• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.78-85
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• 2011

In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3279-3285
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• 2014

This study aimed to understand seasonal and geographical characteristic of chlorophyll-${\alpha}$ (chl-${\alpha}$), COD (chemical oxygen demand) and Escherichia coli at Gwangyang Bay during the period from February 2010 to November 2012. The bay is divided into three different zones based on the pollutant levels and geographical characteristics. During the study periods, water temperature, salinity, Chl. ${\alpha}$, and chemical oxygen demand (COD) varied in the range of $4.68-28.63^{\circ}C$, 1.94-33.84 psu, 0.31-35.10 ${\mu}gL^{-1}$, and 0.70-13.35 $mgL^{-1}$, respectively. Total chl-a concentration were high at the zone I, which can be characterized as a semi-enclosed eutrophic area, and it were low at the zone III, which is influenced by low nutrients of surface warm water current from offshore of the bay. The high concentration of COD was observed at inner bay during the four seasons and the water quality level was kept to be bad condition during spring season at the zone II, which is influenced by Seomjin River water. The highest colony form of E. coli was recorded to be 3550 $cfuL^{-1}$ during summer at station 1 (zone I), whereas it was relatively kept low level during all seasons at the zone III. As a result, the E. coli was correlated with water temperature (r=0.31 p<0.05) and salinity (r=-0.55 p<0.05), implying that those parameters have play an important crucial role in proliferation of E. coli. Consequently, our results indicated that the E. coli can be significantly promoted within pollutant sources including the high nutrients supplied by rive discharge during spring and summer rainy seasons in semi-enclosed area of Gwangyang Bay.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.277-290
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• 2011

Changes of the characteristics in summer rainfall in the Republic of Korea by the regime shift and their causes were examined by analyzing long-term observational data. There has been an abrupt increase in rainfall variability since 1998, which was mainly due to the enhanced rainfall during August~September, although the gradual increase was also detected in June~July. In June~July, the enhanced rainfall developed as a band type covering the whole East Asia while in August~September, it is only found over the Republic of Korea with the greatest increase of 130 mm over Seoul and Gyeonggi area. The two intensified anticyclonic anomalies over the north-northwest/east of the Republic of Korea resulted in producing northerlies/southeasterlies, transporting cold/warm-wet air flows, respectively. The center of the convergence zone from the two separate systems located in the Republic of Korea, leading to a favorable condition for the development of the extreme rainfall. The enhanced barotropic anticyclonic anomalies also affected in warming the sea surface temperature anomalies covering from the eastern coast of East Asia to North Pacific Ocean, which in turn leaded to enhance warm air transporting back to the Republic of Korea.

• Ocean and Polar Research
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• v.30 no.3
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• pp.361-372
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• 2008

A satellite tracked drifter experiment was conducted to observe thermal structure and surface circulation in the northeastern East China Sea. For this experiment, four ADOS buoys, assembled with surface float and thermister chain, were deployed on August 2007 in southern Jeju-do, where the Kuroshio Branch Current is separated from the main stream. Thermal structure in the upper layer of the northeastern East China Sea was successfully observed during the following $1{\sim}3$ months. Strong thermo-haline front in a northeast-southwest direction was observed. In the frontal zone, warm and saline Kuroshio origin water intermixes with fresher coastal water and flows toward the Korean Strait. Typhoon Nari, which passed over the East China Sea 20 days after commencement of study, caused distinct signals in the thermal structure and trajectory of buoys. During the typhoon, surface temperature abruptly dropped to about $4^{\circ}C$, while the thermocline formed at $30{\sim}50$ m depth vanished due to strong vertical mixing. Internal inertial oscillation occurred several days after the typhoon. The fortuitous occurrence of typhoon Nari showed that ADOS buoys can provide useful and accurate air-sea interaction data during typhoons.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.267-275
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• 2011

The common squid Todarodes pacificus is an ecologically and commercially important species in Korea and Japan. However, the distribution pattern of its eggs and larvae in Korean waters has not yet been clarified. To determine the horizontal and temporal distribution of common squid larvae in the northern East China Sea, samples collected using paired, 60 cm diameter Bongo nets from the three surveys conducted in August 2003, May 2004 and November 2005 were examined. In addition, the vertical distribution was examined from the samples collected using a $1\;m^2$ MOCNESS in April 1999 (20 m interval down to 100 m). A total of 218 larvae ranging in mantle length (ML) from 1.2 to 17.0 mm were counted at 27 stations. Larval abundance was highest in May 2004. The larvae mainly occurred in the southeastern area of Jeju Island, where the water temperature and salinity at 50 m deep ranged from $15-23^{\circ}C$ and 34-34.6 psu, respectively. Most larvae were collected in the frontal zone, where the Tsushima Warm Current and inshore waters meet. The results from the MOCNESS samples showed that the larvae occurred mostly in 20-80 m depth ranges (about 90%), although collections were only conducted above 100 m. No significant differences in larval mantle lengths (ANOVA, P>0.05) were found among each depth interval. Given the occurrence sites of the larvae <2.0 mm ML, the spawning ground of this species appears to be within the northern East China Sea, mainly to the southeast and northeast of Jeju Island, in early spring.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.218-234
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• 2004

