• 한국측량학회지
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• 제38권2호
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• pp.123-130
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• 2020

The impact of urbanization on LST (Land Surface Temperature) and TN (Tropical Night) was observed with the analyses of land cover change and LST by associating with the frequency of TN during the period of 1996 to 2016. The analyses of land cover and LST was based on the images of Landast 5 and 8 for September in 1996, 2006, and 2016 at a 10 year interval. The hourly-collected atmospheric temperatures for the months of July and August during the period were collected from AWSs (Automatic Weather Stations) in Seoul for the frequency analysis of TN. The study area was categorized into five land cover classes: urban or built-up area, forest, mixed vegetation, bare soil and water. It was found that vegetation (-7.71%) and bare soil (-9.04%) decreased during the period while built-up (17.29%) area was expanded throughout the whole period (1996-2016), indicating gradual urbanization. The changes came along with the LST rise in the urban area of built-up and bare soil in Seoul. In addition, the frequency of TN has increased in 4.108% and 7.03% for July and August respectively between the two periods of the 10 year interval, 1996-2006 and 2006-2016. By comparing the increasing trends of land cover, LST, and TN, we found a high probability that the frequency of TN had a relationship with land cover changes by the urbanization process in the study area.

• 대한원격탐사학회지
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• 제27권6호
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• pp.653-662
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• 2011

Land surface temperature (LST) is a one of the key variables of land surface which can be estimated from geostationary meteorological satellite. In this study, we have developed the three sets of LST retrieval algorithm from MTSAT-2 data through the radiative transfer simulations under various atmospheric profiles (TIGR data), satellite zenith angle, spectral emissivity, and surface lapse rate conditions using MODTRAN 4. The three LST algorithms are daytime, nighttime and total LST algorithms. The weighting method based on the solar zenith angle is developed for the consistent retrieval of LST at the early morning and evening time. The spectral emissivity of two thermal infrared channels is estimated by using vegetation coverage method with land cover map and 15-day normalized vegetation index data. In general, the three LST algorithms well estimated the LST without regard to the satellite zenith angle, water vapour amount, and surface lapse rate. However, the daytime LST algorithm shows a large bias especially for the warm LST (> 300 K) at day time conditions. The night LST algorithm shows a relatively large error for the LST (260 ~ 280K) at the night time conditions. The sensitivity analysis showed that the performance of weighting method is clearly improved regardless of the impacting conditions although the improvements of the weighted LST compared to the total LST are quite different according to the atmospheric and surface lapse rate conditions. The validation results of daytime (nighttime) LST with MODIS LST showed that the correlation coefficients, bias and RMSE are about 0.62~0.93 (0.44~0.83), -1.47~1.53 (-1.80~0.17), and 2.25~4.77 (2.15~4.27), respectively. However, the performance of daytime/nighttime LST algorithms is slightly degraded compared to that of the total LST algorithm.

• 한국수산과학회지
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• 제41권2호
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• pp.113-118
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• 2008

Diel rhythm of oxygen consumption (OC) of the starry flounder Platichthys stellatus was measured at different water temperatures in a closed recirculating seawater system with a respiratory chamber. The fish consumed 70.5, 79.7, and 90.6 mg $O_2/kg/hr$ at 15, 20, and $25^{\circ}C$, respectively, showing a linear increase in OC with water temperature. The OC of fish showed a clear diel rhythm, with lower values during the day and higher values at night, in accordance with the light (09:00-21:00) and dark (21:00-09:00) phases of the diel cycle (12L:12D) in water at 15 and $20^{\circ}C$. However, the OC of the fish showed an unclear diel rhythm with the light and dark phases of the diel cycle at $25^{\circ}C$. The respective OC at 15, 20 and $25^{\circ}C$ was 63.8, 72.4, and 88.4 mg $O_2/kg/hr$ during the light phases and 77.2, 87.1, and 92.8 mg $O_2/kg/hr$ during the dark phase. The starry flounder is thought to be a nocturnal fish with a higher OC at night, while it rests during the day. Its OC was the most stable in the light, when it did not feed. Consequently, the night-time OC is the active OC and the day-time OC is the resting OC in the starry flounder.

