• 대기
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• 제24권4호
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• pp.555-563
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• 2014

The impacts of dynamic and thermodynamic schemes used in the Community Ice CodE (CICE), the Los Alamos sea ice model, on sea ice concentration, extent and thickness over the Arctic and Antarctic regions are evaluated. Using the six dynamic and thermodynamic schemes such as sea ice strength scheme, conductivity scheme, albedo type, advection scheme, shortwave radiation method, and sea ice thickness distribution approximation, the sensitivity experiments are conducted. It is compared with a control experiment, which is based on the fixed atmospheric and oceanic forcing. For sea ice concentration and extent, it is found that there are remarkable differences between each sensitivity experiment and the control run over the Arctic and Antarctic especially in summer. In contrast, there are little seasonal variations between the experiments for sea ice thickness. In summer, the change of the albedo type has the biggest influence on the Arctic sea ice concentration, and the Antarctic sea ice concentration has a greater sensitivity to not only the albedo type but also advection scheme. The Arctic sea ice thickness is significantly affected by the albedo type and shortwave radiation method, while the Antarctic sea ice thickness is more sensitive to sea ice strength scheme and advection scheme.

• 한국지반환경공학회 논문집
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• 제17권1호
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• pp.49-54
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• 2016

동토지반을 구성하는 지층 중 표층에 분포하는 활동층은 계절에 따라 동결과 융해를 반복하여 지표면의 동상을 야기한다. 동상 높이는 활동층의 두께에 큰 영향을 받으므로, 동토지반 상부 인프라시설의 안전한 설계 및 시공을 위하여 활동층의 두께 산정은 매우 중요한 부분을 차지한다. 본 연구에서는 경량화된 원위치 관입시험 방법인 동적 콘 관입기를 이용하여 동토지반에서 활동층이 분포하는 심도를 평가하고자 하였다. 동적 콘 관입시험을 적용하기 위한 대상현장으로서 알래스카에 위치한 솔로몬 지역의 동토지반이 선택되었으며, 해당 지역의 두 개소에서 지중온도계측 및 동적 콘 관입시험이 수행되었다. 적용실험 결과 동적 콘 관입시험으로부터 획득된 동적 콘 관입지수는 활동층 및 영구동토층에서 서로 상이한 값을 나타내는바 동적 관입특성에 따른 활동층과 영구동토층의 경계부 심도가 산정되었으며, 경계부 심도에서 아이스 렌즈층으로 판단되는 구간이 감지되었다. 해당 개소에서 획득된 지중온도분포도에서 영상 및 영하 온도의 경계 심도는 본 연구의 동적 콘 관입시험으로부터 획득된 활동층 분포 심도와 부합하는 결과를 보였다. 본 연구에서 적용된 동적 콘 관입기는 대형장비의 접근 및 적용에 한계가 있는 극한지 동토 지역의 활동층 심도평가를 위하여 활용될 수 있을 것이라 기대된다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.77-82
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• 2009

Many countries have been interested in sustainable development of buildings for environmental preservation. Thus it is significant to assess building envelopes in terms of $CO_2$ emissions owing to Kyoto Protocol. In this paper, a Double Skin Facade(DSF) installed in a general office building was assessed by $CO_2$ emissions(one of the performance-based assessment). To predict $CO_2$ emissions caused by the building energy consumption, the dynamic simulation program(Energy Plus) and $CO_2$ emission factor was used. Because DSF has various airflow regimes, pre-simulation runs were conducted to decide proximate optimal airflow regimes depending on seasonal variation. It is shown that the DSF can achieve 17.1-36.5% of annual energy savings.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2002년도 춘계학술대회
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• pp.9-15
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• 2002

This paper presents the seasonal forecasting of the occurrence of tropical cyclone (TC) over Western North Pacific (WNP) using the generalized linear model (GLM) and dynamic linear model (DLM) based on 51-year-data (1951-2001) in TC season (June to November). The numbers of TC and TY are predictands and 16 indices (the E1 Nino/Southern Oscillation, the synoptic factors over East asia and WNP) are considered as potential predictors. With 30-year moving windowing, the estimation and prediction of TC and TY are performed using GLM. If GLM forecasts have some systematic error like a bias, DLM is applied to remove the systematic error in order to improve the accuracy of prediction.

• 한국환경과학회지
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• 제19권5호
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• pp.627-637
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• 2010

Emission rate of monoterpene and isoprene was measured in five commonly growing tree species of conifers(Pinus thunbergii, Abies koreana, Cryptomeria japonica, Pinus densiflora, Chamaecyparis obtusa) at the Halla mountain sites. Dynamic flow enclosure technique was used and gas samples were collected into Tenax tube. The highest and lowest hourly emission rate was observed in Abies koreana (1.86 ${\mu}g$/gdw/hr) and Chamaecyparis obtusa (0.52 ${\mu}g$/gdw/hr), respectively. The major species of monoterpene from pine trees were ${\alpha}$-pinene, ${\beta}$-pinene, ${\beta}$-phellandrene, myrcene. Particularly, d-limonene was abundant in Abies koreana but ${\alpha}$-pinene, $d^3$-carene and sabinene was in Cryptomeria japonica. Emission rates of isoprene show less significant than those of monoterpene. And also seasonal emission rates of monoterpene were dependent on environmental factors such as temperature.

• 한국해안해양공학회지
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• 제6권3호
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• pp.298-308
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• 1994

북서태평양의 해수순환을 원시방정식 수처모형을 이용하여 재현하여 알라스카 만에서 관측된 해수순환의 경년변화에 대한 설명을 시도하였다. 모형 결과에 의하면 알라스카 gyre의 계절적 위치 변동은 없으며, 관측된 경년변화는 중규모 와류가 역학심도 계산에 영향을 미친 결과로 보인다. 이러한 중규모 와류는 수온 염분 관측, 부표추적 실험, 그리고 인공위성에 의한 해수면 관측에서도 관측되었다.

