检索结果-南通市图书馆

Classifying moisture sources associated with snowfall in the mountains of Lesotho

Journal of Mountain Science 2024年第6期21卷 1941-1953页

作者： Alexi M.MARINAKI Jennifer M.FITCHETT School of Geography Archaeology and Environmental StudiesUniversity of the WitwatersrandPrivate Bag X3Wits 2050South Africa

An average of eight snowfall events occur each year in the eastern Lesotho Highlands.These snowfall events are typically associated with cut-off low(CoLs)systems and mid-latitude cyclones.However,the moisture sources of the snowfall are unclassified and unclear.The Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model,an air mass back trajectory model,has been used to evaluate moisture source waters locally in southern Africa and internationally in China and Europe.This study uses HYSPLIT to determine the source moisture of snow in Lesotho.A list of all 82 snowfall events in Lesotho spanning 2017 to 2022 was compiled using the snow Report SA Instagram page,including the date and location of snowfall.A 72-hour back trajectory for each snowfall event was initiated for both Afriski and the whole of Lesotho.This amounts to models of moisture source trajectories for 28 and 82 snowfall days,respectively.These air mass pathways are classified according to their frequency per snowfall event,per month in the snow season,per year and for the full period.From this,associated moisture source regions and dominant air mass trajectories were identified.This study reports that the air mass trajectories associated with Afriski and Lesotho as a whole are very similar.The most common pathway of air mass trajectories transporting snow-bearing moisture to Lesotho was an inland trajectory from the northern regions of southern Africa.This pathway makes up 16.6%of all trajectories reported and is associated with the Angola Low,the Congo Air Boundary and the St.Helena High Pressure.

关键词： Eastern Lesotho Highlands Afriski snow Cut-off Lows HYSPLIT Synoptic Climatology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A progress review of black carbon deposition on Arctic snow and ice and its impact on climate change

引用

Advances in Polar Science 2024年第2期35卷 178-191页

作者： ZHANG Zilu ZHOU Libo ZHANG Meigen Department of Lower Atmosphere Observation Research(LAOR) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Science University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The rapid warming of the Arctic,accompanied by glacier and sea ice melt,has significant consequences for the Earth’s climate,ecosystems,and economy.Black carbon(BC)deposition on snow and ice can trigger a significant reduction in snow albedo and accelerate melting of snow and ice in the Arctic.By reviewing the published literatures over the past decades,this work provides an overview of the progress in both the measurement and modeling of BC deposition and its impact on Arctic climate change.In summary,the maximum value of BC deposition appears in the western Russian Arctic(26 ng·g^(–1)),and the minimum value appears in Greenland(3 ng·g^(–1)).BC records in the Arctic ice core already peaked in 1920s and 1970s,and shows a regional difference between Greenland and Canadian Arctic.The different temporal variations of Arctic BC ice core records in different regions are closely related to the large variability of BC emissions and transportation processes across the Arctic region.Model simulations usually underestimate the concentration of BC in snow and ice by 2–3 times,and cannot accurately reflect the seasonal and regional changes in BC deposition.Wet deposition is the main removal mechanism of BC in the Arctic,and observations show different seasonal variations in BC wet deposition in Ny-Ålesund and Barrow.This discrepancy may result from varying contributions of anthropogenic and biomass burning(BB)emissions,given the strong influence by BC from BB emissions at Barrow.Arctic BC deposition significantly influences regional climate change in the Arctic,increasing fire activities in the Arctic have made BB source of Arctic BC more crucial.On average,BC in Arctic snow and ice causes an increase of+0.17 W·m^(–2)in radiative forcing and 8 Gt·a^(–1)in runoff in Greenland.As stressed in the latest Arctic Monitoring and Assessment Programme report,reliable source information and long-term and high-resolution observations on Arctic BC deposition will be crucial for a more comprehensive understanding and a better mitigation

关键词： Arctic climate black carbon albedo snow deposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geodetic study on earth surface loading with GNSS and GRACE

