• Title/Summary/Keyword: Daily minimum air temperature

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Mean Heat Flux at the Port of Yeosu (여수항의 평균 열플럭스)

  • Choi Yong-Kyu;Yang Jun-Hyuk
    • Journal of Environmental Science International
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    • v.15 no.7
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    • pp.653-657
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    • 2006
  • Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDI) (1995-2004), mean heat fluxes were estimated at the port of Yeosu. Net heat flux was transported from the air to the sea surface during February to September, and it amounts to $205 Wm^{-2}$ in daily average value in May. During October to January, the transfer of net heat flux was conversed from the sea surface to the air with $-70 Wm^{-2}$ in minimum of daily average value in December. Short wave radiation was ranged from $167 Wm^{-2}$ in December to $300 Wm^{-2}$ in April. Long wave radiation (Sensible heat) was ranged from $27 (-14) Wm^{-2}$ in July to $90 (79) Wm^{-2}$ in December. Latent heat showed $42 Wm^{-2}$ with its minimum in July and $104 Wm^{-2}$ with its maximum in October in daily average value.

The Relationships between Temperature Changes and Mortality in Seoul, Korea (서울시의 기온변화와 사망자수 간의 관련성 연구)

  • Lee, Sa-Ra;Kim, Ho;Yi, Seung-Muk
    • Journal of Environmental Health Sciences
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    • v.36 no.1
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    • pp.20-26
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    • 2010
  • Temperature change has been shown to affect daily mortality even though different analytical methods produce different results. The effect of air pollution on the relationship between the temperature and the mortality is not large, although differences exist between temperature models. The aim of this study was to examine how the temperature change affected the daily mortality in Seoul by comparing the results from the temperature model using two study periods: one from 1994 to 2007 and the other from 1997 to 2007. Generally mean temperature, minimum temperature and Q10 temperature was derived as an optimal model, even though there are differences between age and cause of death. The analysis of threshold using total mortalities in all ages from 1994 to 2007 and from 1997 to 2007 showed that the number of the deaths increased 7.02% (95% CI: 6.06~7.98) and 2.51% (95% CI: 1.83~3.19), respectively as the mean temperature increased $1^{\circ}C$ from a threshold temperature of $27.5^{\circ}C$ and $25.7^{\circ}C$ respectively. These results indicated that the temperature has less effect on the number of death than does an extreme heat wave period.

On the Characteristics of the SO$_2$ Concentration Variation in Pusan, Korea (부산 지역의 SO$_2$ 농도 변화 특성에 관한 고찰)

  • 전병일;김유근;이화운
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.4
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    • pp.245-251
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    • 1994
  • We considered that characteristics of SO$_2$, concentration level and relations of the meteorological parameters and high pollution concentration from the data measured 7 air quality continuous monitoring stations during 4 years, from 1990 to 1993 in Pusan. The SO$_2$ concentration level showed decreasing trend yearly, it was maximum in Winter, minimum in Summer. The time of SO$_2$ peak concentration lagged from seashore to land because of break-down of the nocturnal inversion layer and seabreeze. Ihe correlations of daily SO$_2$, value between various air quality continuous monitoring stations were highest between Beomcheondong and Meongryundong, lowest between Daeyeondong and Sinpyeongdong because of difference of air Pollution emission sources characteristic. The meteorological parameters affecting SO$_2$ concentration level were minimum temperature, relative humidity, wind speed and air pressure. The SO$_2$ high pollution($\geq$95ppb) occurred almost in Winter, particulaly in such day showing lower wind speed and higher air pressure. Elementary SO$_2$ high Pollution Predictor were high pressure system and stability of lower atmosphere.

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Analyzing Information Value of Temperature Forecast for the Electricity Demand Forecasts (전력 수요 예측 관련 의사결정에 있어서 기온예보의 정보 가치 분석)

  • Han, Chang-Hee;Lee, Joong-Woo;Lee, Ki-Kwang
    • Korean Management Science Review
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    • v.26 no.1
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    • pp.77-91
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    • 2009
  • It is the most important sucess factor for the electricity generation industry to minimize operations cost of surplus electricity generation through accurate demand forecasts. Temperature forecast is a significant input variable, because power demand is mainly linked to the air temperature. This study estimates the information value of the temperature forecast by analyzing the relationship between electricity load and daily air temperature in Korea. Firstly, several characteristics was analyzed by using a population-weighted temperature index, which was transformed from the daily data of the maximum, minimum and mean temperature for the year of 2005 to 2007. A neural network-based load forecaster was derived on the basis of the temperature index. The neural network then was used to evaluate the performance of load forecasts for various types of temperature forecasts (i.e., persistence forecast and perfect forecast) as well as the actual forecast provided by KMA(Korea Meteorological Administration). Finally, the result of the sensitivity analysis indicates that a $0.1^{\circ}C$ improvement in forecast accuracy is worth about $11 million per year.

