• Title/Summary/Keyword: meteorological index

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Comparison of Meteorological Drought and Hydrological Drought Index (기상학적 가뭄지수와 수문학적 가뭄지수의 비교)

  • Lee, Bo-Ram;Sung, Jang Hyun;Chung, Eun-Sung
    • Journal of Korea Water Resources Association
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    • v.48 no.1
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    • pp.69-78
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    • 2015
  • In this study, meteorological drought indices were examined to simulate hydrological drought. SPI (Standardized Precipitation Index) and SPEI (Standardized Precipitation Evapotranspiration Index) was applied to represent meteorological drought. Further, in order to evaluate the hydrological drought, monthly total inflow and SDI (Streamflow Drought Index) was computed. Finally, the correlation between meteorological and hydrological drought indices were analyzed. As a results, in monthly correlation comparison, the correlation between meteorological drought index and monthly total inflow was highest with 0.67 in duration of 270-day. In addition, a meteorological drought index were correlated 0.72 to 0.87 with SDI. In compared to the annual extremes, the relationship between meteorological drought index and minimum monthly inflow was hardly confirmed. But SDI and SPEI showed a slightly higher correlation. There are limitation that analyze extreme hydrological drought using meteorological drought index. For the evaluation of the hydrological drought, drought index which included inflow directly is required.

A Study on the Characteristics of Perceived Temperature over the Korean Peninsula During 2007 Summer (한반도 2007년 여름철 인지온도 특성 연구)

  • Byon, Jae-Young;Kim, Jeong-Sik;Kim, Ji-Young;Choi, Byoung-Cheol;Choi, Young-Jean;Graetz, Angelika
    • Atmosphere
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    • v.18 no.2
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    • pp.137-146
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    • 2008
  • This study examines one thermal index, perceived temperature (PT), over the Korean Peninsula during 2007 summer. Heat/cold stress has been described using air temperature and humidity for warm seasons and air temperature and wind velocity in the cold conditions, while PT is based on a heat budget model of the human body that considers air temperature, humidity, wind velocity and radiation effect regardless of climates, regions and seasons. PT is higher about $4-5^{\circ}C$ than air temperature in the summer. Humidity increases PT, while wind tends to reduces PT possibly by evaporation of water vapor. The geographical distribution of summer PT indicates that the lowest PT happened in the east central region, with the appearance of the highest PT in the inland of southern region in Korea. Although the latitudinal trend shows that PT decreases northward, inland PT is higher than that of coastal region. Compared to the heat index or the discomfort index that considers air temperature and humidity, PT represents distinctive regional characteristics of thermal comfort. The distribution of PT shows that it may be a useful thermal index for the assessment of thermal comfort or stress region in the Korean Peninsula.

A Characteristic of Wintertime Snowfall and Minimum Temperature with Respect to Arctic Oscillation in South Korea During 1979~2011 (1979~2011년, 북극진동지수 측면에서의 겨울철 남한지역 신적설과 최저 온도 특성)

  • Roh, Joon-Woo;Lee, Yong Hee;Choi, Reno K.Y.;Lee, Hee Choon
    • Atmosphere
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    • v.24 no.1
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    • pp.29-38
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    • 2014
  • A characteristic of snowfall and minimum temperature variability in South Korea with respect to the variability of Arctic Oscillation (AO) was investigated. The climatic snowfall regions of South Korea based on daily new fresh snowfall data of 59 Korea Meteorological Administration (KMA) stations data corresponding to the sign of AO index during December to February 1979~2011 were classified. Especially, the differences between snowfalls of eastern regions and that of western regions in South Korea were seen by each mean 1000hPa geopotential height fields, which is one of physical structure, for the selected cases over the East Asia including the Korean Peninsula. Daily minimum temperature variability of 59 KMA station data and daily AO index during the same period were investigated using Cyclo-stationary empirical orthogonal function (CSEOF) analysis. The first CSEOF of wintertime daily AO index and that of minimum temperature of 59 KMA stations explain 33% and 66% of total variability, respectively. Correlation between principal component time series corresponding to the first CSEOF of AO index and that of temperature at the period of 1990s is over about -0.7 when that of AO index leads about 40 days.

