• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.397-408
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• 2006

Due to the temporal and spatial variability of the warming at and near the Antarctic Peninsular, it is required to better understand local climate at the issued region. The purpose of the study are to characterize surface radiation, air temperature and wind direction and investigate their relations at the King Sejong Station near the Antarctic Peninsular during last three and half years. While the study site was a weak radiative energy sink (positive net radiation) with annual mean of 15-20 Wm-2, it played a role as a strong sink in summer (December to January) with mean of 85 Wm-2, a magnitude that was significantly larger than those at other surface covered with snow or ice in Antarctica. Monthly averaged air temperature ranged from -7.7-2.8oC and the variations of monthly averaged air temperature showed the distinct differences with year. Northwesterly, westerly and easterly were dominant and the variability of air temperature could be explained by the variability of the frequency of wind direction with cold easterly and warm northwesterly/northerly to some degree, which in turn influenced radiation budget through albedo in summer.

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.184-203
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• 2013

This study analyzes the variability of Korean summer rainfall associated with the tropical low-frequency oscillation using long-term observation data. From the EOF analysis, the first mode showed opposite phase between the South and the North Korea with the regime shift in rainfall variability since the mid-1990s. The summer precipitation over South Korea tends to increase in southern part during strong El Ni$\tilde{n}$o where the warm sea surface temperature extends to far eastern tropical Pacific. In weak La Ni$\tilde{n}$a, the increased precipitation directly influences from the western tropical Pacific to the mid-latitude. In June, the rainfall over South Korea is positively correlated with the Indian Summer Monsoon while in July, it is negatively correlated with the Western North Pacific Summer Monsoon. In August, highly negative correlation between the rainfall over South Korea and the Indian Summer Monsoon is found.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.532-542
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• 1997

Seasonal variation of a shrimp community in the eelgrass (Zostera marina) bed in Kwangyang Bay, Korea was studied based on the monthly collected samples through a year of 1994. The shrimp community in the eelgrassbed was composed of 26 species of shrimps representing 6 families. The community was dominated by Heptacarpus pandaloides, Crangon affinis, Eualus leptognathus, Latreutes acicularis, Heptacarpus rectirostris, Heptacarpus geniculatus, and Latreutes laminirostris. Most of species were the small-sized species with carapace length smaller than 25 mm. The peak abundance occurred in the late winter and spring and low abundances in autumn. More than 10 species were collected every month except lull (8 species). Species diversity indices showed that the shrimp species were more diverse during the late summer, and lesser during the late autumn. Predominance of Crangon affinis in the late autumn caused such a low diversity. The shrimps in the study area could be grouped into three groups on the basis of their occurrence patterns: resident species, seasonal species, and temporary species. More abundant and more diverse shrimps were collected during nighttime than daytime.

• Journal of the Korean association of regional geographers
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• v.6 no.3
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• pp.139-152
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• 2000

The regional characteristics of summer precipitation in Korea are analyzed with the data observed in 66 stations from 1973 to 1997, using the cluster analysis method. In the phenomena of summer precipitation, the rain-rich regions lie in the south coast region, the northern part of Kyonggi Province, and Yongdong region. The monthly precipitation is mostly influenced by Changma fronts and cyclons in June, Changma fronts in July, typhoons in August, and all of typhoons, Changma, and cyclons in September. The increasing and decreasing trends of the monthly precipitation are equally divided with regard to both regional groups and monthly distribution in the cluster analysis. Especially such trends are considerably clear in the rain-rich regions. The increasing tendency is predominant in the northern part of Kyonggi Province and Yongdong region, while the decreasing trend and the periodicity are noted in the south coast region and Cheju Island. The variation of the monthly precipitation is shown to be great in the rain-rich regions, while it is not much associated with the rain-scare regions. Also, the variation is the greatest in September, while the least variation is shown in July.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.251-265
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• 2006

To investigate the impingement of fish on the traveling screens, fishes were collected from the traveling screens at Hadong Power Plant through the year of 1999. A total of 84 fish species were collected during the study period. The dominant species were Leiognathus nuchalis, Engraulis japonicus, Trichiurus lepturus and Takifugu niphobles. These four species accounted for 78.2% of the total number of individuals and 52.0% of total biomass collected. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The number of species and biomass were high in April and August, and the number of individuals was high in April and July. However, the number of fish species, number of individuals and biomass of fishes showed low values in winter.

