Alexandra Mayette, M. Marcoux, J. Iacozza, M. Ferguson, A. Brower, L. Loseto
In social animals, group composition can cause variations in individual needs that can influence responses to habitat trade-offs, such as predator exposure or foraging opportunities. The Eastern Beaufort Sea beluga whales (Delphinapterus leucas (Pallas, 1776)) form different group types and cover multiple habitat types in summer. This study compares the habitat preference of three beluga social group types: 1) individual belugas, 2) groups of adults, and 3) groups at least one calf. Observations were collected during aerial surveys in July and August 2019. For each month, beluga distribution was analyzed with hierarchical generalized additive models, as a function of group type and four covariates: sea surface temperature, bathymetry, slope, and distance to the coastline. Group type, water temperature and bathymetric features best explained beluga distribution. In July, groups of adults preferred the continental shelf, whereas individual belugas and groups with calves preferred the continental slope. In August, groups of adults and groups with calves were found in Amundsen Gulf at similar depths. For both months, individual belugas associated more with deeper and colder areas. The preferences often corresponded to previously published distributions of the beluga’s main prey species, suggesting that foraging opportunities and size-related energy requirements strongly influence habitat use.
{"title":"Summer distribution and habitat preference of beluga whale social groups in the Eastern Beaufort Sea","authors":"Alexandra Mayette, M. Marcoux, J. Iacozza, M. Ferguson, A. Brower, L. Loseto","doi":"10.1139/as-2022-0035","DOIUrl":"https://doi.org/10.1139/as-2022-0035","url":null,"abstract":"In social animals, group composition can cause variations in individual needs that can influence responses to habitat trade-offs, such as predator exposure or foraging opportunities. The Eastern Beaufort Sea beluga whales (Delphinapterus leucas (Pallas, 1776)) form different group types and cover multiple habitat types in summer. This study compares the habitat preference of three beluga social group types: 1) individual belugas, 2) groups of adults, and 3) groups at least one calf. Observations were collected during aerial surveys in July and August 2019. For each month, beluga distribution was analyzed with hierarchical generalized additive models, as a function of group type and four covariates: sea surface temperature, bathymetry, slope, and distance to the coastline. Group type, water temperature and bathymetric features best explained beluga distribution. In July, groups of adults preferred the continental shelf, whereas individual belugas and groups with calves preferred the continental slope. In August, groups of adults and groups with calves were found in Amundsen Gulf at similar depths. For both months, individual belugas associated more with deeper and colder areas. The preferences often corresponded to previously published distributions of the beluga’s main prey species, suggesting that foraging opportunities and size-related energy requirements strongly influence habitat use.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47174479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As the Arctic warms, permafrost coasts are eroding faster, threatening coastal communities, habitats, and altering sediment and nutrient budgets. The western Canadian Arctic is eroding at a rapid pace, however little is known on changes occurring in the Amundsen Gulf area. This study was conducted in the eastern coast of Parry Peninsula, a neglected rock-dominated coastal area. We used orthorectified aerial photos of 1965 and 1993 and very-high resolution satellite imagery of 2020 to manually delineate the shoreline according to backshore and foreshore centered approaches. Shoreline change rates were calculated and sediment and Organic Carbon transfer from land to sea estimated using digital elevation model, the Northern Circumpolar Soil Carbon Database and ground-ice content. The results show a mean erosion rate of 0.12 m/yr for the backshore zone and 0.16 m/yr for the foreshore zone, with increasing erosion in the Paulatuk Peninsula in recent decades. The average sediment transfer from land to sea was 20 m3/m/yr and the SOC flux was 7 kg C/m/yr. We highlight the importance of using the cliff-top as shoreline reference to accurately estimate sediment and SOC transfers, an approach neglected in automatic shoreline delineation techniques based on remote sensing imagery using the waterline.
