• Proceedings of the KSRS Conference
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• v.2
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• pp.1007-1010
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• 2006

This study investigates the spatial structure of the total cloud liquid water content Q fields over the Northwest Pacific Ocean during winter monsoon. The distributions of Q have been estimated from the brightness temperatures of the ocean - atmosphere system $T_B(f)$, where f is frequency, measured by AQUA AMSR-E in January -March 2003. Marine strati (St) and stratocumuli (Sc) are typical for winter monsoon season. They were analysed using mainly high-frequency channel at f = 36.5 GHz, vertical polarisation. $T_B$ data were accompanied by the data on near surface wind speed, air temperature and humidity from the nearest meteorological stations. Tow one-dimensional spectra were computed for downwind and crosswind sections of Q fields. The AMSR-E antenna field of view (14-8 km) and the cloud field sizes (100-1000 km) restricted the spatial scales. The results of case study Jan 31 2003 are presented. Scale-invariant spectrum is typical. In the cases of extended St levels a spectral slope equals about -1.7, conforming to classical -5/3 of turbulence theory. For Sc cases the absolute magnitude of spectral slope is rather higher, as a rule. The value is about -2. In the case when cloud streets are presented, a strait line form of spectrum is less reliable with a slope being rather lower (about -1.4).

• Proceedings of the KSRS Conference
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• v.2
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• pp.688-691
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• 2006

The current system of the East China Sea, a marginal sea in the northwest Pacific, has a seasonal variation. The Changjiang Diluted Water, Chinese coastal water in the East China Sea, has different seasonal paths. It flows southward along the Chinese coast within a narrow band in winter and does northeastward the Korea/Tsushima Strait in summer, which has been a subject to many researchers. In particular, low salinity in the South Sea of Korea in 1996 and 1998 was in discord with the Changjiang River discharge and the Changjiang Diluted Water seems to play an important role in occurrence of red tide in the South Sea of Korea in 1997 and on the contrary, disappearance in the next year. These facts suggested that the Changjiang Diluted Water does not flow along the same path in every summer. According to the analyses for path of the Changjiang Diluted Water using ocean color images by SeaWiFS and salinity observations by shipboard CTD in August for recent years, the Changjiang Diluted Water in summer flowed within the range of direction from southeastward to north-northeastward anticlockwise. However, the Changjiang Diluted Water flowed northeastward toward Jeju Island of Korea for the most part. It is necessary to examine the influence of major factors on path variability of the CDW in summer such as surface wind, the Changjiang River discharge and background current.

• Proceedings of the KSRS Conference
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• v.1
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• pp.364-367
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• 2006

Nonlinear internal waves (NLIWs) are usually generated by nonlinear process on linear internal waves (IW). Near HengChun Ridge that links Taiwan and Luzon Islands, we found that there are linear internal waves following NLIW and they travel westward at different speed, about 1.5 m/s for IW and 2.9 m/s for NLIW. This phenomenon was observed on site with ship radar and echo sounders, and later verified with thermistor chain. West of Luzon Strait, the separation of NLIW are 5 km or more, while linear internal waves are lines of wave crests at nearly equal distance that is only a few hundred meters apart. The current hypothesis is that most of the energy of internal tide forms a beam that propagates upward from the eastern shoulder of ocean ridge and later interacts with sea surface and thermocline. The interaction with thermocline generates linear internal wave that propagate along the pycnocline at about 1.5 m/s. The interaction with sea surface scatters internal wave energy downward, ensonifies the water column and generates large nonlinear waves that propagate westward at 2.9 m/s as mode 1 in a waveguide.

• Animal Systematics, Evolution and Diversity
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• v.26 no.1
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• pp.21-27
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• 2010

Two marine euplotid ciliates, i.e. Euplotes cristatus Kahl, 1932 and E. minuta Yocom, 1930, were collected from the public waterfront of Incheon on the Yellow Sea and from the Songjeong Beach, Busan, in the Strait of Korea, respectively. These two species were verified as unrecorded species in Korea. These species were described based on live observation, protargol impregnation, and silver nitrate impregnation. In addition, the small subunit ribosomal DNA (SSU rDNA) sequences of the two species were compared with previously known sequences of the Euplotes species. Euplotes cristatus has an elongated oval form, size in vivo of $60-84{\times}38-68\;{\mu}m$, 35-50 adoral zone of membranelles (AZM), 10 frontoventral cirri (FVC), 5 transverse cirri (TC), 4-5 caudal cirri (CC), 8 dorsal kineties (DK), 10-16 dorsal cilia of middle DK, and silverline system of single-vannus type. Euplotes minuta has a small ovoid form ($44-53{\times}26-35\;{\mu}m$ in vivo), 31-41 AZM, 10 FVC, 5 TC, 4 CC, 9 DK, 10-12 dorsal cilia of middle DK, and silverline system of single-vannus type.

• 한국해양학회지
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• v.12 no.1
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• pp.13-32
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• 1977

In order to determine the distributional ecology, and to investigate factors influencing these features, the diatom communities in plankton at depths of one, twenty-five, fifty, and seventy five meters in the area were studied and measured over a fifteen month of period. Measurements of environmental factors including temperature and salinity and algal nutrients such as phosphate, silicate, nitrate, and ammonia were also made at the same depths and locations. The results indicate that the size of diatom communities and the species population changes were heavily dependent upon to season and location parameters as well as nutrient concentrations and hydrographic factors. Major factors influencing population distributions varied with principal species responsible for dominant species and species sucession. Two distinct distributional patterns in total diatom crop were observed in the study area. Maximum standing crop observed during spring and/or summer were related to the concentration of nutrients available at the onset of the spring bloom on a large scale. On a small scale, however, the distributions of total diatom standing crops were significantly correlated with both season/location factors and with hydrographic parameters as well. Vertical stratification of diatoms was observed only in the presence of the thermocline in the water column. Within the study area there was some seasonal consistancy in the composition of the species groups. However, some species association in these environments may vary with the change of season.

