Pub Date : 2024-12-01Epub Date: 2024-05-03DOI: 10.1016/j.polar.2024.101079
Sebastian Biton-Porsmoguer , Françoise Marco-Miralles , Marc Bouchoucha
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 cartilage cells. 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 (e.g., 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.
{"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}
Pub Date : 2024-12-01Epub Date: 2024-10-19DOI: 10.1016/j.polar.2024.101124
Eva Le Merle , Carole Belot , Ergane Fouchet , Mathilde Cancet , Ole Baltazar Andersen , Florent Lyard , Geir Moholdt , Michel Tsamados , Mahmoud El Hajj , Josephine Maton , Jérôme Benveniste , Marco Restano
The knowledge of bathymetry and ocean tides plays a pivotal role at the crossroads of various scientific fields, especially in the Polar regions. Its significance extends to ocean circulation modeling and understanding the coupled dynamical response of the ocean, sea-ice and ice-sheet systems. In the Southern Ocean, conventional satellite altimetry measurements are rare below the 66° parallel. Hydrodynamic models are thus useful tools to provide spatially continuous information about ocean tides. However, the accuracy of ocean tide models around the Antarctic continent is currently limited by the quality of bathymetry. Recent reprocessing of decade-long CryoSat-2 data has facilitated a new computation of bathymetry around Antarctica, bringing innovative information on bathymetry gradients. This, combined with new compilations of bathymetry, ice draft, coastline, and grounding line datasets in ice-shelf regions, allows improving models and knowledge of ocean tides in the Southern Ocean. We developed a new high-resolution tidal model that implements the improved bathymetry data and includes data assimilation of satellite-altimetry tidal retrievals computed from CryoSat-2, filling the gap between the 66°S-limited coverage of the TOPEX-Jason suite missions and the Antarctic coast. Comparisons with tidal estimates derived from tide gauge measurements showed very good consistencies with an RMSE of 3 cm.
{"title":"ALBATROSS: Advancing Southern Ocean tide modelling with high resolution and enhanced bathymetry","authors":"Eva Le Merle , Carole Belot , Ergane Fouchet , Mathilde Cancet , Ole Baltazar Andersen , Florent Lyard , Geir Moholdt , Michel Tsamados , Mahmoud El Hajj , Josephine Maton , Jérôme Benveniste , Marco Restano","doi":"10.1016/j.polar.2024.101124","DOIUrl":"10.1016/j.polar.2024.101124","url":null,"abstract":"<div><div>The knowledge of bathymetry and ocean tides plays a pivotal role at the crossroads of various scientific fields, especially in the Polar regions. Its significance extends to ocean circulation modeling and understanding the coupled dynamical response of the ocean, sea-ice and ice-sheet systems. In the Southern Ocean, conventional satellite altimetry measurements are rare below the 66° parallel. Hydrodynamic models are thus useful tools to provide spatially continuous information about ocean tides. However, the accuracy of ocean tide models around the Antarctic continent is currently limited by the quality of bathymetry. Recent reprocessing of decade-long CryoSat-2 data has facilitated a new computation of bathymetry around Antarctica, bringing innovative information on bathymetry gradients. This, combined with new compilations of bathymetry, ice draft, coastline, and grounding line datasets in ice-shelf regions, allows improving models and knowledge of ocean tides in the Southern Ocean. We developed a new high-resolution tidal model that implements the improved bathymetry data and includes data assimilation of satellite-altimetry tidal retrievals computed from CryoSat-2, filling the gap between the 66°S-limited coverage of the TOPEX-Jason suite missions and the Antarctic coast. Comparisons with tidal estimates derived from tide gauge measurements showed very good consistencies with an RMSE of 3 cm.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101124"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170865","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}
Pub Date : 2024-12-01Epub Date: 2024-07-05DOI: 10.1016/j.polar.2024.101095
Shu-Kuan Wong , Satoshi Imura , Masaki Uchida , Kenichi Watanabe , Mizuho Mori , Sakae Kudoh
Since the establishment of Syowa Station over six decades ago, the study on the terrestrial bacterial community surrounding the station has been notably lacking and inadequately documented. Using the latest sequencing technology, we revealed the soil bacterial composition from soil samples collected from the surrounding of the station. In doing so, we also assessed the effect of human disturbances brought upon by different activities in the proximity of the station, in contrast to those in less human interference and pristine areas. Our results show that human activities near the main station facilities, especially within the 100-m range, visibly changed the structure and functions of the soil microbial community. Areas with high levels of human disturbances displayed a decrease in both microbial diversity and richness, accompanied by a lower count of unique amplicon sequence variants (ASVs) compared to regions with intermediate and low human disturbances. Moreover, higher proportions of functions related to hydrocarbon degradation were also predicted from samples collected within this area. In contrast, soil microbial communities from intermediate and low human disturbances samples have higher proportions of bacterial groups and functions consistent with those in undisturbed natural habitats.