• Korean Journal of Remote Sensing
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• v.25 no.5
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• pp.423-434
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• 2009

The Arctic environment is sensitive to change of sea-ice distribution. The increase and decrease of sea ice work to an index of globe warming progress. In order to predict the progress of hereafter earth global warming, continuous monitoring regarding a change of the sea ice area in the Arctic should be performed. The remote sensing based on an artificial satellite is most effective on the North Pole. The sea ice observation using a passive microwave sensor has been continued from 1970's. The determination of sea ice extent and ice type is one of the great successes of the passive microwave imagers. In this paper, to investigate the seasonal and inter-annual variation of sea-ice distribution we used here the sea ice data from July 2002 to May 2009 around the Arctic within $60^{\circ}N$ for the AMSR-E 12.5km sea-ice concentration, a passive microwave sensor. From an early analysis of these data, the arctic sea-ice extent has been steadily decreasing at a rate of about 3.1%, accounting for about $2{\times}10^5\;km^2$, which was calculated for the sea-ice cover reaching its minimum extent at the end of each summer. It is also revealed that this trend corresponds to a decline in the multi-year ice that is affected mainly by summer sea surface and air temperature increases. The extent of younger and thinner (first-year) ice decreased to the 2007 minimum, but rapidly recovered in 2008 and 2009 due to the dramatic loss in 2007. Seasonal variations of the sea-ice extent show significant year-to-year variation in the seasons of January-March in the Barents and Labrador seas and August-October in the region from the East Siberian and Chukchi seas to the North Pole. The spatial distribution of multi-year ice (7-year old) indicates that the perennial ice fraction has rapidly shrunk recently out of the East Siberian, Laptev, and Kara seas to the high region of the Arctic within the last seven years and the Northeast Passage could become open year-round in near future.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1103-1107
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• 2005

경기도 안양시 만안구 안양3동에 위치한 안양대교보는 길이 40m, 높이 1.3m의 농업용수 취수를 위한 보였으나 도심화로 인하여 원기능을 상실하였다. 수차례에 걸친 개수와 러버보를 설치하는 등 개량하였으나 효능이 약화되어 철거계획이 수립되어 있다. 본 연구에서는 준 2차원 모형인 GSTARS 3.0 모형을 안양천에 적용하여 안양대교보 철거로 인한 하상변동을 모의하여 1차원 유사이동 모형인 HEC-6 모형과 비교하였다. 단면자료는 2000년에 측정된 자료로 구성하였고, 입력자료에 사용된 하상토 자료는 2005년 안양천에서 채취된 자료를 사용하였으며, 유량자료는 2000년 6월부터 10월까지의 유량 관측치를 사용하였다. Meyer-peter와 Muller공식, Ackers 와 White 공식, 그리고 Yang공식의 세 가지 유사이송공식을 사용하여 각각의 공식을 사용하는 데 따른 계산결과를 비교하였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.4
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• pp.108-114
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• 1972

The present paper deals with secular analysis of zooplankton biomass by statistical method in the south sea of Korea during the period of nine years from 1963 through 1971. Data were taken from the Annual Report of Oceanographic Observations, Fisheries Research and Development Agency, Korea. The trend value of annual variations in the 108 month period above was calculated by method of 12 month moving average, and a period analysis was made by ore of correlogram method using autocorrelation coefficients. The trend of zooplankton biomass shows periodical fluctuation for the period of 63 months with high interrelationships. The seasonal variation has teen obvious with growth phase twice a year, in April and October.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.339-340
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• 2006

현재 운영되고 있는 변동비반영전력시장(CBP)은 2001년 4월 개설되어 구조개편 초기의 혼란을 최소화하고 2004년으로 예정된 도매전력시장 운영되기 전까지의 과도기 운영을 목적으로 설계되었다. 이는 제한된 경쟁시장으로 전력시장의 효율성 제고와 안정적인 전력공급에 어느 정도 기여하였으며, 내재된 문제가 제기되어도 곧 도입될 차기 도매전력시장에서 개선하려고 하였다. 참여정부의 배전분할 중단결정에 따라 변동비반영전력 시장의 장기운영이 불가피해지게 되었고, 전력거래소는 배전분할 중단 발표직후인 2004년 7월부터 전력시장 제도개선 논의 시작하였으며, 2005년 말에는 개선방안 연구결과를 발표하였다. 본 논문에서는 연구결과인 개선방안과 이를 시행하기 위한 추진계획을 설명하고 있다.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.256-262
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• 2018

Multiple temporal scale can be a useful method to understand population dynamics in ecosystem. The multi-temporal scale approach for population dynamics has rarely been researched till lately. This study was carried out to identify the factors in affecting the population dynamics of herons, including Eastern Cattle Egret (Bubulcus coromadus), Grey Heron (Ardea cinerea), Great Egret (A. alba), Intermediate Egret (Egretta intermedia) and Little Egret (E. garzetta), at rice paddy fields of Seokmun-myeon in the city of Dangjin, South Chungcheong Province during the main breeding periods from 2014 to 2017. We identified the population dynamics of herons at different time interval (day and month) using the unmanned monitoring system. As a result, monthly population dynamics was mostly affected by time, mean temperature and mean precipitation, whereas daily population dynamics was affected by mean temperature and habitat types. The results suggest that there are differences in the factors affecting the population dynamics of herons according to the time scale.