• 한국수산과학회지
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• 제26권5호
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• pp.424-437
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• 1993

아산만 동물플랑크톤 변이의 약 3/4 가량이 계절에 따른 변이로 파악되었으며 만의 안쪽과 바깥쪽의 차이는 상대적으로 매우 작았다. 그러나 만의 안쪽과 바깥쪽에서의 주요종의 조성율 차이가 시간의 경과에 따라 점차 커지고 있어 방조제 건설 등에 따른 변화가 진행되고 있는 것 같았다. 조사 기간 3년 동안 종별로 가장 많이 출현하는 계절이 서로 달랐으나 각종이 가장 많이 출현하는 계절은 3년 계속 일치하고 있었다. Calanus sinicus와 Acartia bifilosa는 봄철에, Sagitta crassa, Paracalanus parvus, Acartia pacifica, Tortanus spinicaudatus, Corycaeus affinis 및 Decapoda larva는 여름철에, Labidocera euchaeta와 Bivalve larva는 가을철에 가장 많이 출현하였고 겨울철에 가장 많이 나타난 종은 없었다. 대체로 가을철에는 많은 종류가 적게 출현하고, 겨울철에는 종수와 양이 모두 적었고, 이들은 모두 봄에 증가하기 시작하여 여름철에는 많은 종이 모두 다량 출현하는 변화양상 이었다. 지지하는 증거는 불충분하지만 이러한 변화양상에 대한 가설을 제기하였다.

• 한국환경농학회지
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• 제14권2호
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• pp.155-162
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• 1995

계절별로 일조시간과 기온과의 관계를 밝히고 작물재배시 기후자원 활용의 효율을 기하고자 지역별 월별 기상자료를 분석한 결과는 다음과 같다. 1. 강릉지방의 여름이 기온은 높으나 일조시간은 겨울보다도 적은 특징을 나타내었다. 2. 순복사량과 일조시간은 정의 상관이 있으며, 7월에는 일조시간 증가에 따라 순복사량의 증가가 컸다. 3. 일조시간 증가에 따른 현열전달량의 증가는 4월과 10월에 컸고, 7월이 가장 낮았다. 4. 연중(年中) 고온다조지역은 여수, 대구, 포항 등지이고, 저온과조지역은 춘천, 서올, 울릉도 등지이다. 5. 일조시간은 봄과 가을에는 기온교차와 정의 상관관계가 있으며, 여름에는 최고기온과 그리고 겨울에는 최저기온과 부의 상관관계가 있었다. 6. 1월의 일조시간이 평년대비 1시간 길어짐에 따라 평균기온은 평년에 비해 $1{\sim}1.7^{\circ}C$ 정도 낮아졌다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.681-685
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• 2000

A computer software was developed in our laboratory to automatically control the pigs environment by the image analysis system (IAS), which monitors and analyzes the pig's behavior and feeds the results back to the computer hardware. Three feeding trials were conducted with growing pigs ($L{\times}Y$) to test the effectiveness of the IAS under various seasons. In all three trials, the open-sided conventional pens with half-slatted floor were used as controls; for the IAS treatment, fully-slatted floors were used in the windowless pens. Experiment 1 was conducted in the winter for 30 d with 24 growing pigs. There were two treatments (Conventional vs. IAS), and three pens (replicates) per treatment. During the growing period, the feed efficiency was significantly (p<0.05) improved by the IAS. In addition, the pigs reared under the IAS during the growing period displayed better growth rate during the finishing period than did the pigs reared under the conventional conditions. Experiment 2 was conducted in the summer for 30 d with 24 growing pigs. The experimental design was the same as Experiment 1. During the finishing period, all the pigs were kept in conventional open-sided pens until their market weights to evaluate their carcass characteristics. During the growing period, the growth rate and feed efficiency of the pigs in the IAS was better than those of the control pigs. In addition, various carcass characteristics were significantly improved by the IAS rearing during the growing period. Experiment 3 was conducted with 30 growing pigs for 30 d in the spring. The experimental design was the same as Experiment 1. No difference was found in growing performance between the control and IAS pigs. It could be concluded that the IAS is effective in providing optimum conditions for the growing pigs in summer and winter seasons. In addition, providing an optimum environment during the growing period results in improved growth rate, feed efficiency, and carcass qualities for the finishing pigs.

