• Title/Summary/Keyword: Sea

Search Result 17,982, Processing Time 0.053 seconds

VULNERABILITY OF KOREAN COAST TO THE SEA-LEVEL RISE DUE TO $21^{ST}$ GLOBAL WARMING

  • Cho Kwangwoo;Maeng Jun Ho;Yun Jong-Hwui
    • Proceedings of KOSOMES biannual meeting
    • /
    • 2003.11a
    • /
    • pp.219-225
    • /
    • 2003
  • The present study intends to assess the long-term steric sea-level change and its prediction, and potential impacts to the sea-level rise due to the 21st global warming in the coastal zone of the Korea in which much socioeconomic activities have been occurred. The analysis of the 23 tide-gauge data near Korea reveals the overall mean sea-level trend of 2.31 mm/yr.In the satellite altimeter data (Topex/Poseidon and ERS), the sea-level trend in the East Sea is 4.6mm/yr. Both are larger than those of the global average value. However, it is quite questionable that the sea-level trends with the tide-gauge data on the neighboring seas of Korea relate to global warming because of the relatively short observation period and large spatial variability. It is also not clear whether the high trend of altimeter data in the East Sea is related to the acceleration of sea level rise in the Sea, short response time of the Sea, natural variability such as decadal variability, short duration of the altimeter. The coastal zone of Korea appears to be quite vulnerable to the 21st sea level rise such that for the I-m sea level rise with high tide and storm surge, the inundation area is 2,643 km2, which is about $1.2\%$ of total area and the population in the risk areas of inundation is 1.255 million, about $2.6\%$ of total population. The coastal zone west of Korea is appeared to be the most vulnerable area compared to the east and south. In the west of the Korea, the North Korea appears to be more vulnerable than South Korea. In order to cope with the future possible impact of sea-level rise to the coastal zone of Korea effectively, it is essential to improve scientific information in the sea-level rise trend, regional prediction, and vulnerability assessment near Korean coast.

  • PDF

Effects of the Dietary Inclusion of Sea Mud on the Growth and Body Composition of Juvenile Sea Cucumbers Apostichopus japonicus (배합사료 내 펄 분말 첨가가 어린 해삼(Apostichopus japonicus)의 성장 및 체조성에 미치는 영향)

  • Kim, Kyoung-Duck;Bae, Ki-Min;Han, Hyon-Sob;Kim, Kang-Woong;Lee, Bong-Joo;Kim, Sung-Sam;Park, Kie-Young;Kwon, O-Nam
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.49 no.1
    • /
    • pp.26-29
    • /
    • 2016
  • This study investigated the effects of dietary inclusion of sea mud on growth and body composition of juvenile sea cucumber Apostichopus japonicus. In experiment 1, three experimental diets containing sea mud at the level of 0, 30 and 60% were prepared. After feeding trial for 7 weeks, survival was not significantly different among groups. Final mean weight of sea cucumber fed the experimental diet without sea mud supplementation was significantly higher than that of sea cucumber fed the diet containing 30 and 60% sea mud. In experiment 2, three experimental diets containing sea mud at the levels of 0, 15 and 30% were prepared. After feeding trial for 19 weeks, survival was not significantly different among groups. Final mean weight of sea cucumber fed the diet without sea mud supplementation was not significantly different from that of 15%, but was significantly higher than that of sea cucumber fed the diet containing 30% sea mud. It was concluded that dietary inclusion of sea mud may inhibit growth of sea cucumber.

Taxonomical Reexamination and Distribution of Sea horses in the Southern Sea of South Korea (한국 남해연안에 서식하는 해마류의 분포와 분류학적 재검토)

  • KIM, Tae-Il;HAN, Won-Min;LEE, Geun Eui;LEE, Ki-Won
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.28 no.4
    • /
    • pp.1159-1170
    • /
    • 2016
  • This study examines the distribution and taxonomy of sea horses in South Korea, specifically sea horses that were caught in the Southern Sea, centering on Yeosu, South Korea. Specimen collection methods The samples were collected by set net, skimming nets, dragnets, and landing nets on a boat, as well as scuba diving. A total of 128 sea horses belonging to three species were collected. To investigate the exact distribution pattern, the catch per unit effort and the population density per $1,000m^2$ were calculated for each site in the Southern Sea. The result shows the highest catch by set nets was 29 sea horses a day in Site B at Dolsan-eup, Port Impo, and the highest catch by scuba diving was 8 sea horses a day in Site B at Gijang-gun, Busan. The highest population density was 61.2 sea horses in the coast of Gijang-gun, Busan. Genetic information analysis and morphological analysis were performed for determination of species. As a result, four Hippocampus trimaculatus, (flat-faced sea horses), 45 Hippocampus coronatus (Crowned sea horses), and 79 Hippocampus mohnikei (Japanese sea horses) were distinguished.