Recent warm winters were evaluated for a possible shifting of the northern limit for winter barley cultivation in Korea. Therefore, safe zones for winter barley cultivation were reclassified based on the average and minimum January air temperature in recent years. The results are as follows: By analysis of mean values of January average air temperatures for 30 years (1971-2000), the northern limits for safe cultivation of hulled, naked, and malting barley were Ganghwa - Icheon - Chungju - Chunyang - Goseong, Cheonan - Geumsan - Mungyeong - Andong - Sokcho, and Gwangju - Jangheung - Sancheong - Pohang - Uljin lines, respectively. Meanwhile, based on the January average air temperature of 14 years (1987-2000) with warmer winters, the safe cultivation zone of winter barley shifted northward of the normal (1971-2000). So, the northern limits for hulled, naked, and malting barley were Pocheon - Chuncheon - Wonju - Yangpyeong - Chunyang, Ganghwa - Icheon - Chungju - Uiseong - Goseong, and Gunsan - Suncheon - Jinju - Miryang - Yeongdeok - Uljin lines, respectively. Winter barley cultivars with the strongest tolerance to low temperature can be grown up to the adjacent areas of Taebaek Mountains (that is, Inje, Hongcheon, Jecheon, and Taebaek areas). Based on January mean air temperatures of 10-year return period for 30 years (1971-2000), the northern limits for hulled and naked barley were Boryeong - Namwon - Geochang - Gumi - Goseong and Seocheon - Jeongeup - Hapcheon - Yeongdeok - Sokcho lines, respectively. It ~ppears that malting barley can be cultivated only at southern coastal areas (that is, Busan, Tongyeong, Yeosu, and Wando areas). On the other hand, based on the weather conditions of 14 years (1987-2000) with warmer winters, the northern limits for hulled, naked, and malting barley were Ganghwa - Icheon - Yeongju - Goseong, Seosan - Namwon - Mungyeong - Andong - Sokcho, and Gwangju - Jangheung - Sacheon - Ulsan - Uljin lines, respectively. The northern limit for winter barley cultivars including Olbori with the strongest tolerance to low temperature was the Ganghwa - Wonju - Chungju - Chunyang - Goseong line.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.215-228
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• 1991

In the East Sea of Korea the vertical structure functions of the temperature field were evaluated and the characteristic thermal zone was classified by the use of the empirical orthogonal function(EOF) method. The East Sea of Korea within the hydrographic lines of 10-107 of the Fisheries Research and Development Agency of Korea(FRDA) can be divided into three thermal regions by the characteristics of the vertical temperature variability. They are the North Korean Cold Current(NKCC) region near the coast which extends parallel to the north-south direction, the Warm-Core(WC) region which dominates almost all the hydrographic stations of the Line 104 of the FRDA and occupies a few stations of the Line-103 and -105 with its axis at the Line 104, and the East Korea Warm Current(EKWC) region which is bisected into the northern and the southern part by the WC region, respectively. Considering the two most important modes, $85.20-98.20\%$ of the total variance of temperature variation are explained in the NKCC region, $85.20-92.90\%$ in the EKWC region, and$85.50-91.70\%$ in the WC region. The first mode has its peak value at the surface with the annual cycle of variation. The spatial pattern of the first mode portrays a coherent vertical variation in the EKWC region and a clear anti-correlation both in the NKCC region and in the WC region where the zero-crossing depths are loom and 200m, respectively. The second mode of the NKCC region is particularly noticeable, haying its peak at loom with coherent vertical variation. To study the time dependency of the vertical structure functions, the extended EOF(EEOF) method was used. The persistence of the first mode is less than 4 months in the study area. The annual variation of the first mode in the NKCC region is different from those in the WC region and in the EKWC region.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.258-272
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• 2014