• 한국약용작물학회지
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• 제13권4호
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• pp.186-189
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• 2005

식물체의 개화는 온도와 일장에 의하여 크게 영향을 받는다. 본 연구는 night-break 처리로 개화가 억제되는 상태에서 월동중의 유지온도가 일임성 식물인 바위솔의 생장과 개화에 미치는 영향을 파악하고자 자연상태의 대조구와 $10^{\circ}C$와 $20^{\circ}C$ 이하로 온도가 내려갈 경우 가온하는 3개 처리로 구분하여 시험을 수행하였던 바 그 결과를 요약하면 다음과 같다. 1.초장, 화서장, 엽과 포엽수 및 경직경은 자연상태에서 재배되는 것보다는 $10^{\circ}C$ 이상으로 가온하여 재배할 경우 길고 많거나 굵어졌던 반면, $10^{\circ}C$ 또는 $20^{\circ}C$ 이상으로 가온할 경우 차이가 없었다. 2. 엽과 포엽중, 경중, 근중, 지상부중, 전체건물중은 자연상태에 비하여 $10^{\circ}C$ 이상으로 가온할 경우 10월 하순부터 많았던 반면, $10^{\circ}C$ 또는 $20^{\circ}C$ 이상으로 가온할 경우 차이가 거의 없었다. 3. 월동중 유지온도가 높을수록 형성된 소화수는 많았으나, 형성된 소화의 개화는 적어지는 경향을 보였다. 4. 소화가 개화된 개체의 비율은 자연상태에서는 전체가, $10^{\circ}C$ 이상으로 유지할 경우 25% 정도에 이르렀으나, $20^{\circ}C$ 이상으로 유지할 경우 전무하였다.

• 생물환경조절학회지
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• 제4권1호
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• pp.9-16
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• 1995

고추 유묘의 생장, 광합성, 호흡 및 양수분흡수에 미치는 온도 및 주야변온의 영향을 구명하기 위하여 환경조절이 가능한 생장상내에서 실험을 수행한바 얻어진 결과는 다음과 같다. 1. 고추육묘시 적온으로 생각되는 $25^{\circ}C$에 비하여 온도가 12$^{\circ}C$로 저하함에 따라 수분 및 N, P, K 양분흡수에 현저한 감소를 보였으며, 5$^{\circ}C$에는 양수분의 흡수가 거의 이루어지지 않았다. 2. 엽의 광합성은 5$^{\circ}C$에서 $25^{\circ}C$까지는 점차적으로 증가되다가 $25^{\circ}C$에서 최대광합성을 보였으며, 엽과 근의 호흡은 온도가 증가할수록 계속 증가하였다. 3. 지하부 건물중이 가장 높은 적정 주야온도조합은 주간 3$0^{\circ}C$와 야간 $25^{\circ}C$로 나타났고, 주/야 온도 25/$25^{\circ}C$, 30/15$^{\circ}C$, 25/15$^{\circ}C$, 15/$25^{\circ}C$, 10/$25^{\circ}C$ 간에는 큰 차이가 있었으며, 야간온도 5$^{\circ}C$에서는 주간온도에 관계없이 지상부 건물중 증가가 거의 없었다.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• 제25권1호
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• pp.57-81
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• 1997

