• Title/Summary/Keyword: Svalbard

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High Resolution Ocean Color Products Estimation in Fjord of Svalbard, Arctic Sea using Landsat-8 OLI (Landsat-8 OLI를 이용한 북극해 스발바드 피요르드의 고해상도 Ocean Color Product 산출)

  • Kim, Sang-Il;Kim, Hyun-Cheol;Hyun, Chang-Uk
    • Korean Journal of Remote Sensing
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    • v.30 no.6
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    • pp.809-816
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    • 2014
  • Ocean Color products have been used to understand marine ecosystem. In high latitude region, ice melting optically influences the ocean color products. In this study, we assessed optical properties in fjord around Svalbard Arctic sea, and estimated distribution of chlorophyll-a and suspended sediment by using high resolution satellite data, Landsat-8 Operational Land Imager (OLI). To estimate chlorophyll-a and suspended sediment concentrations, various regression models were tested with different band ratio. The regression models were not shown high correlation because of temporal difference between satellite data and in-situ data. However, model-derived distribution of ocean color products from OLI showed a possibility that fjord and coastal areas around Arctic Sea can be monitored with high resolution satellite data. To understand climate change pattern around Arctic Sea, we need to understand ice meting influences on marine ecosystem change. Results of this study will be used to high resolution monitoring of ice melting and its influences on the marine ecosystem change at high latitude. KOPRI (Korea Polar Research Institute) has been operated the Dasan station on Svalbard since 2002, and study was conducted using Arctic station.

Holocene Glaciomarine Sedimentation and Its Paleoclimatic Implication on the Svalbard Fjord in the Arctic Sea (북극해 스발바드 군도 피오르드에서 일어난 홀로세의 빙해양 퇴적작용과 고기후적 의미)

  • Yoon, Ho-Il;Kim, Yea-Dong;Yoo, Kyu-Cheul;Lee, Jae-Il;Nam, Seung-Il
    • Ocean and Polar Research
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    • v.28 no.1
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    • pp.1-12
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    • 2006
  • Analyses of sedimentological and geochemical parameters from two radiocarbon-dated sediment cores (JM98-845-PC and JM98-818-PC) retrieved from the central part of Isfjorden, Svalbard, in the Arctic Sea, reveal detailed paleoclimatic and paleoceanographic histories over the last 15,000 radiocarbon years. The overconsolidated diamicton at the base of core JM98-845-PC is supposed to be a basal till deposited beneath pounding glacier that had advanced during the LGM (Last Glacial Maximum). Deglaciation of the fjord commenced after the glacial maximum, marked by the deposition of interlaminated sand and mud in the ice-proximal zone by subglacial meltwater discharge, and prevailed between 13,700 and 10,800 yr B.P. with enriched-terrigenous organic materials. A return to colder conditions occurred at around 10,800 yr B.P. with a drop in TOC content, which is probably coincident with the Younger Dryas event in the North Atlantic region. At this time, an abrupt decrease of TOC content as well as an increase in C/N ratio suggests enhanced terrigenous input due to the glacial readvance. A climatic optimum is recognized between 8,395 and 2,442 yr B.P., coinciding with 'a mid-Holocene climatic optimum' in Northern Hemisphere sites (e.g., the Laurentide Ice sheet). During this time, as the sea ice receded from the fjord, enhanced primary productivity occurred in open marine conditions, resulting in the deposition of organic-enriched pebbly mud with evidence of TOC maxima and C/N ratio minima in sediments. Fast ice also disappeared from the coast, providing the maximum of IRD (ice-rafted debris) input. Around 2,442 yr B.p. (the onset of Neoglacial), pebbly mud, characterized by a decrease in TOC content, reflects the formation of more extensive sea ice and fast ice, which might cause decreased primary productivity in the surface water, as evidenced by a decrease in TOC content. Our results provide evidence of climatic change on the Svalbard fjords that helps to refine the existence and timing of late Pleistocene and Holocene millennial-scale climatic events in the Northern Hemisphere.