引用

Satellite Navigation 2023年第3期4卷 1-13页

作者： Kosuke Heki Shuanggen Jin Shanghai Astronomical Observatory Chinese Academy of ScienceShanghai 200030China Hokkaido University N10 W8Kita‑kuSapporoHokkaido 060‑0810Japan School of Surveying and Land Information Engineering Henan Polytechnic UniversityJiaozuo 454000China

Ice,snow,and liquid water on the surface of the Earth exert downward force onto the solid earth and deform the lithosphere typically in seasonal timescale.Space techniques,such as Global Navigation Satellite System(GNSS),made it possible to directly measure subtle displacements caused by loading.We can also observe such loads with time-variable gravity using gravity recovery and climate experiment satellites.These techniques made surface loads an attracting scientific target of modern geodesy.In this paper we briefly review the history of geophysical studies of surface loads through geodetic observations of crustal deformation and time-variable gravity.We also review advanced topics such as short-term crustal deformation due to severe meteorological episodes and monitoring of terrestrial water storages.We also present a few related topics such as the change of the obliquity of the Earth due to loads and artificial crustal subsidence signals caused by snow accretion onto GNSS antenna radomes.

关键词： GNSS GRACE Seasonal change Surface load Land hydrology snow

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cryosphere as a temporal sink and source of microplastics in the Arcticregion

引用

Geoscience Frontiers 2023年第4期14卷 187-199页

作者： Yulan Zhang Tanguang Gao Shichang Kang Deonie Allen Zhaoqing Wang Xi Luo Ling Yang Jinlei Chen Zhaofu Hu Pengfei Chen Wentao Du Steve Allen State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China School of Geography Earth and Environmental SciencesUniversity of BirminghamEdgbastonBirminghamB152TTUK School for Resource and Environmental Studies Dalhousie UniversityHalifaxNova Scotia B3H 4R2Canada University of Chinese Academy of Sciences Beijing 100049China

Microplastics(MPs)pollution has become a serious environmental issue of growing global concern due to the increasing plastic production and usage.Under climate warming,the cryosphere,defined as the part of Earth’s layer characterized by the low temperatures and the presence of frozen water,has been experiencing significant changes.The Arctic cryosphere(e.g.,sea ice,snow cover,Greenland ice sheet,permafrost)can store and release pollutants into environments,making Arctic an important temporal sink and source of MPs.Here,we summarized the distributions of MPs in Arctic snow,sea ice,seawater,rivers,and sediments,to illustrate their potential sources,transport pathways,storage and release,and possible effects in this sentinel region.Items concentrations of MPs in snow and ice varied about 1-6 orders of magnitude in different regions,which were mostly attributed to the different sampling and measurement methods,and potential sources of MPs.MPs concentrations from Arctic seawater,river/lake water,and sediments also fluctuated largely,ranging from several items of per unit to>40,000 items m^(-3),100 items m^(-3),and 10,000 items kg^(-1) dw,respectively.Arctic land snow cover can be a temporal storage of MPs,with MPs deposition flux of about(4.9-14.26)×10^(8) items km^(-2) yr^(-1).MPs transported by rivers to Arctic ocean was estimated to be approximately 8-48 ton/yr,with discharge flux of MPs at about(1.65-9.35)×10^(8) items/s.Average storage of MPs in sea ice was estimated to be about 6.1×10^(18) items,with annual release of about 5.1×10^(18) items.Atmospheric transport of MPs from long-distance terrestrial sources contributed significantly to MPs deposition in Arctic land snow cover,sea ice and oceanic surface waters.Arctic Great Rivers can flow MPs into the Arctic Ocean.Sea ice can temporally store,transport and then release MPs in the surrounded environment.Ocean currents from the Atlantic brought high concentrations of MPs into the Arctic.However,there existed large uncertainties of estimation on the storage and re

