• Title/Summary/Keyword: China Seas

Search Result 137, Processing Time 0.038 seconds

PHYTOPLANKTON BLOOMING AND OCEANIC CONDITIONS IN THE SEAS AROUND THE SPRATLY ISLANDS

  • Dien, Tran Van;Tang, DanLing;Kawamura, Hiroshi
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.529-532
    • /
    • 2006
  • The oceanic currents in the South China Sea (SCS) are strongly influenced by monsoon winds. A review on the SCS currents has indicated that previous studies have pointed out an anticyclonic circulation in the area between the southern Vietnam coast and the Spratly Islands. However, its detail is not understood because of less information of in situ observations. The physical-biological interaction is quite new research area, which has been established and promoted by means of the ocean color remote sensing. Temporal/spatial variability of the phytoplankton activities are well captured by ocean color (OC) -derived Chlorophyll-a images. Combining the OC-Chl-a and the other high-resolution satellite data (e.g., SST images), the biological aspects of oceanographic variation is well described. The blooming phenomena in the area between the southern Vietnam coast and the Spratly islands are further investigated. Change in the wind-system related to the El Nino generates upwelling/SST-cooling in the sea south of the Spratly Islands through the air-sea-land interaction was studied. The seasonal upwelling is also associated with the harmful algal bloom (HAB) off two side of Indochina Peninsula have investigated. The seasonal variation of SCS phytoplankton blooming and related oceanic conditions in Vietnam coast was observed. Ocean color satellite data has effective contribute to study the oceanic condition and phytoplankton blooming in South China Sea.

  • PDF

A Study on the Track of Typhoon in the Northwest Pacific Ocean (북태평양 서부에서 발생하는 강풍의 진로에 관한 연구)

  • 윤종화
    • Journal of the Korean Institute of Navigation
    • /
    • v.18 no.3
    • /
    • pp.19-30
    • /
    • 1994
  • By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.

  • PDF

Measurements of Atmospheric Gaseous Elemental Mercury over the Yellow Sea during 2007-2008

  • Nguyen, Duc Luong;Kim, Jin-Young;Shim, Shang-Gyoo;Jin, Hyoun-Cher;Zhang, Xiao-Shan
    • Proceedings of the Korea Air Pollution Research Association Conference
    • /
    • 2009.10a
    • /
    • pp.255-258
    • /
    • 2009
  • This study shows that the $Hg^0$ background concentration over the Yellow Sea was generally higher than those observed over other seas/oceans around the world. $Hg^0$ concentrations measured in the urban stomophere were significantly higher than the background concentration in China. Elevated $Hg^0$ concentrations at Deokjeok Island in Korea were attributed to long-range transport of mercury from high emission areas in China.

  • PDF

The Development Option for Korea Air Defense Identification Zone(KADIZ) (한국방공식별구역(KADIZ) 발전방안)

  • Kim, Dongsoo;Hong, Sungpyo;Chong, Mangseok
    • Journal of Aerospace System Engineering
    • /
    • v.10 no.1
    • /
    • pp.127-132
    • /
    • 2016
  • Recently, China & Japan have expanded their responding ADIZ(Air Defence Identification Zone) to implement each Government's maritime policy and to project their Air Power in preparation for maritime provocation & contingency, especially over the piled area where East Asia countries have claimed to have maritime jurisdiction one another. So this is to guide the Development Option for Korea Air Defence Identification Zone to cope with the maritime intentions of the neighboring countries, considering the international law for ADIZ, the maritime policy and the maritime sovereign & jurisdiction area of the Republic of Korea, etc.

A Review of Tidal Models for the East China and Yellow Seas (동중국해와 황해의 조석수치모형에 관한 과거의 연구)

  • Choi, Byung-Ho;Guohong Fang
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.5 no.2
    • /
    • pp.151-171
    • /
    • 1993
  • The review presented herein covers most of previous works on tidal models of the East China Sea and the Yellow Sea performed over past two decades including some earlier efforts. General description of tides in the region is given based on both numerically derived tidal charts, current ellipses and intelligently drawn empirical tidal charts. Some aspects of bottom tidal dissipation, tidal mixing, tidal sedimentation and tidal circulation utilizing the numerical tidal models are presented, and further discussions on inherent problems and development of the models are also given.

  • PDF

The Making of Southeast Asian Culture and Society (동남아시아 문화와 사회의 형성)

  • Cho, Hung-guk
    • SUVANNABHUMI
    • /
    • v.1 no.1
    • /
    • pp.1-25
    • /
    • 2009
  • The diversity of Southeast Asian culture and society has been made by two factors: geopolitical environment and colonialism. The geopolitical position of the region between China Seas and Indian Ocean has made it possible that diverse cultures from Northeast Asia especially China and India, Middle East and Europe have flowed into the region. The fact that Southeast Asia was colonized by various European nations has provided additional diversity. The diversity manifests itself most clearly in the culture of Southeast Asia which has various layers: On the bottom lay the indigenous one, and above it Chinese and Indian and Islamic cultures and finally European one.