Quality Characteristics of Sulgidduk by the Addition of Sea tangle (다시마를 첨가한 설기떡의 품질 특성)

  • Cho Myung-Suk;Hong Jin-Sook
    • Korean journal of food and cookery science
    • /
    • v.22 no.1 s.91
    • /
    • pp.37-44
    • /
    • 2006
  • This study attempted to determine the optimum addition amount of sea tangle to rice flour in the preparation of sea tangle Sulgidduk. The moisture content of sea tangle Sulgidduk with added sea tangle was $39\sim53%$. With increasing addition of sea tangle, the L-value was decreased. The a- and b-values were the highest at the 25% level, there is no respective comparison here. In the mechanical evaluation of sea tangle Sulgidduk, the hardness was the lowest in the 35% sea tangle Sulgidduk during storage. The adhesiveness and cohesiveness did not differ significantly with the addition of sea tangle for storage period. The springiness was the highest at the 25% level during storage. The gumminess and brittleness were the lowest at the 35% level and the highest at the 0% level during storage. In the sensory evaluation of sea tangle Sulgidduk, the acceptance of the color, taste and chewiness characteristics was the highest at the 25% level. Sea tangle Sulgidduk with the addition of 25% of sea tangle to rice flour was found to be the best recipe in terms of the sensory qualities of color, taste, chewiness and overall acceptability.

Sensitivity Study of Simulated Sea-Ice Concentration and Thickness Using a Global Sea-Ice Model (CICE) (전구 해빙모델(CICE)을 이용한 해빙 농도와 해빙 두께 민감도 비교)

  • Lee, Su-Bong;Ahn, Joong-Bae
    • Atmosphere
    • /
    • v.24 no.4
    • /
    • pp.555-563
    • /
    • 2014
  • The impacts of dynamic and thermodynamic schemes used in the Community Ice CodE (CICE), the Los Alamos sea ice model, on sea ice concentration, extent and thickness over the Arctic and Antarctic regions are evaluated. Using the six dynamic and thermodynamic schemes such as sea ice strength scheme, conductivity scheme, albedo type, advection scheme, shortwave radiation method, and sea ice thickness distribution approximation, the sensitivity experiments are conducted. It is compared with a control experiment, which is based on the fixed atmospheric and oceanic forcing. For sea ice concentration and extent, it is found that there are remarkable differences between each sensitivity experiment and the control run over the Arctic and Antarctic especially in summer. In contrast, there are little seasonal variations between the experiments for sea ice thickness. In summer, the change of the albedo type has the biggest influence on the Arctic sea ice concentration, and the Antarctic sea ice concentration has a greater sensitivity to not only the albedo type but also advection scheme. The Arctic sea ice thickness is significantly affected by the albedo type and shortwave radiation method, while the Antarctic sea ice thickness is more sensitive to sea ice strength scheme and advection scheme.

Abnormal Winter Melting of the Arctic Sea Ice Cap Observed by the Spaceborne Passive Microwave Sensors

  • Lee, Seongsuk;Yi, Yu
    • Journal of Astronomy and Space Sciences
    • /
    • v.33 no.4
    • /
    • pp.305-311
    • /
    • 2016
  • The spatial size and variation of Arctic sea ice play an important role in Earth's climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP) F13 Special Sensor Microwave/Imagers (SSMI) and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA).

Estimation of Instantaneous Sea Level Using SAR Interferometry

  • Kim, Sang-Wan;Won, Joong-Sun
    • Korean Journal of Remote Sensing
    • /
    • v.18 no.5
    • /
    • pp.255-261
    • /
    • 2002
  • Strong and coherent radar backscattering signals are observed over oyster sea farms that consist of artificial structures installed on the bottom. We successfully obtained 21 coherent interferograms from 11 JERS-1 SAR data sets even though orbital baselines (up to 2 km) or temporal baselines (up to 1 year) were relatively large. The coherent phases preserved in the sea farms are probably formed by double bouncing from sea surface and the sea farming structures, and consequently they are correlated with tide height (or instantaneous sea level). Phase unwrapping is required to restore the absolute sea level. We show that radar backscattering intensity is roughly correlated with the sea surface height, and utilize the fact to determine the wrapping counts. While the SAR image intensity gives a rough range of absolute sea level, the interferometric phases provide the detailed relative height variations within a limit of $2{\pi}$ (or 15.3 cm) with respect to the sea level at the moment of the master data acquisition. A combined estimation results in an instantaneous sea level. The radar measurements were verified using tide gauge records, and the results yielded a correlation coefficient of 0.96 with an r.m.s. error of 6.0 cm. The results demonstrate that radar interferometry is a promising approach to sea level measurement in the near coastal regions.