关键词： Microplastics Arctic Sea ice snow Seawater Sediments

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Meteorological and sea ice anomalies in the western Arctic Ocean during the 2018-2019 ice season:a Lagrangian study

引用

Advances in Polar Science 2022年第3期33卷 204-219页

作者： LEI Ruibo ZHANG Fanyi ZHAI Mengxi Key Laboratory of Polar Science MNRPolar Research Institute of ChinaShanghai 200136China Chinese Antarctic Center of Surveying and Mapping Wuhan UniversityWuhan 430079China

Rapid changes in the Arctic climate and those in Arctic sea ice in recent decades are closely coupled.In this study,we used atmospheric reanalysis data and satellite remote sensing products to identify anomalies of meteorological and sea ice conditions during the ice season of 2018-2019 relative to climatological means using a Lagrangian methodology.We obtained the anomalies along the drifting trajectories of eight sea ice mass balance buoys between the marginal ice zone and the pack ice zone in the western Arctic Ocean(~160°W-170°W and 79°N-85°N)from September 2018 toAugust 2019.The temporary collapse of the Beaufort High and a strong positive Arctic Dipole in the winter of 2018-2019 drove the three buoys in the north to drift gradually northeastward and merge into the Transpolar Drift Stream.The most prominent positive temperature anomalies in 2018-2019 along the buoy trajectories relative to 1979-2019 climatology occurred in autumn,early winter,and April,and were concentrated in the southern part of the study area;these anomalies can be partly related to the seasonal and spatial patterns of heat release from the Arctic ice-ocean system to the atmosphere.In the southern part of the study area and in autumn,the sea ice concentration in 2018-2019 was higher than that averaged over the past 10 years.However,we found no ice concentration anomalies for other regions or seasons.The sea ice thickness in the freezing season and the snow depth by the end of the winter of 2018-2019 can also be considered as normal.Although the wind speed in 2018-2019 was slightly lower than that in 1979-2019,the speed of sea ice drift and its ratio to wind speed were significantly higher than the climatology.In 2019,the sea ice surface began to melt at the end of June,which was close to the 1988-2019 climatology.However,spatial variations in the onsets ofsurface melt in 2019 differed from the climatology,and can be explained by the prevalence of a high-pressure system in the south of the Beaufort Sea in June 2019.In addition to seasonal

关键词： sea ice air temperature climate snow motion Arctic Ocean

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution and characteristic of PAHs in snow of Fildes Peninsula

引用

Journal of Environmental Sciences 2011年第9期23卷 1445-1451页

作者： Guangshui Na Chunyang Liu Zhen Wang Linke Ge Xindong Ma Ziwei Yao Key laboratory for Ecological Environment in Coastal Areas National Marine Environmental Monitoring Center Dalian 116023 China School of Bio- Technology Dalian Polytechnic University Dalian 116034 China

Polycyclic aromatic hydrocarbons （PAHs） investigation in different matrices has been reported largely,whereas reports on snow samples were limited.snow,as the main matrix in the polar region,has an important study meaning.PAHs in snow samples were analyzed to investigate the distribution and contamination status of them in the Antarctic,as well as to provide some references for global migration of PAHs.snow samples collected in Fildes Peninsula were enriched and separated by solid-phase membrane disks and eluted by methylene dichloride,then quantified by gas chromatography/mass spectrometry.All types of PAHs were detected except for Benzo（a）pyrene.Principal component analysis method was applied to characterize them.Three factors （Naphthalene,Fluorene and Phenanthrene） accounted for 60.57%,21.61% and 9.80%,respectively.The results showed that the major PAHs sources maybe the atmospheric transportation,and the combustion of fuel in Fildes Peninsula.The comparison of concentration and types of PAHs between accumulated snow and fresh snow showed that the main compound concentrations in accumulated snow samples were higher than those in fresh ones.The risk assessment indicated that the amount of PAHs in the snow samples would not lead to ecological risk.