  • PDF

Water and Salt Budgets for the Yellow Sea

  • Lee, Jae-Hak;An, Byoung-Woong;Bang, Inkweon;Hong, Gi-Hoon
    • Journal of the korean society of oceanography
    • /
    • v.37 no.3
    • /
    • pp.125-133
    • /
    • 2002
  • Water and salt budgets in the Yellow Sea and Bohai are analyzed based on the historical data and CTD data collected recently using box models. The amounts of volume transport and of water exchange across the boundary between the Yellow and East China Seas are estimated to be 2,330-2,840 $\textrm{km}^3$/yr and 109-133 $\textrm{km}^3$/yr, respectively, from the one-layer box model. Corresponding water residence time is 5-6 years. In the Bohai, water residence time is twice as long as that in the Yellow Sea, suggesting that the Yellow Sea and Bohai cannot be considered as a single system in the view of water and salt budgets. The results indicate that water and salt budgets in the Yellow Sea depend almost only on the water exchange between the Yellow and East China Seas. The computation with the coupled two-layer model shows that water residence time is slightly decreased to 4-5 years for the Yellow Sea. In order to reduce uncertainties for the budgeting results the amount of the discharge from the Changjiang that enters into the Yellow Sea, the vertical advection and vertical mixing fluxes across the layer interface have to be quantified. The decreasing trend of the annual Yellow River outflow is likely to result that water residence time is much longer than the current state, especially for the Bohai. The completion of the Three Gorges dam on the Changjiang may be change the water and salt budgets in the Yellow Sea. It is expected that cutting back the discharge from the Changjiang by 10% through the dam would increase water residence time by about 10%.

A Numerical Tidal Model for the Southeast Asian Seas (南東 아시아 海域의 潮汐 數値 模型)

  • Byung Ho Choi;Duk Gu Kim;Dong Hoon Kim
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.9 no.2
    • /
    • pp.63-73
    • /
    • 1997
  • The tidal propagation for the Southeast Asian Seas is described via a high-resolution, two-dimensional hydrodynamic model by the equilibrium tide and co-oscillating tide at the Straits. Computed tidal distributions of four major semidiurnal tides (M$_2$, S$_2$, $K_2$, $N_2$) and four major diurnal tides (K$_1$, $O_1$, P$_1$, Q$_1$) are presented and results are also compared with coastal observations archived in IHO global tidal data base (Canadian Marine Environmental Data Service) and existing tidal charts including Schwiderski GOTD(Global Ocean Tidal Data) maps.

  • PDF

Genetic diversity, relationships and demographic history of the small yellow croaker, Larimichthys polyactis (Pisces: Sciaenidae) from Korea and China inferred from mitochondrial control region sequence data

  • Kim, Jin-Koo;Kim, Yeong-Hye;Kim, Mi-Jung;Park, Jung-Youn
    • Animal cells and systems
    • /
    • v.14 no.1
    • /
    • pp.45-51
    • /
    • 2010
  • Genetic variation was surveyed at the mitochondrial control region (766bp) to test for the presence of genetic stock structure in the small yellow croaker, Larimichthys polyactis from the Yellow and East China Seas. Individuals of the small yellow croaker could not be distinguished on the basis of its location, as demonstrated using the neighbor-joining (NJ) method, unweighted pair-group method, arithmetic average (UPGMA) and the minimum spanning network (MSN). Analysis of molecular variance revealed no significant differences among collections of the small yellow croaker taken from the four locations (two locations each in Korea and China). Neutrality tests and a mismatch distribution analysis indicated that this species has recently expanded. Our findings suggest either that the small yellow croaker has a high migration capability that enables it to overcome the effects of genetic drift, or that this species expanded relatively recently and has not yet had sufficient time to differentiate.

Biogeographical Distribution and Diversity of Bacterial Communities in Surface Sediments of the South China Sea

  • Li, Tao;Wang, Peng
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.5
    • /
    • pp.602-613
    • /
    • 2013
  • This paper aims at an investigation of the features of bacterial communities in surface sediments of the South China Sea (SCS). In particular, biogeographical distribution patterns and the phylogenetic diversity of bacteria found in sediments collected from a coral reef platform, a continental slope, and a deep-sea basin were determined. Bacterial diversity was measured by an observation of 16S rRNA genes, and 18 phylogenetic groups were identified in the bacterial clone library. Planctomycetes, Deltaproteobacteria, candidate division OP11, and Alphaproteobacteria made up the majority of the bacteria in the samples, with their mean bacterial clones being 16%, 15%, 12%, and 9%, respectively. By comparison, the bacterial communities found in the SCS surface sediments were significantly different from other previously observed deep-sea bacterial communities. This research also emphasizes the fact that geographical factors have an impact on the biogeographical distribution patterns of bacterial communities. For instance, canonical correspondence analyses illustrated that the percentage of sand weight and water depth are important factors affecting the bacterial community composition. Therefore, this study highlights the importance of adequately determining the relationship between geographical factors and the distribution of bacteria in the world's seas and oceans.