Polar Science最新文献_第10页

Editorial: Research advances from Larsemann Hills, Antarctica: International cooperation and future prospects 社论：南极洲拉尔斯曼丘陵的研究进展：国际合作与未来展望

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101025

Anand K. Singh , Shailendra Saini , Yogesh Ray , Svetlana Grigoreva , Xiangbin Cui , Xianglan Li , Rahul Mohan , M. Javed Beg , Rasik Ravindra

引用次数: 0

Seasonal and solar activity dependence of TEC over Bharati station, Antarctica 南极洲巴拉蒂站上空 TEC 与季节和太阳活动的关系

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101001

Gopi K. Seemala, Ipsita Katual, Chandan Kapil, Geeta Vichare

{"title":"Seasonal and solar activity dependence of TEC over Bharati station, Antarctica","authors":"Gopi K. Seemala, Ipsita Katual, Chandan Kapil, Geeta Vichare","doi":"10.1016/j.polar.2023.101001","DOIUrl":"10.1016/j.polar.2023.101001","url":null,"abstract":"<div>The total electron content (TEC) is a key parameter that is used to understand the effects of ionosphere on satellite-based navigation and communication signals. The ionosphere at polar is highly dynamic and acts as a major sink for the solar-terrestrial energy transfer processes, different magnetospheric and space weather events. Especially in Antarctica, the observation is still sparse due to a limited number of stations. In this paper, the study of ionosphere variability over Bharati station (69.41° S, 76.19° E), an Indian Antarctic research base at Larsemann Hills, was carried out. During the geomagnetically quiet conditions, the Bharati station is located outside of auroral oval but towards the poleward of auroral oval. The variation of ionosphere for diurnal, seasonal, and solar activity was studied using the TEC data for the years 2010–2022 which covers the solar cycle 24. The TEC diurnal pattern is strong even during polar days and nights with a peak at local noon. The seasonal variability was distinctly observed with about 50% increase in TEC during equinoctial months compared to summer months during high solar active year 2014. However, during low solar active year there is a marginal increase of TEC in equinoxes compared to summer.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"38 ","pages":"Article 101001"},"PeriodicalIF":1.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347979","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

International collaboration- An indispensable tool for Antarctic research: Status report of India's endeavours on the icy continent 国际合作--南极研究不可或缺的工具：印度在冰雪大陆所作努力的现状报告

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101003

Swati Nagar , Yogesh Ray , Rakesh Rao , Avinash Kumar , Rahul Mohan

引用次数: 0

Diversity and composition of fungal communities across diverse environmental niches in Antarctica 南极洲不同环境生态位真菌群落的多样性和组成

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.100973

Namrata Jiya , Prafulla Shede , Avinash Sharma

{"title":"Diversity and composition of fungal communities across diverse environmental niches in Antarctica","authors":"Namrata Jiya , Prafulla Shede , Avinash Sharma","doi":"10.1016/j.polar.2023.100973","DOIUrl":"10.1016/j.polar.2023.100973","url":null,"abstract":"<div>Antarctica harbours a wide range of extreme and diverse ecological niches that support diverse group of microorganisms, making it important to investigate the microbial diversity of this pristine environment. The current study focuses on the diversity and distribution of fungi in diverse environmental niches like exposed soil, accumulated snow, deep sea, and lake sediments in the Larsemann Hills, Antarctica. Ascomycota (61.7%) was the most dominating phylum followed by Basidiomycota (31.1%), Chytridiomycota (5.7%) and Rozellomycota (1.4%). The families Camptobasidiaceae (23.1%), Cladosporiaceae (15.3%), Kriegeriaceae (8.2%), Mycosphaerellaceae (6.8%) and Helotiaceae (6.2%), while at the genus level Glaciozyma (24.8%), Cladosporium (16.8%), Phenoliferia (8.8%), Acrodontium (8%), and Aspergillus (5.4%) were highly prevalent. Interestingly, Austroplaca genus which is mostly indigenous to polar regions was exclusively detected in the accumulated snow sediments. Among the four heterogenous environments analyzed, lake sediments were shown to have a higher number of amplicon sequence variants (ASVs) than the other environments.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"38 ","pages":"Article 100973"},"PeriodicalIF":1.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42928112","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

Surface roughness from in-situ measurements around Indian Antarctic stations 印度南极站周围现场测量的表面粗糙度

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.100971

Megha Maheshwari , Kamaljit Singh Rajkumar , Jayaprasad Pallipad , Dhani Ram Rajak , Sandip Rashmikant Oza , Raj Kumar

