• Animal Systematics, Evolution and Diversity
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• no.nspc5
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• pp.61-70
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• 2005

A new marine interstitial nematode species belonging to the subgenus Quadricoma of order Desmoscolecida is described from Jindo Island, South Korea. The new species, Tricoma (Quadricoma) jindoensis sp. nov., is most allied with T. (Q.) crassicomoides Timm, 1970 in sharing the similar cephalic setae, broadly truncated border of head, lip region including 6 labial papillae, and slender and long spicule among the seven congeners with 44 quadricomoid rings. However, T. (Q.) jindoensis differs from it by the globular protuberance on the penultimate ring, 7 tail rings, and 9 pairs of subdorsal setae in male. This is the first record of Quadricoma nematodes from East Asia.

• Ocean and Polar Research
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• v.43 no.1
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• pp.15-30
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• 2021

In this study, using 16 ORA-IP (Ocean Reanalysis Intercomparison Project) data, we investigated spatial and temporal changes of net surface heat flux in the East Asian seas and presented a new ensemble net surface heat flux index. The ensemble net surface heat flux index is produced considering the data distribution and the standard deviation of each ORA-IP. From the correlation analysis with air temperature averaged over the Korean Peninsula, ensemble net heat flux around the Korea Strait shows the highest correlation (0.731) with a 3 month time lag. For the correlation study regarding precipitation over the Korean Peninsula, it also shows significant correlation especially in winter and spring seasons. Similar results are also found in comparison with climate indices (AO, PDO, and NINO3.4), but ensemble net surface heat flux data in winter season reveals the strongest correlation patterns especially with winter temperature and spring precipitation.

• The Korean Journal of Quaternary Research
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• v.20 no.1 s.26
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• pp.51-66
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• 2006

The climate of the last glacial maximum (LGM) in northeast Asia is simulated with an atmospheric general circulation model of NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. Modern climate is simulated by a prescribed sea surface temperature and sea ice provided from NCAR, and contemporary atmospheric CO2, topography, and orbital parameters, while LGM simulation was forced with the reconstructed CLIMAP sea surface temperatures, sea ice distribution, ice sheet topography, reduced $CO_2$, and orbital parameters. Under LGM conditions, surface temperature is markedly reduced in winter by more than $18^{\circ}C$ in the Korean west sea and continental margin of the Korean east sea, where the ocean exposed to land in the LGM, whereas in these areas surface temperature is warmer than present in summer by up to $2^{\circ}C$. This is due to the difference in heat capacity between ocean and land. Overall, in the LGM surface is cooled by $4{\sim}6^{\circ}C$ in northeast Asia land and by $7.1^{\circ}C$ in the entire area. An analysis of surface heat fluxes show that the surface cooling is due to the increase in outgoing longwave radiation associated with the reduced $CO_2$ concentration. The reduction in surface temperature leads to a weakening of the hydrological cycle. In winter, precipitation decreases largely in the southeastern part of Asia by about $1{\sim}4\;mm/day$, while in summer a larger reduction is found over China. Overall, annual-mean precipitation decreases by about 50% in the LGM. In northeast Asia, evaporation is also overall reduced in the LGM, but the reduction of precipitation is larger, eventually leading to a drier climate. The drier LGM climate simulated in this study is consistent with proxy evidence compiled in other areas. Overall, the high-resolution model captures the climate features reasonably well under global domain.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.169-193
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• 2016

In order to characterize the Neotectonic crustal deformation and current stress field in and around the Korean Peninsula and to interpret their tectonic implications, this paper synthetically analyzes the previous Quaternary fault and focal mechanism solution data and recent geotechnical in-situ stress data and examines the characteristics of crustal deformations and tectonic settings in and around East Asia after the Miocene. Most of the Quaternary fault outcrops in SE Korea occur along major inherited fault zones and show a NS-striking top-to-the-west thrust geometry, indicating that the faults were produced by local reactivation of appropriately oriented preexisting weaknesses under EW-trending pure compressional stress field. The focal mechanism solutions in and around the Korean Peninsula disclose that strike-slip faulting containing some reverse-slip component and reverse-slip faulting are significantly dominant on land and in sea area, respectively. The P-axes are horizontally clustered in ENE-WSW direction, whereas the T-axes are girdle-distributed in NNW direction. The geotechnical in-situ stress data in South Korea also indicate the ENE-trending maximum horizontal stress. The current crustal deformation in the Korean Peninsula is thus characterized by crustal contraction under regional ENE-WSW or E-W compression stress field. Based on the regional stress trajectories in and around East Asia, the current stress regime is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate have not a decisive effect on the stress-regime in the Korean Peninsula due to its high-angle subduction that resulted in dominant crust extension of the back-arc region. It is also interpreted that the Neotectonic crustal deformation and present-day tectonic setting of East Asia commenced with the change of the Pacific Plate motion during 5~3.2 Ma.

