• Title/Summary/Keyword: Indian Ocean

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Trace Element in the Indian Ocean: Current Research Trends and Future Needs (인도양에서 미량원소 연구 동향 및 향후 연구 방향)

  • Kim, Intae
    • Ocean and Polar Research
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    • v.43 no.4
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    • pp.335-352
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    • 2021
  • Trace elements in the ocean have been known as essential micronutrients for the primary production of phytoplankton and the growth of marine organisms. The GEOTRACES program beginning in the mid-2000 provided a new understanding of the distribution, origin and behavior of trace elements in the ocean, together with the establishment of both clean seawater sampling and trace element analysis techniques. The Indian Ocean, one of the major oceans, is relatively the least explored area, despite playing an important role in global climate variability. Although trace element observations have recently been conducted in the Indian Ocean by Japanese-and Indian scientists, relatively not much study has been done compared to the Atlantic, Pacific and Polar Regions. Recently, together with the launch of R/V Isabu, a 5,000-ton grade large- and comprehensive research vessel, the observations of trace elements has been conducted in the Indian Ocean for the first time in Korea since 2018. In this paper, we introduce the key results of currently conducted GEOTRACES expedition in the Indian Ocean to present future trace element research directions in the Indian Ocean, and also reviewed the preliminary results in the Indian Ocean studies from Korea. In the 2020s, new Indian Ocean GEOTRACES projects are planned around European countries, and it is time for Korea to prepare for the next phase of the trace element study in the Indian Ocean in line with these international trends.

Ocean Dynamic Processes Responsible for the Interannual Variability of the Tropical Indian Ocean SST Associated with ENSO

  • Kug, Jong-Seong;An, Soon-Il
    • Atmosphere
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    • v.20 no.2
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    • pp.211-219
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    • 2010
  • The interannual variability of the tropical Indian Ocean SST is investigated by analyzing the ocean assimilation data. It is significant that since 1970, ENSO events frequently followed the Indian Ocean Dipole event. The SST tendency due to the dynamical SST advections over the tropical Indian Ocean sufficiently overwhelms that due to other thermodynamic process during the fall and winter of ENSO. Especially, the strong cooling due to the anomalous vertical advection by the mean upwelling and the warming due to the horizontal advection are attributed to the cold SST during the fall and the warm SST during the winter, respectively. The significant warming between winter and spring over the southwestern Indian Ocean turns out to be due to the vertical advection of the mean subsurface temperature by the anomalous upwelling during the winter and the vertical advection of the anomalous subsurface temperature by the mean upwelling from winter to spring. We speculate that when the Indian Ocean Dipole events concurred with the ENSO, the surface wind is so strong enough as to generate the change in the SST dynamically and overwhelm the SST changes associated with other effects.

The Indian Ocean Scenario in the 14th Century Latin Crusade Tract: Possibilities of a World Historical Approach

  • Chakravarti, Ranabir
    • Asian review of World Histories
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    • v.3 no.1
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    • pp.37-58
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    • 2015
  • The paper examines, in the light of current historiography, the recent trends in the application and applicability of the World Historical studies on the Indian Ocean scenario. Calling for the combination of the breadth of the World Historical studies with the analysis of a historical scenario in its specific spatio-temporal context-instead of a synchronic approach-the present study takes a close look at commerce and politics in the western Indian Ocean in the light of an early 14th century Latin Crusade tract, How to Defeat the Saracens by William of Adam (Guillelmus Ade, Tractatus quomodo Sarraceni sunt expugnandi), a Dominican friar. The text offers remarkable insights into the interlocking of the Indian Ocean and the South Asian subcontinent with the Mamluk Sultanate, the Ilkhanid realm and the Crusades. The paper argues for what is now termed as braided and connected histories.

The Periplus of the Erythraean Sea : A Network Approach

  • SELAND, Eivind Heldaas
    • Asian review of World Histories
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    • v.4 no.2
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    • pp.191-205
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    • 2016
  • The Periplus of the Erythraean Sea is a Roman period guide to trade and navigation in the Indian Ocean. Justly famous for offering a contemporary and descriptive account of early Indian Ocean trade, the work has been subject to and a point of departure for numerous studies. Its extensive influence on scholarship is, however, also problematic, as it reflects the limited information and cultural and personal bias of its unknown author. Arguably this might have led scholars to overemphasise so-called western or Roman participation in early Indian Ocean trade. Network analysis allows us to map, visualize and measure interconnectedness in the Periplus Maris Erythraei. Many of these connections are not explicitly mentioned in the text, but by connecting not only places with places, but also products with places that export and import them, we get a partly different impression of Indian Ocean trade from that conventionally gathered from the Periplus. It allows us to ask questions about the relationship between coastal cabotage and transoceanic shipping, to identify regional trading circuits, and unexpected centres of long-distance exchange.

TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment) Program (태평양-인도양 해양순환 연구 프로그램)

  • Jeon, Dongchull;Kim, Eung;Shin, Chang Woong;Kim, Cheol-Ho;Kug, Jong Seong;Lee, Jae Hak;Lee, Youn-Ho;Kim, Suk Hyun
    • Ocean and Polar Research
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    • v.35 no.3
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    • pp.259-272
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    • 2013
  • One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The 'Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX)' is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1) to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2) to understand the large-scale oceanic-climatic variation including El Nino-Southern Oscillation (ENSO)/Warm Pool/Pacific Decadal Oscillation (PDO)/Indian Ocean Dipole (IOD), and 3) to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

Variability of Satellite-derived Chlorophyll-a Concentration in Relation to Indian Ocean Dipole (IOD) Variation (인도양 쌍극진동 변동에 따른 위성에서 추정된 표층 클로로필-a 농도 변화 연구)

  • Son, Young Baek;Kim, Suk Hyun;Kim, Sang-Hyun;Rho, TaeKeun
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.917-930
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    • 2017
  • To understand the temporal and spatial variations of surface chlorophyll-a concentration (Chl-a) distribution in the Indian Ocean ($30^{\circ}E{\sim}120^{\circ}E$, $30^{\circ}S{\sim}30^{\circ}N$) by the Indian Ocean Dipole (IOD), we conducted EOF and K means analyses of monthly satellite-derived Chl-a data in the region during 1998~2016 periods. Chl-a showed low values in the central region of the Indian Ocean and relatively high values in the upwelling region and around the marginal regions of the Indian Ocean. It also had a strong seasonal variation of Chl-a, showing the lowest value in the spring and the highest value in summer due to the change of the monsoon and current system. The EOF analysis showed that Chl-a variation in EOF mode 1 is related to ENSO (El $Ni{\tilde{n}}o$/Southern Oscillation) and that of mode 2 is linked to IOD. Both modes explained spatially opposite trends of Chl-a in the east and west Indian Ocean. From K means analysis, the Chl-a variation in the east and west Indian Ocean, and around India have relatively good relationship with IOD while that in the tropical and middle Indian Ocean closely associated with ENSO. The spatial and temporal distribution of Chl-a also showed distinct spatial and temporal variations depend on the different types of IOD events. IOD classifies two patterns, which occurred during the developing ENSO (First Type IOD) and the year following ENSO event (Second Type IOD). Chl-a variation in the First Type IOD started in summer and peaked in fall around the east and west Indian Ocean. Chl-a variation in the Second Type IOD occurred started in spring, peaked in summer and fall, and disappeared in winter. In the Chl-a variation related to IOD, developing process appearing in the Chl-a difference between the east and west Indian ocean was similar. Chl-a variation in the northern Indian Ocean were opposite trend with changing developing phase of IOD.

Species Composition and Catch of Korean Tuna Longline Fisheries in the Indian Ocean from 2010 to 2015 (인도양 해역 우리나라 원양 연승어업의 어획물 종조성과 어획동향(2010-2015년))

  • Ku, Jeong Eun;Lee, Sung Il;Kim, Doo Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.3
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    • pp.286-297
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    • 2018
  • We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

Causal Relationship Between Indian Ports' Originated Container Traffic and Total Transshipments of Port of Colombo: A Granger Causality Analysis

  • Bandara, Sooriya;Ryoo, Dong-Keun;Ahn, Ki-Myung
    • Journal of Navigation and Port Research
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    • v.42 no.5
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    • pp.357-364
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    • 2018
  • Colombo noticeably became the most economical gateway to the Indian subcontinent, in terms of cost as well as time. The Colombo Port Expansion Project (CPEP) started commencement with the purpose of accommodating mega ships, under the long-term strategies of making Colombo the hub of South Asia. In this context, the purpose of this study is to investigate the causal relationship between Indian ports' originated container traffic, and total transshipments of the port of Colombo, and also to identify the nature of the causality between the two variables, evaluating Granger causality test results. It finds unidirectional causality from total transshipments of Colombo to Indian ports' originated transshipments in the port of Colombo. It suggested that ongoing port expansion projects, opening up for new markets and attracting new shipping lines in the port of Colombo, have generated significant impact on Indian ports' container traffic, via the port of Colombo. Findings would be valuable for future forecasting of container traffic in Colombo port and the policy-making process in the port as well.

Characteristics on bycatch in Korean tuna purse seine fishery associated with FAD in the Indian Ocean by scientific observer programs (과학옵서버 조사에 의한 인도양 수역 한국 다랑어 선망선 FAD 조업의 부수어획실태)

  • LEE, Sung Il;KIM, Doo Nam;LEE, Kyounghoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.4
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    • pp.277-291
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    • 2020
  • In order to understand characteristics on bycatch of Korean tuna purse seine fishery, especially operations associated with Fish Aggregating Device (FAD) in the Indian Ocean, we conducted analyses related to bycatch by school association type (unassociated school, FAD associated school and log associated school) using the data collected by scientific observers from 2016 to 2018. The FAD used by Korean tuna purse seine fishery in the Indian Ocean was a drifting FAD, which belongs to non-entangling FADs according to the category proposed by the International Seafood Sustainability Foundation (ISSF). The target species of Korean tuna purse seine fishery are skipjack, yellowfin and bigeye tunas, accounting for 99% of the total catch. The ratio of bycatch was 0.97% in total catch and the discard accounted for less than 1%, indicating that most catch was retained on board. In terms of bycatch ratio by school association type, it accounted for 0.12% for unassociated school, 1.09% for FAD associated school and 1.25% for log associated school. As for the catch proportion of shark species by school association type, it accounted for 0.01% for unassociated school, 0.11% for FAD associated school and 0.10% for log associated school, which showed that unassociated school type was the lowest to affect bycatch of non-target and shark species. Given the proportion of bycatch compositions, however, it is considered that FAD associated school of Korean tuna purse seine fishery has less caught bycatch species of non-target and shark, compared to other fleets operating in the Indian Ocean.