{"title":"Shoreline change rates and land to sea sediment and soil organic carbon transfer in eastern Parry Peninsula from 1965 to 2020 (Amundsen Gulf, Canada)","authors":"Rodrigue Tanguy, D. Whalen, G. Prates, G. Vieira","doi":"10.1139/as-2022-0028","DOIUrl":"https://doi.org/10.1139/as-2022-0028","url":null,"abstract":"As the Arctic warms, permafrost coasts are eroding faster, threatening coastal communities, habitats, and altering sediment and nutrient budgets. The western Canadian Arctic is eroding at a rapid pace, however little is known on changes occurring in the Amundsen Gulf area. This study was conducted in the eastern coast of Parry Peninsula, a neglected rock-dominated coastal area. We used orthorectified aerial photos of 1965 and 1993 and very-high resolution satellite imagery of 2020 to manually delineate the shoreline according to backshore and foreshore centered approaches. Shoreline change rates were calculated and sediment and Organic Carbon transfer from land to sea estimated using digital elevation model, the Northern Circumpolar Soil Carbon Database and ground-ice content. The results show a mean erosion rate of 0.12 m/yr for the backshore zone and 0.16 m/yr for the foreshore zone, with increasing erosion in the Paulatuk Peninsula in recent decades. The average sediment transfer from land to sea was 20 m3/m/yr and the SOC flux was 7 kg C/m/yr. We highlight the importance of using the cliff-top as shoreline reference to accurately estimate sediment and SOC transfers, an approach neglected in automatic shoreline delineation techniques based on remote sensing imagery using the waterline.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46268971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas C. Noad, P. Bonnaventure, G. Gilson, H. Jiskoot, Madeleine C. Garibaldi
Assumptions of linear lapse rates in regions prone to surface-based inversions can generate biases in the prediction of surface air temperature. Although studies of Arctic inversions are common, few regional studies of their characteristics exist in high-latitude regions with mountainous topography. To address this gap, vertical atmospheric temperature profiles for five sites in northwestern Canada were analysed using archived radiosonde data from 1990-2016. We present monthly, seasonal, and annual SBI characteristics including the occurrence of transient and persistent SBIs. A novel metric, surface-based inversion impact (SBIimp), was developed by combining the traditional inversion characteristics of depth, strength, and frequency, and was used to quantify the impact of surface-based inversions on cooling the surface-air temperature. SBIimp values of > 5°C yr-1 and ~ 10°C winter-1 occur locally. A weak linear relationship between sea ice coverage in the Beaufort Sea and SBIimp manifests across parts of the study area, though this relationship does not persist after detrending the datasets. Topographic analysis of areas surrounding each radiosonde location reveal highly variable SBIimp in complex mountain areas and more consistent SBIimp across areas of low relief. Our results can help interpret the role of inversions in climatic conditions maintaining cryospheric elements such as permafrost.
{"title":"Surface-based temperature inversion characteristics and impact on surface air temperatures in northwestern Canada from radiosonde data between 1990 and 2016","authors":"Nicholas C. Noad, P. Bonnaventure, G. Gilson, H. Jiskoot, Madeleine C. Garibaldi","doi":"10.1139/as-2022-0031","DOIUrl":"https://doi.org/10.1139/as-2022-0031","url":null,"abstract":"Assumptions of linear lapse rates in regions prone to surface-based inversions can generate biases in the prediction of surface air temperature. Although studies of Arctic inversions are common, few regional studies of their characteristics exist in high-latitude regions with mountainous topography. To address this gap, vertical atmospheric temperature profiles for five sites in northwestern Canada were analysed using archived radiosonde data from 1990-2016. We present monthly, seasonal, and annual SBI characteristics including the occurrence of transient and persistent SBIs. A novel metric, surface-based inversion impact (SBIimp), was developed by combining the traditional inversion characteristics of depth, strength, and frequency, and was used to quantify the impact of surface-based inversions on cooling the surface-air temperature. SBIimp values of > 5°C yr-1 and ~ 10°C winter-1 occur locally. A weak linear relationship between sea ice coverage in the Beaufort Sea and SBIimp manifests across parts of the study area, though this relationship does not persist after detrending the datasets. Topographic analysis of areas surrounding each radiosonde location reveal highly variable SBIimp in complex mountain areas and more consistent SBIimp across areas of low relief. Our results can help interpret the role of inversions in climatic conditions maintaining cryospheric elements such as permafrost.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48035151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Véronique Dubos, Peter L. May, C. Gillis, A. St‐Hilaire, N. Bergeron
This study is a comprehensive documentation of anadromous Arctic char (Salvelinus alpinus) life history in Ungava Bay, Nunavik, Canada, through Inuit knowledge. Inuit experts shared their knowledge during semi-directed interviews and other occasions such as informal discussions and fieldwork. A contextualized synthesis of published western scientific literature is provided for the various life stages of Arctic char. The close year-round relationship Inuit have with Arctic char allows to set evidence of poorly described life history strategies in western literature and to reveal behaviours that, to the best of the authors’ knowledge, have not been documented so far. The connections and paralleling of Inuit knowledge and published studies about Arctic char informs western science with a more holistic understanding of Arctic char ecology. By bringing Inuit knowledge of Arctic char to the foreground, the present study highlights relevant research avenues for co-developed projects on Arctic char ecology.