{"title":"The diversity, composition and functions of soil bacterial communities surrounding Syowa Station, East Antarctica, under different intensities of human disturbances","authors":"Shu-Kuan Wong , Satoshi Imura , Masaki Uchida , Kenichi Watanabe , Mizuho Mori , Sakae Kudoh","doi":"10.1016/j.polar.2024.101095","DOIUrl":"10.1016/j.polar.2024.101095","url":null,"abstract":"<div><div><span>Since the establishment of Syowa Station over six decades ago, the study on the terrestrial bacterial community surrounding the station has been notably lacking and inadequately documented. Using the latest sequencing technology, we revealed the soil bacterial composition from soil samples collected from the surrounding of the station. In doing so, we also assessed the effect of human disturbances brought upon by different activities in the proximity of the station, in contrast to those in less human interference and pristine areas. Our results show that human activities near the main station facilities, especially within the 100-m range, visibly changed the structure and functions of the </span>soil microbial community<span>. Areas with high levels of human disturbances displayed a decrease in both microbial diversity and richness, accompanied by a lower count of unique amplicon sequence variants (ASVs) compared to regions with intermediate and low human disturbances. Moreover, higher proportions of functions related to hydrocarbon degradation were also predicted from samples collected within this area. In contrast, soil microbial communities from intermediate and low human disturbances samples have higher proportions of bacterial groups and functions consistent with those in undisturbed natural habitats.</span></div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101095"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141689529","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}
Information on the glacier velocity is imperative to understand the glacier ice volume, supraglacial feature evolution and glacier-climate interaction. The present study investigates annual velocities of the ablation zone (∼4500–4800 m asl) of Panchi Nala Glacier, western Himalaya through feature tracking. For this, multi-temporal Landsat (TM and OLI) and Sentinel −2 MSI images, acquired between 2000 and 2021, were correlated using the Co-registration of Optically Sensed Images and Correlation (COSI-Corr) tool. Results reveal a mean velocity of the ablation zone to be 10.6 ± 5.6 m/y during 2000–2021, with the highest (13.8 ± 4.6 m/y) and lowest velocity (8.9 ± 2.8 m/y) observed in 2005 and 2015, respectively. There is no significant trend in the velocity, rather it is highly heterogeneous on the inter-annual scale. Further, the influence of several factors such as slope, debris cover, altitude, annual average temperature and precipitation on the glacier velocity was investigated. Results indicate that the inter-annual heterogeneity in velocity is inversely correlated with the variation of summer precipitation implying that an increase in summer precipitation decreases the glacier velocity. The spatio-temporal velocity variations are also linked with the presence of supraglacial ponds, ice cliffs and heterogeneous debris distribution over the glacier. Findings indicate that, though annual glacier velocities have not changed significantly, their magnitudes are consistently low which coupled with consistent debris increase (19.74%) and gentle slope (8.2° over ablation zone) can promote rapid growth of supraglacial ponds and ice cliffs.