{"title":"Surface roughness from in-situ measurements around Indian Antarctic stations","authors":"Megha Maheshwari , Kamaljit Singh Rajkumar , Jayaprasad Pallipad , Dhani Ram Rajak , Sandip Rashmikant Oza , Raj Kumar","doi":"10.1016/j.polar.2023.100971","DOIUrl":"10.1016/j.polar.2023.100971","url":null,"abstract":"<div>Surface roughness is an important parameter in deriving energy balance over the polar ice-sheets and glaciers. In Antarctica, roughness appears as snow patches and is affected by wind transport. It is also influenced by snowfall, snowdrifts, snowmelt, and snow grain size. In this paper, we derive surface roughness using a laser distometer. The roughness measurements were collected during the 32nd Indian Scientific Expedition to Antarctica 2013 (ISEA-32). After removal of all the possible error sources, it is found that around the Indian Antarctic station Bharati (69.41°S, 76.18°E), roughness is in the range of 0.7–1.2 cm. Snowfall and wind introduce fluctuations in surface roughness measurements. Measurements around Maitri (70.76°S, 11.73°E) showed that different ice surfaces have different values of roughness (0.6–1.4 cm), with the minimum roughness in the interior ice sheet surrounded by hummocks. Sastrugi patterns were also captured in the analysis. Backscattering signatures from RADARSAT-2 imagery were examined in conjunction with the roughness measurements.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"38 ","pages":"Article 100971"},"PeriodicalIF":1.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42791447","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

Evidence of Paleoproterozoic metamorphism in Vestfold Hills, East Antarctica: Insights from phase equilibria modelling and monazite CHIME dating 南极洲东部维斯特福尔丘陵古新生代变质作用的证据：相平衡模型和独居石CHIME年代测定的启示

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101004

Aditya Naik , Devsamridhi Arora , Mayuri Pandey , Naresh Chandra Pant , Rashmi Gupta

{"title":"Evidence of Paleoproterozoic metamorphism in Vestfold Hills, East Antarctica: Insights from phase equilibria modelling and monazite CHIME dating","authors":"Aditya Naik , Devsamridhi Arora , Mayuri Pandey , Naresh Chandra Pant , Rashmi Gupta","doi":"10.1016/j.polar.2023.101004","DOIUrl":"10.1016/j.polar.2023.101004","url":null,"abstract":"<div>The Vestfold Hills sector on the coastal fringe of the Princess Elizabeth Land forms part of an Archean to Paleoproterozoic aged cratonic nucleus of the East Antarctic Shield. A charnockite-granite association from the Mossel Gneiss Group in the northern region of the Vestfold Hills is investigated in this work to characterise the metamorphic-magmatic evolution of the area. Conventional thermometry and phase equilibria modelling indicate that the charnockite formed as a result of ultra-high temperature metamorphism at low-intermediate pressure (∼4 kbar). Phase equilibria modelling, reveals that the melt-integrated charnockite composition is a restitic product of a protolith of quartz diorite composition which underwent isobaric heating (peak temperature up to 960 °C) at 4 kbar pressure followed by anatexis. The anatexis of the quartz diorite protolith also resulted in the formation of the associated granitic melt. U–Th-PbTotal ages obtained from monazites of the granite integrated with CHIME ages extracted using the isochron method indicate an emplacement age of ∼2200 Ma and two younger events are recorded at ∼2000 Ma and ∼1700 Ma. The younger ages are ascribed to the resetting during the emplacement of younger basalt dykes that cross cut the charnockite-granite sequence. Vestfold Hills’ geological correlations with Indian and Australian cratons are discussed considering this new data.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"38 ","pages":"Article 101004"},"PeriodicalIF":1.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134937302","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

The current state of Lake Dålk (Larsemann Hills, East Antarctica) 达尔克湖（南极洲东部拉尔斯曼山）的现状

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101006

Anastasiia Sukhanova , Dmitry Bantsev , Sergey Popov , Alina Boronina , Egor Shimanchuk , Sergey Polyakov

引用次数: 0

Spatio-temporal variability of Atmospheric CO2 and CH4 concentrations over Antarctica using Ground and Space-based measurements 利用地基和天基测量数据观测南极洲上空大气二氧化碳和甲烷浓度的时空变化

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-12-01 DOI: 10.1016/j.polar.2023.101012

Mahesh Pathakoti , Mahalakshmi D.V. , Sreenivas Gaddamidi , Alok Taori , Venkata Ramana Muvva , Rajashree Vinod Bothale , Ibrahim Shaik , P. Raja , Prakash Chauhan

