• Journal of the Korean Geographical Society
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• v.43 no.5
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• pp.701-714
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• 2008

This study examines the prevailing synoptic-scale mechanisms favorable for long-lived summer Persistent Positive Temperature Anomalies (PPTAs) as well as winter PPTAs in the United States. Such long-lived PPTAs usually occur in the south-central region of the United States in summer, but in the southwestern part of the United States in winter. Composite analyses of surface and pressure level data demonstrate that the formation of both winter and summer PPTAs is closely related to the movement of subtropical high pressure systems in the Pacific Ocean and Atlantic Ocean, respectively. The occurrence of long-lived summer PPTAs usually coincides with an extremely stable atmospheric condition caused by persistent blocking by mid- to upper-tropospheric anticyclones. Significant surface forcing is also easily identified through relatively high Bowen ratios at the surface. Warm air advection is, however, weak and appears to be an insignificant element in the formation of long-lived summer PPTAs. On the other hand, synergistic warming effects associated with adiabatic heating under an anticyclonic blocking system as well as significant warm air advection characterize the favorable synoptic environments for long-lived winter PPTAs. However, the impact of surface forcing mechanisms on winter PPTAs is insignificant.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.5-14
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• 2008

The deep subseafloor rock in oil reservoirs represents a unique environment in which a high oil contamination and a very low biomass can be observed. Sampling this environment has been a challenge owing to the techniques used for drilling and coring. In this study, the facilities developed by the Brazilian oil company PETROBRAS for accessing deep subsurface oil reservoirs were used to obtain rock samples at 2,822-2,828 m below the ocean floor surface from a virgin field located in the Atlantic Ocean, Rio de Janeiro. To address the bacterial diversity of these rock samples, PCR amplicons were obtained using the DNA from four core sections and universal primers for 16S rRNA and for APS reductase (aps) genes. Clone libraries were generated from these PCR fragments and 87 clones were sequenced. The phylogenetic analyses of the 16S rDNA clone libraries showed a wide distribution of types in the domain bacteria in the four core samples, and the majority of the clones were identified as belonging to Betaproteobacteria. The sulfate-reducing bacteria community could only be amplified by PCR in one sample, and all clones were identified as belonging to Gammaproteobacteria. For the first time, the bacterial community was assessed in such a deep subsurface environment.

• Journal of the Korean earth science society
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• v.21 no.4
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• pp.488-501
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• 2000

'The Voyage of the Beagle' , one of the best record of scientific travels ever made, written by Charles Darwin (1809-82), the greatest naturalist ever born, is reviewed in the viewpoint of the Earth Sciences. Various observations and interpretations on the Earth Sciences are told in the Voyage. First of all, Darwin understood the geological time much more longer than accepted then as well as the geological phenomena and processes such as orogeny, uplifting, subsidence, erosion, and deposition. And he also provided a perfect interpretation on the formation of coral reefs and a good theory on the evolution of organisms. Reasonable paleoenvironmental reconstructions and interpretations based on the fossils were given in the Voyage. His observations on meteorological phenomena were from the dust composed of organisms collected on the 'Beagle' in the Atlantic Ocean, to the movement of air and extreme clear dry condition experienced on the crest of the Andes, and etc. He made several observations on the general oceanography such as the discoloration of the sea, the lights on the sea surface, conchoidal provinces noted on the Galapagos Archipelago, the trees and plants found in the remotely separated islands, and etc. However relatively scarce observation was carried out on astronomy probably due to his relatively much land travelling. Most of his interpretations and suggestions are accepted in this time.

• ALGAE
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• v.29 no.2
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• pp.101-109
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• 2014

