• Title/Summary/Keyword: Daily Maximum Temperature

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Study on the Establishment of Threshold Criteria for Heat Health Watch Warning System in Korea; Part II: Improvement of Criteria (고온건강경보시스템 기준 설정에 관한 연구 ( II ) - 설정 기준 개선 -)

  • Jung, Woo-Sik;Park, Jong-Kil;Kim, Eun-Byul;Song, Jeong-Hui
    • Journal of Environmental Science International
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    • v.18 no.7
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    • pp.781-796
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    • 2009
  • The current standard level of Heat Health Watch Warning System consider both daily maximum temperature and daily maximum heat index(HI), but current standard could not consider daily maximum HI due to the difficulties in forecasting when we consider both daily maximum temperature and daily maximum HI and no considering HI because relative humidity could not observed for some regions. So, Newly established standard level of Heat Health Watch Warning System is based on daily maximum temperature exceeding $30^{\circ}C$ for two consecutive days or daily minimum temperature exceeding $25^{\circ}C$ and daily maximum temperature exceeding $30^{\circ}C$. These days are called "extreme heat days". On extreme heat days, the standard of extreme heat advisory is based on daily maximum temperature among exceeding $32.7^{\circ}C$ and not exceeding $34.8^{\circ}C$, and extreme heat warning is based on daily maximum temperature exceeding $34.8^{\circ}C$. ANOVA analysis was carried out using the data of Seoul Metropolitan City in 1994 to check the robustness of the new standard level of Heat Health Watch Warning System from this study, in particular for mortality variable. The results reveal that the new standard specifies excess mortality well, showing significance level of 0.05 in the difference of excess mortality for each phase.

Study on the examination and revision about the standard level of the Extreme heat watch warning system for reduction of personal or property injury (인명.재해 피해 저감을 위한 폭염특보기준 검토 및 보완에 관한 연구)

  • Park, Jong-Kil;Jung, Woo-Sik;Song, Jeong-Hui;Kim, Eun-Byul
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.89-92
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    • 2008
  • The extreme heat watch warning system(EHWWS) that Korea Meterological Administration carried out a preliminary from July 1, 2007, considered both daily maximum temperature and daily maximum heat index simultaneously. It was requested revision of the standard level of EHWWS to solve the difficulty of forecasting occurred when we were considering two parameters simultaneously and we did not considering heat index according to areas. For this, we established three type standard, such as type 1 that considered both daily maximum temperature and daily maximum heat index, Under the extreme heat day that daily minimum temperature was more than $25^{\circ}C$, type 2 that considered daily maximum temperature and type 3 that considered only daily maximum heat index and then analyzed whether these 3 types satisfies the excess mortality of the extreme heat warning or not. As a results, type 1 and 2 were more explain away excess mortality each warning step than type 3. type 2 could also apply case of not to consider heat index according to areas and had a merit for extreme heat forecasting easily because the standard was simple. Therefore we think type 2 is more suitable and reasonable standard for Korea extreme heat watch warning system(KEHWWS) than type 1. In addition, we need to develop model that exactly predicts the excess mortality will be take place during the extreme heat warning and construct KEHWWS.

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On Recent Variations in Solar Radiation and Daily Maximum Temperature in Summer (여름철 일 최고기온과 일사량의 최근 변동에 관하여)

  • Choi, Mi-Hee;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.11 no.4
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    • pp.185-191
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    • 2009
  • Few studies have attempted to analyze variations of daily maximum temperature in the summer whereas many studies have analyzed warming trends in other seasons with respect to greenhouse gases or urban heat islands. We analyzed daily maximum temperature data for the summer season (June to August) at 18 locations in South Korea from 1983 to 2007. Compared to the climatic normal (from 1971 to 2000), an average increase of $0.1^{\circ}C$ was found for the summer daily maximum temperature along with an increase of $0.61MJ\;m^{-2}$ in daily solar radiation. Approximately 65% of the annual variations of the summer daily maximum temperature could be explained by the solar radiance alone. Higher atmospheric transmittance due to lower aerosol concentration (especially of sulfur dioxide) is believed to have caused the recent increase in solar irradiance. Daily maximum temperature of the summer is expected to keep rising if the clean air activities are maintained in the future.