Bats hibernating in caves and unused mines were surveyed during six hibernation periods (from December to February, 2005 and 2011) in Korea. We recorded 13,288 individuals of 11 species at 140 hibernacula (60 caves and 80 abandoned mines): Rhinolophus ferrumequinum (n=3,509), Eptesicus serotinus (n=6), Hypsugo alaschanicus (n=349), Miniopterus fuliginosus (n=5,919), Murina hilgendorfi (n=417), Myotis aurascens (n=294), Myotis bombinus (n=2), Myotis formosus (n=401), Myotis macrodactylus (M.mac, n=151), Myotis petax (n=2,131) and Plecotus ognevi (n=109). We studied the thermal preference and selection of hibernacula of seven dominant bat species. Four species (Myotis petax, Hypsugo alaschanicus, Plecotus ognevi and Murina hilgendorfi) hibernated mainly at the cold site below than $7^{\circ}C$, while three species (Myotis formosus, Rhinolophus ferrumequinum and Miniopterus fuliginosus) hibernated at warm site above than $7^{\circ}C$. Rhinolophus ferrumequinum had broad-ranged temperature zone for their hibernating site. The mean body temperature of each species was $2.64{\pm}0.98^{\circ}C$ for Murina hilgendorfi, $2.76{\pm}1.68^{\circ}C$ for Hypsugo alaschanicus, $2.78{\pm}0.98^{\circ}C$ for Plecotus ognevi, $4.52{\pm}1.02^{\circ}C$ for Myotis petax, $7.83{\pm}1.94^{\circ}C$ for Miniopterus fuliginosus, $9.19{\pm}2.35^{\circ}C$ for Rhinolophus ferrumequinum and $13.64{\pm}0.76^{\circ}C$ for Myotis formosus, respectively. The body temperatures of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. In conclusion, the diversity of bats community in hibernacula were closely related to the range of inner ambient temperature of hibernacula, and more species of bats were occupied at sites presenting a broad range of ambient temperatures.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.503-514
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• 2020

Climate change leads to changes in phenological response and movement of plant habitats. Korea's evergreen broad-leaved forest has widened its distribution area compared for the past 20 years, and the range of its native habitats is moving northward. We analyzed climate indices such as the warmth index, the cold index, the lowest temperature in the coldest month, and the annual average temperature, which are closely related to vegetation distribution, to predict the change in the native habitat of Lauraceae evergreen broad-leaved trees. We also analyzed the change and spatial distribution to identify the habitat climate characteristics of 8 species of Lauraceae evergreen broad-leaved trees distributed in the warm temperate zone in Korea. Moreover, we predicted the natural habitat change in the 21st century according to the climate change scenario (RCP 4.5/8.5), applying the MaxEnt species distribution model. The monthly average climate index of the 8 species of Lauraceae evergreen broad-leaved trees was 116.9±10.8℃ for the temperate index, the cold index 3.9±3.8℃, 1495.7±455.4mm for the annual precipitation, 11.7±3.5 for the humidity index, 14.4±1.1℃ for the annual average temperature, and 1.0±2.1℃ for the lowest temperature of winter. Based on the climate change scenario RCP 4.5, the distribution of the Lauraceae evergreen broad-leaved trees was analyzed to expand to islands of Jeollanam-do and Gyeongsangnam-do, adjacent areas of the west and south coasts, and Goseong, Gangwon-do on the east coast. In the case of the distribution based on the climate change scenario RCP 8.5, it was analyzed that the distribution would expand to all of Jeollanam-do and Gyeongsangnam-do, and most regions except for some parts of Jeollabuk-do, Chungcheongnam-do, Gyeongsangbuk-do, and the capital region. For the conservation of Lauraceae evergreen broad-leaved trees to prepare for climate change, it is necessary to establish standards for conservation plans such as in-situ and ex-situ conservation and analyze various physical and chemical characteristics of native habitats. Moreover, it is necessary to preemptively detect changes such as distribution, migration, and decline of Lauraceae evergreen broad-leaved trees following climate change based on phenological response data based on climate indicators and establish conservation management plans.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.227-237
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• 2020

Microclimatic data were measured, and the human thermal sensation was analyzed at 10 local climate zones based on the major land cover classification to investigate the thermal environment of urban areas during summer nighttime. From the results, the green infrastructure areas (GNIAs) showed an average air temperature of 1.6℃ and up to 2.4℃ lower air temperature than the gray infrastructure areas (GYIAs), and the GNIAs showed an average relative humidity of 9.0% and up to 15.0% higher relative humidity. The wind speed of the GNIAs and GYIAs had minimal difference and showed no significance at all locations, except for the forest location, which had the lowest wind speed owing to the influence of trees. The local winds and the surface roughness, which was determined based on the heights of buildings and trees, appeared to be the main factors that influenced wind speed. At the mean radiant temperature, the forest location showed the maximum value, owing to the influence of trees. Except at the forest location, the GNIAs showed an average decrease of 5.5℃ compared to GYIAs. The main factor that influenced the mean radiant temperature was the sky view factor. In the analysis of the human thermal sensation, the GNIAs showed a "neutral" thermal perception level that was neither hot nor cold, and the GYIAs showed a "slightly warm" level, which was a level higher than those of the GNIAs. The GNIAs showed a 3.2℃ decrease compared to the GYIAs, except at the highest forest location, which indicated a half-level improvement in the human thermal environment.