• Title/Summary/Keyword: meteorological phenomena

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Analytic Study on the Variation of Regional Wind Resources Associated with the Change of El Niño/La Niña Intensity (엘니뇨/라니냐 강도 변화에 따른 국지적 풍력자원의 변동)

  • Lee, Soon-Hwan;Lee, Hwa-Woon;Kim, Dong-Hyuk;Kim, Min-Jung;Kim, Hyun-Goo
    • Journal of the Korean earth science society
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    • v.32 no.2
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    • pp.180-189
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    • 2011
  • In order to clarify the relation between El Ni$\tilde{n}$o/La Ni$\tilde{n}$a and wind resources of the Korean Peninsula, observed meteorological data for 20 years were used in this study. Although the wind speed tends to decrease in Eurasia Continent, it gradually increases in the peninsula for 10 years. The seasonal variation of wind speed due to El Ni$\tilde{n}$o/La Ni$\tilde{n}$a development is not so small and negative anomalies of SST tend to lead the beginning of the wind speed increase over the Korean Peninsula. Wind speed variation caused by the global scale meteorological phenomena is more sensitive in mountainous area than in any other areas because of the relatively weak mesoscale forcing at mountainous area.

Atmospheric Total Gaseous Mercury (TGM) Concentration and Characteristics in Seoul, Korea (서울시 대기 중 총 가스상 수은의 농도 및 특성 분석)

  • Lee, Yong-Mi;Heo, Jong-Bae;Yi, Seung-Muk
    • Journal of Environmental Health Sciences
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    • v.34 no.1
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    • pp.42-48
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    • 2008
  • The objectives of this study were to measure ambient TGM concentrations in Seoul Korea, to determine the temporal variation of TGM, and to analyze the relationships among TGM, meteorological data and PM2.5 measured at the same time. Ambient TGM and PM2.5 concentrations were measured at the roof of the Graduate School of Public Health building in Seoul, Korea for the period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17ng/m^3$. The average TGM was at a low concentration similar to those of background sites in other countries. The temporal variations and meteorological phenomena of TGM were not statistically significant. There was a positive link between TGM and PM2.5. It didn't indicate that reduction of $Hg^{2+}$ to Hg0 had occurred in liquid water contained in smog as in a previous study, but it shows that PM2.5 and TGM could be emitted from the same sources such as power plants and combustion engines. Also, the strong correlation between TGM and $SO_2$ concentrations indicated that the source of TGM was from fossil fuel combustions including coal combustion. Specifically, $SO_2\;and\;SO_4{^2-}$ concentrations correlated to TGM concentrations could be linked to TGM emitted from local and regional sources as well.

UHF and S-Band Radar Networks (UHF와 S밴드 레이더 관측망 구축)

  • Kim, Park-Sa;Kim, Kwang-Ho;Campistrom, Bernard;Yoon, Hong-Joo;Kwon, Byung-Hyuk
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.2
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    • pp.305-312
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    • 2018
  • The quality of the radar and profiler network was estimated to forecast difficult meteorological situations. A network of UHF Doppler wind profilers and Doppler weather radars have been deployed all over the Korean Peninsular, with dense spatial resolution between instruments. The radar network allows to retrieve the three dimensional dynamics and to analyze the numerical model outputs at small and meso scales. This work has seldom been performed in any other place of the world, with such a high resolution. The wind field from radar network is a good agreement with the background wind fields based on the numerical modeling. This study will be helpful to forecast severe weathers as well as local meteorological phenomena.

An Evaluation of Landslide Probability by Maximum Continuous Rainfall in Gangwon, Korea (강원지역의 최대연속강우량에 의한 산사태 발생가능성 평가)

  • Yang, In-Tae;Park, Jae-Kook;Jeon, Woo-Hyun;Chun, Ki-Sun
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.4
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    • pp.11-20
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    • 2007
  • Most natural disasters in Korea are caused by meteorological natural phenomena, which include storms, heavy rains, heavy snow, hail, tidal waves, and earthquakes. Rainfall is the most frequent cause of disasters and accounts for about 80% of all disasters. Particularly in recent years, Korea has seen annual occurrences of natural disasters associated with landslides (slope and retaining wall collapse and burying) due to meteorological causes from the increasing intensity of heavy rains including local heavy rainfalls. In Korea, it is critical to analyze the characteristics of landslides according to rainfall characteristics and to take necessary and proper measures for them. This study assessed the possibility of landslides in the Gangwon region with a geographic information system by taking into account the inducer factors of landslides and the maximum continuous rainfall of each area. It also analyzed areas susceptible to landslides and checked the distribution of landslide-prone areas by considering the rainfall characteristics of those areas.