Crime Prediction Model based on Meteorological Changes and Discomfort Index (기상변화 및 불쾌지수에 따른 범죄발생 예측 모델)

  • Kim, JongMin;Kim, MinSu;Kim, Kuinam J.
    • Convergence Security Journal
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    • v.14 no.6_2
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    • pp.89-95
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    • 2014
  • This study analyzed a correlation between crime and meteorological changes and discomfort index of Seoul and p resented a prediction expression through the regression analysis. For data used in this study, crime data from Januar y 2008 to December 2012 of Seoul Metropolitan Police Agency and meteorological records and discomfort index recor ded in the Meteorological Agency through the portal sites were used. Based on this data, SPSS 18.0 was used for the regression analysis and the analysis of correlation between crime and meteorological changes and discomfort index and a prediction expression was derived through the analysis and the risk index was shown in 5 steps depending on predicted values obtained through the prediction expression derived. The risk index of 5 steps classified like this is considered to be used as important data for crime prevention activities.

Comparison of Meteorological Drought Indices Using Past Drought Cases of Taebaek and Sokcho (태백, 속초 과거 가뭄사례를 이용한 기상학적 가뭄지수의 비교 고찰)

  • Kang, Dong Ho;Nam, Dong Ho;Kim, Byung Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.735-742
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    • 2019
  • Drought is a social phenomenon in which the degree of perception varies depending on the affected factors, and is defined as various relative concepts such as meteorological drought, hydrological drought, agricultural drought, and climatological drought. In this study, a comparative analysis of meteorological drought among variously defined droughts was conducted and the applicability of the drought index was examined by comparing the actual drought cases and the results of meteorological drought index analysis. In order to compare the drought index, we used standardized Precipitation Index (SPI), China-Z Index (CZI), Modified CZI (MCZI) and Z-Score Index Respectively. Four drought indices were used for the Taebaek and Sokcho areas. The drought index was analyzed using the meteorological data from 1986 to 2015 for a duration of 3 months. As a result of the analysis, the SPI drought index was analyzed to be highly reproducible for the case of drought with past limited water series. In the case of CZI and MCZI drought indices, the number of extreme dry occurrences is similar to that of the past cases, but the reproducibility is low for the actual drought years. In the case of ZSI drought index, it is analyzed that the number of occurrences and the comparison with the past cases are inferior in reproducibility. For the meteorological drought index using precipitation, it would be effective to use the SPI drought index with the highest reproducibility and the past drought case.

Forecast and verification of perceived temperature using a mesoscale model over the Korean Peninsula during 2007 summer (중규모 수치 모델 자료를 이용한 2007년 여름철 한반도 인지온도 예보와 검증)

  • Byon, Jae-Young;Kim, Jiyoung;Choi, Byoung-Cheol;Choi, Young-Jean
    • Atmosphere
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    • v.18 no.3
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    • pp.237-248
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    • 2008
  • A thermal index which considers metabolic heat generation of human body is proposed for operational forecasting. The new thermal index, Perceived Temperature (PT), is forecasted using Weather Research and Forecasting (WRF) mesoscale model and validated. Forecasted PT shows the characteristics of diurnal variation and topographic and latitudinal effect. Statistical skill scores such as correlation, bias, and RMSE are employed for objective verification of PT and input meteorological variables which are used for calculating PT. Verification result indicates that the accuracy of air temperature and wind forecast is higher in the initial forecast time, while relative humidity is improved as the forecast time increases. The forecasted PT during 2007 summer is lower than PT calculated by observation data. The predicted PT has a minimum Root-Mean-Square-Error (RMSE) of $7-8^{\circ}C$ at 9-18 hour forecast. Spatial distribution of PT shows that it is overestimated in western region, while PT in middle-eastern region is underestimated due to strong wind and low temperature forecast. Underestimation of wind speed and overestimation of relative humidity have caused higher PT than observation in southern region. The predicted PT from the mesoscale model gives appropriate information as a thermal index forecast. This study suggests that forecasted PT is applicable to the prediction of health warning based on the relationship between PT and mortality.

Relationship between Summer Heat Stress (Perceived Temperature) and Daily Excess Mortality in Seoul during 1991~2005 (인지온도를 이용한 여름철 폭염 스트레스와 일 사망률 증가와의 관련성 연구: 1991~2005, 서울)

  • Lee, Dae-Geun;Byon, Jae-Young;Choi, Young-Jean;Kim, Kyu-Rang
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.3
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    • pp.253-264
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    • 2010
  • This study investigates the relationship between daily mortality and heat stress in Seoul, using perceived temperatures (PT) derived from a heat budget model. During the summer season, observed PT intensity showed the biggest magnitude of summer heat stress from the middle 10 days of July to the first 10 days of August. The elderly (65 and above) were found to be the most vulnerable to heat stress. The threshold PT, with a significant increase in excess mortality, was $38^{\circ}C$. No time lagged effect was observed with summer heat stress, while a high correlation was observed between anomalies in PT and relative deviation of mortality. A comparison of the heat index and the discomfort index with excess mortality revealed that the discomfort index underestimated excess mortality, whereas the heat index could not appropriately explain the increase in excess mortality correlated with the increase in excess heat. In contrast, PT was found to be the weather element that best represents excess mortality due to heat stress, and is thus expected to serve as a more reliable forecast index of human biometeorology.

