• 한국토양비료학회지
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• 제45권6호
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• pp.1211-1215
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• 2012

Terrestrial ecosystem are a strong sink of carbon. Forest ecosystem, one of them, has been expected to play an important role in climate changing process by absorbing atmospheric carbon dioxide. On the other hand, agricultural ecosystem that consists mainly of annual crops is regarded as poor contributor to carbon accumulation, because its production (carbon hydrate) is decomposed into carbon at a short period, which is emitted to the atmosphere. However, it is thought that fruit tree plays a great role in decreasing atmospheric carbon dioxide concentration, same as forest. Net ecosystem exchange of $CO_2$ (NEE) was measured to estimate carbon fixation capacity using an eddy covariance (EC) system method in 2 years from 2005 to 2006 at an apple orchard in Uiseong, Gyeongbuk. Average air temperature values were higher in 2006 than in 2005 during the dormant season, and lower by about $5^{\circ}C$ over the growing season causing visible cold injuries. Accordingly, we investigated long-term exchange of carbon to determine how much difference of carbon fixation capacity was shown between 2006 and 2005 in terms of environmental and plant variables such as NEE, leaf area index (LAI), and Albedo. NEE was $4.8Mg\;C\;ha^{-1}yr^{-1}$ in 2005 and $4.7Mg\;C\;ha^{-1}yr^{-1}$ in 2006, respectively. Low temperature after July in 2006 decreased LAI values faster than those in 2005. Meanwhile, Albedo values were higher after July in 2006 than in 2005. These results show that the low temperature after July in 2006 apparently affected apple growth.

• 대기
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• 제31권5호
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• pp.539-551
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• 2021

In this paper, the weather records in 'Nanjung Ilgi' were investigated and the weather characteristics of the southern coast of Korea (SC_Korea) was discussed. The Nanjung Ilgi is a personal diary written by admiral Yi Sun-sin from January 1592 to November 1598 during the 7-year war caused by the Japanese invasion. He is a respected great leader in the history of world naval warfare, winning all 23 battles against the Japanese. Of the 1593 days of diaries currently preserved, only 42 days have no weather records. Weather was recorded in detail, including sky conditions, precipitation, wind characteristics and others. Weather records were extracted from the diary, converted to the solar calendar, and compared with the meteorological data of Yeosu. The average annual precipitation day is about 90 days, which is similar to the current 95~100 days. As in the current climate, precipitation frequently occurs for about 30 days in summer, but less than 15 days in other seasons, and the rainy season starts from June 14 to 21 and ends from July 6 to 17. It seems that the abnormal cold and heat phenomena, which deviate significantly from the seasonal average climate, occurred on 6 and 21 days, respectively, over 7 years. This means that the weather records of Nanjung Ilgi can be used as valuable data on the climate of SC_Korea in the late 16th century. The fact that he recorded the weather even in such extreme battle conditions shows that he clearly recognized the importance of weather in warfare.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.114-127
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• 2015

In the Mexico City Metropolitan Area (MCMA), ozone ($O_3$) concentration is still higher than in other urban areas in developed countries. In order to reveal the current state of photochemical air pollution and to provide data for validation of chemical transport models, vertical profiles of meteorological parameters and ozone concentrations were measured by ozonesonde in two field campaigns: the first one, during the change of season from wet to dry-cold (November 2011) and the second during the dry-warm season (March 2012). Unlike previous similar field campaigns, ozonesonde was launched twice daily. The observation data were used to analyze the production and distribution of ozone in the convective boundary layer. The observation days covered a wide range of meteorological conditions, and various profiles were obtained. The evolution of the mixing layer (ML) height was analyzed, revealing that ML evolution was faster during daytime in March 2012 than in November 2011. On a day in November 2011, the early-morning strong wind and the resulting vertical mixing was observed to have brought the high-ozone-concentration air-mass to the ground and caused relatively high surface ozone concentration in the morning. The amount of produced ozone in the MCMA was estimated by taking the difference between the two profiles on each day. In addition to the well-known positive correlation between daily maximum temperature and ozone production, effect of the ML height and wind stagnation was identified for a day in March 2012 when the maximum ground-level ozone concentration was observed during the two field campaigns. The relatively low ventilation coefficient in the morning and the relatively high value in the afternoon on this day implied efficient accumulation of the $O_3$ precursors and rapid production of $O_3$ in the ML.