Spatial Characteristics of Meiobenthic Community of Kongfjorden Sediment in the Svalbard Island, the Arctic Sea (북극해 스발바드 군도 Kongsfjorden 퇴적물에 서식하는 중형저서동물 군집의 공간 특성)

  • Kim, Dong-Sung;Shin, Jae-Chul;Kang, Sung-Ho;Chung, Ho-Sung
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.299-309
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    • 2005
  • The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.

Monitoring on the Marine Environment and Phytoplankton of Kongsfjorden, Svalbard, Arctic (북극 스발바드섬 Kongsfjorden의 해양 환경 및 식물플랑크톤 모니터링 연구)

  • Kang, Sung-Ho;Kim, Yea-Dong;Kang, Jae-Shin;Yoo, Kyu-Cheul;Yoon, Ho-Il;Lee, Won-Cheol
    • Ocean and Polar Research
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    • v.25 no.2
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    • pp.213-226
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    • 2003
  • Kongsfjorden near Korean Arctic Station, Dasan, is a glacial fjord in the Svalbard archipelago, Arctic that is influenced by both Atlantic and Arctic water masses. During the Arctic field season August 2002, surface temperature, salinity, density, and phytoplankton biomass (chi a) was measured in Kongsfjorden. A total of 15 surface samples were collected for the phytoplankton related measurements. Chl a values ranged from 0.08 to 1.4mg chi a $m^{-3}$ (mean of 0.53mg chl a $m^{-3}$) in the overall surface stations. The highest values of the chi a concentrations (> 1.0mg chi a $m^{-3}$) were found near glacier in the northeastern part of Kongsfjorden. Nanoplanktonic (< $20{\mu}m$) phytoflagellates were important contributors for the increase of the chi a. The nano-sized phytoflagellates accounted for more than 90% of the total chi a biomass in the study area. Surface temperatures and salinities ranged from 2.5 to $7.18^{\circ}C$ (mean of $4.65^{\circ}C$) and from 22.55 to 32.97 psu (mean of 30.16 psu), respectively. The physical factors were not highly correlated with phytoplankton distribution. The character of surface water due to down-fjord wind was highly similar to phytoplankton distribution. Drifting ice, freshwater, and semdiment inputs from large tidal glaciers located in the inner part of Konsfjorden create steep physico- and biogeochemical environmental gradients along the length of this ford. The glacial inputs cause reduced biodiversity biomass and productivity in the pelagic community in the inner fjord. Primary production of benthic and pelagic microalgae is reduced due to the limited light levels in the turbid and mixed inner waters. The magnitude of glacial effects diminishes towards the outer fjord. Kongsfjorden is an important feeding ground fer marine mammals and seabirds. Especially, seabirds play the largest energy intake and also export nutrients for primary production of the marine microalgae. Kongsfjorden has received a lot of research attention as a site for exploring the impacts of climate changes. Dasan Station in Kongsfjorden will be an important Arctic site for monitoring and detecting future environmental changes.

Soil development and bacterial community shifts along the chronosequence of the Midtre Lovénbreen glacier foreland in Svalbard

  • Kwon, Hye Young;Jung, Ji Young;Kim, Ok-Sun;Laffly, Dominique;Lim, Hyoun Soo;Lee, Yoo Kyung
    • Journal of Ecology and Environment
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    • v.38 no.4
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    • pp.461-476
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    • 2015
  • Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.

Metal Concentrations in some Brown Seaweeds from Kongsfjorden on Spitsbergen, Svalbard Islands (스발바드군도 스피츠베르겐섬 콩스피요르드에 서식하는 갈조류의 중금속 농도)

