• 한국환경과학회지
• /
• 제23권5호
• /
• pp.873-885
• /
• 2014

To identify the characteristics of extreme heat events and tropical nights in major cities, the correlations between automated synoptic observing station (ASOS), automatic weather station (AWS), and temperature in seven metropolitan areas were analyzed. Temperatures at ASOS were found to be useful sources of the reference temperature of each area. To set the standard for identifying dates of extreme heat events in relation to regional topography and the natural environment, the monthly and yearly frequency of extreme heat in each region was examined, based on the standards for extreme heat day (EHD), tropical night day (TND), and extreme heat and tropical night day (ETD). All three cases identified 1994 as the year with the most frequent heat waves. The frequency was low according to all three cases in 1993, 2003 and 2009. Meanwhile, the yearly rate of increase was the highest in 1994, followed by 2010 and 2004, indicating that the frequency of extreme heat changed significantly between 1993 and 1994, 2003 and 2004, and 2009 and 2010. Therefore all three indexes can be used as a standard for high temperature events. According to monthly frequency data for EHD, TND, and ETD, July and August accounted for 80% or more of the extreme heat of the entire year.

• 한국작물학회지
• /
• 제42권4호
• /
• pp.473-482
• /
• 1997

Temperature, humidity and wetness duration were monitored for fully developed paddy rice canopies with 3 different structures induced by the seeding method(puddled-soil drill seeding, DS ; hand broadcasting, HB ; machine broadcasting, MB). Within-canopy air temperature averaged over "clear sky" hours during the study period(maximum tillering through heading) was lower than the screen temperature at a nearby standard weather station, especially in the night. The same trend was true for "overcast sky" hours except the diurnal distinction. Vapor pressure within the canopy was high during the daytime and low in the night, making the daytime deviation from outside the canopy more significant on clear days. Under the overcast sky, the canopy maintained a steady 5 to 10％ higher vapor pressure than the outside regardless of day or night. Daily maximum temperature was observed to be higher within the canopies with more leaf mass, making MB the highest, HB the lowest, and DS in between. Relative humidity was over 90％ in the night and dropped to 70％ in the mid-afternoon, but vapor pressure within the canopy was highest at around 13:00 LST. Dew point depression was lowest and, combined with the temperature, the relative humidity was highest in HB. Mean period of wetting duration was in the order of DS＞HB＞MB, while the dew point depression was greatest in DS.

• 대기
• /
• 제21권4호
• /
• pp.361-371
• /
• 2011

In this study, characteristics and trends of tropical night (TN) are investigated by using the KMA 14 observation data for the recent 50 years (1958-2007) over South Korea. The TN is defined as a day with a daily minimum temperature exceeds the absolute threshold temperature ($25^{\circ}C$), and the relative deviation from normal temperature, 95th percentile of all observed daily minimum temperature. Although the spatial distribution of TN occurrence depends on the choice of the definitions, the frequency of TN shows strong spatial and interannual variations with the minimum at high land area (Chupungnyeong and wet years) and maximum at southern coastal area and large city area (Jeju, Busan, Seoul, Daegu). Most of TN occurs in August (56%) and July (41%), and the duration date of TN is proportional to the frequency of TN without regard to the definition method. In general, increasing trends are found in the TN time series without regard to the analysis method, but the trends are clearly depending on the analysis period and geographic locations. Decreasing trends are prominent during the most of analysis period, especially until the mid of 1990, whereas strong increasing trends are found during recent 30 years (1988-2007), especially at Jeju, Ulsan, Daegu and Pohang. Also the severity of TN is significantly increased in recent years.

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

• 한국수산과학회지
• /
• 제38권5호
• /
• pp.323-330
• /
• 2005

Monthly distributions of fishing boats at night in the East Sea are described, using defense meteorological satellite program (DMSP)/operational linescan system (OLS) images and common squid (Todarodes pacificus) catches data. We also estimated temperature in 50m, which is main catch depth of the squid, by MCSST (multi-channel sea surface temperature). We examined DMSP/OLS, MCSST and other observation data from 1993 to 2000. We assumed that squid were caught in areas where fishing boats were located. Fishing boats at night appeared only near the Korea/Tsushima Strait from January to March. Fishing boats moved to the northward from April to Jun, distribution of fishing boats in spring appeared greater than those in winter. In summer (July-September), center of fishing grounds was formed near the Uleung Island in the south east coast of Korea. The north-south distribution range of fishing boats in October appeared to be greater than that in other months. In particular, we estimated main season of squid catches based on distribution range reflecting the number of fishing boats of north-south and east-west directions from September to December. Relationship between satellite estimate SST and in situ SST showed high correlation (0.91). The correlation between the SST and 50m depth temperature, estimated based on the satellite SST, was relatively high in February, April and October.