• Journal of the Korean earth science society
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• v.44 no.1
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• pp.1-12
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• 2023

Oceanic wind waves have been recognized as one of the important indicators of global warming and climate change. It is necessary to study the spatial and temporal variability of significant wave height (SWH) and wave direction in the Yellow Sea and a part of the East China Sea, which is directly affected by the East Asian monsoon and climate change. In this study, the spatial and temporal variability including seasonal and interannual variability of SWH and wave direction in the Yellow Sea and East China Sea were analyzed using European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5) data. Prior to analyzing the variability of SWH and wave direction using the model reanalysis, the accuracy was verified through comparison with SWH and wave direction measurements from Ieodo Ocean Science Station (I-ORS). The mean SWH ranged from 0.3 to 1.6 m, and was higher in the south than in the north and higher in the center of the Yellow Sea than in the coast. The standard deviation of the SWH also showed a pattern similar to the mean. In the Yellow Sea, SWH and wave direction showed clear seasonal variability. SWH was generally highest in winter and lowest in late spring or early summer. Due to the influence of the monsoon, the wave direction propagated mainly to the south in winter and to the north in summer. The seasonal variability of SWH showed predominant interannual variability with strong variability of annual amplitudes due to the influence of typhoons in summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.2
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• pp.49-57
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• 2016

Even if an external forcing that will drive a climate change is given uniformly over the globe, the corresponding climate change and the feedbacks by the climate system differ by region. Thus the detection of global warming signal has been made on a regional scale as well as on a global average against the internal variabilities and other noises involved in the climate change. The purpose of this study is to estimate a timing of unprecedented climate due to global warming and to analyze the regional differences in the estimated results. For this purpose, unlike previous studies that used climate simulation data, we used an observational dataset to estimate a magnitude of internal variability and a future temperature change. We calculated a linear trend in surface temperature using a historical temperature record from 1880 to 2014 and a magnitude of internal variability as the largest temperature displacement from the linear trend. A timing of unprecedented climate was defined as the first year when a predicted minimum temperature exceeds the maximum temperature record in a historical data and remains as such since then. Presumed that the linear trend and the maximum displacement will be maintained in the future, an unprecedented climate over the land would come within 200 years from now in the western area of Africa, the low latitudes including India and the southern part of Arabian Peninsula in Eurasia, the high latitudes including Greenland and the mid-western part of Canada in North America, the low latitudes including Amazon in South America, the areas surrounding the Ross Sea in Antarctica, and parts of East Asia including Korean Peninsula. On the other hand, an unprecedented climate would come later after 400 years in the high latitudes of Eurasia including the northern Europe, the middle and southern parts of North America including the U.S.A. and Mexico. For the ocean, an unprecedented climate would come within 200 years over the Indian Ocean, the middle latitudes of the North Atlantic and the South Atlantic, parts of the Southern Ocean, the Antarctic Ross Sea, and parts of the Arctic Sea. In the meantime, an unprecedented climate would come even after thousands of years over some other regions of ocean including the eastern tropical Pacific and the North Pacific middle latitudes where an internal variability is large. In summary, spatial pattern in timing of unprecedented climate are different for each continent. For the ocean, it is highly affected by large internal variability except for the high-latitude regions with a significant warming trend. As such, a timing of an unprecedented climate would not be uniform over the globe but considerably different by region. Our results suggest that it is necessary to consider an internal variability as well as a regional warming rate when planning a climate change mitigation and adaption policy.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.509-518
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• 2019

Analyses with various Sea Surface Temperature (SST) products indicate that the interannual variability of the area-averaged SST in the East/Japan Sea (EJS) is well correlated to that of Pacific Decadal Oscillation (PDO) during 1979-2018, especially in the autumn. The regression analysis with the wind vectors at 200 hPa, where the strongest jet stream flows, suggests that the long-term variability of the intensity as well as the meridional movement of the jet stream are related to the coupling of the autumn EJS SST and PDO. When the axis of the jet stream moves poleward (equatorward) with its weakening (strengthening), both the EJS SST and North Pacific SST increase (decrease). This suggests that both the intensity and meridional movement of the jet stream are possibly related to the coupling of the autumn EJS SST and PDO. However, effects of a weak jet stream during the summer and the strong East Asian winter monsoon make weak coupling between the EJS SST and PDO.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.84-84
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• 2018