  • Ahn, In-Young;Choi, Hee-Seon;Ji, Jung-Youn;Chung, Ho-Sung;Kim, Ji-Hee
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.121-132
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    • 2004
  • Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn were determined in four arctic brown algae (Laminaria saccharina, L. digitata, Alaria esculenta, Desmarestia aculeata) in an attempt to examine for their metal accumulation capacity and also to assess their contamination levels. Macroalgae were collected from shallow subtidal waters (<20m) of Kongsfjorden (Kings Bay) on Spitsbergen during the period of the late July to early August 2003. Metal concentrations highly varied between sampling sites, species and tissue parts. Input of melt-water laden with terrigenous sediment particles seemed to have a large influence on baseline accumulations of some metals (Al, Fe, Mn, Pb etc.) in the macroalgae, causing a significant spatial variation. There were also significant concentration differences between the young and old tissue parts in L. saccharina, L. digitata and A. esculenta. While Al, Fe, Mn, Pb were higher in the perennial parts (stipes and holdfast below meristematic region), Cd and As concentrations were significantly higher in the young blades above the meristematic region. Zn and Cr, on the other hand, showed little differences between the tissue parts. The highest metal concentrations were found in D. aculeata, which seems to be due to its filamentous fine branches leading to high surface/volume ratios. The lowest concentrations were found in the two Laminaria spp., the blades of which are thicker than D. aculeata and A. esculenta. No distinct signs of contamination were detected in the brown algal species analyzed. Added to this, the results of the present studies suggest the potential utility of L. saccharina, L. digitata and A. esculenta as biomonitors for metal pollution monitoring in this area.

A Gravity Characteristic of Svalbard Archipelago in Arctic by Using ArcGP Data (ArcGP 자료를 이용한 북극 스발바드 군도의 중력특성)

  • Yu Sang Hoon;Kim Chang Hwan;Hwang Jong Sun;Min Kyung Duck
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.255-260
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    • 2005
  • A Gravity characteristic of Svalbard archipelago in Arctic was studied by using ArcGP data. There are situated the Dasan science station. After bouguer correction, an edge effect of free-air anomaly, which is similar to topography, are not shown at passive continent margin, and after terrain correction with GTOPO30 data, gravity anomaly increases from continent to marine. that is deep connected with rise of Moho discontinuity. The correlation of topography and free-air anomaly shows that the isostasy of continent attains a little less than marine. After filtering, the residual anomaly are shown high and low anomalies related to fracture zone in continent and base depression or thick sedimentary layer in continental slope, marine.

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Prediction of ship resistance in level ice based on empirical approach

  • Jeong, Seong-Yeob;Choi, Kyungsik;Kang, Kuk-Jin;Ha, Jung-Seok
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.6
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    • pp.613-623
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    • 2017
  • A semi-empirical model to predict ship resistance in level ice based on Lindqvist's model is presented. This model assumes that contact between the ship and the ice is a case of symmetrical collision, and two contact cases are considered. Submersion force is calculated via Lindqvist's formula, and the crushing and breaking forces are determined by a concept of energy consideration during ship and ice impact. The effect of the contact coefficient is analyzed in the ice resistance prediction. To validate this model, the predicted results are compared with model test data of USCGC Healy and icebreaker Araon, and full-scale data of the icebreaker KV Svalbard. A relatively good agreement is achieved. As a result, the presented model is recommended for preliminary total resistance prediction in advance of the evaluation of the icebreaking performance of vessels.

AN IMPLEMENTATION OF EXTERNAL INTERFACE FOR PROVIDING THE KOMPSAT-2 CATALOGUE SERVICE

  • Park, Jae-Hong;Lee, Sun-Gu;Kim, Youn-Soo
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.236-239
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    • 2008
  • Korea Aerospace Research Institute (KARI) has been trying for utilizing the polar station in Svalbard, Norway to receive the KOMPSAT-2 images, which are distributed and applied directly for Europe Space Agency (ESA) users. Now, KARI is operating the SpaceCapture-2 system that provides the KOMPSAT-2 catalogue service via the internet, whereas ESA is operating the EOLI-SA tool that provides access to the online ESA catalogues of Earth Observation (EO) products. This paper describes external interface based on service-oriented architecture in order to provide the KOMPSAT-2 catalogue service from the SpaceCapture-2 system to the EOLI-SA tool. As the KOMPSAT-2 catalogue service is available in the EOLI-SA tool through an implementation of external interface, the extend use of KOMPSAT-2 imageries is expected.

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