Azimuthal Distribution of Daily Maximum Temperatures Observed at Sideslopes of a Grass-covered Inactive Parasitic Volcano ("Ohreum") in Jeju Island (제주도 초지피복 기생화산("오름")의 방위별 일 최고기온 분포)

  • Seo, Hee-Chul;Jeon, Seung-Jong;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.10 no.1
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    • pp.25-31
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    • 2008
  • Information on daily maximum air temperature is important in predicting the status of plants and insects, but the uneven and sparse distribution of weather stations prohibits timely access to the data in regions with complex topography. Since cumulative solar irradiance plays a critical role in determining daily maximum temperature on any sloping surfaces, derivation of a quantitative relationship between cumulative solar irradiance and the resultant daily maximum temperature is a prerequisite to development of such estimation models. Air temperatures at 8 sideslope locations with similar elevation and slope angle but aspect, circumventing a cone-shaped, grass-covered parasitic volcano (c.a., 570 m diameter for the bottom circle and 90m bottom-to-top height), were measured from June to December in 2007. Daily maximum temperatures from each location were compared with the average of 8 locations (assumed to be the temperature measured at a "horizontal reference" position). The temperature deviation at all locations increased with the day of year (or sun elevation) from summer solstice to winter solstice. Averaged over the entire period, the south facing location was warmer by $1^{\circ}C$ in daily maximum temperature than "horizontal reference" and the north facing location was cooler by $0.8^{\circ}C$ than the reference, resulting in the year round average south-north temperature difference of $1.8^{\circ}C$. In November, both south and north facing slopes showed the greatest deviation of $+2.0^{\circ}C$ and $-1.3^{\circ}C$, respectively in daily maximum temperature at monthly scale. On a daily scale, the greatest deviation was +3.8 and $2.7^{\circ}C$ at the south and north slope, respectively. The cumulative solar irradiance (on the slope for 4 hours from 11:00 to 15:00 TST) explained >60% of the variance in daily maximum temperature deviations among 8 locations, suggesting a feasibility of developing an estimation model for daily maximum temperature over complex topography at landscape scales.

A Study on the Thermal Characteristics of Midsummer in Daegu Metropolitan Area

  • Park, Myung-Hee;Lee, Joon-Soo;Ahn, Won-Shik;Kim, Hae-Dong;Oh, Sung-Nam
    • Journal of Environmental Science International
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    • v.22 no.6
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    • pp.667-677
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    • 2013
  • This study aims to examine the actual status of the urban heat island in Daegu by analyzing the data of 17 automatic weather stations installed in the Daegu area. And the results can be summarized as follows: First, regarding the temperature distribution in Daegu by summer time zones, for the 31 days(August 1st till 31st), 18 days showed daily maximum temperature over $30^{\circ}C$, and 11 days indicated daily minimum temperature over $25^{\circ}C$. The day that showed the highest daily maximum temperature was August 5th, which indicated $36^{\circ}C$. Second, about the spatial distribution of time ratio exceeding $30^{\circ}C$ and $25^{\circ}C$, the area with the highest time ratio exceeding $30^{\circ}C$ is mostly the downtown(central area), eastern area, and northern area. Meanwhile, regarding the time ratio exceeding $25^{\circ}C$, the downtown area centering around the central area were high as over 70%, and the outskirts were low as under 65%. Third, considering the temporal distribution of daily maximum temperature and daily minimum temperature, daily maximum temperature was shown around 14:00 to 15:00 while the daily minimum temperature was indicated around 17:00 to 18:00. Daily maximum and minimum temperature were appeared at northeast and downtown, respectively. Fourth, regarding the spatial distribution of tropical days and tropical night days, tropical days showed 77% and tropical night days indicated 42% before and after the 24th and also the 13th each. Tropical days were occurred up to 24 days at northeastern area. And the southwestern area of Daegu showed under 22 days. The downtown showed the 14 days of the tropical night. However, the outskirts indicated relatively few days as under 10 days. Fifth, about the spatial distribution of the average daily temperature range (the difference between the highest temperature and lowest temperature), the central area, the central part of the city, showed the smallest as $7.2^{\circ}C$, and as it was closer to the northern area, it became larger, so in the eastern and northern area, it was over $8.8^{\circ}C$ or so.

Development of calculating daily maximum ground surface temperature depending on fluctuations of impermeable and green area ratio by urban land cover types (도시 토지피복별 불투수면적률과 녹지면적률에 따른 지표면 일최고온도 변화량 산정방법)