{"title":"Annual velocities of the ablation zone of Panchi Nala Glacier, western Himalaya: Trends and controlling factors","authors":"Purushottam Kumar Garg , Mohit Prajapati , Aparna Shukla , Supratim Guha , Iram Ali","doi":"10.1016/j.polar.2024.101068","DOIUrl":"10.1016/j.polar.2024.101068","url":null,"abstract":"<div><div>Information on the glacier velocity is imperative to understand the glacier ice volume, supraglacial feature evolution and glacier-climate interaction. The present study investigates annual velocities of the ablation zone (∼4500–4800 m asl) of Panchi Nala Glacier, western Himalaya through feature tracking. For this, multi-temporal Landsat (TM and OLI) and Sentinel −2 MSI images, acquired between 2000 and 2021, were correlated using the Co-registration of Optically Sensed Images and Correlation (COSI-Corr) tool. Results reveal a mean velocity of the ablation zone to be 10.6 ± 5.6 m/y during 2000–2021, with the highest (13.8 ± 4.6 m/y) and lowest velocity (8.9 ± 2.8 m/y) observed in 2005 and 2015, respectively. There is no significant trend in the velocity, rather it is highly heterogeneous on the inter-annual scale. Further, the influence of several factors such as slope, debris cover, altitude, annual average temperature and precipitation on the glacier velocity was investigated. Results indicate that the inter-annual heterogeneity in velocity is inversely correlated with the variation of summer precipitation implying that an increase in summer precipitation decreases the glacier velocity. The spatio-temporal velocity variations are also linked with the presence of supraglacial ponds, ice cliffs and heterogeneous debris distribution over the glacier. Findings indicate that, though annual glacier velocities have not changed significantly, their magnitudes are consistently low which coupled with consistent debris increase (19.74%) and gentle slope (8.2° over ablation zone) can promote rapid growth of supraglacial ponds and ice cliffs.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101068"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140398817","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}
Pub Date : 2024-12-01Epub Date: 2024-03-29DOI: 10.1016/j.polar.2024.101072
Aleksandr Yu Kozhevnikov , Nikita A. Shutskiy , Semen L. Shestakov , Alexey V. Malkov , Dmitriy E. Lahmanov
Snowpack properties allow using snow as a convenient indicator of atmospheric air pollution, precipitation, and eventually soil pollution. There is a high probability of trace elements and organic pollutants accumulation on the snow cover acting as the deposit matrix. In this study, we analyzed the dynamics of the content of metals (Ca, Mn, Fe, Zn, Sr, Pb and Ba) in filtered and unfiltered samples and the content of polyaromatic hydrocarbons (18 basic PAHs) in weekly snow sampling in the city and nearby. The obtained results were collated with the content of the same contaminants in the snow sampled layer by layer at the end of the season (layer thickness was 0.1 m). In result of the study, we concluded that the sampling should be carried out right after the precipitation for the purpose of atmospheric pollution estimation, because most of heavy metals migrate through the snow layers into soil cover and get lost by the end of the season. The organic pollutants, such as PAHs, are also lost. The sampling of snow during the whole season allows identifying the global and local sources of contaminants released into the atmosphere.
{"title":"Dynamics of pollutants accumulation in the snow of an urban agglomeration","authors":"Aleksandr Yu Kozhevnikov , Nikita A. Shutskiy , Semen L. Shestakov , Alexey V. Malkov , Dmitriy E. Lahmanov","doi":"10.1016/j.polar.2024.101072","DOIUrl":"10.1016/j.polar.2024.101072","url":null,"abstract":"<div><div><span>Snowpack<span><span> properties allow using snow as a convenient indicator of atmospheric air pollution, precipitation, and eventually soil pollution. There is a high probability of trace elements and </span>organic pollutants accumulation on the snow cover acting as the deposit matrix. In this study, we analyzed the dynamics of the content of metals (Ca, Mn, Fe, Zn, Sr, Pb and Ba) in filtered and unfiltered samples and the content of </span></span>polyaromatic hydrocarbons<span> (18 basic PAHs) in weekly snow sampling in the city and nearby. The obtained results were collated with the content of the same contaminants in the snow sampled layer by layer at the end of the season (layer thickness was 0.1 m). In result of the study, we concluded that the sampling should be carried out right after the precipitation for the purpose of atmospheric pollution estimation, because most of heavy metals migrate through the snow layers into soil cover and get lost by the end of the season. The organic pollutants, such as PAHs, are also lost. The sampling of snow during the whole season allows identifying the global and local sources of contaminants released into the atmosphere.