• Title/Summary/Keyword: 기온 상승

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Nocturnal temperature distribution on orange orchards in Cheju Island (II) (제주도 감귤 과수원의 야간 기온 분포(II))

  • ;;Lee, Seung-Ho;Lee, Hyong-Young
    • Journal of the Korean Geographical Society
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    • v.30 no.3
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    • pp.230-241
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    • 1995
  • The Characteristics of nocturnal temperature fields were analyzed to understand the factors of freezing-and-cold damages on orange orchards in Cheju Island. Temperatures were measured from January 7th through 27, 1995 at 25 sites in an area of 1x1.25$ extrm{km}^2$, Wasan-ri, Chochon-up, Pukcheju-kun located on the northeastern slope of Mt.Hanla. Several other weather elements such as wind and cloud were observed as supplementary data. Surface weather maps were also analyzed to clarify the influence of prevailing pressure patterns on the temperature fields. The vertical temperature profiles were obtained at the height from the ground up to 360 cm in 30 cm intervals at site 3, a frost hollow, and site 10 on the upper slope. The results show that freezing damages occured in the hollows, terrain depressions, rather than at the upper slope due to nocturnal radiation cooling as well as accumulation of cold airflow from Mt.Hanla. Windbreaks of densely planted Japanese ceders with stone-walls also roled as obstacles to the cold airflow in nights with Clear skies and light winds. The maximum intensity of temperature inversion in hollows, quasi-cold air lake, was 3.1$^{\circ}C$. Cold air from Mt.Hanla was trapped in the depressions up to a height of 90cm forming frost pocket. Man-made facilities such as shelterbelt or stone-wall which are built to prevent the penetration of cold north-westeries in winter aggravated the cold damage. The differance of daily minimum temperatures between before and behind shelterbelts was 2.$0^{\circ}C$. The man-made convection by smudgin which raised the temperatures up to 3.8$^{\circ}C$ can reduce the cold damage in the hellows.

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Distributional Change and Climate Condition of Warm-temperate Evergreen Broad-leaved Trees in Korea (한반도 난온대 상록활엽수의 분포변화 및 기후조건)

  • Yun, Jong-Hak;Kim, Jung-Hyun;Oh, Kyoung-Hee;Lee, Byoung-Yoon
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.47-56
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    • 2011
  • The research was conducted to find optimal habitats of warm-temperate evergreen broad-leaved trees, and to investigate climate factors to determine their distribution using classification tree (CT) analysis. The warm-temperate evergreen broad-leaved trees model (EG-model) constructed by CT analysis showed that Mean minimum temperature of the coldest month (TMC) is a major climate factor in determining distribution of warm-temperate evergreen broad-leaved trees. The areas above the $-5.95^{\circ}C$ of TMC revealed the optimal habitats of the trees. The coldest month mean temperature (CMT) equitable to $-5.95^{\circ}C$ of TMC is $-1.7^{\circ}C$, which is lower than $-1^{\circ}C$ of CMT of warm-temperate evergreen broad-leaved trees. Suitable habitats were defined for warm-temperate evergreen broad-leaved trees in Korea. These habitats were classified into two areas according to the value of TMC. One area with more than$-5.95^{\circ}C$ of TMC was favorable to trees if the summer precipitation (PRS) is above 826.5mm; the other one with less than $-5.95^{\circ}C$ of TMC was favorable if PRS is above 1219mm. These favorable conditions of habitats were similar to those of warm-temperate evergreen broad-leaved trees in Japan. We figured out from these results that distribution of warm-temperate evergreen broad-leaved trees were expanded to inland areas of southern parts of Korean peninsula, and ares with the higher latitude. Finally, the northern limits of warm-temperate evergreen broad-leaved trees might be adjusted accordingly.