• 한국해양학회지
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• v.12 no.1
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• pp.7-12
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• 1977

Vertical mixing in the ocean affects the formation of water masses as well as the vertical distribution of nutrients and dissolved substances. this study is to investigate the effect of stability on the intensity of vertical transfer in the case of shallow and straitfied channel. It is found that the relation of the stability and vertical turbulent diffusion is given by K$\sub$z/ = -${\beta}$-(c+${\beta}$) / ${\alpha}$(E-1/${\alpha}$) where K$\sub$z/ and E denotes the vertical turbulent diffusion coefficient and stability, respectively. The empirical coefficients ${\alpha}$, ${\beta}$ and c depend on the magnitude of vertical components and stability, i.e., through thermocline intensity. The study indicates that the diffusivity of the surface mixed layer is (K$\sub$z/)=300∼1,200$\textrm{cm}^2$/sec, the thermocline layer is (K$\sub$z/)= 50∼200$\textrm{cm}^2$/sec and the cold layer is (K$\sub$z/)=200∼600$\textrm{cm}^2$/sec based on near- minimum least-squares error estimates from the regression analysis. An important result of our study comes out that the model is in accordance with the general trends of the effect of stability on the vertical turbulent diffusion coefficients in the case of shallow and strongly stratified channel.

• Ocean Science Journal
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• v.42 no.3
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• pp.165-170
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• 2007

The structure of the nematodes communities has been studied in the sediments on two sites located outside and under the layer of Ahnfeltia tobuchiensis (Kanno and Matsubara 1932; Makijenko 1970). Bottom sediments at the stations were represented by sands with a different degree of silting. Specific structure of nematodes at the stations was significantly different under the similar environmental conditions (water depth, dissolved oxygen saturation, salinity, temperature of the bottom layer and organic carbon content inside of the sediment). Nematodes dominated (75.7 %) in meiobenthos community under the layer of A. tobuchiensis where concentration of silt particles was 12 %. Representatives of the family Comesomatidae were dominant. Low index of species diversity and high Simpson domination index were detected in this community. Under a layer of A. tobuchiensis with the thickness of 30 cm concentration of the silt particles was 5.39 %; nematodes density was low and made 32.1 % of the general density of meiobenthos. Species of the families Xyalidae and Monoposthiidae were dominant. Outside of A. tobuchiensis, field percentage of silt particles was minimal (3.1 %) and representatives of families Cyatholaimidae and Axonolaimidae dominated. The specific structure of nematodes in this type of the ground is characterized by high index of species diversity and low level of domination.

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.124-128
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• 2000

A total of 46 Gnathagnus elongatus larvae, 2.7~8.7 mm BL (Body length), were collected by bongo net and trawl-shaped fish larvae net in the coastal area of Cheju Island during 1997~1999. This species was found in the coastal area of Cheju Island and the Korea Strait. This paper describes morphological features of these specimens throughout their development. 1) The soft ray of fin appeared at about 5 mm BL and attained to a fixed number at about 8.7 mm BL. 2) Pigments pattern changed suddenly about 3 mm BL. 3) A series of pigments in the upper and the lower part of the urostyle were found less than 4.3 mm BL. 4) The pigments of caudal peduncle were found more than 6 mm BL.

• Animal Systematics, Evolution and Diversity
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• v.18 no.1
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• pp.53-58
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• 2002

Some siphonophores and scyphomedusae were collected from the coasts of Hoopo(Sea of Japan) and Geojedo Island, Changson(Korea Strait) in Korea respectively. They identified into Porpita umbella O. F. Muller, 1776 of the order Siphonophora in the Hydrozoa and Dactylometra quinquecirrha L. Agassiz, 1862 of the Semaeostomeae in the Scyphozoa. P. umbella looks like a bule button. It's chitinous float is light brown and the other body protions are turquoise blue. D. quinquecirrha has four long curtain-like oral lobes which are highly flexible and ornamented with numerous nematocyst warts, and 32 radiating reddish brown stripes upon exumbrella. The Siphonophora is reported for the first time and three scyphomedusae are reported in Korea so far.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.311-318
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• 2017

Four species of sea turtles (Chelonia mydas, Caretta caretta, Dermochelys coriacea, and Eretmochelys imbricata) have been recorded in Korean waters. However, nationwide surveys on the distribution and occurrence of each species have rarelybeen conducted in Korean waters. In this study, we comparatively analyzed the trends in occurrence of sea turtles and their morphological characteristics based on 148 reliable observations and stuffed specimen data and suggested Korean names for each species. Chelonia mydas (57 cases, 58.8%) and C. caretta (52 cases, 31.5%) were dominant species, and occupied > 90% of all observations. Most of observations of sea turtles in Korean waters were obtained through stranding (61 cases) and incidental catches (62 cases). A coastal set net was the main fishing gear for incidental catches (82%). Sea turtles were found mainly around Jeju-do and the Korea Strait from June to November. Most C. caretta found were adults, whereas most C. mydas were juveniles. Additionally, we provide detailed morphological characteristics of C. mydas (n=8) and C. caretta (n=4) using stuffed specimens. Finally, based on a literature search, we suggest appropriate Korean names, such as "Pureunbada-geobuk" for C. mydas, "Bulgeunbadageobuk" for C. caretta, "Jangsu-geobuk" for D. coriacea, and "Maeburibada-geobuk" for E. imbricate.