• 대한토목학회논문집
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• 제43권3호
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• pp.337-352
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• 2023

일반적으로 강우-유출모형의 매개변수 최적화는 가용 자료 전체를 대상으로 수행하여 고유의 매개변수 집합을 활용한다. 그러나, 계절에 따른 강수량의 편차가 큰 국내의 기후 특성과 더불어 기후변화로 인하여 계절성에 따른 편차 및 변동성이 증가할 것으로 전망되고 있어, 물 수요자들에 대한 안정적인 공급을 위한 장기간의 계획에서 계절성을 반영한 매개변수 추정은 효율적인 물배분에 중요한 요소라 할 수 있다. 본 연구에서는 기후특성에 따른 강우-유출모형의 변동성을 분석하기 위하여 소양강댐 유역을 대상으로 GR4J 강우-유출모형을 활용한 지역적 민감도 분석을 수행하였으며, 산출된 민감도 분석 결과와 기상자료를 결합하여 SOM을 활용해 군집화하였다. 이를 통해 계절 분리를 수행하고 각 계절의 특징을 분석하여 강우-유출모형의 보정 기법을 개발하였으며, 통계적 지표를 이용하여 성능을 평가하였다. 결과적으로 비교적 유량이 적은 Cold 기간의 모형 성능이 개선되는 것을 확인할 수 있었다. 이는 몬순기후 등 강수편차가 큰 지역을 대상으로 수문모형의 성능 및 예측도를 높일 수 있을 것으로 판단된다.

• 한국농림기상학회지
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• 제10권4호
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• pp.121-131
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• 2008

본 연구에서는 국가표준 시나리오 A1B와 A2 조건에서 예상되는 2071-2100 평년의 최저기온 예상도와, 휴면심도로부터 추정한 단기내동성 분포도에 근거하여, 남한 전역에 대해 사방 270m 간격으로 경관규모의 국지적인 동해위험 정도를 분석함으로써 현재 평년(1971-2000)에 비해 어떤 결과를 보일지 예측하고자 하였다. 실험에 필요한 270m 해상도의 일별 기온자료와 1월 최저기온자료는 농림수산식품부의 전자기후도 및 그 파생산물, 그리고 국립기상연구소의 기후시나리오자료를 이용하여 준비하였다. 대상작물로서 'Campbell Early' 포도를 선정하고 현재와 미래 평년에 대해 각각 휴면심도를 계산하여 비교한 결과, 단기내동성 유지면적(휴면심도 -150 이하)과 저온내습지역($-15^{\circ}$ 이하)은 두 가지 시나리오 모두 미래기후 조건에서 동시에 줄어들었다. 기온과 휴면심도 두 요인을 종합해 분석해보면 현재 평년에 비해 100년 후 미래 평년에 동해위험이 감소하는 지역은 증가하는 지역보다 더 늘어나므로 포도재배에 있어서 저온피해의 위협은 감소할 것이다. 하지만 피해율 30% 이하의 월동 안전지역의 면적이 현재 평년의 59%에서 미래에는 55% (A1B)${\sim}$63% (A2)로서 뚜렷이 증가하지 않으며, 피해율 70% 이상의 월동 위험지역의 면적은 오히려 현재 평년의 13%에서 미래에는 23% (A1B)${\sim}$25% (A2)로 크게 증가할 것으로 예측되었다. 본 연구에서 사용된 전자기후도에 근거한 동해위험도 분석기술은 국내 주요 과수품종에 적용할 수 있으므로 재배적지의 재배치 등 기후변화대과 수산업분야 적응전략 마련에 유용하게 쓰일 수 있을 것이다.

• 대한토목학회논문집
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• 제36권1호
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• pp.49-63
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• 2016

본 연구는 열대 태평양지역 ENSO (El $Ni{\tilde{n}}o$-Southern Oscillation) 패턴 변화에 따른 우리나라 여름철(June-September, JJAS) 지역 수문변동 영향 분석을 위하여, 우리나라 5대강 113개 중권역의 강수량과 유출량 자료를 대상으로 합성편차 분석(Composit Analysis, CA)과 Student's t-test에 의한 유의성 검정을 실시하였다. 분석 결과, 유역별로 다소 차이는 있으나 전반적으로 WP (Warm-Pool) El $Ni{\tilde{n}}o$ 해에는 평년에 비하여 강수량과 유출량의 증가 특성이 뚜렷이 나타났으며, CT (Cold-Tongue) El $Ni{\tilde{n}}o$ 해에는 주로 감소하는 경향이, La $Ni{\tilde{n}}a$ 해에는 다소 증가 또는 평년 상태를 유지하는 것을 분석되었다. 또한 백분위 기후값 편차의 산포도분석 결과 여름철 강수량의 증가/감소에 따른 유출량 증 감의 선형적 분포특성을 확인할 수 있었으며, 산포도의 중심은 WP El $Ni{\tilde{n}}o$ 해에는 +17.93%, +26.99%, CT El $Ni{\tilde{n}}o$ 해에는 -8.20%, -15.73%, 그리고 La $Ni{\tilde{n}}a$ 해에는 +8.89%, +15.85%로 분석되었다. 본 연구의 결과는 El $Ni{\tilde{n}}o$ La $Ni{\tilde{n}}a$ 등 열대 태평양 지역 기후현상이 뚜렷한 시기의 우리나라 수자원 장기예측의 불확실성을 줄여 주어 유역차원의 안정적인 중 장기 물공급 전망 등 수방정책지원을 위한 참고자료로 활용이 가능할 것이다.