Analysis on the Characteristics of Ventilation and Cooling for Greenhouses Constructed in Reclaimed Lands (간척지 온실의 환기 및 냉방 특성 분석)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.26 no.3
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    • pp.181-187
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    • 2017
  • The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. The climatic conditions around seven major reclaimed land areas with a plan to install advanced horticultural complexes in Korea were analyzed. The characteristics of natural ventilation and temperature rise through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. Results of comparing the ventilation rate of the greenhouse according to the presence or absence of plants showed the greenhouse with plants had the lower ventilation rate, but the smaller rise of indoor temperature due to the evapotranspiration of plants. In the greenhouse with plants, the number of air changes was in the range of 0.3 to 0.9 volumes/min and the average was 0.7 volumes/min. The rise of indoor temperature relative to outdoor temperature was in the range of 1 to $5^{\circ}C$ and the average $2.5^{\circ}C$. The natural ventilation performance of the experimental greenhouse constructed in the reclaimed land almost satisfied the recommended ventilation rate in summer and the rise of indoor temperature relative to outdoor temperature did not deviate considerably from the cultivation environment of plants. Therefore, it was determined that the greenhouse cultivation in Saemangeum reclaimed land is possible with only natural ventilation systems without cooling facilities. As the reclaimed land is located in the seaside, the wind is stronger than the inland area, and the fog is frequent. This strong wind speed increases the ventilation rate of greenhouses, which is considered to be a factor for reducing the cooling load. In addition, since the fog duration is remarkably longer than that of inland area, the seasonal cooling load is expected to decrease, which is considered to be advantageous in terms of the operation cost of cooling facilities.

Influence of Accumulated Hours of Low Temperature in Dormant and Changing Temperature after Bud Breaking on Flowering of Main Apple Cultivars in Korea (휴면기 저온 누적 시간 및 발아 후 변온이 국내 주요 사과품종의 개화에 미치는 영향)

  • Kweon, Hun-Joong;Park, Moo-Yong;Song, Yang-Yik;Sagong, Dong-Hoon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.4
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    • pp.252-269
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    • 2017
  • This study was carried out to examine the base temperature to flowering and the average days to flowering by accumulated hours of low temperature ($5.0^{\circ}C$) or changing temperature after bud breaking. Over-all, the prediction of flowering time in the commercial apple cultivars ('Fuji' and 'Tsugaru') and apple cultivars ('Chukwang', 'Gamhong', 'Hongan', 'Honggeum', 'Hongro', 'Hongso', 'Hwahong', 'Summer dream', 'Sunhong') bred in Korea at the Gunwi region for 4 years (from 2009 to 2012) was investigated. Also, this study estimated the flowering time when the air temperature of Gunwi region rises at $5.0^{\circ}C$ was investigated using the same data. The range of accumulated hours of low temperature (chilling requirement) was from 0 hour to 1,671 hours, and the range of high temperature (heat requirements) to flowering after low temperature treatment was from $5.0^{\circ}C$ to $29.0^{\circ}C$. The treatments of changing temperature after bud breaking were classified as constant temperature treatment (control) and $5.0{\sim}10.0^{\circ}C$ elevation or descent treatments. The results show that the average days to flowering was longer with shorter accumulated hours of low temperature, and the average days from bud breaking to flowering of 0 hour treatment was longer about 2~4 weeks than that of 1,335~1,503 hours treatments. In comparing to apple cultivars, the all cultivars were not flowered under $10.0^{\circ}C$ after bud breaking, and the cultivars with low chilling requirements needed low heat requirements for flowering. The average days to flowering of treatments that the air temperature after bud breaking was controlled about $15.0^{\circ}C$ was shorter about 1~3 weeks than that of treatments was controlled about $10.0^{\circ}C$. In the treatment of changing temperature after bud breaking, the average days from bud breaking to flowering of temperature elevation treatment was shorter than that of constant temperature treatment. By use of these results, the base temperature to flowering of main apple cultivars in Korea was seemed to $10.0^{\circ}C$, and if the air temperature of Gunwi region rises about $5.0^{\circ}C$ than that of current, the flowering time was estimated to be delayed by 1 week.

