Polar Science最新文献_第2页

Nutrient dynamics and biogeochemical processes at the Polar front of Indian sector of the Southern Ocean: Influence of Circumpolar deep water intrusion 南大洋印度板块极地锋的营养动态和生物地球化学过程：环极深水入侵的影响

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2024.101130

Melena A. Soares , R.K. Mishra , P. Sabu , V. Venkataramana , R.K. Naik , A. Sarkar , R. Chacko , N. Anilkumar

{"title":"Nutrient dynamics and biogeochemical processes at the Polar front of Indian sector of the Southern Ocean: Influence of Circumpolar deep water intrusion","authors":"Melena A. Soares , R.K. Mishra , P. Sabu , V. Venkataramana , R.K. Naik , A. Sarkar , R. Chacko , N. Anilkumar","doi":"10.1016/j.polar.2024.101130","DOIUrl":"10.1016/j.polar.2024.101130","url":null,"abstract":"<div><div>The Circumpolar Deep water (CDW) is one of the largest water masses in the Southern Ocean. The cross-frontal flow of the CDW is a vital mode of redistribution and transport of heat, salts, nutrients, etc. in the ocean. The present study aims to understand the role of the CDW intrusion on nutrient dynamics and biogeochemical processes at the Polar frontal region. The study noted a patch of high nutrients layer at ∼300–400 m in the Polar Front-II, underlying the dicothermal layer or the temperature minimum layer. This high nutrient patch was attributed to the intrusion of the CDW at the Polar front, influencing the physico-chemical processes in the water column. It was evident that, the density gradient, stratification and overall, the combined effect of physico-chemical and biological factors as a consequence of intrusion of the CDW contributed to the formation of the high nitrate patch at the Polar Front-II. Even though, the CDW intrusion did not significantly impact the photic layer dynamics during this study, the possible barrier effect during austral summer contribute to the formation of the high nitrate layer. This feature may be responsible for trapping nutrients in the subsurface due to stratification, and made available to the photic region via upwelling processes, consequently triggering changes in the biological community structure and biogeochemical processes.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101130"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatial and temporal occurrence of two Gyrodinium species in the seasonal ice zone off Wilkes Land, Southern Ocean 南大洋威尔克斯陆附近季节性冰区两种 Gyrodinium 的时空分布情况

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2025.101169

Ryo Matsuda , Masayoshi Sano , Chiho Tsuchiya , Keigo D. Takahashi , Shintaro Takao , Kohei Mizobata , Masato Moteki , Ryosuke Makabe , Norio Kurosawa

{"title":"Spatial and temporal occurrence of two Gyrodinium species in the seasonal ice zone off Wilkes Land, Southern Ocean","authors":"Ryo Matsuda , Masayoshi Sano , Chiho Tsuchiya , Keigo D. Takahashi , Shintaro Takao , Kohei Mizobata , Masato Moteki , Ryosuke Makabe , Norio Kurosawa","doi":"10.1016/j.polar.2025.101169","DOIUrl":"10.1016/j.polar.2025.101169","url":null,"abstract":"<div><div>Sea ice is crucial for regulating primary production and carbon export. Among sea ice-dwelling organisms, the genus <em>Gyrodinium</em> (Dinophyceae) are particularly significant, with their release into the water column influencing carbon flow in the lower food web. Specifically, <em>G. rubrum</em> and <em>G. heterogrammum</em> feed on phytoplankton and may contribute to carbon export, as their cells resemble fecal pellets. However, due to the challenges in quantifying <em>Gyrodinium</em> cells microscopically, the species-specific dynamics of these organisms remained unclear in the seasonal ice zone of the Southern Ocean. This study investigates the abundance of <em>G. rubrum</em> and <em>G. heterogrammum</em> in sea ice, seawater, and sinking particles using quantitative PCR analysis. Our results indicate that <em>G. rubrum</em> is widely distributed from coastal polynyas to continental slopes, whereas <em>G. heterogrammum</em> is confined to coastal areas. Sediment trap data showed <em>G. rubrum</em> flux at 60 m depth increased with sea ice melting. In contrast, <em>G. heterogrammum</em> fluxes at depths of 150 and 500 m were observed more frequently than those of <em>G. rubrum</em>, with no apparent correlation to sea ice melting. These findings suggest that <em>G. rubrum</em> distribution is closely linked to sea ice melt, whereas <em>G. heterogrammum</em> appears to be unaffected by such changes.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101169"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ice thickness inversion assessment: A comparison study for Waldemarbreen and Irenebreen glaciers, Svalbard 冰厚反演评价：斯瓦尔巴群岛Waldemarbreen和Irenebreen冰川的比较研究