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Hourly Rainfall Surface Prediction with Meteorological Radar Data (기상레이더 자료를 이용한 시우량곡면 예측)

  • 정재성;이재형
    • Water for future
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    • v.29 no.3
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    • pp.187-195
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    • 1996
  • In this study, a methodology for the hourly prediction of rainfall surfaces was applied to the Pyungchang river basin at the upstream of South Han river with meteorological radar and ground rainfall data. The methods for the exclusion of abnormal echoes, and suppression of ground clutter, and the augmentation of attenuation effects associated with rainfall phenomena were reviewed, and the relationship between radar reflectivity (Z) and rainfall rate (R) was analyzed. The transformation of augmented radar reflectivities into the rdar rainfall surfaces was carried out, and afterward they were synthesized with the ground rainfall data generating the hourly rainfall surfaces. For the prediction of hourly rainfall surface, the moving factors of rainfall field estimated by the cross correlation coefficient method and the temporal variation of radar rainfall intensities were considered. The synthesized hourly rainfall surfaces were used to predict the hourly rainfall surfaces up to 3 hours in advance and subsequently the results were compared with the measured and the synthesized. It seems that the prediction method need to be verified with more data and be complemented further to consider the physical characteristics of rainfall field and the topography of the basin.

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A Review on the Decision-making Process for Extratropical Transition of Typhoon from an Operational Forecast Point of View (현업예보 관점에서 태풍의 온대저기압화 판단 과정에 대한 고찰)

  • Cha, Eun-Jeong;Shim, Jae-Kwan;Kwon, H.Joe
    • Journal of the Korean earth science society
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    • v.29 no.7
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    • pp.567-578
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    • 2008
  • The extratropically transitioning cyclones have been shown to have a large effect on weather system in the midlatitues and cause sometimes the severe weather phenomena. However, both operational forecasting and research aspect of ET remain a significant challenge. Because it is difficult to distinguish ET stage due to obscure configuration of the cyclone itself. Furthermore, any definition of ET should not only be precise enough to satisfy the needs of the operational and research communities. Therefore, the "operational deterministic process for ET" was proposed and has been used to diagnose both structure and subsequent process of ET in 2007. In this study, it has been examined the maximum wind and SST in the 1st step, satellite image in the 2nd step, sounding in the 3rd step, surface weather chart analysis in the final step. This operational manual has allowed better monitoring and understanding of the changes in the structure as ET occurs.

A Study on the Precursors of Aviation Turbulence via QAR Data Analysis (QAR 데이터 분석을 통한 항공난류 조기 인지 가능성 연구)

  • Kim, In Gyu;Chang, Jo Won
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.26 no.4
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    • pp.36-42
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    • 2018
  • Although continuous passenger injuries and physical damages are repeated due to the unexpected aviation turbulence encountered during operations, there is still exist the limitation for preventing recurrence of similar events because the lack of real-time information and delay in technological developments regarding various operating conditions and variable weather phenomena. The purpose of this study is to compare and analyze the meteorological data of the aviation turbulence occurred and actual flight data extracted from the Quick Access Recorder(QAR) to provide some precursors that the pilot can identify aviation turbulence early by referring thru the flight instrumentation indications. The case applied for this study was recent event, a scheduled flight from Incheon Airport, Korea to Narita Airport, Japan that suddenly encountered turbulence at an altitude of approximately 14,000 feet during approach. According to the Korea Meteorological Administration(KMA)'s Regional Data Assessment and Prediction System(RDAPS) data, it was observed that the strong amount of vorticity in the rear area of jet stream, which existed near Mount Fuji at that time. The QAR data analysis shows significant changes in the aircraft's parameters such as Pitch and Roll angle, Static Air Temperature(SAT), and wind speed and direction in tens of seconds to minutes before encounter the turbulence. If the accumulate reliability of the data in addition and verification of various parameters with continuous analysis of additional cases, it can be the precursors for the pilot's effective and pre-emptive action and conservative prevention measures against aviation turbulence to reduce subsequent passenger injuries in the aviation operations.