A Review of Recent Climate Trends and Causes over the Korean Peninsula (한반도 기후변화의 추세와 원인 고찰)

  • An, Soon-Il;Ha, Kyung-Ja;Seo, Kyong-Hwan;Yeh, Sang-Wook;Min, Seung-Ki;Ho, Chang-Hoi
    • Journal of Climate Change Research
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    • v.2 no.4
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    • pp.237-251
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    • 2011
  • This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

Climate Change by Global Warming and Its Effects on Production Efficiency of Lactating Dairy Cows in Korea : a Simulation Modeling Approach (지구온난화에 따른 국내 기후변화와 젖소 착유우의 생산효율에 미치는 영향 평가 : 모델 시뮬레이션을 이용한 접근)

  • Lee, Jung-Jin;Lee, Jun-Sung;Kim, Jong-Nam;Seo, Ja-Keum;Jo, Nam-Chul;Park, Seong-Min;Ki, Kwang-Seok;Seo, Seong-Won
    • Korean Journal of Organic Agriculture
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    • v.21 no.4
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    • pp.711-723
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    • 2013
  • The objectives of this study were to access climate change by global warming in Korea, and to investigate its effects on production efficiency of lactating dairy cows. Two regions, Daegu and Daekwanryung, were selected to represent a warm and a cold area, respectively. Time-series analyses on meteorological records for 25 years (from January 1, 1988 to December 31, 2012) revealed significant and different climate changes in two regions. In the warm area there has been a significant (P<0.05) increase in low temperature during the summer, which can cause heat stress to the animal. On the other hand, a decrease in low temperature during the winter was observed in the cold region (P<0.01), and cold stress in winter can thus be an issue in this region. Simulations using a model integrated the Korean feeding standard for dairy cattle and the environmental effect module of Cornell Net Carbohydrate and Protein System, indicated that a reduction in feed efficiency can be a problem during the winter in the cold region while during the summer in the warm area. We conclude that the effect of climate change by global warming varies in different areas in Korea and a region-specific management strategy should be developed in order to maintain productivity, health and welfare of lactating dairy cows.

Impacts of Three-dimensional Land Cover on Urban Air Temperatures (도시기온에 작용하는 입체적 토지피복의 영향)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.3
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    • pp.54-60
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    • 2009
  • The purpose of this study is to analyze the impacts of three-dimensional land cover on changing urban air temperatures and to explore some strategies of urban landscaping towards mitigation of heat build-up. This study located study spaces within a diameter of 300m around 24 Automatic Weather Stations(AWS) in Seoul, and collected data of diverse variables which could affect summer energy budgets and air temperatures. The study also selected reflecting study objectives 6 smaller-scale spaces with a diameter of 30m in Chuncheon, and measured summer air temperatures and three-dimensional land cover to compare their relationships with results from Seoul's AWS. Linear regression models derived from data of Seoul's AWS revealed that vegetation volume, greenspace area, building volume, building area, population density, and pavement area contributed to a statistically significant change in summer air temperatures. Of these variables, vegetation and building volume indicated the highest accountability for total variability of changes in the air temperatures. Multiple regression models derived from combinations of the significant variables also showed that both vegetation and building volume generated a model with the best fitness. Based on this multiple regression model, a 10% increase of vegetation volume decreased the air temperatures by approximately 0.14%, while a 10% increase of building volume raised them by 0.26%. Relationships between Chuncheon's summer air temperatures and land cover distribution for the smaller-scale spaces also disclosed that the air temperatures were negatively correlated to vegetation volume and greenspace area, while they were positively correlated to hardscape area. Similarly to the case of Seoul's AWS, the air temperatures for the smaller-scale spaces decreased by 0.32% ($0.08^{\circ}C$) as vegetation volume increased by 10%, based on the most appropriate linear model. Thus, urban landscaping for the reduction of summer air temperatures requires strategies to improve vegetation volume and simultaneously to decrease building volume. For Seoul's AWS, the impact of building volume on changing the air temperatures was about 2 times greater than that of vegetation volume. Wall and rooftop greening for shading and evapotranspiration is suggested to control atmospheric heating by three-dimensional building surfaces, enlarging vegetation volume through multilayered plantings on soil surfaces.