• Journal of Forest and Environmental Science
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• 제28권4호
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• pp.232-241
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• 2012

We investigated the relationship between vegetation type and soil carbon dynamics in even-aged alder (Alnus hirsuta) and Korean pine (Pinus koraiensis) plantations in central Korea. Both forests were located on the same soil parent material and occupied similar topographic positions. Soil $CO_2$ efflux in the two plantations was determined using a dynamic chamber method accompanied by measurements of soil moisture content and temperature. Mean soil temperature was similar in the two plantations, but mean soil water content was significantly higher in the alder plantation than in the pine plantation. In both plantations, seasonal patterns in soil $CO_2$ efflux exhibited pronounced variation that corresponded to soil temperature. Soil water content did not affect the seasonal variation in soil $CO_2$ efflux. However, in summer, when soil temperature was above $17^{\circ}C$, soil $CO_2$ efflux increased linearly with soil water content in the alder plantation. Estimated $Q_{10}$ was 3.3 for the alder plantation and 2.7 for the pine plantation. Mean soil respiration during the measurement period in the alder plantation was 0.43 g $CO_2\;m^{-2}\;h^{-1}$, which was 1.3 times higher than in the pine plantation (0.33 g $CO_2\;m^{-2}\;h^{-1}$). Higher soil $CO_2$ efflux in the alder plantation might be related to nitrogen availability, particularly the concentration of $NO_3{^-}$, which was measured using the ion-exchange resin bag method.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1291-1298
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• 2010

The aim of this research was to investigate the dynamic changes of the level of total prolactin receptor (PRLR) mRNA and the short form prolactin receptor (S-PRLR) mRNA in skin of cashmere goats from the initiation of cashmere fibre growth to active growth. Eighteen half-sib wethers were allocated randomly to two groups. Melatonin implants were used in order to initiate growth of cashmere fibre before the normal time and reduce blood plasma prolactin (PRL) concentration. Real-time reverse transcription quantitative polymerase chain reaction (real-time PCR) was used to determine PRLR mRNA expression levels of skin from June to November. The results showed that, in Chinese Inner Mongolia cashmere goats, there were seasonal variations in expression of total PRLR mRNA in skin with levels decreasing from June to October. Synchronously, the cashmere fibre growth rate gradually increased during this period, but the expression levels of S-PRLR mRNA did not decrease along with seasonal variation from initiation to active growth of cashmere fibre. These results suggest that expression levels of S- PRLR mRNA might be involved in the process of cashmere growth. It was also possible that the change of alternative splicing of PRLR occurred in the skin of cashmere goats from proanagen to anagen.

• 생태와환경
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• 제45권2호
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• pp.232-241
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• 2012

2009년 8월부터 2010년 4월까지 계절별로 조사된 운문댐의 식물플랑크톤은 총 121종류였으며, 이들은 녹조류(47종류)와 규조류(45종류)가 출현종의 76%를 차지하여 가장 중요한 분류군으로 조사되었다. 조사지점별 출현종 수는 동창천과 운문천의 유입부 지점이 합류부나 취수탑 부근보다 출현종 수가 많았다. 식물플랑크톤 현존량은 동창천 유입부 지점에서 가장 높은 현존량을 나타내었으며, 계절별로는 봄철에 가장 높은 현존량을 나타내었다. 식물플랑크톤 현존량의 강별 구성은 가을철에는 와편모조류가 가장 높은 구성비를 차지한 반면 나머지 계절 동안에는 규조류가 가장 높은 구성비를 나타내었고, 남조류는 여름철에 비교적 높은 구성비를 나타내었다. 식물플랑크톤 군집의 우점종은 여름철에는 규조류Aulacoseira granulata가 우점종으로 나타났고, 가을철에는 와편모조류 Peirdinium voltzii, 겨울과 봄철에는 규조류 Asterionella formosa가 우점종으로 조사되었다. 운문댐의 식물플랑크톤 군집의 종풍부도와 종다양성지수는 가을철에 가장 높게 나타났으며, 우점도지수는 봄철에 가장 높게 나타났다.

• 대기
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• 제31권5호
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• pp.637-656
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• 2021

The United States has been known as the world's major producer of crops such as wheat, corn, and soybeans. Therefore, using meteorological long-term forecast data to project reliable crop yields in the United States is important for planning domestic food policies. The current study is part of an effort to improve the seasonal predictability of regional-scale precipitation across the United States for estimating crop production in the country. For the purpose, a dynamic downscaling method using Weather Research and Forecasting (WRF) model is utilized. The WRF simulation covers the crop-growing period (March to October) during 2000-2020. The initial and lateral boundary conditions of WRF are derived from the Pusan National University Coupled General Circulation Model (PNU CGCM), a participant model of Asia-Pacific Economic Cooperation Climate Center (APCC) Long-Term Multi-Model Ensemble Prediction System. For bias correction of downscaled daily precipitation, empirical quantile mapping (EQM) is applied. The downscaled data set without and with correction are called WRF_UC and WRF_C, respectively. In terms of mean precipitation, the EQM effectively reduces the wet biases over most of the United States and improves the spatial correlation coefficient with observation. The daily precipitation of WRF_C shows the better performance in terms of frequency and extreme precipitation intensity compared to WRF_UC. In addition, WRF_C shows a more reasonable performance in predicting drought frequency according to intensity than WRF_UC.