• Title/Summary/Keyword: meteorology purpose

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On the Meteorology of Pre-age of Aristotle (아리스토텔레스 이전 시대의 기상학에 대해서)

  • Yoon, Ill-Hee
    • Journal of Science Education
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    • v.38 no.1
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    • pp.96-102
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    • 2014
  • The advent of meteorology was not appeared by instance. At first, Meteorology was accomplished by Aristotle, who was Greek natural philosopher. In a book he called Meteorologica, which dates to around 340 BCE, Aristotle dealt with the properties and processes of weather phenomena which described in the pre-age of Aristotle. This book's title originate to the word of meteorology. Aristotle's Meteorologica was assembled by his theories, as well as the wisdoms of historian, philosopher and epic in pre-age of Aristotle and his age. The purpose of this study was to search for the scientific background of writing of historically important book, Meteorogica.

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Determination of Algerian Weighted Mean Temperature Model for forthcoming GNSS Meteorology Application in Algeria

  • Song, Dong-Seob;Boutiouta, Seddik
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.6_2
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    • pp.615-622
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    • 2012
  • Since the accuracy of precipitable/integrated water vapor estimates from GNSS measurements is proportional to the accuracy of water vapor Weighted Mean Temperature Model (WMTM), the WMTM is a significant formulation in the retrieval of precipitable water vapor from zenith wet delay of GNSS signal. The purpose of this paper is to develop available the WMTM to apply for GNSS meteorology in the region of Algeria, by using the Algerian radiosonde network in the World Meteorological Organization (WMO). It can be concluded that the available GNSS precipitable water vapor which is retrieved by the developed Algerian Weighted Mean Temperature Equation (AWMTE) can be useful technique for sensing of water vapor in the Algeria, after Algerian Continuously Operating Reference System (CORS) will be constructed.

Development and Evaluation of Urban Canopy Model Based on Unified Model Input Data Using Urban Building Information Data in Seoul (서울 건물정보 자료를 활용한 UM 기반의 도시캐노피 모델 입력자료 구축 및 평가)

  • Kim, Do-Hyoung;Hong, Seon-Ok;Byon, Jae-Yong;Park, HyangSuk;Ha, Jong-Chul
    • Atmosphere
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    • v.29 no.4
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    • pp.417-427
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    • 2019
  • The purpose of this study is to build urban canopy model (Met Office Reading Urban Surface Exchange Scheme, MORUSES) based to Unified Model (UM) by using urban building information data in Seoul, and then to compare the improving urban canopy model simulation result with that of Seoul Automatic Weather Station (AWS) observation site data. UM-MORUSES is based on building information database in London, we performed a sensitivity experiment of UM-MOURSES model using urban building information database in Seoul. Geographic Information System (GIS) analysis of 1.5 km resolution Seoul building data is applied instead of London building information data. Frontal-area index and planar-area index of Seoul are used to calculate building height. The height of the highest building in Seoul is 40m, showing high in Yeoido-gu, Gangnam-gu and Jamsil-gu areas. The street aspect ratio is high in Gangnam-gu, and the repetition rate of buildings is lower in Eunpyeong-gu and Gangbuk-gu. UM-MORUSES model is improved to consider the building geometry parameter in Seoul. It is noticed that the Root Mean Square Error (RMSE) of wind speed is decreases from 0.8 to 0.6 m s-1 by 25 number AWS in Seoul. The surface air temperature forecast tends to underestimate in pre-improvement model, while it is improved at night time by UM-MORUSES model. This study shows that the post-improvement UM-MORUSES model can provide detailed Seoul building information data and accurate surface air temperature and wind speed in urban region.

