• Title/Summary/Keyword: The Korean peninsula

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Climatological Study of 1994's Summer Droughts in Korea (한국에 있어서 1994년 하계한발의 기후학적 연구)

  • Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
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    • v.2 no.2
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    • pp.93-102
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    • 1996
  • The Korean Peninsula is located on the east coast of monsoon Asia of the midlatitude, where the Pacific polar front moves. As a result variations of spatial and temporal distribution of precipitation occur. A great variation of precipitation during the summer months created frequent droughts and floods. The purpose of this study is to identify distributional characteristics and to analyze synopic characteristics of summer droughts in Korea. The research methods used are ; (1) to identify droughts based on the anomaly of monthly precipitation during summer of 1994. (2) to analyze correlations between drought and weather systems by using the calender of rain days. (3) to compare a synoptic mechanism of summer droughts with that of typical normal summer. The characteristics of summer droughts of 1994 may be summarized as follows ; 1) While most regions were affected by the droughts some regions displayed specific characteristics. The southern part of the Korean Peninsula was severely affected during the month of June. August droughts severely affected east part of the Sobek Mountains, thus showing that the droughts of June and August are highly localized. 2) In the pressure anomaly of surface field. the positive anomaly appears in June around Korean Peninsula, but in July when all parts of the South Korea were under severe droughts, the anomaly changes and becomes negative. 3) Extracyclones occurred less frequently in the summer of 1994. Those that did occur were located in areas far off the Korean Peninsula having little consequences on the drought patterns. 4) The trough of westerly wave at 500hPa height patterns in June is located far from the eastern sea of Korean Peninsula, but in July and August Korean Peninsula belongs to ridge of westerly wave. 5) In June the positive height anomaly at 500hPa surface appears zonally from Siberia to the western Parts of North Pacific Ocean, and in July and August, the strong positive anomaly appears around Korean Peninsula. As a result the zonal index of westerlies at during each month of summer in Korean sector has a large value, which in turn implies that drought will prevails when zonal flow is strong.

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A Study on the Field Strength Prediction of a Ground-wave Based Time Broadcasting Transmitter Station in the Korean Peninsula

  • Lee, Sun Yong;Choi, Yun Sub;Hwang, Sang-Wook;Yang, Sung-Hoon;Lee, Chang-Bok;Lee, Sang Jeong
    • Journal of Positioning, Navigation, and Timing
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    • v.3 no.2
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    • pp.83-90
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    • 2014
  • In this study, to improve an existing ground-wave based time broadcasting system, a study that predicts the field distribution and field strength of the transmitted signal of a new ground-wave based time broadcasting system was performed. The prediction area was assumed to be the Korean peninsula; and to reflect the mountainous terrain of the Korean peninsula in the prediction of the variations of field distribution and field strength, a new prediction method based on the Monteath model was proposed and utilized. As field distribution changes depending on the position of a transmitter station, potential sites for the transmitter station were selected considering the geographical characteristics. In this regard, the ground conductivity information of North Korea cannot be obtained, and thus, the ground conductivity of the North Korean region was reflected considering the geological characteristics of South Korea and North Korea. Based on this, the variations of field distribution and field strength were predicted by setting the Korean peninsula as the prediction area, and the prediction results depending on the position of the transmitter station were discussed.

The Global Geopotential Models in the Region of Korean Peninsula

  • Yun, Hong-Sic;Adam, Jozsef
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.95-106
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    • 1994
  • The purpose of this paper is to establish the optimum reference field as testing some geopotential model, gravity data and GPS data. We have to decide a best fitting geopotential model as a reference surface for establishing the optimum geoid solutions. We conduct some tests on the Korean Peninsula gravity data to establish which of the model would be prove to be the best one. Three ways were used to compare the geopotential coefficient solutions. One of the tests is to compare the residual gravity anomaly remaining after the anomaly computed from the geopotential model has been subtracted from the "observed" gravity anomaly. The second method is a comparison of several geopotential solutions in terms of differences in gravity anomalies and quasi-geoid undulations. The third method is a comparison between the undulation obtained by GPS and the corresponding undulation from each geopotential model. The result showed that OSU91A model is a best fitting model as a reference in the region of Korean Peninsula.Peninsula.