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2025.101167

Lelde Švinka, Jānis Karušs, Kristaps Lamsters

{"title":"Ice thickness inversion assessment: A comparison study for Waldemarbreen and Irenebreen glaciers, Svalbard","authors":"Lelde Švinka, Jānis Karušs, Kristaps Lamsters","doi":"10.1016/j.polar.2025.101167","DOIUrl":"10.1016/j.polar.2025.101167","url":null,"abstract":"<div><div>Accurate ice thickness estimates are crucial for solving both glaciological and hydrological problems, and ice thickness inversion models are generally used to obtain these estimates. Several studies have assessed the accuracy of model inversions, however, usually the evaluation is done against a sparse set of field measurements. In this study, we employ the open-source models GlabTop2 and Open Global Glacier Model (OGGM) to estimate ice thickness and volume for the Waldemarbreen and Irenebreen glaciers (Svalbard archipelago), evaluating their accuracy against ground-penetrating radar (GPR) measurements. The results show that the ice thickness root-mean-square errors for GlabTop2 and OGGM are 28.5 and 13.9 m and the relative volume errors are 17.4 and 39.9%, respectively. Calibration of glacier shape factor slightly improves GlabTop2 results, however, this model tends to provide good average estimates but falls short on accurate spatial thickness distribution. On the contrary, the OGGM model is highly dependent on the chosen dataset for mass balance calibration and tends to provide better spatial distribution while performing worse regarding average thickness and overall glacier volume. Both inversion models present severe thickness errors among studied glaciers, implying the need for improvements in models and underlying theoretical assumptions that require continuous and extensive field measurements.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101167"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of atmospheric river evolutions on Greenland ice sheet mass changes over the last two decades, 2000–2019 2000-2019年过去二十年大气河流演变对格陵兰冰盖质量变化的影响

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2024.101158

Jingming Li , Xinyu Qin , Wenhao Li , C.K. Shum , Fei Li , Shengkai Zhang

{"title":"Impact of atmospheric river evolutions on Greenland ice sheet mass changes over the last two decades, 2000–2019","authors":"Jingming Li , Xinyu Qin , Wenhao Li , C.K. Shum , Fei Li , Shengkai Zhang","doi":"10.1016/j.polar.2024.101158","DOIUrl":"10.1016/j.polar.2024.101158","url":null,"abstract":"<div><div>Atmospheric rivers (ARs) serve as mechanisms that transport water vapor to the poles, triggering extreme weather events, altering weather patterns over Greenland, and even impacting mass changes in the Greenland ice sheet. In this study, we detected and extracted ARs spatiotemporal evolution characteristics over Greenland from the past two decades. And subsequently analyzed the Greenland mass changes. Our findings indicate that between 2000 and 2019, the annual occurrences of ARs varied from 13 to 27 times, with durations ranging from 156 to 610 h. Interestingly, the ARs exhibited distinct migration patterns across different periods, transitioning from a uniform distribution towards the west side of Greenland and eventually towards the east side. To delve deeper into the relationship between ARs and mass changes, we assessed the contribution of ARs to Greenland's surface mass balance using a five-year study period. The results show that the contribution of AR to SMB has a tendency to increase in stages, 20.5% from 2000 to 2004, 31.5% from 2005 to 2009, 46.4% from 2010 to 2014, and 48.2% from 2015 to 2019.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101158"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unpacking inclusivity of the Antarctic Treaty System amidst contemporary challenges 在当代挑战中揭示《南极条约体系》的包容性

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2024.101144

Zia Madani

引用次数: 0

Estimation of annual and seasonal glaciological-based mass balance of Ladakh range in cold-arid Himalayan region – Case studies of Phuche and Khardung glaciers in 2014–2017 喜马拉雅寒冷干旱地区拉达克山脉年度和季节性冰川学物质平衡估算——以2014-2017年普彻和卡东冰川为例

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2024.101132

Jaydeo K. Dharpure , Ajanta Goswami , Akansha Patel , Sanjay K. Jain , Anil V. Kulkarni