• 대기
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• 제28권4호
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• pp.415-425
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• 2018

The roles of atmospheric heating formation and distribution on the global circulation are of utmost importance, and those are directly related to not only spatial but also temporal characteristics of monsoon system. In this study, before we clarify the characteristics of apparent heat source <$Q_1$> and moisture sink <$Q_2$>, comparisons of three reanalysis datasets (NCEP2, ERA-Interim, and JRA-55) in its global or regional patterns are performed to clearly evaluate differences among datasets. Considering inter-hemispheric difference of global monsoon regions, seasonal means of June-July-August and December-January-February, which is summer (winter) and winter (summer) in the Northern (Southern) Hemisphere are employed respectively. Here we show the characteristics of eight different regional monsoon regions and find contributions of <$Q_2$> to <$Q_1$> for the regional monsoon regions. Each term in apparent heat source and moisture sink is shown to come from the ERA-Interim dataset, since the ERA-Interim could be representative of three datasets. The NCEP2 data has a different characteristic in the ratio of <$Q_2$> and <$Q_1$> because it overestimates <$Q_1$> compared to the other two different datasets. The Australia monsoon has been performing better over time, while some regional monsoons (South America, North America, and North Africa) have been showing increasing data inconsistency. In addition, the three reanalysis datasets are getting different marching with time, in particular since the early 2000s over South America, North America, and North Africa monsoon regions. The recent inconsistency among the three datasets that may be associated with the global warming hiatus remains unexplored.

• 한국환경농학회지
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• 제40권4호
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• pp.330-334
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• 2021

BACKGROUND: More recently, it has been shown that atmospheric ammonia (NH₃) plays a primary role in the formation of secondary particulate matter by reacting with the acidic species, e.g. SO₂, NOx, to form PM2.5 aerosols in the atmosphere. The Jeonbuk region is an area with high concentration of particulate matter. Due to environmental changes in the Saemangeum reclaimed land with an area of 219 km², it is necessary to evaluate the impact of the particulate matter and atmospheric ammonia in the Jeonbuk region. METHODS AND RESULTS: Atmospheric ammonia concentrations were measured from June 2020 to May 2021 using a passive sampler and CRDS analyzer. Seasonal and annual atmospheric ammonia concentration measured using passive sampler was significantly lower in Jangjado (background concentration), and the concentration ranged from 11.4 ㎍/m³ to 18.2 ㎍/m³. Atmospheric ammonia concentrations in Buan, Gimje, Gunsan, and Wanju regions did not show a significant difference, although there was a slight seasonal difference. The maximum atmospheric ammonia concentration measured using the CRDS analyzer installed in the IAMS near the Saemangeum reclaimed land was 51.5 ㎍/m³ in autumn, 48.0 ㎍/m³ in summer, 37.6 ㎍/m³ in winter, and 32.7 ㎍/m³ in spring. The minimum concentration was 4.9 ㎍/m³ in spring, 4.2 ㎍/m³ in summer, and 3.5 ㎍/m³ in autumn and winter. The annual average concentration was 14.6 ㎍/m³. CONCLUSION(S): Long term monitoring of atmospheric ammonia in agricultural areas is required to evaluate the formation of fine particulate matter and its impact on the environment. In addition, continuous technology development is needed to reduce ammonia emitted from farmland.

• 해양환경안전학회지
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• 제17권4호
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• pp.331-337
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• 2011

본 연구에서는 동북아시아 NOAA AVHRR 위성관측 16년간(1990-2005) 해양표면 수온영상을 이용하여 에러 값 제거와 결측 자료 보완을 위하여 마르코프 계수를 결정하였고, 이 값에서 현재 수온평년 값을 더하여 구름 없는 해양표면수온 생성 기법을 제시하였다. 마르코프 연쇄 모델의 결과에 의하면, 마르코프 계수는 해류가 강한 쿠로시오 해역 등이 해류가 약한 동해 북서부의 대부분 해역과 동중국해보다 그 계수가 상대적으로 낮게 나타났다. 평균 수온의 변동은 봄과 가을이 겨울과 여름에 비하여 분산이 크게 나타났고, 계절별 일간 수온 차이도 수온의 계절적 변동이 큰 봄과 가을이 여름과 겨울에 비하여 큰 지역적인 차이를 보였다. 그 지역적인 분포는 봄과 가을의 경우 전 해역의 대륙 인접부에서 대부분 크게 나타났고, 동해 극전선 남부해역과 쿠로시오해역에서는 난류에 의한 열수송으로 일간 수온의 차이가 작았다.