• 농업과학연구
• /
• 제11권1호
• /
• pp.77-84
• /
• 1984

국내(國內)에서 많이 소비(消費)되는 킹건고추와 일본(日本) 재래종(在來種)인 십방(十房)을 공시(供試)하여 고추의 생육(生育)에 중요(重要)한 온도(溫度)와 시비량(施肥量)을 달리하여 처리(處理)함으로써 고추의 생장(生長)과 광합성(光合成)에 미치는 영향(影響)을 조사(調査)하여 고추재배법(栽培法) 개선(改善)에 필요한 기초자료(基礎資料)를 얻고자 수행(遂行)된 본(本) 시험(試驗)의 결과(結果)는 다음과 같다. 1. 킹건 고추는 십방(十房)에 비하여 초장(草長), 간장(稈長), 화아수(花芽數), 건물중(乾物重), 동화량(同化量)이 많았고 십방(十房)은 킹건고추보다 엽수(葉數), 절수(節數), 엽면적(葉面積)이 많은 경향(傾向)이었다. 2. 시비량간(施肥量間)에는 증비구(增肥區)가 보비구(普肥區)보다 초장(草長), 엽수(葉數), 절수(節數), 화아수(花芽數), 건물중(乾物重), 엽면적(葉面積), 광합성(光合成)이 현저히 증가(增加)되었다. 3. 온도간(溫度間)에는 고야온(高夜溫) ($25^{\circ}C$) 처리시(處理時) 초장(草長), 간장(稈長), 엽수(葉數), 절수(節數), 화아수(花芽數), 분기수(分技數), 건물중(乾物重), 엽면적(葉面積)이 현저하게 많은 경향(傾向)을 보였다. 4. 상대생장율(相對生長率), 엽면적율(葉面積率)은 증비구(增肥區)와 고야온(高夜溫) 처리시(處理時) 높아졌으나 순동화율(純同化率)은 엽수(葉數)가 많은 십방(十房)이 킹건고추보다 적었으며 고야온(高夜溫) 처리시(處理時) 오히려 감소(減少)하였다. 5. 광합성(光合成)은 킹건고추에서 증비(增肥) 광도(光度)가 높아질수록 현저하게 증가(增加)되었다. 6. 고추 수량(收量)을 좌우하는 화아수(花芽數)는 킹건고추에서 증비(增肥), 고야간온도(高夜間溫度)($25^{\circ}C$)조건(條件)에서 많았다.

• 한국지리정보학회지
• /
• 제17권1호
• /
• pp.35-49
• /
• 2014

서울과 주변을 포함하는 수도권에서 발생하는 열섬현상의 특성들을 정량적으로 이해하기 위하여 GIS 및 AWS 관측 자료들을 이용하여 여름과 겨울 야간 기온분포의 공간 경향 그래프를 작성하였다. 또한 기온 변동성에 영향을 미치는 요인들과 31개 AWS 지점들의 야간 평균기온과의 상관성을 분석을 하였다. 그 결과, 야간 평균기온(2004년~2011년) 최고지점과 최저지점의 차이는 여름 $4.5^{\circ}C$, 겨울 $7.1^{\circ}C$ 임을 확인하였다. AWS 지점들 주변의 국지적 지표특성과 기온과의 상관성 분석 결과, 지점별 야간 평균 기온과 반경 1km 이내의 인공피복의 상관계수가 여름(0.84)과 겨울(0.78) 모두에서 높게 나타나 지표면 피복이 중규모적인 도시 열환경 관리에 있어 다른 요인들보다 더 큰 영향을 주는 요인임을 확인하였다. 한편 수도권 야간기온에 대한 회귀모형을 변수선택법을 이용하여 개발한 결과 1km 규모에서 보다 200m 규모에서 상세한 지표특성 변수가 선택됨을 알 수 있었는데, 규모에 따른 모형의 설명력에는 큰 차이가 없었다. 따라서 200m 정도의 상세한 지표특성 자료를 이용하는 기후분석 모델의 구현이 가능함을 알 수 있었으며, 모델의 설명력은 1km 수준으로 분석하였을 때와 비슷한 수준인 57%(겨울)~72%(여름)이었다.