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Errors of MODIS product of Gross Primary Production by using Data Assimilation Office Meteorological Data (MODIS 총일차생산성 산출물의 오차요인 분석: 입력기상자료의 영향)

  • Kang Sinkyu;Kim Youngil;Kim Youngjin
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.2
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    • pp.171-183
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    • 2005
  • In order to monitor the global terrestrial carbon cycle, NASA (National Aeronautics and Space Administration) provides 8-day GPP images by use of satellite remote-sensing reflectance data from MODIS (Moderate Resolution Imaging Spectroradiometer) at l-km nadir spatial resolution since December, 1999. MODIS GPP algorithm adopts DAO (Data Assimilation Office) meteorological data to calculate daily GPP. By evaluating reliability of DAO data with respect to surface weather station data, we examined the effect of errors from DAO data on MODIS GPP estimation in the Korean Peninsula from 2001 to 2003. Our analyses showed that DAO data underestimated daily average temperature, daily minimum temperature, and daily vapor pressure deficity (VPD), but overestimated daily shortwave radiation during the study period. Each meteorological variable resulted in different spatial patterns of error distribution across the Korean Peninsula. In MODIS GPP estimation, DAO data resulted in overestimation of GPP by $25\%$ for all biome types but up to $40\%$ for forest biomes, the major biome type in the Korean Peninsula. MODIS GPP was more sensitive to errors in solar radiation and VPD than in temperatures. Our results indicate that more reliable gridded meteorological data than DAO data are necessary for satisfactory estimation of MODIS GPP in the Korean Peninsula.

Geomagnetic Depth Sounding to Investigate the Trend of Electrical Conductivity in and around the Korean Peninsula (지자기 수직 탐사에 의한 한반도 주변의 전기전도도 구조)

  • 오석훈;양준모;이덕기;남재철
    • Economic and Environmental Geology
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    • v.35 no.5
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    • pp.437-444
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    • 2002
  • Geomagnetic depth sounding (GDS) was performed to analyze the characteristics of deep resistivity structure in and around the Korean Peninsula. The data that have 0.01 nT precision were collected from 5 geomagnetic observatories and measured every one or five second. In this study, amount of 16 days of geomagnetic data were used for analyzing. Generally the sea affects the GDS data seriously due to its high conductivity. However, though the Korean peninsula is surrounded by seas in three sides, the results given by induction arrow strongly show that the trend of electrical conductivity at neighborhood of the Korean Peninsula is reigned by some geological features. Also it is believed that observation in Jeju island is related with the electrical structure around the East China Sea.

Comments on Seismicity and Crustal Structure of the Korean Peninsula (한반도의 지진활동과 지각구조)

  • Lee, Kie-Hwa
    • Geophysics and Geophysical Exploration
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    • v.13 no.3
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    • pp.256-267
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    • 2010
  • Earthquakes in the Korean Peninsula occur along the faults formed and boundaries between major geological units ruptured due to violent tectonic activities during the Mesozoic. E-W and/or ENE-SSW compressive stress regime resulting from collisions between the Eurasian plate and neighbouring the Indian plate, the Pacific plate and the Philippine plate trigger Korean earthquakes of thrust faulting with predominant strike-slip components along the mostly NNE-SSW trending active faults. Seismicity of the Korean peninsula has been moderate to low during the past 20 centuries except for the period from the 15th to the 18th centuries of exceptionally high seismicity, showing the typical irregularity of intraplate seismicity. The structure of the Korean peninsula is rather homogeneous without the Conrad discontinuity sharply dividing the upper and lower crust. Lateral heterogeneities exist in the crust. The crust with an average thickness of about 33 km is thicker in the mountainous region than the plain due to the Airy-type isostatic equilibrium maintained in the peninsula. Crustal P-wave velocity with average of about 6.3 km/sec increases gradually from the near surface to the Moho. The upper mantle P-wave (Pn) velocity is about 7.8 km/sec.

Isothermal Distribution Map on the Korean Peninsula to Improve the Accuracy of the Environmental Planning (국토환경계획 정도(精度) 향상 목적의 지형고도속성을 반영한 한반도 등온분포도 작성)

  • Kim, Won-Joo;Lee, Gwan-Gyu
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.3
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    • pp.87-93
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    • 2008
  • In order to manage national environment effectively, one has to understand its ecological traits. The difference of temperature determines ecological traits of each respective region. In other words, temperature differentials on surface make a great impact on botanical structure. Currently, isothermal data-produced by meteorological stations based upon time series analysis-are widely used to plan and manage national environment. Nonetheless, the isothermal data do not reflect real surface temperature of regions. Because of numerous mountainous terrains in the Korean peninsula where temperature varies widely according to altitude, the range of temperature distribution-that reflects altitudinal change-has to be paid special attention. This study aims at expressing in space isothermal distribution that is necessary to plan and manage national environment effectively. In addition, not just South Korea, but also North Korea was included for isothermal distribution. As a result, this study corrected established isothermal lines up to date and demonstrated that altitude, latitude, and distance from coastal lines greatly influence temperature distribution of the Korean peninsula.