The Operational Procedure on Estimating Typhoon Center Intensity using Meteorological Satellite Images in KMA

  • Park, Jeong-Hyun;Park, Jong-Seo;Kim, Baek-Min;Suh, Ae-Sook
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.278-281
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    • 2006
  • Korea Meteorological Administration(KMA) has issued the tropical storm(typhoon) warning or advisories when it was developed to tropical storm from tropical depression and a typhoon is expected to influence the Korean peninsula and adjacent seas. Typhoon information includes current typhoon position and intensity. KMA has used the Dvorak Technique to analyze the center of typhoon and it's intensity by using available geostationary satellites' images such as GMS, GOES-9 and MTSAT-1R since 2001. The Dvorak technique is so subjective that the analysis results could be variable according to analysts. To reduce the subjective errors, QuikSCAT seawind data have been used with various analysis data including sea surface temperature from geostationary meteorological satellites, polar orbit satellites, and other observation data. On the other hand, there is an advantage of using the Subjective Dvorak Technique(SDT). SDT can get information about intensity and center of typhoon by using only infrared images of geostationary meteorology satellites. However, there has been a limitation to use the SDT on operational purpose because of lack of observation and information from polar orbit satellites such as SSM/I. Therefore, KMA has established Advanced Objective Dvorak Technique(AODT) system developed by UW/CIMSS(University of Wisconsin-Madison/Cooperative Institude for Meteorological Satellite Studies) to improve current typhoon analysis technique, and the performance has been tested since 2005. We have developed statistical relationships to correct AODT CI numbers according to the SDT CI numbers that have been presumed as truths of typhoons occurred in northwestern pacific ocean by using linear, nonlinear regressions, and neural network principal component analysis. In conclusion, the neural network nonlinear principal component analysis has fitted best to the SDT, and shown Root Mean Square Error(RMSE) 0.42 and coefficient of determination($R^2$) 0.91 by using MTSAT-1R satellite images of 2005. KMA has operated typhoon intensity analysis using SDT and AODT since 2006 and keep trying to correct CI numbers.

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A Case Study on the Impact of Ground-based Glaciogenic Seeding on Winter Orographic Clouds at Daegwallyeong (겨울철 대관령지역 지형성 구름에 대한 지상기반 구름씨뿌리기 영향 사례연구)

  • Yang, Ha-Young;Chae, Sanghee;Jeong, Jin-Yim;Seo, Seong-Kyu;Park, Young-San;Kim, Baek-Jo
    • Journal of the Korean earth science society
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    • v.36 no.4
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    • pp.301-314
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    • 2015
  • The purpose of this study was to investigate the impact of ground-based glaciogenic seeding on orographic clouds in the Daegwallyeong area on 13 March, 2013. The experiments was conducted by releasing silver iodide (AgI) under following conditions: surface temperature below $-4^{\circ}C$, wind direction between 45 and $130^{\circ}$, and wind speed less than $5ms^{-1}$. Two seeding rates, $38gh^{-1}$ (SR1) and $113gh^{-1}$ (SR2), were tested to obtain an appropriate AgI ratio for snowfall enhancement in the Daegwallyeong area. Numerical simulations were carried out by using the WRF (Weather Research and Forecast) model with AgI point-source module which predicted dispersion fields of AgI particles. The results indicated that the target orographic clouds contained adequate amount of supercooled liquid water and that the dispersion of AgI particles tended to move along the prevailing wind direction. To validate the seeding effects, the observation data from FM-120 and MPS as well as PARSIVEL disdrometer were analyzed. In this case study, glaciogenic seeding significantly increased the concentration of small ice particles below 1 mm in diameter. The observation results suggest that SR1 seeding be reasonable to use the ground-based seeding in the Daegwallyeong area.