Numerical prediction of nocturnal thermal high in summer of the 1995 near Taegu city located in a basin has been carried out by a non-hydrostatic numerical model over complex terrain through one-way double nesting technique in the Z following coordinate system. Under the prevailing westerly winds, vertical turbulent fluxes of momentum and heat over mountains for daytime hours are quite strong with a large magnitude of more than $120W/\textrm{m}^2$, but a small one of $5W/\textrm{m}^2$ at the surface of the basin. Convective boundary layer (CBL) is developed with a thickness of about 600m over the ground in the lee side of Mt. Hyungje, and extends to the edge of inland at the interface of land sea in the east. Sensible heat flux near the surface of the top of the mountain is $50W/\textrm{m}^2$, but its flux in the basin is almost zero. Convergence of sensible heat flux occurs from the ground surface toward the atmosphere in the lower layer, causing the layer over the mountain to be warmed up, but no convergance of the flux over the basin results from the significant mixing of air within the CBL. As horizontal transport of sensible heat flux from the top of the mountain toward over the basin results in the continuous accumulation of heat with time, enhancing air temperature at the surface of the basin, especially Taegu city to be higher than $39.3^{\circ}C$. Since latent heat fluxes are $270W/\textrm{m}^2$ near the top of the mountain and $300W/\textrm{m}^2$ along the slope of the mountain and the basin, evaporation of water vapor from the surface of the basin is much higher than one from the mountain and then, horizontal transport of latent heat flux is from the basin toward the mountain, showing relative humidity of 65 to 75% over the mountain to be much greater than 50% to 55% in the basin. At night, sensible heat fluxes have negative values of $-120W/\textrm{m}^2$ along the slope near the top of the mountain and $-50W/\textrm{m}^2$ at the surface of the basin, which indicate gain of heat from the lower atmosphere. Nighttime radiative cooling produces a shallow nocturnal surface inversion layer with a thickness of about 100m, which is much lower than common surface inversion layer, and lifts extremely heated air masses for daytime hours, namely, a warm pool of $34^{\circ}C$ to be isolated over the ground surface in the basin. As heat transfer from the warm pool in the lower atmosphere toward the ground of the basin occurs, the air near the surface of the basin does not much cool down, resulting in the persistence of high temperature at night, called nocturnal thermal high or tropical night. High relative humidity of 75% is found at the surface of the basin under the moderate wind, while slightly low relative humidity of 60% is along the eastern slope of the high mountain, due to adiabatic heating by the srong downslope wind. Air temperature near the surface of the basin with high moisture in the evening does not get lower than that during the day and the high temperature produces nocturnal warming situation.

• 현장농수산연구지
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• 제20권2호
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• pp.39-47
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• 2018

본 연구에서는 토마토 모종을 대상으로 육묘기간 중 야간에 단시간 동안의 저온 노출에 따른 토마토의 잎과 줄기의 온도변화를 실시간으로 측정하였으며, 저온 스트레스가 항산화물질 생성에 미치는 영향과 생육을 분석하여 육묘 시 단시간의 변온관리 가능 여부를 구명하였다. 야간 변온실험은 첫날 18시부터 6일 후 9시까지 15℃ 항온, 15℃ 2시간과 11℃ 2시간 변온, 15℃ 2시간과 11℃ 4시간 변온처리를 하여 잎과 줄기의 온도, 생육정도 및 플라보노이드 함량을 측정하여 저온 스트레스 영향을 분석하였다. 실험결과, 토마토 모종은 기온에 따라 엽과 줄기 온도가 비슷해지는 경향을 보였으며, 15℃와 11℃ 각각 2시간씩 반복 변온처리한 토마토 묘와 15℃ 항온처리한 토마토 묘의 생육과 플라보노이드 함량 간의 차이가 작은 것으로 나타났다. 본 실험을 통해 육묘시 야간온도를 15℃ 2시간과 11℃ 2시간으로 반복하도록 관리하여도 저온 스트레스 영향이 적은 것으로 나타났다. 이러한 결과로 미루어 볼 때 육묘시 야간의 변온처리로 난방비 절감이 가능할 것으로 사료된다.