{"title":"Nunavik anadromous Arctic char life histories, behaviour and habitat use informed by both Inuit knowledge and western science: A year in Ungava Bay","authors":"Véronique Dubos, Peter L. May, C. Gillis, A. St‐Hilaire, N. Bergeron","doi":"10.1139/as-2022-0019","DOIUrl":"https://doi.org/10.1139/as-2022-0019","url":null,"abstract":"This study is a comprehensive documentation of anadromous Arctic char (Salvelinus alpinus) life history in Ungava Bay, Nunavik, Canada, through Inuit knowledge. Inuit experts shared their knowledge during semi-directed interviews and other occasions such as informal discussions and fieldwork. A contextualized synthesis of published western scientific literature is provided for the various life stages of Arctic char. The close year-round relationship Inuit have with Arctic char allows to set evidence of poorly described life history strategies in western literature and to reveal behaviours that, to the best of the authors’ knowledge, have not been documented so far. The connections and paralleling of Inuit knowledge and published studies about Arctic char informs western science with a more holistic understanding of Arctic char ecology. By bringing Inuit knowledge of Arctic char to the foreground, the present study highlights relevant research avenues for co-developed projects on Arctic char ecology.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42919131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander I. Culley, Mary Thaler, W. Kochtitzky, Pilipoosie Iqaluk, J. Rapp, M. Rautio, M. Kumagai, L. Copland, W. Vincent, C. Girard
We describe limnological datasets from Thores Lake, a large ice-contact proglacial lake in northern Ellesmere Island, Nunavut (82.65°N). The lake is formed due to damming by Thores Glacier at its northwest margin, has multi-year ice cover and a cold (< 1.54°C), freshwater column with a layer of < 0°C, high-conductivity water in the deepest basin. Thores Lake is ultra-oligotrophic, with low nutrient and phytoplankton stocks. Accessory pigment data and metagenomics were used to describe the eukaryotic microbial community. Taxonomic composition was homogenous to a depth of 40 m, consistent with density profiles. Surface water at the glacier interface had high turbidity and total phosphorus concentrations, and a distinct phytoplankton community dominated by chlorophytes, whereas the lake water column had higher relative abundances of chrysophytes and photosynthetic dinoflagellates. Thores Lake has a contracted pelagic food-web, with the highest trophic level occupied by phytoplankton-feeding rotifers, and no crustacean zooplankton; profiles showed that omega-3 fatty acids (FA) ranged from < 1% (interface) to 3.6% (lake) of total seston FA. Given the stability of the Thores Glacier and the persistence of cold water capped by perennial ice, Thores Lake provides a baseline to assess the impact of climate change on far northern lakes.