Characterization of Particle Losses in a Perma Pure Dryer

  • R. B. Xiang;Lee, K. W.;C. H. Jung;Kim, J. Y.;Park, B. C.
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.237-238
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    • 2002
  • Particle - bound water changes the physical and chemical properties of aerosol particles, such as size and light scattering properties. Consequently, it is necessary to remove water vapor from ambient aerosols before aerosol particles are sized and counted. Silicon gel diffusion dryer is commonly employed for this purpose. However, it can not be operated continuously While in operation, silicon gel becomes progressively more loaded with water and must periodically be regenerated by drying off the water. (omitted)

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Uncertainty of Agrometeorological Advisories Caused by the Spatiotemporally Averaged Climate References (시공간평균 기준기후에 기인한 농업기상특보의 불확실성)

  • Kim, Dae-jun;Kim, Jin-Hee;Kim, Soo-Ock
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.3
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    • pp.120-129
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    • 2017
  • Agrometeorological advisories for farms and orchards are issued when daily weather exceeds a predefined range of the local reference climate, which is a long-term average of daily weather for the location. The reference climate at local scales is prepared by various simplification methods, resulting in uncertainty in the agrometeorological advisories. We restored daily weather data for the 1981-2010 period and analyzed the differences in prediction results of weather risk by comparing with the temporal and spatial simplified normal climate values. For this purpose, we selected the agricultural drought index (ADI) among various disaster related indices because ADI requires many kinds of weather data to calculate it. Ten rural counties within the Seomjin River Basin were selected for this study. The normal value of 'temporal simplification' was calculated by using the daily average value for 30 years (1981-2010). The normal value of 'spatial simplification' is the zonal average of the temporally simplified normal values falling within a standard watershed. For residual moisture index, temporal simplification normal values were overestimated, whereas spatial simplification normal values were underestimated in comparison with non-simplified normal values. The ADI's calculated from January to July 2017 showed a significant deviation in terms of the extent of drought depending on the normal values used. Through this study, we confirmed that the result of weather risk calculation using normal climatic values from 'simplified' methods can affect reliability of the agrometeorological advisories.

Dynamics Modeling and Simulation of Korean Communication, Ocean, and Meteorology Satellite

  • No, Tae-Soo;Lee, Sang-Uk;Kim, Sung-Ju
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.2
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    • pp.89-97
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    • 2007
  • COMS(Communication, Oceanography, and Meteorology Satellite) is the first Korean multi-purpose satellite which is planned to be deployed at the altitude of geosynchronous orbit above the Korean peninsular. Noting that COMS is composed of the main BUS structure, two deployable solar panels, one yoke, five reactions wheels, COMS is treated as a collection of 9 bodies and its nonlinear equations of motion are obtained using the multi-body dynamics approach. Also, a computer program is developed to analyze the COMS motion during the various mission phase. Quite often, the equations of motion have to be derived repeatedly to reflect the fact that the spacecraft dynamics change as its configuration, and therefore its degree of freedom varies. However, the equations of motion and simulation software presented in this paper are general enough to represent the COMS dynamics of various configurations with a minimum change in input files. There is no need to derive the equations of motion repeatedly. To show the capability of the simulation program, the spacecraft motion during the solar array partial and full deployment has been simulated and the results are summarized in this paper.

Air Pollution Effects on the Photosynthesis and Chlorophyll Contents of Street Trees in Seoul (대기오염 피해를 받은 서울시내 가로수의 엽록소함량과 광합성 특성)

  • 우수영;이성한;이동섭
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.6 no.1
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    • pp.24-29
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    • 2004
  • The purpose of this study was to identify the effects of air pollution on the street trees in Seoul. Ten Gingko biloba street trees were selected in both Jongno(polluted area as a control) and Yangjae(non-polluted area) to investigate chlorophyll contents, photosynthesis and antioxidant enzymes such as APX(Ascorbate peroxidase) and GR(Glutathione reductase). The sampling, measurements and analysis were conducted in August. Chlorophyll contents and photosynthesis of Gingko biloba grown in Yangjae were higher than those of Jongno in the August measurement. In contrast, APX and GR activities of Gingko biloba grown in Yangjae were lower than those of Jongno. The observed tree responses are considered to be atypical compensatory response to polluted locations.