关键词： PAHs snow Antarctic principal component analysis risk assessment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chemical composition of natural waters at Broknes Peninsula, Larsemann Hills, Antarctica

引用

Advances in Polar Science 2023年第4期34卷 318-339页

作者： Sergey KAKAREKA Tamara KUKHARCHYK Yury GIGINYAK Peter KURMAN Institute for Nature Management National Academy of Sciences of BelarusLaboratory of Transboundary PollutionMinsk 220076Belarus Scientific and Practical Center for Bioresources National Academy of Sciences of BelarusMinsk 220072Belarus Institute of Bioorganic Chemistry National Academy of Sciences of BelarusLaboratory of Physical and Chemical MethodsMinsk 220141Belarus

The article contributes to the study of the content of major and trace elements in various types of natural waters of the Broknes Peninsula,Larsemann Hills,Antarctica collected in January–February 2014 and 2020 during the 7th and 12th Belarusian Antarctic Expeditions.Samples of old(13 samples)and newly fallen snow(5),lakes(23)and groundwater(8)were analyzed.The content of 25 major and trace elements was determined using ICP-MS method,main anions was determined by titrimetric and turbidimetric methods.Good similarity chemical composition of snow,groundwater and lake waters in spite of differences in the content of major ions and trace elements has been obtained.The influence of marine salts on natural waters are analyzed,and their accumulation in lake waters especially in the endorheic small and shallow lakes in spite of ultra-oligotrophic atmospheric precipitates are shown.The spatial heterogeneity of groundwater and temporal and spatial heterogeneity of lake waters have been demonstrated.The results are important for understanding the variabilities of major and trace elements content in snow,groundwater and lake waters,and their relationship,as well as for identifying trends in their change,taking into account anthropogenic loads in the region and climate change.

关键词： Antarctica snow groundwater lake major element trace element

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Current state of research on microplastics in the marine- atmosphere environment of the Arctic region

引用

Advances in Polar Science 2023年第4期34卷 251-261页

作者： GONG Tianjiao XU Guojie CHEN Liqi ZHANG Miming China Meteorological Administration Aerosol-Cloud and Precipitation Key Laboratory Nanjing University of Information Science&TechnologyNanjing 210044China Polar and Marine Research Institute College of Harbor and Coastal EngineeringJimei UniversityXiamen 361021China Key Laboratory of Global Change and Marine-Atmospheric Chemistry(GCMAC)of Ministry of Natural Resources(MNR) Third Institute of Oceanography(TIO)Xiamen 361005China

Microplastics,plastic particles smaller than 5 mm in size,are a growing source of environmental pollution.Microplastic pollution has been observed in situ in the remote Arctic,where it has been found in the land,sea,cryosphere,and atmosphere.This review summarizes the sample pretreatment techniques and analytical methods commonly used in microplastic research,as well as the pollution status of microplastics in the Arctic,their sources,and their effects on the environment.In the Arctic,the size distribution of microplastics is more inclined to small-scale aggregation,the shape of microplastics is mostly fibrous,with the proportion of fibers often accounting for more than 70%.There are marked differences among studies in terms of abundance and polymer composition,but polyester is generally dominant in seawater.Many microplastic particles are transported to the Arctic by ocean currents and rivers,but atmospheric transport and deposition are slowly being recognized as an important transport route.Sea ice is particularly important for the temporary storage,transport,and release of Arctic microplastics.The average storage of microplastics in sea ice was estimated to be approximately 6.1×108 items.Given their properties,microplastics can affect glacier melting,sea surface temperature changes,and even the carbon cycle.Urgent measures must be taken to improve research standards and overcome sampling difficulties in the Arctic region to achieve time continuity and large-scale distribution patterns of Arctic microplastics.