</span></div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101072"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140406458","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}
Pub Date : 2024-12-01Epub Date: 2024-10-24DOI: 10.1016/j.polar.2024.101128
Alessandra D'Angelo , Cynthia Garcia , Zak Kerrigan , Jacob Strock , Frances Crable , Nikolas VanKeersbilck , Humair Raziuddin , Theressa Ewa , Samira Umar , Andrew L. King , Miquel Gonzalez-Meler , Brice Loose
In the Arctic Ocean, methane concentrations surpassing global averages are prevalent, especially along sub-Arctic and Arctic continental shelf margins. Despite elevated dissolved methane levels, the Arctic Ocean exhibits minimal methane fluxes to the atmosphere, indicating a potential role of water column oxidation in methane processing. During the Northwest Passage Project in the summer of 2019, we integrated thermohaline, chemical, and biological data with in-situ and in-vitro methane data in Canadian Arctic Archipelago (CAA) waters. Elevated in-situ dissolved methane was prominent in near-surface Pacific waters (between 2 and 7 m), particularly in meltwater regions, with av. concentrations of 5.8 ± 2.5 nM within the upper 30m. While methane oxidation constants were generally low (av. 0.006 ± 0.002 d−1), surface waters in Wellington Channel and Croker Bay exhibited higher rates (av. 0.01 ± 0.0004 d−1), associated with Pacific-origin microbial taxa like Oleispira and Aurantivirga. Deeper layers (>200 m) displayed lower methane concentrations (av. 3.1 ± 1.1 nM) and oxidation rates (av. 0.005 ± 0.001 d−1). Sea ice showed elevated dissolved methane concentrations (av. 9.2 ± 5 nM). Waters in the western CAA exhibited a 25% increase in methane concentrations compared to ice-free areas. The overall picture suggested supersaturation of in-situ methane in shallow waters (between 2 and 50 m), coupled with faster oxidation rates in meltwater and Pacific dominant layers, suggesting rapid seasonal cycling of methane and prevention of the methane migration into the atmosphere.
在北冰洋，甲烷浓度普遍超过全球平均水平，特别是沿亚北极和北极大陆架边缘。尽管溶解的甲烷含量升高，北冰洋向大气的甲烷通量却很少，这表明水柱氧化在甲烷加工过程中可能起作用。在2019年夏季的西北航道项目中，我们将加拿大北极群岛（CAA）水域的热盐、化学和生物数据与原位和体外甲烷数据相结合。在太平洋近地表水域（2 - 7米），特别是在融水区，原位溶解甲烷浓度显著升高，在30米以上的水域，ava浓度为5.8±2.5 nM。惠灵顿海峡和克罗克湾的甲烷氧化常数普遍较低（av. 0.006±0.002 d - 1），而威灵顿海峡和克罗克湾的甲烷氧化常数较高（av. 0.01±0.0004 d - 1），与太平洋起源的微生物类群如Oleispira和Aurantivirga有关。深层（>200 m）显示较低的甲烷浓度（av. 3.1±1.1 nM）和氧化速率（av. 0.005±0.001 d - 1）。海冰溶解甲烷浓度升高（平均9.2±5 nM）。与无冰区相比，CAA西部水域的甲烷浓度增加了25%。整体情况表明，浅水（2 - 50米）的原位甲烷过饱和，加上融水和太平洋优势层中更快的氧化速率，表明甲烷的快速季节性循环和阻止甲烷迁移到大气中。
{"title":"The marine methane cycle in the Canadian Arctic Archipelago during summer","authors":"Alessandra D'Angelo , Cynthia Garcia , Zak Kerrigan , Jacob Strock , Frances Crable , Nikolas VanKeersbilck , Humair Raziuddin , Theressa Ewa , Samira Umar , Andrew L. King , Miquel Gonzalez-Meler , Brice Loose","doi":"10.1016/j.polar.2024.101128","DOIUrl":"10.1016/j.polar.2024.101128","url":null,"abstract":"<div><div>In the Arctic Ocean, methane concentrations surpassing global averages are prevalent, especially along sub-Arctic and Arctic continental shelf margins. Despite elevated dissolved methane levels, the Arctic Ocean exhibits minimal methane fluxes to the atmosphere, indicating a potential role of water column oxidation in methane processing. During the Northwest Passage Project in the summer of 2019, we integrated thermohaline, chemical, and biological data with in-situ and in-vitro methane data in Canadian Arctic Archipelago (CAA) waters. Elevated in-situ dissolved methane was prominent in near-surface Pacific waters (between 2 and 7 m), particularly in meltwater regions, with av. concentrations of 5.8 ± 2.5 nM within the upper 30m. While methane oxidation constants were generally low (av. 0.006 ± 0.002 d<sup>−1</sup>), surface waters in Wellington Channel and Croker Bay exhibited higher rates (av. 0.01 ± 0.0004 d<sup>−1</sup>), associated with Pacific-origin microbial taxa like <em>Oleispira</em> and <em>Aurantivirga</em>. Deeper layers (>200 m) displayed lower methane concentrations (av. 3.1 ± 1.1 nM) and oxidation rates (av. 0.005 ± 0.001 d<sup>−1</sup>). Sea ice showed elevated dissolved methane concentrations (av. 9.2 ± 5 nM). Waters in the western CAA exhibited a 25% increase in methane concentrations compared to ice-free areas. The overall picture suggested supersaturation of in-situ methane in shallow waters (between 2 and 50 m), coupled with faster oxidation rates in meltwater and Pacific dominant layers, suggesting rapid seasonal cycling of methane and prevention of the methane migration into the atmosphere.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101128"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170862","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}
Pub Date : 2024-12-01Epub Date: 2024-08-26DOI: 10.1016/j.polar.2024.101108
Ananthu Pradeep , A. Mukherjee
In this article, the interannual variability of sea ice in the Antarctic sea ice regions between 2013–2018 is studied using a global ocean sea ice coupled model and satellite observation. The numerical model reasonably well simulates satellite observed interannual variability of sea ice concentration (SIC) and sea surface temperature (SST) in the Antarctic regions of Southern Ocean during all four austral seasons; summer (December–February), autumn (March–May), winter (June–August), and spring (September–November).
A comparison of satellite and model shows that, during last two decades between 2001–2020, summertime of 2016–2017 had the lowest (highest) SIC (SST) across the Antarctic sea ice regions. Mixed layer heat budget analysis has been performed to comprehend how thermodynamic processes affect changes in SIC and SST in the Antarctic sea ice regions. The strong positive net atmospheric heat flux and the negative ocean vertical entrainment during summertime of 2016–2017 resulted in increased SST compared to other years, which lead to decreased SIC during above years. Also, loss of sea ice during summertime of 2016–2017 in the Antarctic sea ice regions are linked with significant decrease of wind stress magnitude and increase of wind stress curl.
{"title":"Role of atmospheric and oceanic processes on interannual summertime (2016–2017) decrease of sea ice in the Antarctic regions of the Southern Ocean","authors":"Ananthu Pradeep , A. Mukherjee","doi":"10.1016/j.polar.2024.101108","DOIUrl":"10.1016/j.polar.2024.101108","url":null,"abstract":"<div><div>In this article, the interannual variability of sea ice in the Antarctic sea ice regions between 2013–2018 is studied using a global ocean sea ice coupled model and satellite observation. The numerical model reasonably well simulates satellite observed interannual variability of sea ice concentration (SIC) and sea surface temperature (SST) in the Antarctic regions of Southern Ocean during all four austral seasons; summer (December–February), autumn (March–May), winter (June–August), and spring (September–November).</div><div>A comparison of satellite and model shows that, during last two decades between 2001–2020, summertime of 2016–2017 had the lowest (highest) SIC (SST) across the Antarctic sea ice regions. Mixed layer heat budget analysis has been performed to comprehend how thermodynamic processes affect changes in SIC and SST in the Antarctic sea ice regions. The strong positive net atmospheric heat flux and the negative ocean vertical entrainment during summertime of 2016–2017 resulted in increased SST compared to other years, which lead to decreased SIC during above years. Also, loss of sea ice during summertime of 2016–2017 in the Antarctic sea ice regions are linked with significant decrease of wind stress magnitude and increase of wind stress curl.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101108"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179323","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}
Pub Date : 2024-12-01Epub Date: 2024-10-23DOI: 10.1016/j.polar.2024.101126
