• 제목/요약/키워드: Meteorological phenomena

검색결과 167건 처리시간 0.021초

ANALYSIS OF DROUGHT PHENOMENA USING MODIS NORMALIZED DIFFERENCE VEGETATION INDEX AND LAND SURFACE TEMPERATURE PRODUCTS

  • Park Jung-Sool;Kim Kyung-Tak;Lee Kyo-Sung;Kim Joo-Hun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.193-196
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    • 2005
  • As global warming proceeds, South Eastern Asia is undergoing drought, and the harshness of drought in the middle area of Korea is increasing. Especially, there has been the worst spring drought in 2001 since the first meteorological observation, and the damages caused by that drought are being ana lysed in various ways. In this study, spectral indices derived from satellites are used to examine 2001 spring drought, and the application of MODIS Data products as the quantitative tool to analyse drought in the future is examined.

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HOURLY VARIATION OF PENMAN EVAPOTRANSPIRATlON CONSIDERING SOIL MOISTURE CONDITION

  • Rim, Chang-Soo
    • Water Engineering Research
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    • 제5권1호
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    • pp.1-16
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    • 2004
  • The purpose of this study is to understand the characteristics of hourly PET(Potential Evapo Transpiration) variation estimated using Penman ET model. The estimated PET using Penman model was compared with measured ET. For this study, two subwatersheds were selected, and fluxes, meteorological data and soil moisture data were measured during the summer and winter days. During the winter days, the aerodynamic term of Penman ET is much greater than that of energy term of Penman ET for dry soil condition. The opposite phenomena appeared fer wet soil condition. During the summer days, energy term is much more important factor for ET estimation compared with aerodynamic term regardless of soil moisture condition. Penman ET, measured ET, and energy term show the similar hourly variation pattern mainly because the influence of net radiation on the estimation of Penman ET is much more significant compared with other variables. Even though there are much more soil moisture in the soil during the wet days, the estimated hourly ET from Penman model and measured hourly ET have smaller values compared with those of dry days, indicating the effect of cloudy weather condition.

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연안도시지역에서 대기오염의 3차원 수치예측모델링 -(I) 침적현상이 대기질에 미치는 영향예측 (3-D Numerical Prediction Modeling of Air Pollution in Coastal Urban Region -(I) An Effect Prediction for Deposition Phenomenon affecting on Air Quality)

  • 원경미;이화운
    • 한국대기환경학회지
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    • 제15권5호
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    • pp.625-638
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    • 1999
  • Air quality modeling for coastal urban region has been composed of a complex system including meteorological, chemical and physical processes and emission characteristics in complex terrain. In this study, we studied about an effect prediction for deposition phenomenon affecting on air quality in Pusan metopolitan metropolitan city. In air quality modeling including ship sources, a situation considered deposition process habe better result than not considered when compared with observed value. Air pollutants emitted into urban air during the daytime nearly removed through urban atmosphere polluted. Also these phenomena correlated concentration variation connent with sea/land breezes and terrain effect. Therefore we conclude that the concentration was low at daytime when deposition flux is high, and deposition effect on industrial complex and Dongrae region is considerable in particular.

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지상우량계와 기상레이더 강우강도의 비교연구 (A Comparative Study of the Rainfall Intensity Between Ground Rain Gauge and Weather Radar)

  • 류찬수;강인숙;임재환
    • 통합자연과학논문집
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    • 제4권3호
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    • pp.229-237
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    • 2011
  • Today they use a weather radar with spatially high resolution in predicting rainfall intensity and utilizing the information for super short-range forecast in order to make predictions of such severe meteorological phenomena as heavy rainfall and snow. For a weather radar, they use the Z-R relation between the reflectivity factor(Z) and rainfall intensity(R) by rainfall particles in the atmosphere in order to estimate intensity. Most used among the various Z-R relation is $Z=200R^{1.6}$ applied to stratiform rain. It's also used to estimate basic rainfall intensity of a weather radar run by the weather center. This study set out to compare rainfall intensity between the reflectivity of a weather radar and the ground rainfall of ASOS(Automatic Surface Observation System) by analyzing many different cases of heavy rain, analyze the errors of different weather radars and identify their problems, and investigate their applicability to nowcasting in case of severe weather.

Determination of Moisture Index in Korea

  • Ra, Jong Bum
    • Journal of the Korean Wood Science and Technology
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    • 제46권4호
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    • pp.301-308
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    • 2018
  • This study aimed to obtain basic climate information for effective moisture control in wood in Korea. Two independent climate indexes, namely drying index (DI) and wetting index (WI), were determined using hourly weather data for 82 locations recorded from 2009 to 2017. These data were collected from the Korea Meteorological Administration (KMA). Hourly data had not been measured prior to 2009. DI and WI revealed that all regions were cold and wet except Baengnyeongdo, which was classified as a cold and dry region. DI and WI were normalized assuming that wetting and drying were equally important phenomena. Then, the normalized indexes were combined into moisture index (MI) to rank the moisture loading of the regions. The MIs showed that Seogwipo had the greatest moisture loading in Korea, followed by Seongsan, Namhae, and Geoje. The MIs suggested that Korea exhibited severe moisture loading. Further studies are required to investigate the relation between MI and moisture content on wood surfaces from a wood maintenance point of view.