• Animal cells and systems
• /
• 제6권3호
• /
• pp.239-245
• /
• 2002

Plasma melatonin, thyroid-stimulating hormone (TSH) and body temperature were measured simultaneously and continuously before and after the sleep-wake cycle was shifted in 4 healthy males and changes in the circadian rhythm itself and in the phase relationship among these circadian rhythms were determined. Normal sleep-wake cycle (sleep hours: 2300-0700) was delayed by 10 h (sleep hours: 0900-1700) during the experiment. Even after this shift the typical melatonin rhythm was maintained: low during daytime and high during night. The melatonin rhythm was gradually delayed day by day. The TSH rhythm was also maintained fundamentally during 3 consecutive days of altered sleep-wake cycle. The phase was also delayed gradually but remarkably. The daily rhythm of body temperature was changed by the alteration of sleep-wake cycle. The body temperature began to decrease at the similar clock time as in the control but the decline during night awake period was less steep and the lowered body temperature persisted during sleep. The hormonal profiles during the days of shifted sleep/wake cycle suggest that plasma melatonin and TSH rhythms are basically regulated by an endogenous biological clock. The parallel phase shift of melatonin and TSH upon the change in sleep-wake cycle suggests that a common unitary pacemaker probably regulates these two rhythms. The reversal phase relationship between body temperature and melatonin suggests that melatonin may have a hypothermic effect on body temperature. The altered body temperature rhythm suggests that the awake status during night may inhibit the circadian decrease in body temperature and that sleep sustains the lowered body temperature. It is probable but uncertain that there ave causal relationships among sleep, melatonin, TSH, and body temperature.

• 한국환경과학회지
• /
• 제10권3호
• /
• pp.179-185
• /
• 2001

To investigate daily variations of water mass distribution in the west and the east parts of Jeju Island, we implemented observations from June 20 to 22, 1997. (The results are as follows : Temperatures in the east and the west were similar in the surface, but $15.02^{\circ}C$ and $13.8^{\circ}C$ in the bottom, respectively.) In the east and west, the surface and the deep salinities are 33.81, 33.34 and 34.33, 34.11 respectively. The east shows higher temperature and salinity than the west. The distributions of nitrate in the east and the west were very similar in the surface regions.(In the deep regions, however, the east shows higher than the west.) The east shows higher phosphates than the west both in surface and deep regions. The silicate had similar distributions to nitrate. Chlorophyll-a of the west was twice higher than that of the east. The daily variations of temperature and salinity were largest at 30m depth, and pH was not much changed in the depth and the pH in day was higher than that at night. The variations of nutrients were much changed in the depth, and nitrate and phosphate at night were higher than those in day. Daily variations of silicate, however, was not much changed in the observation times. Ratio of N/P in the east and the west were 13 and 16, respectively, so that the west was higher than the east. However the ratios were two times higher both in the east and the west in day, when planktons are more active than at night. Si/P ratio showed little different between day and night and between surface and deep regions. The correlation of nitrogen and phosphorus was high (plus relation), and the correlation of AOU, nitrogen and phosphorus was high(plus relation) in the east, however, not high in the west.

• 한국작물학회지
• /
• 제14권
• /
• pp.47-51
• /
• 1973

수도 분얼 기간의 기온의 고저 및 교차가 수도 생육에 미치는 영향을 알고저 분얼기를 활착후 10일간씩 초기, 중기, 후기로 나누어 주간 온도를 $25^{\circ}C$, $30^{\circ}C$, 야간 온도를 10,15,20,$25^{\circ}C$로 7조합을 하여 작물시험장 인공 기상실에서 시험한 결과를 요약하면 다음과 같다. 1. 최고 분얼수는 조기, 중기 처리에서 많고 후기 처리에서 영향이 적었다. 2. 온도 처리 완료후의 초장$\times$경수의 적은 조, 중기에서 주간 $30^{\circ}C$, 야간$25^{\circ}C$에서 컸으며 후기 처리는 차이가 적었다. 3. R.G.R(g/g/day)는 조기 처리에서 높았다. 4. 성숙기 엽중은 조기 처리에서 가장 많고 후기 처리에서 적었다. 5. 따라서 수도 생육에 미치는 온도의 영향은 분얼 초기에 크다고 하겠다.