John C. Seigle , Alexander K. Prichard , Adrian E. Gall , Thomas Nukapigak
Long-term fisheries datasets are particularly rare in Arctic environments and are essential to understanding the variability in harvest rates. We analyzed 30 years of harvest monitoring data and compared results to fish monitoring data from nearshore waters of Prudhoe Bay, Alaska, to determine the importance of age-0 recruitment and intra-annual factors on subsequent harvests of Arctic cisco in the Colville River delta (CRD), Alaska. While age-0 recruitment to Prudhoe Bay was positively associated with annual harvest success in the CRD, wind and salinity patterns and subsistence fishing location and timing also contributed significantly in explaining adult harvest variability. Harvest rates were highest closest to the river mouth and early in the season. Harvest rates increased with increasing salinity up to 25 ppt, then declined. As the climate changes in the region, we may see shifts in nearshore ocean and river conditions which will impact recruitment and fishing activity. These long-term monitoring efforts will continue to inform sustainable fisheries management in the face of a rapidly changing climate, and with ongoing infrastructure development in the region.
{"title":"Factors influencing harvest success for an Arctic under-ice subsistence fishery","authors":"John C. Seigle , Alexander K. Prichard , Adrian E. Gall , Thomas Nukapigak","doi":"10.1016/j.polar.2024.101126","DOIUrl":"10.1016/j.polar.2024.101126","url":null,"abstract":"<div><div>Long-term fisheries datasets are particularly rare in Arctic environments and are essential to understanding the variability in harvest rates. We analyzed 30 years of harvest monitoring data and compared results to fish monitoring data from nearshore waters of Prudhoe Bay, Alaska, to determine the importance of age-0 recruitment and intra-annual factors on subsequent harvests of Arctic cisco in the Colville River delta (CRD), Alaska. While age-0 recruitment to Prudhoe Bay was positively associated with annual harvest success in the CRD, wind and salinity patterns and subsistence fishing location and timing also contributed significantly in explaining adult harvest variability. Harvest rates were highest closest to the river mouth and early in the season. Harvest rates increased with increasing salinity up to 25 ppt, then declined. As the climate changes in the region, we may see shifts in nearshore ocean and river conditions which will impact recruitment and fishing activity. These long-term monitoring efforts will continue to inform sustainable fisheries management in the face of a rapidly changing climate, and with ongoing infrastructure development in the region.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101126"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170863","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}
Pub Date : 2024-12-01Epub Date: 2024-10-23DOI: 10.1016/j.polar.2024.101127
David Kirner, Kamil Láska, Zdeněk Stachoň
This study evaluates the effectiveness of different Land Surface Temperature (LST) retrieval algorithms applied to Landsat 8 Thermal Infrared Sensor (TIRS) data in the ice-free regions of the Antarctic Peninsula. The primary objective is to determine the most accurate algorithm for LST estimation in these environments. Three algorithms, namely radiative transfer equation (RTE), single channel (SC), and mono window (MW), were utilised and compared to in-situ measurements at two locations in the northern part of James Ross Island (JRI), Antarctic Peninsula. The study considered various factors influencing LST accuracy, including land surface emissivity, atmospheric conditions, and sun elevation angles. The findings reveal that all three algorithms demonstrate significant sensitivity to emissivity. The MW algorithm emerged as the most suitable, showing the lowest root mean square error (RMSE) of 3.06 °C, followed by the SC and RTE algorithms with RMSE values of 3.68 and 3.98 °C, respectively. The study also underscores a strong positive correlation between LST retrieval accuracy and sun elevation angle, with more accurate results obtained from satellite images acquired in February, characterised by lower sun elevation angles. No significant relationship with water vapour content in the atmosphere was identified during the investigated period.