{"title":"The Thores Lake proglacial system: remnant stability in the rapidly changing Canadian High Arctic","authors":"Alexander I. Culley, Mary Thaler, W. Kochtitzky, Pilipoosie Iqaluk, J. Rapp, M. Rautio, M. Kumagai, L. Copland, W. Vincent, C. Girard","doi":"10.1139/as-2022-0023","DOIUrl":"https://doi.org/10.1139/as-2022-0023","url":null,"abstract":"We describe limnological datasets from Thores Lake, a large ice-contact proglacial lake in northern Ellesmere Island, Nunavut (82.65°N). The lake is formed due to damming by Thores Glacier at its northwest margin, has multi-year ice cover and a cold (< 1.54°C), freshwater column with a layer of < 0°C, high-conductivity water in the deepest basin. Thores Lake is ultra-oligotrophic, with low nutrient and phytoplankton stocks. Accessory pigment data and metagenomics were used to describe the eukaryotic microbial community. Taxonomic composition was homogenous to a depth of 40 m, consistent with density profiles. Surface water at the glacier interface had high turbidity and total phosphorus concentrations, and a distinct phytoplankton community dominated by chlorophytes, whereas the lake water column had higher relative abundances of chrysophytes and photosynthetic dinoflagellates. Thores Lake has a contracted pelagic food-web, with the highest trophic level occupied by phytoplankton-feeding rotifers, and no crustacean zooplankton; profiles showed that omega-3 fatty acids (FA) ranged from < 1% (interface) to 3.6% (lake) of total seston FA. Given the stability of the Thores Glacier and the persistence of cold water capped by perennial ice, Thores Lake provides a baseline to assess the impact of climate change on far northern lakes.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47564085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amid growing recognition for the role of global conservation initiatives in protecting biodiversity and mitigating climate change impacts, the interest in Indigenous-led and Indigenous-centered conservation in the circumpolar Arctic is also on the rise. Through literature and practice, Indigenous communities in the Arctic are shaping the global discourse around conservation approaches, mechanisms, and strategies and challenging colonial conceptions of how lands, waters, and species should be used, managed, and protected. Indigenous approaches, mechanisms, and strategies often differ from those found in the global conservation toolbox and rather focus on local priorities, Indigenous knowledge, traditional practices, sovereignty, and self-determination. Direction on how conservation should evolve and overcome challenges and related burdens is best given by Indigenous communities, scholars, organizations, and governments. Valuing Indigenous knowledge and supporting community-level initiatives, strategies, and practices comes with the benefits of understanding, forwarding, and implementing community priorities, needs, and values through attention and focus on funding, Indigenous-led research and management, and mutual mentorship. In addition to benefiting conservation itself, biodiversity research conducted within Indigenous homelands has the opportunity to serve as a model for how regional, national, and international initiatives best engage with Indigenous knowledge, conservation practice, and policy development in the Arctic and beyond.
{"title":"Indigenous-led conservation in the Arctic supports global conservation practices","authors":"V. Buschman, Enooyaq Sudlovenick","doi":"10.1139/as-2022-0025","DOIUrl":"https://doi.org/10.1139/as-2022-0025","url":null,"abstract":"Amid growing recognition for the role of global conservation initiatives in protecting biodiversity and mitigating climate change impacts, the interest in Indigenous-led and Indigenous-centered conservation in the circumpolar Arctic is also on the rise. Through literature and practice, Indigenous communities in the Arctic are shaping the global discourse around conservation approaches, mechanisms, and strategies and challenging colonial conceptions of how lands, waters, and species should be used, managed, and protected. Indigenous approaches, mechanisms, and strategies often differ from those found in the global conservation toolbox and rather focus on local priorities, Indigenous knowledge, traditional practices, sovereignty, and self-determination. Direction on how conservation should evolve and overcome challenges and related burdens is best given by Indigenous communities, scholars, organizations, and governments. Valuing Indigenous knowledge and supporting community-level initiatives, strategies, and practices comes with the benefits of understanding, forwarding, and implementing community priorities, needs, and values through attention and focus on funding, Indigenous-led research and management, and mutual mentorship. In addition to benefiting conservation itself, biodiversity research conducted within Indigenous homelands has the opportunity to serve as a model for how regional, national, and international initiatives best engage with Indigenous knowledge, conservation practice, and policy development in the Arctic and beyond.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43013270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. E. Roos, J. Asplund, T. Birkemoe, A. Halbritter, S. Olsen, Linn Vassvik, Kristel van Zuijlen, K. Klanderud
The International Tundra Experiment (ITEX) was established to understand how environmental change impacts Arctic and alpine ecosystems. The success of the ITEX-network has allowed for several important across-site syntheses, and for some ITEX-sites enough data have now been collected to perform within-site syntheses on the effects of environmental change across ecological scales. In this study, we analyze climate data and synthesize three decades of research on the ecological effects of environmental change at the ITEX-site at Finse, southern Norway. We found a modest warming rate of +0.36 °C per decade and minor effects on growing season length. Maximum winter snow depth was highest in winters with a positive North Atlantic Oscillation. Our synthesis included 80 ecological studies from Finse, biased towards primary producers with few studies on ecological processes. Species distributions depended on microtopography and microclimate. Experimental warming had contrasting effects on abundance and traits of individual species and only modest effects at the community-level above and below ground. In contrast, nutrient addition experiments caused strong responses in primary producer and arthropod communities. This within-site synthesis enabled us to conclude how different environmental changes (experimental and ambient warming, nutrient addition, and environmental gradients) impact across ecological scales, which is challenging to achieve with across-site approaches.