참억새(Miscanthus sienesis)는 화본목 벼과 억새속에 속한 다년생 단자엽식물로 동아시아와 오세아니아 동쪽 해역에 자생하고 있으며, 국내에서는 관상가치가 높아 정원용이나 조경용 소재로 이용되고 있는 대표적인 산림식물이다. 억새속(Miscanthus)은 물억새(M. sachariflorus), 참억새(M. sinensis), 억새아재비(M. longiberbis), 장억새(M. changii)로 분류하고 있으며, 이는 종을 구분하는 화기구조가 작고, 변이가 다양하기 때문이다. 그 중 참억새는 이러한 변이를 이용하여 다양한 초장과 엽 무늬를 가진 재배품종이 많이 개발되었으며, 내한성 또한 강해 정원용 관상식물로서의 가치가 높이 평가되고 있다(Lewandowsik et al, 1964). 지금까지 참억새 재배품종은 엽 무늬를 중심으로 개발되어 품종간 높은 유사성을 가지고 있어 구별하는데 어려움이 있었다. 본 연구에서는 새로운 참억새 품종개발시 기존품종과의 차이를 구별할 수 있는 기준을 제시하고자 기존 참억새 재배품종들에 대해 형태적 특성을 조사 분석하여 고찰해 보았다. 조사결과 가로무늬를 가진 'Strictus'와 'Zebrinus' 품종은 형태적으로 매우 유사하였으나 전체적인 모습에서 'Zebrinus'가 'Strictus' 품종에 비해 잎의 끝부분이 늘어지는 정도가 커 처진 특성을 나타내었다. 또한, 세로무늬를 가진 'Cosmopolitan'과 'Carbaret' 품종의 경우 초장 및 엽신의 길이가 유사하였으나 엽 무늬 위치에 차이가 있는 것으로 나타났다. 엽 폭이 좁은 세엽종인 'Morning Light'와 'Little Kitten' 품종은 형태적 차이는 없지만 가장자리 엽 무늬 유무로 구분이 가능하였다. 반면에 'Adagio'와 'Little Kitten, 품종은 형태적으로 매우 유사하여 좀 더 세밀한 조사가 필요할 것으로 보인다. 앞으로 더 많은 참억새 재배품종의 형태적 특성을 조사한 자료를 이용한다면 신품종 개발시 기존 재배품종과의 차이를 비교하는데 효율적으로 이용될 것으로 기대된다.

• Ocean and Polar Research
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• v.31 no.1
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• pp.51-61
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• 2009

In this study we define the two different types of El $Ni{\tilde{n}}o$, i.e., the eastern Pacific El $Ni{\tilde{n}}o$ (i.e., EP-El $Ni{\tilde{n}}o$) versus the central Pacific El $Ni{\tilde{n}}o$ (i.e., CP-El $Ni{\tilde{n}}o$), during the boreal summer (June-July-August, JJA) and winter (December-January-February, DJF) using the two NINO indices in the tropical Pacific. The two different types of El $Ni{\tilde{n}}o$ significantly differ in terms of the location of the maximum anomalous sea surface temperature (SST) in the tropical Pacific. The CP-El $Ni{\tilde{n}}o$ has been observed more frequently during recent decades compared to the EP-El $Ni{\tilde{n}}o$. In addition, our analysis indicates that the statistics of CP-El $Ni{\tilde{n}}o$ during JJA is closely associated with the warming trend in the central equatorial Pacific. We also examine the different responses of the East Asian marginal SST to the two types of El $Ni{\tilde{n}}o$ during JJA and DJF. The CP-El $Ni{\tilde{n}}o$ during both JJA and DJF is concurrent with warm SST anomalies around the Korean Peninsula including the East China Sea, which is in contrast to the EP-El $Ni{\tilde{n}}o$. Such different responses are associated with the difference in tropics/mid-latitude teleconnections via atmosphere between the two types of El $Ni{\tilde{n}}o$. Furthermore, our results indicate that atmospheric diabatic forcing in relation to the precipitation variability is different in the tropical Pacific between the EP-El $Ni{\tilde{n}}o$ and the CP-El $Ni{\tilde{n}}o$.

• Journal of Aerospace System Engineering
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• v.11 no.2
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• pp.35-42
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• 2017

This paper analyzes the intention of the PRC (People's Republic of China) to establish and operate CADIZ to implement the government's maritime policy and strategy and to project its air power in preparation for maritime provocation and contingency, especially over the area where East Asia countries have claimed to have maritime jurisdiction over one another. This paper is also intended to guide the Republic of Korea's response measures for coping with the maritime intention and threat of China by such measures as reinforcing military power, constructing the strategic air base in Jeju, and expanding the present KADIZ.