Variations of Soil Temperatures in Winter and Spring at a High Elevation Area (Boulder, Colorado)

  • Lee, Jin-Yong;Lim, Hyoun Soo;Yoon, Ho Il;Kim, Poongsung
    • Journal of Soil and Groundwater Environment
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    • v.20 no.5
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    • pp.16-25
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    • 2015
  • The City of Boulder is located at an average elevation of 1,655 m (5,430 feet), the foothills of the Rocky Mountains in Colorado. Its daily air temperature is much varying and snow is very frequent and heavy even in spring. This paper examines characteristics of shallow (surface and depth = 10 cm) soil temperatures measured from January to May 2015 in the high elevation city Boulder, Colorado. The surface soil temperature quickly responded to the air temperature with the strongest periodicity of 1 day while the subsurface soil temperatures showed a less correlation and delayed response with that. The short-time Fourier of the soil temperatures uncovered their very low frequencies characteristics in heavy snow days while it revealed high frequencies of their variations in warm spring season. The daily minimum air temperature exhibited high cross-correlations with the soil temperatures without lags unlike the maximum air temperature, which is derived from its higher and longer auto-correlation and stronger spectrums of low frequencies than the maximum air temperature. The snow depth showed an inverse relationship with the soil temperature variations due to snow's low thermal conductivity and high albedo. Multiple regression for the soil temperatures using the air temperature and snow depth presented its predicting possibility of them even though the multiple r2 of the regression is not that much satisfactory (r2 = 0.35-0.64).

A Geospatial Evaluation of Potential Sea Effects on Observed Air Temperature (해안지대 기온에 미치는 바다효과의 공간분석)

  • Kim, Soo-Ock;Yun, Jin-I.;Chung, U-Ran;Hwang, Kyu-Hong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.4
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    • pp.217-224
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    • 2010
  • This study was carried out to quantify potential effects of the surrounding ocean on the observed air temperature at coastal weather stations in the Korean Peninsula. Daily maximum and minimum temperature data for 2001-2009 were collected from 66 Korea Meteorological Administration (KMA) stations and the monthly averages were calculated for further analyses. Monthly data from 27 inland sites were used to generate a gridded temperature surface for the whole Peninsula based on an inverse distance weighting and the local temperature at the remaining 39 sites were estimated by recent techniques in geospatial climatology which are widely used in correction of small - scale climate controls like cold air drainage, urban heat island, topography as well as elevation. Deviations from the observed temperature were regarded as the 'apparent' sea effect and showed a quasi-logarithmic relationship with the distance of each site from the nearest coastline. Potential effects of the sea on daily temperature might exceed $6.0^{\circ}C$ cooling in summer and $6.5^{\circ}C$ warming in winter according to this relationship. We classified 25 sites within the 10 km distance from the nearest coastline into 'coastal sites' and the remaining 15 'fringe sites'. When the average deviations of the fringe sites ($0.5^{\circ}C$ for daily maximum and $1.0^{\circ}C$ for daily minimum temperature) were used as the 'noise' and subtracted from the 'apparent' sea effects of the coastal sites, maximum cooling effects of the sea were identified as $1.5^{\circ}C$ on the west coast and $3.0^{\circ}C$ on the east and the south coast in summer months. The warming effects of the sea in winter ranged from $1.0^{\circ}C$ on the west and $3.5^{\circ}C$ on the south and east coasts.

Factors Affecting Acer mono sap Exudation : Kwangyang Region in Korea (고로쇠나무 수액의 출수에 미치는 영향 인자 분석 : (I) 광양지역)

  • Choi, Won-Sil;Park, Mi-Jin;Lee, Hak-Ju;Choi, In-Gyu;Kang, Ha-Young
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.1
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    • pp.66-74
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    • 2010
  • This study was carried out to investigate the optimum condition for sap exudation of Acer mono Max. tree in a site of Mt. Baekun, Kwangyang city, Korea. Amount of sap exudation, air temperature, relative air humidity and tree diameter at breast height (DBH) were monitored for the period of January 5 through March 28, 2008, and correlation analysis of several factors affecting on sap exudation was carried out. As the diameter of Acer mono at breast height increased, the amount of sap was linearly proportional. Sap exudation initiated at February 18, and occurred intensively in the period of February 28 through March 10, resulting in 84% of total sap amount by volume. During sap exudation, the minimum temperature was averaged at $-2.4{\pm}1.5^{\circ}C$ and the maximum at $6.0{\pm}1.8^{\circ}C$, while there was no sap exudation whenever temperature was below or above $0^{\circ}C$ all the day long. The maximum temperature, range of temperature and the maximum, minimum and mean humidities in air were significant factors affecting on amount of sap. The maximum air temperature had the highest correlation coefficient with 0.768 (P < 0.01) and was also considered as the principal factor by partial-correlation analysis. These results showed that sap exudation required daily air-temperature fluctuation from below to above $0^{\circ}C$, and the amount of sap was strongly dependent on the highest daily-temperature and DBH of tree.