{"title":"Three decades of environmental change studies at alpine Finse, Norway: climate trends and responses across ecological scales","authors":"R. E. Roos, J. Asplund, T. Birkemoe, A. Halbritter, S. Olsen, Linn Vassvik, Kristel van Zuijlen, K. Klanderud","doi":"10.1139/as-2020-0051","DOIUrl":"https://doi.org/10.1139/as-2020-0051","url":null,"abstract":"The International Tundra Experiment (ITEX) was established to understand how environmental change impacts Arctic and alpine ecosystems. The success of the ITEX-network has allowed for several important across-site syntheses, and for some ITEX-sites enough data have now been collected to perform within-site syntheses on the effects of environmental change across ecological scales. In this study, we analyze climate data and synthesize three decades of research on the ecological effects of environmental change at the ITEX-site at Finse, southern Norway. We found a modest warming rate of +0.36 °C per decade and minor effects on growing season length. Maximum winter snow depth was highest in winters with a positive North Atlantic Oscillation. Our synthesis included 80 ecological studies from Finse, biased towards primary producers with few studies on ecological processes. Species distributions depended on microtopography and microclimate. Experimental warming had contrasting effects on abundance and traits of individual species and only modest effects at the community-level above and below ground. In contrast, nutrient addition experiments caused strong responses in primary producer and arthropod communities. This within-site synthesis enabled us to conclude how different environmental changes (experimental and ambient warming, nutrient addition, and environmental gradients) impact across ecological scales, which is challenging to achieve with across-site approaches.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45290527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Kochtitzky, L. Copland, T. Wohlleben, Pilipoosie Iqaluk, C. Girard, W. Vincent, Alexander I. Culley
Relatively little is known about the glaciers of northern Ellesmere Island, Canada. Here we describe the first field and remote sensing observations of Thores Glacier, located 50 km inland from the Arctic Ocean. The glacier is slow-moving, with maximum velocities of 26 m a−1 and a maximum observed thickness of 360 ± 4.3 m. There has been little change in terminus position since at least 1959, with a maximum advance of 170 m at the northwest terminus ending on land and retreat up to 130 m at the southeast terminus ending in Thores Lake. There is little evidence for change since the Little Ice Age as bedrock weathering patterns suggest retreat of no more than 20–30 m around most of the glacier margin. The supraglacial drainage network is generally poorly developed, without moulins and with few crevasses, and therefore no evidence of water reaching the glacier bed. This is supported by one-dimensional modelling, which suggests current basal temperatures of −7.0 °C to −12.0 °C along the centerline. Thores Glacier currently dams Thores Lake, which causes drainage to flow to the southeast. However, if the glacier thins or retreats sufficiently, regional drainage will reverse and flow to the north, and Thores Lake would no longer exist.
对加拿大埃尔斯米尔岛北部的冰川了解相对较少。在这里，我们描述了位于北冰洋内陆50公里处的Thores冰川的首次野外和遥感观测。冰川移动缓慢，最大速度为26 m a−1，观测到的最大厚度为360±4.3 m。至少自1959年以来，终点位置几乎没有变化，西北终点的最大前进距离为170 m，终点为陆地，东南终点的最大后退距离为130 m，终点位于Thores湖。自小冰期以来，几乎没有证据表明发生了变化，因为基岩风化模式表明冰川边缘大部分地区的退缩不超过20-30米。冰川上的排水网络通常发育不良，没有丘，也没有裂缝，因此没有证据表明水到达了冰川床。这得到了一维模型的支持，该模型表明，沿中心线的当前基础温度为−7.0°C至−12.0°C。Thores冰川目前在Thores湖筑坝，导致排水流向东南部。然而，如果冰川充分变薄或退缩，区域排水将逆转并向北流动，Thores湖将不复存在。
{"title":"Slow change since the Little Ice Age at a far northern glacier with the potential for system reorganization: Thores Glacier, northern Ellesmere Island, Canada","authors":"W. Kochtitzky, L. Copland, T. Wohlleben, Pilipoosie Iqaluk, C. Girard, W. Vincent, Alexander I. Culley","doi":"10.1139/as-2022-0012","DOIUrl":"https://doi.org/10.1139/as-2022-0012","url":null,"abstract":"Relatively little is known about the glaciers of northern Ellesmere Island, Canada. Here we describe the first field and remote sensing observations of Thores Glacier, located 50 km inland from the Arctic Ocean. The glacier is slow-moving, with maximum velocities of 26 m a−1 and a maximum observed thickness of 360 ± 4.3 m. There has been little change in terminus position since at least 1959, with a maximum advance of 170 m at the northwest terminus ending on land and retreat up to 130 m at the southeast terminus ending in Thores Lake. There is little evidence