Field measurements of wind characteristics over hilly terrain within surface layer

  • He, Y.C.;Chan, P.W.;Li, Q.S.
    • Wind and Structures
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    • 제19권5호
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    • pp.541-563
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    • 2014
  • This paper investigates the topographic effects on wind characteristics over hilly terrain, based on wind data recorded at a number of meteorological stations in or near complex terrain. The multiply data sources allow a more detailed investigation of the flow field than is normally possible. Vertical profiles of mean and turbulent wind components from a Sodar profiler were presented and then modeled as functions of height and wind speed. The correlations between longitudinal and vertical wind components were discussed. The phenomena of flow separation and generation of vortices were observed. The distance-dependence of the topographic effects on gust factors was revealed subsequently. Furthermore, the canyon effect was identified and discussed based on the observations of wind at a saddle point between two mountain peaks. This study aims to further understanding of the characteristics of surface wind over rugged terrain. The presented results are expected to be useful for structural design, prevention of pollutant dispersion, and validation of CFD (computational fluid dynamics) models or techniques over complex terrains.

GIS 기법을 이용한 대기온도 변화 분포 분석 (Analysis of Air Temperature Change Distribution that Using GIS technique)

  • 정규용;강인준;김수겸;주홍식
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2010년 춘계학술발표회 논문집
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    • pp.395-397
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    • 2010
  • AWS that exist in Pusan is watching local meteorological phenomena established in place that the weather observatory does not exist by real time, and is used usefully to early input data of numerical weather forecasting model. I wished to display downtown of Pusan and air temperature change of peripheral area using this AWS data. Analyzed volatility using AWS observation data for 5 years to recognize air temperature change of Pusan area through data about temperature among them. Drew air temperature distribution chart by season of recapitulative Pusan area applying IDW linear interpolation with this.

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온도.습도분포 및 혼화재를 고려한 염분침투에 관한 연구 (A Study About Chloride Penetration Considering Temperature, Humidity Distribution and Admixtures)

  • 최종권;김기현;차수원;장승엽;장승필
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.553-556
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    • 2006
  • Chloride penetration is the main reason which causes the deterioration of concrete structures. Chloride penetration of concrete structures due to chemical-physical phenomena can be profitably analyzed by means of model-based simulations. The main purpose of this paper is to analyze chloride penetration considering self-desiccation, convection and admixture(GBFS: granulated blast-furnace slag) effects. Basic governing equations are modified properly to apply these effects to chloride penetration analysis. Temperature and relative humidity data of In-Cheon from Korea Meteorological Administration are used for analyzing chloride penetration.

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타타르(간관) 해협의 해류 (The Tartar (Mamiya) Strait Currents)

  • Ponomarev, Vladimir I.;Yurasov, Gennadiy I.
    • 한국해안해양공학회지
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    • 제6권4호
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    • pp.335-339
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    • 1994
  • 관측치와 모형 계산결과를 이용하여 Tartar 해협에서의 해류를 흐름 규모별로 분석하였으며, 조석현상과 일반적인 순환특성에 주안점을 두었다. 최대조류의 발생지점은 안정된 경계 흐름지역내에 위치함을 할 수 있었다. 다양한 기상조건 하에서의 흐름의 안정성과 소역에서의 에너지 집중은 바닥이 거친 지역에서 발생하는 조류의 비선형 효과로서 설명될 수 있다.

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겨울철 ESSAY (Experiment on Snow Storms At Yeongdong) 기간 동안 수증기량과 강수량의 연관성 분석 (Analysis of the Relationship of Water Vapor with Precipitation for the Winter ESSAY (Experiment on Snow Storms At Yeongdong) Period)

  • 고아름;김병곤;은승희;박영산;최병철
    • 대기
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    • 제26권1호
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    • pp.19-33
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    • 2016
  • Water vapor in the atmosphere is an important element that generates various meteorological phenomena and modifies a hydrological cycle. In general, the Yeongdong region has a lot of snow compared to the other regions in winter due to the complex topography and an adjacent East Sea. However, the phase change from water vapor to ice cloud and further snowfall has little been examined in detail. Therefore, in this study, we investigated phase change of liquid water in terms of a quantitative budget as well as time lag of water vapor conversion to snowfall in the ESSAY (Experiment on Snow Storms At Yeongdong) campaign that had been carried out from 2012 to 2015. First, we classified 3 distinctive synoptic patterns such as Low Crossing, Low Passing, and Stagnation. In general, the amount of water vapor of Low Crossing is highest, and Low Passing, Stagnation in order. The snowfall intensity of Stagnation is highest, whereas that of Low Crossing is the lowest, when a sharp increase in water vapor and accordingly a following increase in precipitation are shown with the remarkable time lag. Interestingly, the conversion rate of water vapor to snowfall seems to be higher (about 10%) in case of the Stagnation type in comparison with the other types at Bukgangneung, which appears to be attributable to significant cooling caused by cold surge in the lower atmosphere. Although the snowfall is generally preceded by an increase in water vapor, its amount converted into the snowfall is also controlled by the atmosphere condition such as temperature, super-saturation, etc. These results would be a fundamental resource for an improvement of snowfall forecast in the Yeongdong region and the successful experiment of weather modification in the near future.