• 한국의류산업학회지
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• 제6권5호
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• pp.613-617
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• 2004

The intent of this study was to determine whether different light exposure could modify the clothing behavior in the evening cold environment or not. Nine female subjects volunteered to this study. In a bright light or a dim light condition, light intensity was controlled 3000 lx or 10 lx respectively. Subjects were introduced to wear various kinds of garments whenever they need to feel comfortable as the room temperature began to decrease. The room temperature was lowered from $30^{\circ}C$ to $15^{\circ}C$ for one hour (21:00 h~22:00 h) and maintained at $15^{\circ}C$ for additional one hour (22:00 h~23:00 h). Subjects stayed in chamber from 08:00 to the next day 07:00. Clothing behavior, core temperature, subjective temperature sensation and melatonin secretion were measured. Most subjects put on the clothing more quickly and more thickerly in the bright light rather than in the dim light condition. The fall of core temperature during night was significantly less under the bright light in the late afternoon, suggesting that the set-point of core temperature has been set at a higher level during the evening and the night, being supported by the less amount of melatonin secretion. Thus, it is concluded that the quicker dressing behavior with thicker clothing in the "Bright" condition is advantageous in evening cold exposure, since it enables the core temperature to reach its set-point value more easily.

• 한국작물학회지
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• 제51권1호
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• pp.41-47
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• 2006

To understand the heading habit of recently developed 20 Korean rice cultivars, rice plants in a phytotron were exposed to different temperature: $22.5^{\circ}C(day\;27^{\circ}C/night\;18^{\circ}C),\;27.5^{\circ}C(day\;32^{\circ}C/night\;23^{\circ}C)$, and day-length conditions: 10, 12, 13, 14, 15 hours. Four rice cultivars (Sobibyeo, Juanbyeo, Ilpumbyeo and Shindongjinbyeo) showed relatively short Basic Vegetative Phase (BVP) of 17 to 18 days, while Dasanbyeo showed the longest (35 days) BVP, compared to other remaining 15 tested cultivars which exhibited 24 to 31 days of BVP. In this experiment, it was tried out to separate the eliminable vegetative phase into photosensitivity and thermo-sensitivity with two different pathways. Many tested cultivars, however, exhibited quite different responses under low temperature and / or long day-length conditions. Especially, Surabyeo and Juanbyeo were the most difficult cultivars to separate into photo- or thermo-sensitivity in that the eliminable vegetative phase of these two cultivars increased greatly only under low temperature $(22.5^{\circ}C)$ and long day-length (15 hr.) conditions. Regarding the heading response to temperatures, tested cultivars could be categorized into 2 groups. In 1st group of rice cultivars, the eliminable vegetative phase decreased almost equally as the temperature changed from $20.0^{\circ}C\rightarrow22.5^{\circ}C\rightarrow25.0^{\circ}C\rightarrow27.5^{\circ}C$. In contrast, the 2nd group of rice cultivars exhibited eliminable vegetative phase slowly decreasing when the temperature changed from $22.5^{\circ}C\rightarrow25.0^{\circ}C\rightarrow27.5^{\circ}C$, but rapidly decreasing when the mean temperature changed from $20.0^{\circ}C\;to\;22.5^{\circ}C$. All the cultivars belonged to 2nd group, the heading date would be very delayed if cool summer comes.

• 한국환경과학회지
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• 제12권7호
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• pp.697-704
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• 2003

Through data analysis using the meteorological data during 40 years(1961∼2000) for 2 stations(Daegu and Chupungnyong), we studied the present condition and long-term trends in urban climatic environments of Daegu. It was found that there was about 1.5$^{\circ}C$ rise in annual mean temperature of Daegu from 1961 to 2000. On the other hand, that of Chupungnyung was not more than 0.4$^{\circ}C$ for the same period. The regional disparity in temperature changes has been caused by the difference of urban effects on climate between two regions. In particular, the urban warming appears more significant in winter season. There was about 3$^{\circ}C$ rise in annual mean daily minimum temperature of winter season(Dec.∼Feb.) in Daegu. As the result, the number of winter days continuously decreased from 115 days(1961) to 75 days(2000). The long-term trends of relative humidity were also studied to exame the effects of urbanization on climate in Daegu. It was found that there was about 7% decrease in relative humidity of Daegu during past 40 years(1961∼2000). On the other side, the decrease of Chupungnyung was not more than 2% for the same period. The long-term trends of the other climatic factors(fog days, tropical night days, etc) were also studied in this study.