• The Korean Journal of Physiology
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• 제6권2호
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• pp.23-30
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• 1972

Contrary to most of European and American investigators failed to find out the seasonal variations of basal metabolic rate in man, Japanese and Korean investigators reported the increase in winter, decrease in summer season. But the causes of variation were not found clearly. To find out whether metabolic acclimatization to climate could be arise or not in human being, the basal metabolic rate was determined monthly for a period of one year in Airmen volunteers who live in Seoul, with 9 l Collins spirometer. The results obtained were as follows: 1. The average ambient temperature was lowest in February $(-5.88^{\circ}C)$ and highest in July $(27.34^{\circ}C)$. 2. Basal metabolic rate was lowest in June and highest in December showing seasonal variations. Interestingly, the increase of basal metabolic rate followed after the drop of ambient temperature below $0^{\circ}C$ (December) and the decrease followed after the elevation of ambient temperature from optimum to hot (June) or cold to warm (March). 3, Mean skinfold thickness increased in spring, decreased in winter. 4. These findings indicate that the basal metabolic rate of Korean reveals the seasonal variation affected by ambient temperature highly.

• 한국토양비료학회지
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• 제50권5호
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• pp.422-433
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• 2017

Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we developed for estimating garlic growth at field scale model in major cultivation regions. We used the $NDVI_{UAV}$ that reflects the crop conditions, and seven meteorological elements for 3 major cultivation regions from 2015 to 2017. For this study, UAV imagery was taken at Taean, Changnyeong, and Hapcheon regions nine times from early February to late June during the garlic growing season. Four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.), and fresh weight (F.W.) were measured for twenty plants per plot for each field campaign. The multiple linear regression models were suggested by using backward elimination and stepwise selection in the extraction of independent variables. As a result, model of cold type explain 82.1%, 65.9%, 64.5%, and 61.7% of the P.H., F.W., L.N., P.D. with a root mean square error (RMSE) of 7.98 cm, 5.91 g, 1.05, and 3.43 cm. Especially, model of warm type explain 92.9%, 88.6%, 62.8%, 54.6% of the P.H., P.D., L.N., F.W. with a root mean square error (RMSE) of 16.41 cm, 9.08 cm, 1.12, 19.51 g. The spatial distribution map of garlic growth was in strong agreement with the field measurements in terms of field variation and relative numerical values when $NDVI_{UAV}$ was applied to multiple linear regression models. These results will also be useful for determining the UAV multi-spectral imagery necessary to estimate growth parameters of garlic.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.150-150
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• 2022

Plant reproduction associated with crop yields is highly vulnerable to global climate change components such as high and cold temperatures. The objectives of this study were to determine the effects of season-high exposure to temperature treatments in pollen morphology on Adzuki bean (V. angularis) and Mung bean (V. radiate). V. angularis and V. radiata were treated at high temperatures in the high temperature gradient greenhouse designed to cause temperature deviation. The pollen shapes treated at high temperature were compared by an electron scanning microscope. As a result, it was confirmed that the number of abnormal pollens morphology at high temperature was the least in V. radiata, and V. angularis was vulnerable to high temperatures. Also, it was found that the number of abnormal pollen morphology atT4 (Con +5~6℃) varied according to the cultivars of V. angularis. Therefore, the differences in Vigna species or cultivars with thermo-tolerance in pollen morphology to high temperature are projected to occur in the changeable future climate.

• KIEAE Journal
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• 제6권2호
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• pp.43-50
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• 2006

A Double Facade System(DFS) is well known as an innovative solution of ecological facade in the west european countries. There are more than 200 various realized DFS in Germany. At the same time, the korean engineers have researched to find out the physical advantages of DFS in the moderate korean climate, which has a very humid summer with high temperature and a dry winter with low temperature. For example, the monthly mean temperature in Korea comes up to 28K, while that in Germany comes up to only 19K. That is, why a other solution of DFS is needed in Korea. This study has experimented the physical performance of the natural ventilation in the heating period. The preheating function of the cold air by DFS can improve no doubt the performance of the natural ventilation at the cold season as well as spring and autumn. The physical difference between single and double facade on natural ventilation has been tested at the newly constructed laboratory, which can turn $360^{\circ}$ to confirm the characteristic of a facade with the various directions. The results show the natural ventilation of the DFS has definitely much more comfortable than that of the single facade system. The air velocity of the inflow as well as the air temperature in the DFS provide a more stable condition than in the SFS. The theoretical limit(air velocity max 0.2m/s, air temperature min. $18^{\circ}C$, temperature difference between 100mm and 1700mm height max. 3K) on the indoor comfortableness doesn't go over in the DFS. On the other hand, the SFS showed an unstable condition with an excess of comfortableness limit on air velocity as well as temperature. In view of the researching results so far achieved, the research came to a conclusion, that the DFS can provide a more comfortable indoor condition by the preheating in the heating period than a SFS, and the period of natural ventilation in winter time could be definitely increased at the DFS.