  • Kim, Youngran;Hwang, Seonghwan
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.2
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    • pp.163-174
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    • 2021
  • Heatwaves are one of the most common phenomena originating from changes in the urban thermal environment. They are caused mainly by the evapotranspiration decrease of surface impermeable areas from increases in temperature and reflected heat, leading to a dry urban environment that can deteriorate aspects of everyday life. This study aimed to calculate daily maximum ground surface temperature affecting heatwaves, to quantify the effects of urban thermal environment control through water cycle restoration while validating its feasibility. The maximum surface temperature regression equation according to the impermeable area ratios of urban land cover types was derived. The estimated values from daily maximum ground surface temperature regression equation were compared with actual measured values to validate the calculation method's feasibility. The land cover classification and derivation of specific parameters were conducted by classifying land cover into buildings, roads, rivers, and lands. Detailed parameters were classified by the river area ratio, land impermeable area ratio, and green area ratio of each land-cover type, with the exception of the rivers, to derive the maximum surface temperature regression equation of each land cover type. The regression equation feasibility assessment showed that the estimated maximum surface temperature values were within the level of significance. The maximum surface temperature decreased by 0.0450℃ when the green area ratio increased by 1% and increased by 0.0321℃ when the impermeable area ratio increased by 1%. It was determined that the surface reduction effect through increases in the green area ratio was 29% higher than the increasing effect of surface temperature due to the impermeable land ratio.

An Analysis of a Winter-time Temperature Change and an Extreme Cold Waves Frequency in Korea (우리나라의 겨울철 기온 변화 및 한파 발생빈도 분석)

  • Jeon, Mi Jeong;Cho, Yongsung
    • Journal of Climate Change Research
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    • v.6 no.2
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    • pp.87-94
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    • 2015
  • To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.

Estimation of daily maximum air temperature using NOAA/AVHRR data (NOAA/AVHRR 자료를 이용한 일 최고기온 추정에 관한 연구)

  • 변민정;한영호;김영섭
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.291-296
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    • 2003
  • This study estimated surface temperature by using split-window technique and NOAA/AVHRR data was used. For surface monitoring, cloud masking procedure was carried out using threshold algorithm. The daily maximum air temperature is estimated by multiple regression method using independent variables such as satellite-derived surface temperature, EDD, and latitude. When the EDD data added, the highest correlation shown. This indicates that EDD data is the necessary element for estimation of the daily maximum air temperature. We derived correlation and experience equation by three approaching method to estimate daily maximum air temperature. 1) non-considering landcover method as season, 2) considering landcover method as season, and 3) just method as landcover. The last approaching method shows the highest correlation. So cross-validation procedure was used in third method for validation of the estimated value. For all landcover type 5, the results using the cross-validation procedure show reasonable agreement with measured values(slope=0.97, intercept=-0.30, R$^2$=0.84, RMSE=4.24$^{\circ}C$). Also, for all landcover type 7, the results using the cross-validation procedure show reasonable agreement with measured values(slope=0.993, Intercept=0.062, R$^2$=0.84, RMSE=4.43$^{\circ}C$).

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The Spatial and temporal distributions of NET(Net Effective Temperature) with a Function of Temperature, Humidity and Wind Speed in Korea (한반도의 날씨 스트레스 지수 NET(Net Effective Temperature) 분포의 특성)

  • 허인혜;최영은;권원태
    • Journal of the Korean Geographical Society
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    • v.39 no.1
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    • pp.13-26
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    • 2004
  • This paper examined the possibility of NET application for a relative weather stress index in Korea. The characteristic of NET distribution used temperature, relative humidity, wind speed which forecasting at Korean Meteorological Administration were analyzed. Regional critical values of daily maximum NET of stress index for summer resembled the distribution of daily maximum temperature because were not impacted wind and humidity but temperature. Regional critical values of daily minimum NET of stress index for winter distributed variously compared with summer. The highland region and the northern region of Seoul were impacted of low temperature and coastal region which strong wind. The occurrences of stressful days did not vary in summer, but obviously increased in winter after mid-1990s.

Development of an Algorithm for Searching Optimal Temperature Setpoint for Lettuce in Greenhouse Using Crop Growth Model (작물생장모델을 이용한 상추의 온실 최적설정온도 탐색 알고리즘의 개발)

  • 류관희;김기영;김희구;채희연
    • Journal of Biosystems Engineering
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    • v.24 no.5
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    • pp.445-452
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    • 1999
  • This study was conducted to develop a searching algorithm for optimal daily temperature setpoint greenhouse. An algorithm using crop growth and energy models was developed to determine optimum crop growth environment. The results of this study were as follows: 1. Mathematical models for crop growth and energy consumption were derived to define optimal daily temperature setpoint. 2. Optimum temperature setpoint, which could maximize performance criterion, was determined by using Pontryagin maximum principle. 3. Dynamic control of daily temperature using the developed algorithm showed higher performance criterion than static control with fixed temperature setpoint. Performance criteria for dynamic control models were with simulated periodic weather data and with real weather data, increased by 48% and 60%, respectively.

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