Long-term Simulation of Water Temperature in Soyanggang Reservoir in Response to RCP 4.5 Climate Scenario (RCP 4.5 기후 시나리오에 따른 소양호 수온 변화 장기 모의)

  • Yun, Yeojeong;Park, Hyungseok;Chung, Sewoong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.265-265
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    • 2019
  • 기후변화로 의한 기온의 상승은 가뭄, 홍수와 같은 재해를 일으킬 뿐만 아니라 깊은 호수나 저수지와 같은 수자원에도 용존 산소, 물질, 영양소 및 식물플랑크톤의 수직적 분포 등과 같은 다양한 부분에 영향을 미친다. 본 연구의 목적은 SWAT, HEC-ResSim 및 CE-QUAL-W2(이하 W2)모델을 사용하여 미래의 기후 변화에 따른 소양호의 수온, 성층강도 및 열적 안정성의 변화를 장기 예측하고 그 영향을 평가하는데 있다. W2 모델의 보정은 2005 년부터 2015 년까지의 실측 과거 데이터를 이용하여 보정하였고 기후변화 시나리오는 IPCC의 AR5 RCP 4.5 시나리오를 사용하였다. 기후자료는 GCM 모델인 HadGEM2-AO 결과를 상세화하여 모의기간의 자료를 생성하였다. SWAT모델을 이용하여 모의기간인 2016 년부터 2070 년까지 일단위로 저수지 유입을 예측했으며 HEC-ResSim모델을 이용하여 소양강댐 저수지 운영 조건에 따라 저수지 방류량 및 수위 변화를 모의하였다. 수온 해석을 위해 W2를 적용하여 저수지의 장기간의 수온 변화를 예측하였다. 결과적으로 대기 온도는 $0.0279^{\circ}C/year$(p < 0.05) 상승할 것으로 예측되었으며, 동일기간 상층(수면으로부터 5m 깊이)과 하층 (바닥으로부터 5m 높이) 수온은 각각 $0.0191^{\circ}C$/년(p < 0.05) 및 $0.008^{\circ}C$/년(p < 0.05) 상승할 것으로 예측되었다. 모의된 수온을 계절별로 분석했을 때 상층수온은 여름철 가장 큰 폭으로 상승하였으며 하층의 경우 겨울철에 가장 큰 폭으로 상승하였다. 계절별 상-하층 수온의 차는 여름이 가장 컸으며, 겨울에 온도차가 가장 작았다. 또한 미래 온도의 상승에 따라, 소양호의 성층 강도가 강해지는 경향을 보였으며 상층 및 하층의 온도차 $5^{\circ}C$를 기준으로 성층이 형성되는 기간은 큰 변동이 없었으나 소멸되는 시점이 점점 늦어지는 추세를 보여 성층 형성 기간이 길어지는 것으로 나타났다. 저수지 표면의 수온 상승은 식물플랑크톤의 계절 성장률에 영향을 미쳤는데, 특정 조건에서 규조류는 최적 성장 범위를 벗어나는 고온 조건에서 성장속도가 감소하였으나 녹조류와 남조류의 출현 시기가 빨라지며 장기화될 것으로 예측되었다.

