christian Vincent, Delphine Six

引用次数: 0

Modelled frontal ablation and velocities at Kronebreen, Svalbard, are sensitive to the choice of submarine melt rate scenario 模拟的斯瓦尔巴群岛克罗内布林的锋面消融和速度对海底融化速率情景的选择很敏感