Small red algae, especially those previously referred to as 'primitive' are often overlooked, but can be quite abundant. These 'primitive' red algae are now placed in several classes distinct from the Florideophyceae, for example the Stylonematophyceae. A brownish-red filamentous alga was collected from a sandy tide pool at Cape Tribulation, Queensland, Australia. Cultured specimens were identified as Bangiopsis and conformed to the morphological characters of the genus (multicellular base, erect filaments branched or unbranched, uniseriate to multiseriate-tubular, single multilobed purple-red to red-brown plastid with central pyrenoid, vegetative cells released directly as spores). Molecular data of two plastid genes (rbcL, psbA) support placement of the Australian isolate and isolates from India in Bangiopsis. The genetic variation between these isolates and isolates from Puerto Rico previously attributed to B. subsimplex indicates that these should be considered as a separate species. As the type locality is in the Atlantic Ocean, French Guiana, and not far from Puerto Rico, and the Puerto Rican isolate has been used often in phylogenetic analyses, we propose that the Indian and Pacific Ocean isolates be designated a new species, B. franklynottii, to acknowledge Ott's many years of research on inconspicuous freshwater and marine red algae. Our research also highlights the lack of careful descriptions in many of the records of this genus and the lack of morphological characters to distinguish species. Especially within the morphologically simple red algae, morphological distinctness does not necessarily reflect evolutionary divergences.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.2
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• pp.188-193
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• 2021

On March 13, 2018 two postflexion larval specimens (18.28 mm and 16.80 mm in standard length) belonging to the family Cryptacanthodidae, suborder Zoarcoidei were collected from Sokcho and Gangneung in Gangwon Province. The family Cryptacanthodidae comprises 4 species worldwide: 3 in the North Pacific Ocean and 1 in the western North Atlantic Ocean. As a result of analyzing 620 bp of the mtDNA COI region, the two postflexion larvae collected in this study were identified as Cryptacanthodes bergi by 99.5% agreement with C. bergi adult registered in NCBI. Postflexion larvae of C. bergi are compressed with large eyes and radial pectoral fins and the anus located in front of the center of the body. Melanophores were intensively distributed along the dorsal midline, except for caudal peduncle, and sporadically distributed on the back of the anus. In addition, there were limited star-like melanophores on the back of the gut. This species showed 0.058 genetic distance when compared mtDNA COI region of C. aleutensis, and it was well distinguished in the distribution pattern of black vesicles of the head, count and measurement traits. Considering the morphological and ecological characteristics of this species, we suggest a new Korean name, " Gwisin-jang-gaeng-i ".

• Ocean and Polar Research
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• v.27 no.3
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• pp.265-276
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• 2005

In order to grasp the structure and dynamics of phytoplankton communities, chlorophyll-a (Chl-a) and cell abundance were measured at 20 stations during the period from August 9 to August 21, 2003 in the southeastern Barents Sea on surface and subsurface chlorophyll maximum depth (SCM). Surface temperatures were varied from minimum $-0.7^{\circ}C(st. 18)$ to maximum $10.4^{\circ}C(st.1)$. Salinities were varied from minimum 29.9 psu(st. 18) to maximum 35.8 psu(st.2). The maximum nutrient(phosphate, nitrate, silicate) concentrations were $0.12{\mu}M,\;0.11{\mu}M,\;7.53{\mu}M$ and minimum concentrations were $0.01{\mu}M,\;0.03{\mu}M,\;1.43{\mu}M$, respectively. On SCM physical environmental factor were almost similar. Chl-a concentrations ranged from 0.23 to $2.13{\mu}g\;chi-a\;l^{-1}$ at SCM. Nano- and pico phytoplankton were the important contributors for increase of the Chl-a. It was about seven times difference between highest concentration to lowest. Phytoplankton communities were composed of diatoms, dinoflagellates, cryptophyceae, silicoflagellate, and prymnesiophyceae showing 37 taxa at surface and 38 taxa at SCM. Picophytoplankton was the most dominant in all stations and all layers, but the second groups were 2 and/or 3 taxa. Phytoplankton abundance ranged from minimum $4.3{\times}10^5\;cells\;l^{-1}$ (st. 20) to maximum $2.4{\times}10^6\;cells\;l^{\-1}$. (st. 17) at surface water. As a result, phytoplankton might be controlled by physical factors such as North Atlantic ocean currents and northern melt water among environmental factors in Barents Set h addition the dominant species were nano- and pico phytoplankton such as Phaeocystis, Cryptomonas and Dinobryon in the study area.

