• Title/Summary/Keyword: Wind climate

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Estimation of Typhoon Center Using Satellite SAR Imagery (인공위성 SAR 영상 기반 태풍 중심 산정)

  • Jung, Jun-Beom;Park, Kyung-Ae;Byun, Do-Seong;Jeong, Kwang-Yeong;Lee, Eunil
    • Journal of the Korean earth science society
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    • v.40 no.5
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    • pp.502-517
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    • 2019
  • Global warming and rapid climate change have long affected the characteristics of typhoons in the Northwest Pacific, which has induced increasing devastating disasters along the coastal regions of the Korean peninsula. Synthetic Aperature Radar (SAR), as one of the microwave sensors, makes it possible to produce high-resolution sea surface wind field around the typhoon under cloudy atmospheric conditions, which has been impossible to obtain the winds from satellite optical and infrared sensors. The Geophysical Model Functions (GMFs) for sea surface wind retrieval from SAR data requires the input of wind direction, which should be based on the accurate estimation of the center of the typhoon. This study estimated the typhoon centers using Sentinel-1A images to improve the problem of typhoon center detection method and to reflect it in retrieving the sea surface wind. The results were validated by comparing with the typhoon best track data provided by the Korea Meteorological Administration (KMA) and Japan Meteorological Agency (JMA), and also by using infrared images of Himawari-8 satellite. The initial center position of the typhoon was determined by using VH polarization, thereby reducing the possibility of error. The detected center showed a difference of 23.76 km on average with the best track data of the four typhoons provided by the KMA and JMA. Compared to the typhoon center estimated by Himawari-8 satellite, the results showed an average spatial variation of 11.80 km except one typhoon located near land with a large difference of 58.73 km. This result suggests that high-resolution SAR images can be used to estimate the center and retrieve sea surface wind around typhoons.

A STUDY ON EXTRACTING THE SURFACE TEMPERATURE USING THERMAL INFRARED OF ASTER IMAGES IN URBAN AREA

  • Jo Myung-Hee;Kim Hyung-Sub;Kim Sung-Jae;Yu Seong-Ok
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.717-720
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    • 2005
  • Recently as large sized urban development and the city ward drifting of population are caused, the urban surface temperature is raised very seriously and rapidly. These artificial developments have destroyed the inner and outer landscapes such as topography and have changed complex local climate such as a sudden rise in temperature, the change of wind field and air pollution. In order to clarify this problem visually, the studies on extracting the thermal infrared and the characteristic analysis of local climate in urban area had been performed by using the sixth band of Landsat TM and ETM+. However, there is a need to alternate Landsat TM and ETM+ because these satellite images are not applied any more. Therefore, in this paper it is proposed to use 2 Aster image (2004.4.17 daily 2b03, 2004.10.10 night 2b03) of EOS AM and to extract the surface temperature. Also, the pattern of surface temperature in urban area and the application possibility in local climate study are proposed by verifying the correlation with A WS data. Also, IKONOS image was used to figure out the artificial development area in visual.

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A Study on Mitigation of Rail Corrosion using Sacrificial Anode Cathodic Protection Method (희생양극법을 이용한 레일부식 저감 방안에 관한 연구)

  • Choi, Jung-Youl;Kim, Jun-Hyung;Lee, Kyu-Yong;Kim, Young-Ki;Park, Jong-Yoon;Song, Bong-Hwan;Seol, Jin-Woong
    • Journal of the Korean Society of Safety
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    • v.32 no.6
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    • pp.54-60
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    • 2017
  • A railway rail will be corroded by the repetitive sea wind and fog in the splash and tidal zone such as Youngjong grand bridge. And these rusts of rail could be increased by increasing service period, and it frequently occurred the safety accidents or disorders in electrical problem. In this study, the sacrificial anode cathodic protection method was proposed as a measures for reducing the corrosion of the railway rails in the oceanic climate conditions. As the results of immersion test using the salt water during four months, the sacrificial anode cathodic protection method using the aluminum anode(Al-anode) was evaluated that a distinct effect on corrosion reduction in the rails. Therefore the sacrificial anode cathodic protection method was experimentally proven that a disorders in aspects electric and signal of railway operation condition such as direct fixation track system in Youngjong grand bridge could be prevented by reducing rust falling from the rail. In addition, the installation conditions of the anodes directly affect the transmission range of corrosion potential, the sectional loss of anode, and the corrosion reduction effect. Therefore, to expect the corrosion reduction effect of rails under the oceanic climate conditions for railway track, it was important to adopted the appropriate spacing of anode installation by considering the actual field conditions.