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The Effects of Experimental Warming on Seed Germination and Growth of Two Oak Species (Quercus mongolica and Q. serrata) (온난화 처리가 신갈나무(Quercus mongolica)와 졸참나무(Q. serrate)의 종자발아와 생장에 미치는 영향)

  • Park, Sung-ae;Kim, Taekyu;Shim, Kyuyoung;Kong, Hak-Yang;Yang, Byeong-Gug;Suh, Sanguk;Lee, Chang Seok
    • Korean Journal of Ecology and Environment
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    • v.52 no.3
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    • pp.210-220
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    • 2019
  • Population growth and the increase of energy consumption due to civilization caused global warming. Temperature on the Earth rose about $0.7^{\circ}C$ for the last 100 years, the rate is accelerated since 2000. Temperature is a factor, which determines physiological action, growth and development, survival, etc. of the plant together with light intensity and precipitation. Therefore, it is expected that global warming would affect broadly geographic distribution of the plant as well as structure and function ecosystem. In order to understand the effect of global warming on the ecosystem, a study about the effect of temperature rise on germination and growth in the plant is required necessarily. This study was carried out to investigate the effects of experimental warming on the germination and growth of two oak species(Quercus mongolica and Q. serrata) in temperature gradient chamber(TGC). This study was conducted in control, medium warming treatment($+1.7^{\circ}C$; Tm), and high warming treatment ($+3.2^{\circ}C$; Th) conditions. The final germination percentage, mean germination time and germination rate of two oak species increased by the warming treatment, and the increase in Q. serrata was higher than that in Q. mongolica. Root collar diameter, seedling height, leaf dry weight, stem dry weight, root dry weight, and total biomass were the highest in Tm treatment. Butthey were not significantly different in the Th treatment. In the Th treatment, Q. serrata had significantly higher H/D ratio, S/R ratio, and low root mass ratio (RMR) compared with control plot. Q. mongolica had lower RMR and higher S/R ratio in the Tm and Th treatments compared with control plot. Therefore, growth of Q. mongolica are expected to be more vulnerable to warming than that of Q. serrata. The main findings of this study, species-specific responses to experimental warming, could be applied to predict ecosystem changes from global warming. From the result of this study, we could deduce that temperature rise would increase germination of Q. serrata and Q. mongolica and consequently contribute to increase establishment rate in the early growth stage of the plants. But we have to consider diverse variables to understand properly the effects that global warming influences germination in natural condition. Treatment of global warming in the medium level increased the growth and the biomass of both Q. serrata and Q. mongolica. But the result of treatment in the high level showed different aspects. In particular, Q. mongolica, which grows in cooler zones of higher elevation on mountains or northward in latitude, responded more sensitively. Synthesized the results mentioned above, continuous global warming would function in stable establishment of both plants unfavorably. Compared the responses of both sample plants on temperature rise, Q. serrata increased germination rate more than Q. mongolica and Q. mongolica responded more sensitively than Q. serrata in biomass allocation with the increase of temperature. It was estimated that these results would due to a difference of microclimate originated from the spatial distribution of both plants.

Review on Coastline Change and Its Response Along the Cotonou Coast, Benin in the Gulf of Guinea, West Africa (서아프리카 기니만에 있는 베냉 코토누의 해안선 변화와 대응에 대한 고찰)

  • Yang, Chan-Su;Hong, Hyeyeon;Shin, Dae-Woon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.5
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    • pp.691-699
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    • 2021
  • The global surface temperature has risen critically over the past century and according to the IPCC Fifth Assessment Report 2014, existing risks in natural and human systems will worsen. Coastal erosion is mostly caused by climate change and among all the coastal areas at risk, Benin, which is part of the Gulf of Guinea, has been ranked very highly as a vulnerable region. Therefore, in this review, we focus on the evolution of coastline change in Cotonou of Benin, summarizing its resultant impacts and applied measures around the coast area by reviewing previous studies. Signs of coastal erosion in Cotonou appeared in 1963. After 39 years, the east shoreline of Cotonou has retreated by 885 m, resulting in the disappearance of more than 800 houses. To solve this problem, Benin authorities built seven groynes in 2013, and have increased the number of the structure as a way to interrupt water flow and limit the movement of sediment. Over the region, shorelines appeared preserved accordingly. In contrast, areas located further east, where groynes were not installed, have suf ered from intensive erosion at a rate of 49 m/yr. In the future, as a next step, the effectiveness of groynes should be studied with local and broader perspectives.