• Korean Journal of Remote Sensing
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• v.22 no.4
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• pp.235-242
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• 2006

This study compared between tropospheric column ozone by applying the SAM method to TOMS and OMI data for northern summer. Tropospheric ozone from the SAM represents a peak over the tropical Atlantic, where it is related with biomass burning. This feature is also seen in the distribution of the model and CO. Additionally, enhancement of the SAM ozone over the Middle East, and South and North America agrees well with the model and CO distribution. However, the SAM results show more ozone than the model results over the northern hemisphere, especially the ocean (e.g. the North Pacific and the North Atlantic). The tropospheric ozone distribution from OMI data shows more ozone than that from TOMS data. This can be caused by different viewing angle, sampling frequency, and a-priori ozone profiles between OMI and TOMS. The correlation between the SAM tropospheric ozone and CO is better than that between the model and CO in the tropics. However, that correlation is reversed in the mid-latitude.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.225-231
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• 1991

In order to suggest the useful information on the fishing ground of the bigeye tuna Thunnus obesus(LOWE), a data base system was formed with catch data of the Korean tuna long liners during from 1975 to 1987 by using a set of 16 bits personal computer. This data base was constructed of the handling program and 4 types of data file processed from the monthly and yearly catch data of the whole tunas and the bigeye tuna. And when the system was started, the map of one among various Oceans such as the Pacific, the Atlantic and the Indian Ocean. is drawn on the monitor. And then the catch rates of the whole tunas or the catch ratios of bigeye tunas are indicated by the figured symbols and the colors on the sea divisions of 5$^{\circ}$ space of longitude and latitude respectively at the same time. Also this system has the preestimating program on the catch rates of the whole tunas and the bigeye tuna in the desired month and sea divisions. In the results than this data base system was handled and tested, very useful informations were obtained for the detection of tunas, especially bigeye tuna, and the preestimation was possible in a desired level.

• ALGAE
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• v.34 no.1
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• pp.7-21
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• 2019

The genus Heterocapsa is one of the major dinoflagellate groups, with some of its species having worldwide distributions. However, prior to the present study, the phototrophic species Heterocapsa minima has been reported only from the northeast Atlantic Ocean. Recently, H. minima was found in the Korean waters, and a clonal culture was established. This culture was used to examine the morphology of the Korean strain H. minima HMMJ1604 through light and scanning electron microscopy, as well as for its genetic characterization. Furthermore, to determine the nationwide distribution of H. minima in Korea, its abundance was quantified in the waters of 28 stations in all four seasons in 2016-2018 using the quantitative real-time polymerase chain reaction method. The overall morphology of H. minima HMMJ1604 was very similar to that of the Irish strain H. minima JK2. However, the Korean strain had five pores around the pore plate, whereas the Irish strain had six pores. When properly aligned, the sequences of the large subunit and internal transcribed spacer regions of the ribosomal DNA of the Korean strain were identical to those of the Irish strain. This species was detected in the waters of 26 out of 28 stations, but its abundance was greater than $1.0cells\;mL^{-1}$ at 8 stations. The highest abundance of H. minima was $44.4cells\;mL^{-1}$. Although this species was found in all seasons, its abundance was greater than $1.0cells\;mL^{-1}$ when the water temperature and salinity were $10.9-25.0^{\circ}C$ and 17.5-34.1, respectively. To the best knowledge, the present study reported for the first time that H. minima lives in the Pacific Ocean and is widely distributed in the Korean waters.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.5
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• pp.488-497
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• 2009

The freak wave, also known as New-Year-Wave in the north Atlantic, is relatively large and spontaneous ocean surface wave that can sink even large ships and destroy maritime structures. To understand oceanic conditions that develop freak waves, we simulated and generated two versions of scale-downed waves (1:64 and 1:42) in a numerical wave tank and compared the results with the experiment in wave flume. Both of the breaking and non-breaking waves were generated in the simulation. The numerical simulation was implemented based on the finite volume method and a genetic optimization algorithm. Random values were assigned as the initial values for the parameter in the control function, which produced signals representing the motion of wave-maker. The same signal obtained from the optimization process was used for both of the simulation and the experiment. By varying the object function and restrictions of the simulation, a best profile of design wave was selected based on the characteristics, height and period of simulated waves. Results showed that the simulation and experiment with the scale of 1:42 agreed better with freak waves in the natural condition. The presented simulation method will contribute to saving the time and cost for conducting subsequent response analyses of motion under freak waves in the course of the model test for ship and maritime structure.