{"title":"Estimation of annual and seasonal glaciological-based mass balance of Ladakh range in cold-arid Himalayan region – Case studies of Phuche and Khardung glaciers in 2014–2017","authors":"Jaydeo K. Dharpure , Ajanta Goswami , Akansha Patel , Sanjay K. Jain , Anil V. Kulkarni","doi":"10.1016/j.polar.2024.101132","DOIUrl":"10.1016/j.polar.2024.101132","url":null,"abstract":"<div><div>The continuous estimation of glacier surface mass balance (MB) in the cold-arid trans-Himalayan region is crucial for understanding glacier-atmospheric interactions and managing future water resources. Therefore, it is essential to investigate glacier mass variability and its sensitivity to climate drivers. This study uses the direct glaciological surface MB measurements for the Phuche and Khardung glaciers from 2014 to 2017. The mean annual surface MB was observed to be −0.17 for the Phuche glacier and −0.63 m w.e. for the Khardung glacier. The maximum mass loss occurred in 2015/16 for both glaciers. The Phuche glacier experienced positive surface MB in 2014/15 and 2016/17, while the Khardung glacier exhibited negative surface MB throughout the study period. No equilibrium line altitude (ELA) or accumulation area ratio (AAR) was observed either glacier in 2015/16 period. However, the two-year average (2014/15 and 2016/17) ELA and AAR of the Phuche glacier were approximately 5480 m above sea level (asl) and 92%, respectively, while the Khardung glacier they were 5500 m asl and 13%. Results demonstrated that the timing of snowpack melt during the ablation periods significantly influenced glacier mass balance. Overall, the Khardung glacier experienced 3.7 times more mass loss than the Phuche glacier. This higher glacier melt may be attributed to changes in climatic variables and topographical variations.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101132"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Granulite facies metamorphism of the metasediments from Tallaksenvarden and Starheimtind nunataks, central Dronning Maud Land (cDML), East Antarctica and their correlation with the eastern granulites of the East African Orogen (EAO) 东南极洲中部Dronning Maud Land (cDML) Tallaksenvarden和Starheimtind nunataks沉积的麻粒岩相变质作用及其与东非造山带东部麻粒岩的对比

IF 1.5 4区地球科学

Polar Science Pub Date : 2025-03-01 DOI: 10.1016/j.polar.2025.101166

Raghuram , Mohd Yunus Shah , Monika Mishra , Anubha Bhandari , Raymond Duraiswami

{"title":"Granulite facies metamorphism of the metasediments from Tallaksenvarden and Starheimtind nunataks, central Dronning Maud Land (cDML), East Antarctica and their correlation with the eastern granulites of the East African Orogen (EAO)","authors":"Raghuram , Mohd Yunus Shah , Monika Mishra , Anubha Bhandari , Raymond Duraiswami","doi":"10.1016/j.polar.2025.101166","DOIUrl":"10.1016/j.polar.2025.101166","url":null,"abstract":"<div><div>There are eight nunataks in cDML exposed through the vast expanse of the ice sheet between Schirmacher Oasis and the Gruber–Wohlthat Mountains. Tallaksenvarden and Starheimtind are two important nunataks that mark the eastern and western limits of their exposures. There is paucity of the metamorphic data from these nunataks which otherwise lie between the well-studied Schirmacher Oasis and Humboldt Range. These nunataks comprise a sequence of granulite facies metasedimentary rocks interlayered with pyroxene granulite. The granulite facies assemblage in the pelitic granulite is garnet + sillimanite ± kyanite + biotite + quartz + perthite ± plagioclase ± rutile ± ilmenite. <em>P-T-t</em> path estimations reveal ultrahigh temperature (UHT) metamorphism (M<sub>2</sub>, ca.630-570 Ma) with a clockwise path (>900 °C at ≥8 kbar) during the Cryogenian-Cambrian period well above the wet granite solidus for incongruent melting with significant increase in melt volume during decompression. Yttrium in garnet thermometry combined with textural evidence (symplectitic quartz, biotite and plagioclase embayment in porphyroblasts) suggest initiation of porphyroblasts growth in the pelitic granulite at c. 550 °C with continued growth during increase in temperature (∼645 °C) followed by resorption and growth coinciding with increased melt generation. These nunataks and Schirmacher Oasis expose the same lithopackage with identical metamorphic and structural evolution possibly extending southward till the inland mountains of the cDML. This study also identifies that these nunataks indeed represent a portion of the EAO with a possible transpressive deformation regime.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"43 ","pages":"Article 101166"},"PeriodicalIF":1.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of various microwave brightness temperature products and methods for surface melt detection over Greenland ice sheet 格陵兰冰盖表面融化探测的各种微波亮度温度产品和方法评估

IF 1.5 4区地球科学

Polar Science Pub Date : 2024-12-01 DOI: 10.1016/j.polar.2024.101097

Pooja Mishra , Naveen Tripathi , S.R. Oza , S.K. Singh , N.Y. Bhatt , P.M. Solanki