{"title":"Spatio-temporal variability of Atmospheric CO2 and CH4 concentrations over Antarctica using Ground and Space-based measurements","authors":"Mahesh Pathakoti , Mahalakshmi D.V. , Sreenivas Gaddamidi , Alok Taori , Venkata Ramana Muvva , Rajashree Vinod Bothale , Ibrahim Shaik , P. Raja , Prakash Chauhan","doi":"10.1016/j.polar.2023.101012","DOIUrl":"10.1016/j.polar.2023.101012","url":null,"abstract":"<div>The present study reports on the variability of atmospheric carbon dioxide (CO2) and methane (CH4) concentrations over Antarctica using data collected during the 2015–2016 and 2016–2017 as part of the Indian Scientific Expedition to Antarctica (ISEA). During the austral summer (January–March), this study examined the spatio-temporal variability in atmospheric CO2 and CH4 concentrations at the Indian Antarctic Stations (IAS). An average atmospheric CO2 concentration was observed to be 396.25 ± 4.20 ppm at Bharati station during 2015-16 austral summer period, whereas CO2 (CH4) concentrations were 398.7 ± 0.46 ppm (1780 ± 2 ppb) and 399.1 ± 0.41 ppm (1780 ± 3 ppb) at Bharati and Maitri stations, respectively during 2016–17. During the study period, the Orbiting Carbon Observatory-2 (OCO-2) based column averaged CO2 concentration shows similar values against records. At Bharati and Maitri, the diurnal amplitudes of CO2 (CH4) are varied from 0.11 ppm (0.37 ppb) to 8.90 ppm (11.44 ppb) and 0.54 ppm (1.96 ppb) to 7.30 ppm (16 ppb), respectively. In the austral summer, dominant winds at the IAS are from the east, northeast, and southeast.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"38 ","pages":"Article 101012"},"PeriodicalIF":1.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136128088","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

Estimating spatio-temporal changes in front edge of the Ronne Ice Shelf in context of climate change using remote sensing based integrated approach 基于遥感综合方法估算气候变化背景下Ronne冰架前缘时空变化

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100967

Bishakha Kundu , Avinash Kumar , Aakriti Srivastava , Debrupa Chatterjee , Fumming Xie , Dharmaveer Singh

{"title":"Estimating spatio-temporal changes in front edge of the Ronne Ice Shelf in context of climate change using remote sensing based integrated approach","authors":"Bishakha Kundu , Avinash Kumar , Aakriti Srivastava , Debrupa Chatterjee , Fumming Xie , Dharmaveer Singh","doi":"10.1016/j.polar.2023.100967","DOIUrl":"10.1016/j.polar.2023.100967","url":null,"abstract":"<div>Climate variability is thought to have an impact on the Ronne Ice Shelf (RIS), one of the largest ice shelf in Antarctica, located at the mouth of the Weddell Sea. However, investigations evaluating the impact of climate variability on the geometry (front edge) of this ice body have not yet been done. This study examines a spatial-temporal shift in the front edge of the Ronne Ice Shelf during the years 2004–2019 using an integrated approach based on remote sensing and climate data. The Moderate Resolution Imaging Spectro-radiometer (MODIS) satellite images have been used to study the changes in the ice shelf along transects drawn at a constant interval of 5 km throughout the 16-year period over the second half of the austral summer months (February to March). The study reveals that there has been net progradation of ∼20 km in the front edge of the ice shelf in the sector 2 between 2004 and 2019. This progradation in the ice shelf may be attributed to draining of upper ice streams to the RIS and the decrease in temperature. Thus, the present study establishes how a combination of the use of satellite imagery and statistics can effectively be used to comprehend and quantify changes in the variability of the front edge of the ice shelf.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"37 ","pages":"Article 100967"},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43141062","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

Investigating noble gases and nitrogen in Zag (H3-6) and ALH 77216 (L3.7–3.9): The ordinary chondrites with solar type neon and argon Zag（H3-6）和ALH 77216（L3.7–3.9）中稀有气体和氮的研究：具有太阳型氖和氩的普通球粒陨石

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100966

Ramakant R. Mahajan

{"title":"Investigating noble gases and nitrogen in Zag (H3-6) and ALH 77216 (L3.7–3.9): The ordinary chondrites with solar type neon and argon","authors":"Ramakant R. Mahajan","doi":"10.1016/j.polar.2023.100966","DOIUrl":"10.1016/j.polar.2023.100966","url":null,"abstract":"<div>Concentrations and isotopic compositions of noble gases (He, Ne, Ar, Kr, and Xe) and nitrogen in two ordinary chondrites (OCs), Zag (H3-6) and ALH 77216 (L3.7–3.9), are presented. The aim of the study is to examine the cosmic ray exposure history, radiogenic ages and isotopic signatures of trapped gases in them. The results of stepwise heating analyses indicate that light noble gases (He and Ne) are mixture of trapped and cosmic ray produced components. Neon isotopes are enriched from solar wind (SW), while shows a trend towards galactic cosmic ray (GCR) region in both the meteorites. Phase-Q neon is not observed in any of the meteorite. The heavy noble gases Ar, Kr and Xe indicate mixture of Q-HL-SW and cosmogenic. Elemental ratios of trapped 36Ar, 84Kr and 132Xe indicate that noble gases in Zag and ALH 77216 are mixtures of the three components Q, HL and SW. The cosmic-ray exposure (CRE) ages calculated from neon for Zag and ALH 77216 are 5.6 ± 0.3 Ma and 28.5 ± 0.4 Ma, respectively. These ages are within the range typically observed for the respective meteorite types of OCs. Nitrogen isotopes indicate presence of multiple components in both the chondrites. Isotopic signature of trapped nitrogen in both the chondrites is distinct from that of SW, Q and HL, indicating additional source of nitrogen in the meteorites.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"37 ","pages":"Article 100966"},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47061221","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: 1