Developing of Forest Fire Occurrence Probability Model by Using the Meteorological Characteristics in Korea (기상특성을 이용한 전국 산불발생확률모형 개발)

  • Lee Si Young;Han Sang Yoel;Won Myoung Soo;An Sang Hyun;Lee Myung Bo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.6 no.4
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    • pp.242-249
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    • 2004
  • This study was conducted to develop a forest fire occurrence model using meteorological characteristics for the practical purpose of forecasting forest fire danger. Forest fire in South Korea is highly influenced by humidity, wind speed, and temperature. To effectively forecast forest fire occurrence, we need to develop a forest fire danger rating model using weather factors associated with forest fire. Forest fore occurrence patterns were investigated statistically to develop a forest fire danger rating index using time series weather data sets collected from 8 meteorological observation centers. The data sets were for 5 years from 1997 through 2001. Development of the forest fire occurrence probability model used a logistic regression function with forest fire occurrence data and meteorological variables. An eight-province probability model by was developed. The meteorological variables that emerged as affective to forest fire occurrence are effective humidity, wind speed, and temperature. A forest fire occurrence danger rating index of through 10 was developed as a function of daily weather index (DWI).

Drought analysis of Cheongmicheon watershed using meteorological, agricultural and hydrological drought indices (기상학적, 농업학적, 수문학적 가뭄지수를 이용한 청미천 유역의 가뭄 분석)

  • Won, Kwang Jai;Chung, Eun-Sung
    • Journal of Korea Water Resources Association
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    • v.49 no.6
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    • pp.509-518
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    • 2016
  • This study assessed drought of Cheongmicheon watershed from 1985 to 2015 according to duration. In order to quantify drought, we used meteorological and hydrological drought index. Standardized Precipitation Index(SPI) based on precipitation and Standardized Precipitation Evapotranspiration Index(SPEI) based on precipitation and evapotranspiration were applied as meteorological drought index. Palmer Drought Severity Index(PDSI) and Stream Drought Index(SDI) based on simulation of Soil and Water Assessment Tool(SWAT) model were applied as agricultural and hydrological drought index. As a result, in case average of extreme and averaged drought, 2014 and 2015 have the most vulnerable in all drought indices. Variation of drought showed different trend with regard to analysis of frequency. Also, the extreme and averaged drought have high correlation between drought indices excluding between PDSIs. However, each drought index showed different occurrence year and severity of drought Therefore, drought indices with various characteristics were used to analysis drought.

Effects of Land Cover Change on Summer Urban Heat Island Intensity and Heat Index in Seoul Metropolitan Area, Korea (서울 수도권 지역의 토지 피복 변화가 여름철 도시열섬 강도와 체감온도에 미치는 영향)

  • Hong, Seon-Ok;Byon, Jae-Young;Kim, Do-Hyeong;Lee, Sang-Sam;Kim, Yeon-Hee
    • Atmosphere
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    • v.31 no.2
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    • pp.143-156
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    • 2021
  • This study investigates the impacts of land cover change due to urbanization on the Urban Heat Island Intensity (UHII) and the Heat Index (HI) over the Seoul metropolitan area using the Unified Model (UM) with the Met Office Reading Urban Surface Exchange Scheme (MORUSES) during the heat wave from 16, July to 5, August 2018. Two simulations are performed with the late 1980s land-use (EXP1980) and the late 2000s land-use (EXP2000). EXP2000 is verified using Automatic Weather Station (AWS) data from 85 points in the study area, and observation sites are classified into two categories according to the urban fraction change over 20 years; Category A is 0.2 or less increase, and Category B is 0.2 or more increase. The 1.5-m temperature and relative humidity in Category B increase by up to 1.1℃ and decreased by 7% at 1900 LST and 2000 LST, respectively. This means that the effect of the urban fraction changes is higher at night. UHII increases by up to 0.3℃ in Category A and 1.3℃ in Category B at 1900 LST. Analysis of the surface energy balance shows that the heat store for a short time during the daytime and release at nighttime with upward sensible heat flux. As a result of the HI, there is no significant difference between the two experiments during the daytime, but it increases 1.6℃ in category B during the nighttime (2200 LST). The results indicate that the urbanization increase both UHII, and HI, but the times of maximum difference between EXP1980 and EXP2000 are different.