Analysis of Agricultural Climatology in Cheju Island I. Distribution of Daily Minimum Temperature in Winter Season Estimated from a Topoclimatological Method (제주도의 농업기후 분석 I. 지형기후 추정법과 동계 일최저기온 분포)

  • 윤진일;유근배;이민영;정귀원
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.3
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    • pp.261-269
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    • 1989
  • Agricultural activities in Chejudo require more specialized weather services in this region. The meteorological information available from the Korea Meteorological Service (KMS) is limited in its areal coverage because the KMS stations are located along the narrow band of coastal area. topoclimatological technique which makes use of empirical relationships between the topography and the weather can be applied to produce reasonable estimates of the climatic variables such as air temperature and precipitation over remote land area where routine observations are rare. Presentation of these estimates in a from of fine-mesh grid map can also be helpful to upgrade the quality of weather services in this region. Altitude values of the 250 m grid points were read from a 1: 25000 topographic map and the mean altitude, the mean slope, and the aspect of the slope were determined for each 1 km$^2$ land area from these altitude data. Daily minimum air temperature data were collected from 18 points in Chejudo during the winter period from November 1987 to February 1988. The data were grouped into 3 sets based on synoptic pressure pattern. Departures from the KMS observations were regressed to the topographical variables to delineate empirical relationships between the local minimum temperature under specific pressure patterns and the site topography. The selected regression equations were used to calculate the daily minimum temperature for each 1 km$^2$ land area under the specific pressure patterns. The outputs were presented in a fine-mesh grid map with a 6-level contour capability.

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Characteristics of Air Temperature Variations under Different Land Covers during Summer (여름철 토지피복별 기온변화 특성)

  • Kim, Jin-Soo;Park, Jong-Wha;Jung, Gu-Young;Oh, Kwang-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.1
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    • pp.79-88
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    • 2007
  • We investigated the characteristics of temperature variations under different land covers (paddy field, upland, urban park, and urban residential area) during hot summer (July 15 to August 19, 2005). The temperatures were monitored using data loggers at one hour intervals in study sites. The mean temperature generally increased with the distance from edge of paddy fields, being $1.5^{\circ}C$ higher at a site 170-m far from paddy fields than at a paddy field area at 22 h. The mean daily temperatures in the study period followed the ordo. of paddy field $(26.6^{\circ}C)$ < upland $(27.0^{\circ}C)$ < park $(27.5^{\circ}C)$ < residential area $(28.0^{\circ}C)$. The paddy field area has shown remarkable cooling effects compared to the residential area: Mean duration of temperature below $25^{\circ}C$ in the paddy field area was longer (8.6 hrs) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area was sooner (22.4 hr) than in the residential area; Mean daily minimum temperature in the paddy field area was much lower $(2.4^{\circ}C)$ than in the residential area. More research is needed to better clarify the mechanism of cooling effect of a paddy field area by investigating heat balance of a paddy field.

Differences in Temperature between Korea and Japan, and its Inference in Rice Planting (한국(韓國)과 일본(日本)의 기온조건(氣溫條件)의 차이(差異)와 수도작(水稻作)에의 의미(意味))

  • Tani, Nobu Teru;Jung, Yeong-Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.4
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    • pp.348-351
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    • 1985
  • Air temperature and its inference in rice planting were briefly analyzed to compare the difference in agricultural climatic condition in Korea and Japan. The results were as follows: 1. The mean air temperatures of August showed similar range at the same latitude in both countries but those of Korea in January were much lower than of Japan showing the greater annual range. 2. The daily fluctuations of air temperature during spring and autumn in Korea were greater than in Japan, and it was prominent in the daily minimum temperature. At the same cumulative temperature for maturing of rice plant, the cumulative cooling temperature lower than the certain marginal temperature, say $12^{\circ}C$ or $13^{\circ}C$, was greater in Korea than in Japan. Therefore, in analysis of temperature data relating to rice cropping, authors suggested that the cumulative cooling temperature be considered.

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