Polar Science最新文献_第9页

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

Cellulose δ18O as a hydrological proxy: A case study for willows growing in Indigirka river lowland, Northeastern Siberia 纤维素δ18O作为水文指标：以西伯利亚东北部Indigirka河低地柳树为例

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100964

Rong Fan , Trofim C. Maximov , Atsuko Sugimoto

{"title":"Cellulose δ18O as a hydrological proxy: A case study for willows growing in Indigirka river lowland, Northeastern Siberia","authors":"Rong Fan , Trofim C. Maximov , Atsuko Sugimoto","doi":"10.1016/j.polar.2023.100964","DOIUrl":"10.1016/j.polar.2023.100964","url":null,"abstract":"<div>During the last few decades, stable oxygen isotopic composition of cellulose (δ18Ocell) has been employed as a potential tool for understanding hydrological cycles on modern and past environments. In the present study, we measured the δ18O values of stem water (δ18Osw) and the δ18Ocell values of willows, which are growing on transects along the river with multiple water sources and different levels of humidity in Northeastern Siberia, further to evaluate the contribution of (1) the δ18Osw values, (2) the ratio of ambient/intercellular water (i.e., ea/ei), and (3) the δ18O values of water vapor (δ18Ov), to the δ18Ocell values. The results well demonstrate that the cross-plot of δ18Ocell/δ18Osw can be used to evaluate the contributions of δ18Osw values and ea/ei to the variation of δ18Ocell values. Also, the contribution of the δ18Ov values on the δ18Ocell values are significantly increased, where the water vapor near the plants is isotopically equilibrated to large water pools (e.g., rivers, lakes, ponds, etc.) rather than the source water (e.g., precipitation) of plants. Based on these findings, we predict that full consideration of the above (1)–(3) permits us to enhance accuracy in our understanding of plant δ18Ocell values with respect to hydrological cycles.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"37 ","pages":"Article 100964"},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48886159","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

Study on movement characteristics of snow-wind flow based on SPH method 基于SPH方法的雪气流运动特性研究

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100965

Shuzhi Zhang, Afang Jin, Yong Dai

{"title":"Study on movement characteristics of snow-wind flow based on SPH method","authors":"Shuzhi Zhang, Afang Jin, Yong Dai","doi":"10.1016/j.polar.2023.100965","DOIUrl":"10.1016/j.polar.2023.100965","url":null,"abstract":"<div>Snowstorm disasters seriously endanger human life and the social economy. In order to find out the influence of the sublimation of snow on motion characteristic of snow-wind flow, based on Smoothed Particle Hydrodynamics (SPH), this paper simulates motion to propose the method and basic theory of the SPH model of snow-wind flow. The basic idea of the SPH method is to decompose the computational domain into independent particles. These computational particles carry their physical properties. And it can move with the governing equations, which is consistent with the discrete nature of snow particles. According to the advantages of the SPH method and the characteristics of snow flow, this paper improves and rectifies SPH theory, so that SPH shows its unique advantages in dealing with the coupling of two substances in the snow two-phase flow. This new model can able to achieving two functions: moisture diffusion and snow particle physical properties change with time and environment. And it can dynamically display the movement state of the salting snow particles of the whole snow-wind flow process to obtain each particle's speed, trajectory, and mass change. In this paper, the dynamic characteristics of snow particle swarm motion behavior are obtained through the microscopic analysis of a single snow particle motion physical quantity.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"37 ","pages":"Article 100965"},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43863790","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

On the water circulation and chemical parameter distributions in the western and central Chukchi Sea in summer 2002 and summer 2019 2002年夏季和2019年夏季楚科奇海西部和中部水循环和化学参数分布

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100962

Andrey Andreev, Irina Pipko, Svetlana Pugach

引用次数: 0

First characterization of a nursery ground for the commercial sea cucumber Cucumaria frondosa 商品海参Cucumaria frondosa育苗场的首次鉴定

IF 1.8 4区地球科学

Polar Science Pub Date : 2023-09-01 DOI: 10.1016/j.polar.2023.100963

Jean-François Hamel , Rachel Morrison , Sara Jobson , Annie Mercier

{"title":"First characterization of a nursery ground for the commercial sea cucumber Cucumaria frondosa","authors":"Jean-François Hamel , Rachel Morrison , Sara Jobson , Annie Mercier","doi":"10.1016/j.polar.2023.100963","DOIUrl":"10.1016/j.polar.2023.100963","url":null,"abstract":"<div>This study characterised the nursery ground of the cold-water sea cucumber Cucumaria frondosa for the first time. New recruits and early juveniles 0.9–40 mm in length were discovered at depths of 1.8–2.5 m in Qikiqtait (traditional name of the Belcher Islands, Nunavut, Canada) at a site with salinities ≥27 psu. They were primarily attached to live individuals and empty shells of the blue mussel Mytilus edulis and to stones. Based on laboratory rearing and known spawning times, the smallest individuals (0.9–1.4 mm) found in October 2021 and June 2022 were estimated to be 3–4 and 11–12 months old, respectively (year class 0-I). Other juveniles found at the same time were mostly ≤4-year-old, likely representing subsequent anual recruitment pulses. Densities of juveniles measuring 0.9–40 mm varied between 4 and 104 ind. m−2. Recruits <2 mm occurred in complex substrata, mostly mussel byssal threads, while larger juveniles, especially those >9 mm, were on exposed surfaces of shells and stones. No adults occupied the shallow nursery site. This study draws attention to ontogenetic migration allowing the occurrence of cryptic nursery sites that may occur in shallower environments than the typical adult habitats, of particular significance for the management of commercial species.</div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"37 ","pages":"Article 100963"},"PeriodicalIF":1.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46656386","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