• 한국군사과학기술학회지
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• 제12권4호
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• pp.415-423
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• 2009

To investigate low frequency acoustic transmissions in the Sub-Polar Front(SPF) of the East Sea, numerical experiments are conducted with Range dependent Acoustic Model(RAM) using Circulation Research of the East Asian Marginal Seas(CREAMS) data and Autonomous Profiling Explorer(APEX)) data. Significant seasonal variations of sea water properties are existed across the Sub-Polar Front(SPF) region from the north and the south. The model results show that Transmission Loss(TL) decrease(about 20dB) with ideal front in the warm region whereas TL increase(about 25dB) with ideal front in the cold region. Regardless of season(both in summer and winter), when the sound source is located in the cold region of the SPF, the model results show weak TL, compared to the case of the source in the warm region(Maximum difference of TL reaches 28dB). This difference between the cases when the source is located in the cold region and the warm region, is accounted for from the different vertical profiles of sound speed in both regions.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.43-48
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• 2013

The geomagnetic activity shows the semiannual variation stronger in vernal and autumnal equinoxes than in summer and winter solstices. The semiannual variation has been explained by three main hypotheses such as Axial hypothesis, Equinoctial hypothesis, and Russell-McPherron Effect. Many studies using the various geomagnetic indices have done to support three main hypotheses. In recent, Oh & Yi (2011) examined the solar magnetic polarity dependency of the geomagnetic storm occurrence defined by Dst index. They reported that there is no dependency of the semiannual variation on the sign of the solar polar fields. This study examines the solar magnetic polarity dependency of quiet time geomagnetic activity. Using Dxt index (Karinen & Mursula 2005) and Dcx index (Mursula & Karinen 2005) which are recently suggested, in addition to Dst index, we analyze the data of three-year at each solar minimum for eight solar cycles since 1932. As a result, the geomagnetic activity is stronger in the period that the solar magnetic polarity is anti-parallel with the Earth's magnetic polarity. There exists the difference between vernal and autumnal equinoxes regarding the solar magnetic polarity dependency. However, the difference is not statistically significant. Thus, we conclude that there is no solar magnetic polarity dependency of the semiannual variation for quiet time geomagnetic activity.

• 한국수산과학회지
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• 제39권1호
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• pp.42-48
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• 2006

Analysis of stomach content for common squid was carried out to investigate the difference in seasonal and ontogenetic feeding behavior. Totals of 1368 common squid were collected monthly off Busan from September 2004 to August, 2005. Size range of common squid was 8.5-31.8 cm mantle length (ML) during the study period. Of the 1368 stomachs examined, 599 specimens (43.8%) were empty. Stomach contents indicated that common squid was carnivore: Large portion of stomach contents consisted of fish and mollusca (mainly common squid). The stomach contents index (SCI) seemed to increase with size, though there was no statistical difference between size classes significantly. Cannibalism was minimum in size range of 15-20 cm ML, but was steadily increased with size. Cephalopods were the major prey during spring and summer when common squid were small, but fish replaced it during autumn and winter when they became large.

• 한국환경생태학회지
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• 제34권1호
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• pp.55-62
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• 2020

이 연구는 강원대학교 학술림 내의 산지계류를 대상으로 2년간(2017~2018)의 현지 모니터링에 기초하여 수온과 강우, 유량 및 기온 등 환경인자간의 관계를 분석하고, 계절별 산지계류의 수온변화 예측기법에 대하여 검토하였다. 동절기를 제외한 봄, 여름 및 가을철로 구분하여 단계적 다중선형회귀분석을 실시하였으며, 계절별 산지계류의 수온변화에 미치는 환경인자의 영향을 분석하였다. 그 결과, 산지계류의 일평균 수온은 봄철 6.9~17.7℃로 기온과 유의적 관계를 나타내었고, 여름철 12.2~26.3℃로 기온, 유량과 유의적 관계를 나타냈으며, 가을철 3.6~19.3℃로 기온 및 유량과 유의적 관계를 나타내는 등 계절별로 산지계류의 수온에 미치는 영향인자는 다르게 나타났다. 다중선형회귀식은 봄철 (0.553×기온)+(0.086×유량)+4.145(R²=0.505; p<0.01), 여름철 (0.756×기온)+(-0.072×유량)+2.670(R²=0.510; p<0.01), 가을철 (0.738×기온)+(0.028×강우)+2.660(R²=0.844; p<0.01)이었다. 도출된 모든 회귀식의 결정계수(R²)는 기온만으로 예측한 경우보다 높게 나타났고, 봄철에서 가을철로 갈수록 증가하였다. 향후 정밀도 높은 산지계류의 수온변화 예측을 위해서는 지속적인 현지 모니터링과 함께 시·공간적 데이터의 확보가 중요하다고 판단된다.