Climate and Human coronaviruses 229E and Human coronaviruses OC43 Infections: Respiratory Viral Infections Prevalence in Hospitalized Children in Cheonan, Korea

  • Kim, Jang Mook;Jeon, Jae Sik;Kim, Jae Kyung
    • Journal of Microbiology and Biotechnology
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    • v.30 no.10
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    • pp.1495-1499
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    • 2020
  • The study of climate and respiratory viral infections using big data may enable the recognition and interpretation of relationships between disease occurrence and climatic variables. In this study, real-time reverse transcription quantitative PCR (qPCR) methods were used to identify Human respiratory coronaviruses (HCoV). infections in patients below 10 years of age with respiratory infections who visited Dankook University Hospital in Cheonan, South Korea, from January 1, 2012, to December 31, 2018. Out of the 9010 patients who underwent respiratory virus real-time reverse transcription qPCR test, 364 tested positive for HCoV infections. Among these 364 patients, 72.8% (n = 265) were below 10 years of age. Data regarding the frequency of infections was used to uncover the seasonal pattern of the two viral strains, which was then compared with local meteorological data for the same time period. HCoV-229E and HCoV-OC43 showed high infection rates in patients below 10 years of age. There was a negative relationship between HCoV-229E and HCoV-OC43 infections with air temperature and wind-chill temperatures. Both HCoV-229E and HCoV-OC43 rates of infection were positively related to atmospheric pressure, while HCoV-229E was also positively associated with particulate matter concentrations. Our results suggest that climatic variables affect the rate in which children below 10 years of age are infected with HCoV. These findings may help to predict when prevention strategies may be most effective.

APPLICATION OF MERGED MICROWAVE GEOPHYSICAL OCEAN PRODUCTS TO CLIMATE RESEARCH AND NEAR-REAL-TIME ANALYSIS

  • Wentz, Frank J.;Kim, Seung-Bum;Smith, Deborah K.;Gentemann, Chelle
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.150-152
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    • 2006
  • The DISCOVER Project (${\underline{D}}istributed$ ${\underline{I}}nformation$ ${\underline{S}}ervices$ for ${\underline{C}}limate$ and ${\underline{O}}cean$ products and ${\underline{V}}isualizations$ for ${\underline{E}}arth$ ${\underline{R}}esearch$) is a NASA funded Earth Science REASoN project that strives to provide highly accurate, carefully calibrated, long-term climate data records and near-real-time ocean products suitable for the most demanding Earth research applications via easy-to-use display and data access tools. A key element of DISCOVER is the merging of data from the multiple sensors on multiple platforms into geophysical data sets consistent in both time and space. The project is a follow-on to the SSM/I Pathfinder and Passive Microwave ESIP projects which pioneered the simultaneous retrieval of sea surface temperature, surface wind speed, columnar water vapor, cloud liquid water content, and rain rate from SSM/I and TMI observations. The ocean products available through DISCOVER are derived from multi-sensor observations combined into daily products and a consistent multi-decadal climate time series. The DISCOVER team has a strong track record in identifying and removing unexpected sources of systematic error in radiometric measurements, including misspecification of SSM/I pointing geometry, the slightly emissive TMI antenna, and problems with the hot calibration source on AMSR-E. This in-depth experience with inter-calibration is absolutely essential for achieving our objective of merging multi-sensor observations into consistent data sets. Extreme care in satellite inter-calibration and commonality of geophysical algorithms is applied to all sensors. This presentation will introduce the DISCOVER products currently available from the web site, http://www.discover-earth.org and provide examples of the scientific application of both the diurnally corrected optimally interpolated global sea surface temperature product and the 4x-daily global microwave water vapor product.