Paleoenvironmental Changes in the Northern East China Sea and the Yellow Sea During the Last 60 ka

  • Nam, Seung-Il;Chang, Jeong-Hae;Yoo, Dong-Geun
    • The Korean Journal of Quaternary Research
    • /
    • v.17 no.2
    • /
    • pp.165-165
    • /
    • 2003
  • A borehole core ECSDP-102 (about 68.5 m long) has been investigated to get information on paleoenvironmental changes in response to the sea-level fluctuations during the period of late Quaternary. Several AMS $\^$14/C ages show that the core ECSDP-102 recorded the depositional environments of the northern East China Sea for approximately 60 ka. The Yangtze River discharged huge amounts of sediment into the northern East China Sea during the marine isotope stage (MIS) 3. In particular, $\delta$$\^$13/Corg values reveal that the sedimentary environments of the northern East China Sea, which is similar to the Holocene conditions, have taken place three times during the MIS 3. It is supported by the relatively enriched $\delta$$\^$13/Corg values of -23 to -21$\textperthousand$ during the marine settings of MIS 3 that are characterized by the predominance of marine organic matter akin to the Holocene. Furthermore, we investigated the three Holocene sediment cores, ECSDP-101, ECSDP-101 and YMGR-102, taken from the northern East China Sea off the mouth of the Yangtze River and from the southern Yellow Sea, respectively. Our study was focused primarily on the onset of the post-glacial marine transgression and the reconstructing of paleoenvironmental changes in the East China Sea and the Yellow Sea during the Holocene. AMS $\^$14/C ages indicate that the northern East China Sea and the southern Yellow Sea began to have been flooded at about 13.2 ka BP which is in agreement with the initial marine transgression of the central Yellow Sea (core CC-02). $\delta$$\^$18/O and $\delta$$\^$13/C records of benthic foraminifera Ammonia ketienziensis and $\delta$$\^$13/Corg values provide information on paleoenvironmental changes from brackish (estuarine) to modem marine conditions caused by globally rapid sea-level rise since the last deglaciation. Termination 1 (T1) ended at about 9.0-8.7 ka BP in the southern and central Yellow Sea, whereas T1 lasted until about 6.8 ka BP in the northern East China Sea. This time lag between the two seas indicates that the timing of the post-glacial marine transgression seems to have been primarily influenced by the bathymetry. The present marine regimes in the northern East China Sea and the whole Yellow Sea have been contemporaneously established at about 6.0 ka BP. This is strongly supported by remarkably changes in occurrence of benthic foraminiferal assemblages, $\delta$$\^$18/O and $\delta$$\^$13/C compositions of A. ketienziensis, TOC content and $\delta$$\^$13/Corg values. The $\delta$$\^$18/O values of A. ketienziensis show a distinct shift to heavier values of about 1$\textperthousand$ from the northern East China Sea through the southern to central Yellow Sea. The northward shift of $\^$18/O enrichment may reflect gradually decrease of the bottom water temperature in the northern East China Sea and the Yellow Sea.

  • PDF

The study on the safety of Sea Lane for LSA (경량항공기용 착수대 안전성 확보에 대한 연구)

  • Shin, Dai-Won
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.25 no.2
    • /
    • pp.1-11
    • /
    • 2017
  • In this study, we surveyed the regulations of the Seaplane base and Sea Lane for the Light Sport Aircraft(LSA), and analyzed the water landing/takeoff roll distance of LSA in Korea. Based on the information, we presented the situation of the Sea Lane and the Sea Lane Protection Zone concept, to ensure the Rectangle type Sea Lane and the Omni direction type Sea Lane. We analyzed the availability elements of the safety of Sea Lane for LSA in Korea. A Rectangle type Sea Lane 350 meters long and 40 meters wide, the diameter 350 meters for the An Omni direction type Sea Lane.

SEA LEVEL VARIATIONS IN THE LONG TERM IN THE EAST SEA OF KOREA

  • Cho, Keun-Han;Kim, Hee-Jong;Lee, Dong-In;Yoon, Hong-Joo
    • Proceedings of the KSRS Conference
    • /
    • 2007.10a
    • /
    • pp.37-40
    • /
    • 2007
  • Satellite altimetric data from 1993 to 2006 are used to study sea level variations in the long tenn in the East Sea. The trend of sea level in the East Sea is rising 4.16 mm/yr and indicate that it rose 5.82 cm in 2006 against to 1993. The South Ses is the fastest in the study areas (4.89 mm/yr, 6.84cm) and the Yellow Sea is 4.10 mm/yr and 5.75cm, respectively. The both of Mokho coast and Ulleung island are minimal sea level in March to May and maximal sea level in September to November. For periods above 20.9days, coherences are found to be higher than 95% confidence level, and the phase differences are near zero.

  • PDF