关键词： microplastics Arctic atmosphere environmental effects sea ice seawater snow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

snow damages on trees of an uneven age in mixed broadleaf forests:effects of topographical conditions and tree characteristics

引用

Journal of Forestry Research 2019年第4期30卷 1383-1394页

作者： Farzam Tavankar Angela Lo Monaco Mehrdad Nikooy Rachele Venanzi Amireslam Bonyad Rodolfo Picchio Department of Forestry Khalkhal BranchIslamic Azad UniversityKhalkhalIran Department of Agriculture and Forest Sciences(DAFNE) Tuscia UniversityVia S.Camillo de Lellis01100 ViterboItaly Department of Forestry Faculty of Natural ResourcesUniversity of GuilanSomehsaraIran

snow damage on natural stands is an important problem concerning mountainous forest management.In the present research,the frequency and intensity of heavy snow damage on natural stands and the relationship of damages with characteristics of trees,stand and topography were studied in mountainous forests of northern Iran.A systematic sampling design was applied to the study area(140 ha),with 122 circular plots.The grid dimension was100 m and each plot area was 1000 m^2.The four types of snow damage to trees include:crown damage(8.6%),stem breakage(5.4%),uprooting(3.2%),and bending(1.4%).The frequency of crown damage grew with an increase inthe diameter at breast height(DBH),while the frequency of stem breakage,uprooting and bending decreased with an increase the DBH.The frequency of crown damage,stem breakage,and total damages was related to tree species(psnow damage.The amount of damage grew with increasing elevation and slope angle and decreased with increasing soil depth.Young trees(DBHsnow damage than other trees.snow damage decreased by as the trees in the stand became more mixed in age.The susceptibility of trees to snow damage increased by height and slenderness coefficient.With adequate silvicultural operation,snow damage can be reduced to a minimum level in these natural forests.

关键词： Mixed forest Slenderness coefficient snow damage Stem breakage Uprooting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

snow cover estimation from MODIS and Sentinel-1 SAR data using machine learning algorithms in the western part of the Tianshan Mountains

引用

Journal of Mountain Science 2020年第4期17卷 884-897页

作者： LIU Yang CHEN Xi HAO Jian-Sheng LI Lan-hai State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Ili Station for Watershed Ecosystem Research Chinese Academy of SciencesXinyuan 835800China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China Xinjiang Regional Center of Resources and Environmental Science Instrument Chinese Academy of SciencesUrumqi 830011China

Obtaining the spatial distribution of snow cover in mountainous areas using the optical image of remote sensing technology is difficult because of cloud and fog. In this study, the object-based principle component analysis–support vector machine(PCA–SVM) method is proposed for snow cover mapping through the integration of moderateresolution imaging spectroradiometer(MODIS) snow cover products and the Sentinel-1 synthetic aperture radar(SAR) scattering characteristics. First, derived from the Sentinel-1 A SAR images, the feature parameters, including VV/VH backscatter, scattering entropy, and scattering alpha, were used to describe the variations of snow and non-snow covers. Second, the optimum feature combinations of snow cover were formed from the feature parameters using the principle component analysis(PCA) algorithm. Finally, using the optimum feature combinations, a snow cover map with a 20 m spatial resolution was extracted by means of an object-based SVM classifier. This method was applied in the study area of the Xinyuan County, which is located in the western part of the Tianshan Mountains in Xinjiang, China. The accuracies in this method were analyzed according to the data observed at different experimental sites. Results showed that the snow cover pixels of the extraction were less than those in the actual situation(FB1=93.86, FB2=59.78). The evaluation of the threat score(TS), probability of detection(POD), and false alarm ratio(FAR) for the snow-covered pixels obtained from the two-stage SAR images were different(TS1=86.84, POD1=90.10, FAR1=4.01;TS2=56.40, POD2=57.62, FAR2=3.62). False and misclassifications of the snow cover and non-snow cover pixels were found. Although the classifications were not highly accurate, the approach showed potential for integrating different sources to retrieve the spatial distribution of snow covers during a stable period.

关键词： snow cover Estimation Sentinel-1/2 MODIS Machine learning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：