Analysis of Weather Records in Admiral Yi Sun-sin's Nanjung Ilgi (이순신장군의 난중일기에 기록된 기상자료의 분석)

  • Suh, Myoung-Seok;Cha, So-Yeong
    • Atmosphere
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    • v.31 no.5
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    • pp.539-551
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    • 2021
  • In this paper, the weather records in 'Nanjung Ilgi' were investigated and the weather characteristics of the southern coast of Korea (SC_Korea) was discussed. The Nanjung Ilgi is a personal diary written by admiral Yi Sun-sin from January 1592 to November 1598 during the 7-year war caused by the Japanese invasion. He is a respected great leader in the history of world naval warfare, winning all 23 battles against the Japanese. Of the 1593 days of diaries currently preserved, only 42 days have no weather records. Weather was recorded in detail, including sky conditions, precipitation, wind characteristics and others. Weather records were extracted from the diary, converted to the solar calendar, and compared with the meteorological data of Yeosu. The average annual precipitation day is about 90 days, which is similar to the current 95~100 days. As in the current climate, precipitation frequently occurs for about 30 days in summer, but less than 15 days in other seasons, and the rainy season starts from June 14 to 21 and ends from July 6 to 17. It seems that the abnormal cold and heat phenomena, which deviate significantly from the seasonal average climate, occurred on 6 and 21 days, respectively, over 7 years. This means that the weather records of Nanjung Ilgi can be used as valuable data on the climate of SC_Korea in the late 16th century. The fact that he recorded the weather even in such extreme battle conditions shows that he clearly recognized the importance of weather in warfare.

El Niño-Southern Oscillation, Indian Ocean Dipole Mode, a Relationship between the Two Phenomena, and Their Impact on the Climate over the Korean Peninsula (엘니뇨-남방진동, 인도양 쌍극자 모드, 두 현상의 관련성, 그리고 한반도 기후에 대한 영향)

  • Cha, Eun-Jeong
    • Journal of the Korean earth science society
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    • v.28 no.1
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    • pp.35-44
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    • 2007
  • This paper investigated the relationship between El $Ni\widetilde{n}o-Southern$ Oscillation (ENSO) and Indian Ocean Dipole (IOD) mode events and the impacts of these two phenomena on the climate, temperature and precipitation, of the Korean Peninsula. Data gathered from 1954 to 2004 were used for analysis, which included NINO 3 index, IOD index, and monthly mean precipitation and temperature at eleven locations in Korea. Statistical results showed that the IOD and ENSO were significantly correlated in Spring and Fall. It was clearly shown that the distribution of the sea surface temperature in the Indian Ocean has seen the Southern and Northern Oscillation in El $Ni\widetilde{n}o$ year, and Eastern and Western in IOD year. On the other hand, in El $Ni\widetilde{n}o$ you, the mean temperature of the Korea Peninsula was lower than normal in Summer and higher in Winter and its precipitation was more than normal in both Summer and Winter. However, significant correlation was not found in IOD year. In addition, the global atmospheric circulations during the major IOD years are less influential, unlike those of El $Ni\widetilde{n}o$ events.

Weather Characteristics and Efforts to Reduce Disasters during the Reign of King Sejo in the Chosun Dynasty (조선 세조대 기후특성과 재해 경감 노력)

  • Lee, Uk;Hong, Yoon
    • Atmosphere
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    • v.22 no.2
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    • pp.199-208
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    • 2012
  • This study was conducted in order to analyze weather characteristics during the reign of King Sejo in the Chosun Dynasty based on The Annals of the Chosun Dynasty. For this purpose, first of all, we need to determine whether The Annals of the Chosun Dynasty is a reliable material for research on weather characteristics. Thus, we compared weather phenomena during the reign of King Sejo with those in China and Japan in the same period. From the results, it was found that The Annals of the Chosun Dynasty is a useful material at least to grasp macroscopic trends in weather phenomena. Based on this assumption, we analyzed weather characteristics during the reign of King Sejo using data from The Annals of the Chosun Dynasty. During the days of King Sejo, the climate was not changed violently and there were not many disasters caused by abnormal climate such as bad harvests. This suggests that the climate was relatively stable during the period of King Sejo. As a consequence of stable weather, famine decreased markedly. However, this was not only because of stable climate but also because of the government's active efforts to reduce disasters. As droughts and floods were not frequent, social costs for recovery from disasters also decreased considerably and the saved money could be invested in the construction of social safety nets for the prevention of disasters. One of factors supporting the enthronement of King Sejo was a series of heavily damaging bad harvests during the reign of Kings Munjong and Danjong. The prevention of bad harvests was a historical mission given to the regime of King Sejo. During his reign, King Sejo promoted various policies in order to stop bad harvests. Such efforts included the government's active construction of embankments, introduction of seeds suitable for reclaimed lands, and inspiration of the consciousness of forceful farming enduring natural disasters such as floods. As a result, abnormal weathers such as floods and droughts did not lead directly to bad harvests.