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Seasonal Variation in Carcass Characteristics of Korean Cattle Steers

  • Piao, M.Y.;Baik, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.3
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    • pp.442-450
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    • 2015
  • Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of $28.4^{\circ}C$ and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of $-4.0^{\circ}C$ and a wind-chill temperature of $-6.2^{\circ}C$. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated ($r{\geq}0.71$; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated ($r{\leq}-0.74$; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

삼음삼양(三陰三陽)에 관(關)한 연구(硏究)

  • Yun, Chang-Yeol
    • Journal of Haehwa Medicine
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    • v.4 no.2
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    • pp.337-353
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    • 1996
  • The following results are obtained through study on the Three Eum and Three Yang. 1. Up to nowadays, many people confuse the Great Yang, the lesser Eum, the Great Eum, and the lesser Yang of the Sasang with the Great Yang, the lesser Yang, the Sunlight, the Great Eum, the lesser Eum, and the absolute Eum of the Three Eum and Three Yang becuase they are expressed with the same letters. But the former is the second specialization of the Eum and Yang, and the latter is the transformation of the six climate, so they cannot be the same thing, and there is no connection between them. 2. Three Eum and Three Yang is the outer expression of the six climate, which is coldness, heat, dryness, humidity, wind, and the fire, and it is the conception of the formation of objects which possess SI-JUNG-JONG & BON-JUNG-MAL, and it represents one term of the status of transformation in which the life and the Yang Qi are born, grown, united, and completed. 3. The Three Eum and Three Yang is not only applyed to the outer expression of the six climate, but also to the twelve channels which correspond with the twelve viscera, six differentiation of the disease of the cold, various illness, and the form of pulse. 4. The combination of the Three Eum and Three Yang and the twelve channels is divided into the channel of Sahwa and the channel of Jonghwa, and it also has important relationship with the physiology of the viscera. 5. The division of the six channels of disease of the cold suggested by Junggyung originates from the heat theory in Neagyung, but the six channels in the heat theory are of pathological conception, so the six channels of Junggyung includes the disease of the channels and the viscera. 6. The difference of the Pyo, Bon, Jung Qi of the Three Eum and Three Yang makes the syndrom of the disease diverse so it can be used in the diagnosis and the treatment of disease, and further studies are necessary on this part.

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Sea Surface Temperature Related to the Characteristic of the Coastal Climate in the Southern Part of Korea (우리나라 남부해안 기후의 특성과 해면수온과의 관계)

  • 한영호
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.17 no.2
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    • pp.65-69
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    • 1981
  • The oceanic effect on the climate of the southern coast of Korea was analysed based on the sea surface temperature and in order to study relationships between the fluctuation of the sea surface temperature and that of climatic elements. Meteolorogical data from 1960 to 1979 were used. In the year when difference between the air and water temperature was maximum, the air temperature in southern coast was higher than normal year. A fluctuation of the sea surface temperature plays an important influence to determine the variation of the air temperature in the coastal area. Humidity of the coastal climate depends upon the oceanic effect in summer, but not in winter. This results may be due to prevailing wind effect. The oceanic effect on the precipitation in the coastal area is not found.

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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.

Developing Korean Forest Fire Occurrence Probability Model Reflecting Climate Change in the Spring of 2000s (2000년대 기후변화를 반영한 봄철 산불발생확률모형 개발)

  • Won, Myoungsoo;Yoon, Sukhee;Jang, Keunchang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.199-207
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    • 2016
  • This study was conducted to develop a forest fire occurrence model using meteorological characteristics for practical forecasting of forest fire danger rate by reflecting the climate change for the time period of 2000yrs. Forest fire in South Korea is highly influenced by humidity, wind speed, temperature, and precipitation. To effectively forecast forest fire occurrence, we developed a forest fire danger rating model using weather factors associated with forest fire in 2000yrs. Forest fire occurrence patterns were investigated statistically to develop a forest fire danger rating index using times series weather data sets collected from 76 meteorological observation centers. The data sets were used for 11 years from 2000 to 2010. Development of the national forest fire occurrence probability model used a logistic regression analysis with forest fire occurrence data and meteorological variables. Nine probability models for individual nine provinces including Jeju Island have been developed. The results of the statistical analysis show that the logistic models (p<0.05) strongly depends on the effective and relative humidity, temperature, wind speed, and rainfall. The results of verification showed that the probability of randomly selected fires ranges from 0.687 to 0.981, which represent a relatively high accuracy of the developed model. These findings may be beneficial to the policy makers in South Korea for the prevention of forest fires.