Newly recorded and rarely known species of Noctukdae (Lepidoptera) from the Korean Peninsula (한국산 밤나방과의 미기록종을 포함한 몇몇 종들에 대한 보고)

  • 안성복;V.S.코노넨코;원갑재
    • Korean journal of applied entomology
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    • v.35 no.4
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    • pp.287-296
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    • 1996
  • Twenty four newly recorded and rarely known noctuid species from the Korean peninsula, which are preserved in domestic and foreign museums, are discussed in this article. Eleven species; Hypenodes curvilinea Sugi, Polydesma boarmoides (Guenee), Catocala bokhaica (Kononenko), Xanthomantis contaminata (Draudt), Craniophora harmandi (Poujade), Amphipyra acheron Draudt, Orthogonia tapaishana (Draudt), Chasminodes u.ssurica Kononenko, Oncocnemis campicola Lederer, Protomiselia bilinea (Hampson) and Xestia (Anomogyna) albonigra (Kononenko) are newly reported from the Korean peninsula. Among them, P. bilinea (Hampson), which has been known in Japan, is reported for the first time from the Continental Asia. The occurrence of Athetis pallidipennis Sugi, Pseudocosmia maculata Kononenko, Callopistria miracula Herz and Lacanobia dentata Kononenko are reconfirmed in Korea. Eudocyma salamina (Cramer) and Polydesma boarmoides Guenee are .considered to be tropical migrating species. A previously misidentified species, Hypenodes rectifascia Sugi is corrected as H. curvilinea Sugi.

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Hydrological impact of Atmospheric River landfall on the Korean Peninsula (Atmospheric River의 한반도 수문학적 영향에 대한 연구)

  • Han, Heechan;Choi, Changhyun;Moon, Heyjin;Jung, Jaewon;Lee, Choongke;Kim, Hung Soo
    • Journal of Korea Water Resources Association
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    • v.53 no.11
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    • pp.1039-1047
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    • 2020
  • Atmospheric rivers, which transport large amount of water vapor from mid-latitude to the inland, are an important driving force of water cycle and extreme hydrologic phenomenas. The main objective of this study is to analyze the hydrological impact of the AR landfalls on the Korean Peninsula in 2000 - 2015. The result showed that the AR is closely related to the characteristics of precipitation, water level and runoff in the Korean Peninsula. The landfalls of the AR affected about 57% of annual precipitation on the Korean Peninsula, and had a greatest impact on the summer rainfall. It also affected the water level and runoff at the five major rivers of Korea, and water levels exceeding the thresholds of flood warning were observed when the AR landed. Moreover, it was found that the runoff above the third quartile with AR landfalls. These results suggest that the AR not only has a significant influence on the hydrological characteristics of the Korean Peninsula, but also have a close relationship with the extreme hydrological events like floods. The results of this study are expected to be used as the reference for the analysis of the impact of the AR on the various fields in the Korean Peninsula.

Stochastic Self-similarity Analysis and Visualization of Earthquakes on the Korean Peninsula (한반도에서 발생한 지진의 통계적 자기 유사성 분석 및 시각화)

  • JaeMin Hwang;Jiyoung Lim;Hae-Duck J. Jeong
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.11
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    • pp.493-504
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    • 2023
  • The Republic of Korea is located far from the boundary of the earthquake plate, and the intra-plate earthquake occurring in these areas is generally small in size and less frequent than the interplate earthquake. Nevertheless, as a result of investigating and analyzing earthquakes that occurred on the Korean Peninsula between the past two years and 1904 and earthquakes that occurred after observing recent earthquakes on the Korean Peninsula, it was found that of a magnitude of 9. In this paper, the Korean Peninsula Historical Earthquake Record (2 years to 1904) published by the National Meteorological Research Institute is used to analyze the relationship between earthquakes on the Korean Peninsula and statistical self-similarity. In addition, the problem solved through this paper was the first to investigate the relationship between earthquake data occurring on the Korean Peninsula and statistical self-similarity. As a result of measuring the degree of self-similarity of earthquakes on the Korean Peninsula using three quantitative estimation methods, the self-similarity parameter H value (0.5 < H < 1) was found to be above 0.8 on average, indicating a high degree of self-similarity. And through graph visualization, it can be easily figured out in which region earthquakes occur most often, and it is expected that it can be used in the development of a prediction system that can predict damage in the event of an earthquake in the future and minimize damage to property and people, as well as in earthquake data analysis and modeling research. Based on the findings of this study, the self-similar process is expected to help understand the patterns and statistical characteristics of seismic activities, group and classify similar seismic events, and be used for prediction of seismic activities, seismic risk assessments, and seismic engineering.