for change since the Little Ice Age as bedrock weathering patterns suggest retreat of no more than 20–30 m around most of the glacier margin. The supraglacial drainage network is generally poorly developed, without moulins and with few crevasses, and therefore no evidence of water reaching the glacier bed. This is supported by one-dimensional modelling, which suggests current basal temperatures of −7.0 °C to −12.0 °C along the centerline. Thores Glacier currently dams Thores Lake, which causes drainage to flow to the southeast. However, if the glacier thins or retreats sufficiently, regional drainage will reverse and flow to the north, and Thores Lake would no longer exist.","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44607691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Outflow from north-flowing circumpolar rivers has a strong influence on the Arctic Ocean. The Peel and Arctic Red Rivers are tributaries of the Mackenzie Delta, a large, lake-rich floodplain that forms the interface between the Mackenzie River and the Beaufort Sea basin of the Arctic Ocean. Here, we present water quality data that were collected from the Peel and Arctic Red Rivers between 2007 and 2010 as part of an International Polar Year project that investigated the seasonal hydrology and biogeochemistry of the Mackenzie River and its delta. The Peel River was sampled 57 times between May 2007 and September 2010 upstream of the community of Fort McPherson, NT, while the Arctic Red River was sampled 32 times between May 2007 and August 2008 (with one additional sample in June 2010) approximately 0.5 km upstream of its confluence with the Mackenzie River near the community of Tsiigehtchic, NT. Each water sample was analyzed for up to 22 water quality parameters, including water temperature, specific conductivity, pH, chlorophyll-a, total suspended sediments, particulate nutrients (carbon, nitrogen, and phosphorus), soluble reactive silica, major ions (calcium, magnesium, potassium, sodium, chloride, and sulfate), dissolved carbon (inorganic and organic fractions), and dissolved nutrients (three nitrogen and two phosphorus fractions). This dataset, which is available for download and reuse, provides important baseline information about water quality in the Peel and Arctic Red Rivers, complements other data that have been collected in these watersheds, and will be of interest to researchers, resource managers, Indigenous organizations, and governments that are active in the region
{"title":"Water quality parameters and constituent concentrations measured in the Peel and Arctic Red Rivers, 2007-2010.","authors":"Jolie A. L. Gareis, L. Lesack","doi":"10.1139/as-2022-0020","DOIUrl":"https://doi.org/10.1139/as-2022-0020","url":null,"abstract":"Outflow from north-flowing circumpolar rivers has a strong influence on the Arctic Ocean. The Peel and Arctic Red Rivers are tributaries of the Mackenzie Delta, a large, lake-rich floodplain that forms the interface between the Mackenzie River and the Beaufort Sea basin of the Arctic Ocean. Here, we present water quality data that were collected from the Peel and Arctic Red Rivers between 2007 and 2010 as part of an International Polar Year project that investigated the seasonal hydrology and biogeochemistry of the Mackenzie River and its delta. The Peel River was sampled 57 times between May 2007 and September 2010 upstream of the community of Fort McPherson, NT, while the Arctic Red River was sampled 32 times between May 2007 and August 2008 (with one additional sample in June 2010) approximately 0.5 km upstream of its confluence with the Mackenzie River near the community of Tsiigehtchic, NT. Each water sample was analyzed for up to 22 water quality parameters, including water temperature, specific conductivity, pH, chlorophyll-a, total suspended sediments, particulate nutrients (carbon, nitrogen, and phosphorus), soluble reactive silica, major ions (calcium, magnesium, potassium, sodium, chloride, and sulfate), dissolved carbon (inorganic and organic fractions), and dissolved nutrients (three nitrogen and two phosphorus fractions). This dataset, which is available for download and reuse, provides important baseline information about water quality in the Peel and Arctic Red Rivers, complements other data that have been collected in these watersheds, and will be of interest to researchers, resource managers, Indigenous organizations, and governments that are active in the region","PeriodicalId":48575,"journal":{"name":"Arctic Science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45746109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：