{"title":"Assessment of various microwave brightness temperature products and methods for surface melt detection over Greenland ice sheet","authors":"Pooja Mishra , Naveen Tripathi , S.R. Oza , S.K. Singh , N.Y. Bhatt , P.M. Solanki","doi":"10.1016/j.polar.2024.101097","DOIUrl":"10.1016/j.polar.2024.101097","url":null,"abstract":"<div><div><span><span>Microwave brightness temperature have widely been used for the detection of the ice sheet's surface melt conditions and understanding their spatio-temporal variability. In this study, we investigated the sensitivity of microwave brightness temperature products from three different sensors, namely, Advanced Microwave Scanning Radiometer-2 (AMSR2), Special Sensor Microwave Imager/Sounder (SSMIS) and Indian scatterometer satellite (SCATSAT-1) for surface melt detection over the Greenland ice sheet (GrIS). In-situ air temperature measurements from GC-Net </span>AWSs were used for sensitivity and inter-comparison analysis. Our findings show that brightness temperature (T</span><sub>b</sub>) from SSMIS better correlates (P<sub>coef</sub> = 0.81 for 19 GHz) with air temperature measurements in comparison to AMSR2 (P<sub>coef</sub> = 0.7 for 18 GHz) and SCATSAT-1 (P<sub>coef</sub> = 0.67). However, interestingly, AMSR2 and SCATSAT-1 uniquely discriminated the surface conditions during pre- and post-melt period, due to their heterogeneity in T<sub>b</sub> values during the two period. Error analysis with respect to AWS melt days shows that SSMIS 19 GHz T<sub>b</sub> (T<sub>b/SSMIS/19H</sub>) products with <span><em>TED</em></span> method giving the most promising observations. A wide variability in T<sub>b</sub> values is observed during the melt season across the various AWS sites depending upon the elevation, location and frequency. During our study period, using T<sub>b/SSMIS/19H</sub> for <em>TED</em> method, we observed the highest melt extent area for the extreme melt event in year 2019 (∼1.12 million km<sup>2</sup>), followed by another melt event year 2021 when it went as high as ∼1.02 million km<sup>2</sup>.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101097"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141691479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Rapid deceleration in the ice-flow velocity of the Shirase Glacier ice tongue and its influence on the velocity field: Observations from Sentinel-1 C-SAR 白濑冰川冰舌冰流速度的快速减速及其对速度场的影响：来自哨兵-1 C-SAR 的观测数据

IF 1.5 4区地球科学

Polar Science Pub Date : 2024-12-01 DOI: 10.1016/j.polar.2024.101109

S. Ohkawa , K. Doi , K. Nakamura , Y. Aoyama , H. Nagai

引用次数: 0

Mercury levels in tissues (cartilage, skin, and muscle) of the Greenland shark (Somniosus microcephalus): Potential contamination sources and implications for health and conservation 格陵兰鲨（Somniosus microcephalus）组织（软骨、皮肤和肌肉）中的汞含量：潜在污染源及其对健康和保护的影响

IF 1.5 4区地球科学

Polar Science Pub Date : 2024-12-01 DOI: 10.1016/j.polar.2024.101079

Sebastian Biton-Porsmoguer , Françoise Marco-Miralles , Marc Bouchoucha

{"title":"Mercury levels in tissues (cartilage, skin, and muscle) of the Greenland shark (Somniosus microcephalus): Potential contamination sources and implications for health and conservation","authors":"Sebastian Biton-Porsmoguer , Françoise Marco-Miralles , Marc Bouchoucha","doi":"10.1016/j.polar.2024.101079","DOIUrl":"10.1016/j.polar.2024.101079","url":null,"abstract":"<div><div><span><span>The jaws of the Greenland shark have high levels of mercury. Hg of cartilage in comparison with skin and muscle from the same specimen makes it possible to apprehend the distribution of the pollutant in the body. The level of the pollutant between jaw, skin and fresh meat (muscle) shows a strong correlation. The muscle is the most contaminated element in comparison with the skin and cartilage. The species presents the highest levels among different groups of sharks and the results are in accordance with previous studies. Marine ecosystems in the Arctic are globally contaminated by mercury (atmosphere, water, sediments, food web). The methylmercury reduces blood calcium levels, directly affecting the metabolism of </span>cartilage cells<span>. Even if cases of malformations could not be observed in the Greenland shark, numerous cases for other shark species have been documented in connection with heavy metals (</span></span><em>e.g</em><span>., Hg), and in particular for aplacental viviparous with potential morphological anomalies on embryos. The situation of the Greenland shark is worrying due to the conservation status, the fishing catches, the tardive sexual maturity and reproduction, the climate change and the level of mercury on its organism. The results incite to recommend ecological, environmental and fisheries management measures.</span></div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101079"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141024327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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