{"title":"Assessment and validation of Land Surface Temperature retrieval algorithms using Landsat 8 TIRS data in Antarctic ice-free areas","authors":"David Kirner, Kamil Láska, Zdeněk Stachoň","doi":"10.1016/j.polar.2024.101127","DOIUrl":"10.1016/j.polar.2024.101127","url":null,"abstract":"<div><div>This study evaluates the effectiveness of different Land Surface Temperature (LST) retrieval algorithms applied to Landsat 8 Thermal Infrared Sensor (TIRS) data in the ice-free regions of the Antarctic Peninsula. The primary objective is to determine the most accurate algorithm for LST estimation in these environments. Three algorithms, namely radiative transfer equation (RTE), single channel (SC), and mono window (MW), were utilised and compared to in-situ measurements at two locations in the northern part of James Ross Island (JRI), Antarctic Peninsula. The study considered various factors influencing LST accuracy, including land surface emissivity, atmospheric conditions, and sun elevation angles. The findings reveal that all three algorithms demonstrate significant sensitivity to emissivity. The MW algorithm emerged as the most suitable, showing the lowest root mean square error (RMSE) of 3.06 °C, followed by the SC and RTE algorithms with RMSE values of 3.68 and 3.98 °C, respectively. The study also underscores a strong positive correlation between LST retrieval accuracy and sun elevation angle, with more accurate results obtained from satellite images acquired in February, characterised by lower sun elevation angles. No significant relationship with water vapour content in the atmosphere was identified during the investigated period.</div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101127"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169670","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}
Pub Date : 2024-12-01Epub Date: 2024-04-29DOI: 10.1016/j.polar.2024.101075
Suhail Ahmad Dar , Md. Omar Sarif
This review work presented a detailed review of snow cover area, mass balance status, glacial area loss, surface velocities and applications of snowmelt runoff model (SRM) applied in the Kashmir Himalayas and Upper Indus Basin (UIB) of the Himalayas. This study reviewed all the studies done in the past which are done on the Kashmir Himalayas and UIB glaciers by different methods. The geodetic and glaciological methods suggested that the glaciers in the Kashmir Himalayas and UIB are having a negative glacial mass balance and are losing ice mass at higher rates during the last two decades and are losing glacial area every year. And the glaciers in the Zanskar range are also having negative mass balance but are losing less ice mass as compared to the Glaciers in Kashmir Himalayas, while the glaciers in the Karakorum range are having positive mass balance and are losing glacial area at slower rates. Studies have found that higher surface velocities are observed in the glaciers which are present in the Kashmir region and indicate rapid melting because of higher temperatures recorded in this part of the world because of global warming. This review reflects an increasing understanding that how much of the water reservoirs we have lost and in which era we are heading to.
{"title":"Status on snow cover area, mass balance, glacial area loss, surface velocities and applications of snowmelt runoff model over Kashmir Himalayas and Upper Indus Basin: A review","authors":"Suhail Ahmad Dar , Md. Omar Sarif","doi":"10.1016/j.polar.2024.101075","DOIUrl":"10.1016/j.polar.2024.101075","url":null,"abstract":"<div><div>This review work presented a detailed review of snow cover area, mass balance status, glacial area loss, surface velocities and applications of snowmelt runoff model (SRM) applied in the Kashmir Himalayas<span> and Upper Indus Basin (UIB) of the Himalayas. This study reviewed all the studies done in the past which are done on the Kashmir Himalayas and UIB glaciers by different methods. The geodetic and glaciological methods suggested that the glaciers in the Kashmir Himalayas and UIB are having a negative glacial mass balance and are losing ice mass at higher rates during the last two decades and are losing glacial area every year. And the glaciers in the Zanskar range are also having negative mass balance but are losing less ice mass as compared to the Glaciers in Kashmir Himalayas, while the glaciers in the Karakorum range are having positive mass balance and are losing glacial area at slower rates. Studies have found that higher surface velocities are observed in the glaciers which are present in the Kashmir region and indicate rapid melting because of higher temperatures recorded in this part of the world because of global warming. This review reflects an increasing understanding that how much of the water reservoirs we have lost and in which era we are heading to.</span></div></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"42 ","pages":"Article 101075"},"PeriodicalIF":1.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059897","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}
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