• Atmosphere
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• v.32 no.2
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• pp.135-148
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• 2022

This study investigates the influence of atmospheric river (AR) on precipitation over South Korea with a focus on regional characteristics. The 42-year-long catalog of ARs, which is obtained by applying the automatic AR detection algorithm to ERA5 reanalysis data and the insitu precipitation data recorded at 56 weather stations across the country are used to quantify their relationship. Approximately 51% of the climatological annual precipitation is associated with AR. The AR-related precipitation is most pronounced in summer by approximately 58%, while only limited fraction of precipitation (26%) is AR-related in winter. The heavy precipitation (> 30 mm day^-1) is more prone to AR activity (59%) than weak precipitation (5~30 mm day^-1; 33%) in all seasons. By grouping weather stations into the four sub-regions based on orography, it is found that the contribution of AR precipitation to the total is largest in the southern coast (57%) and smallest in the eastern coast (36%). Similar regional variations in AR precipitation fractions also occur in weak precipitation events. The regional contrast between the northern and southern stations is related to the seasonal variation of AR-frequency. In addition, the regional contrast between the western and eastern stations is partly modulated by the orographic forcing. The fractional contribution of AR to heavy precipitation exceeds 50% in all seasons, but this is true only in summer along the eastern coast. This result indicates that ARs play a critical role in heavy precipitation in South Korea, thus routine monitoring of ARs is needed for improving operational hydrometeorological forecasting.

• 한국해양학회지
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• v.27 no.2
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• pp.123-136
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• 1992

As a result of faunal analysis on 50 bottom samples bearing a total of 183 species of the Recent benthonic foraminifers from the West and South Sea of korea, five bioassociations (groups of species) and five biotopes (groups of samples) were discriminated. From the areal distribution of biotopes in combination with bioassociations and the available ecological data of foraminiferal species, five biofacies are recognized: (1) Southern Inner Shelf Biofacies; (2) Southern Coast Biofacies; (3) Northern Middle Shelf Biofacies; (4) Central Middle Shelf Biofacies; and (5) Southern Outer Shelf and Upper Slope Biofacies. The biofacies are defined by a group of sampling stations containing a diagnostic species association and can be related to the major current pasterns and water masses in the West and South Sea of Korea: Southern Inner Shelf Biofacies is related to the Coastal Waters and drainage from China; Southern Coast Biofacies is related to the Coastal Waters and drainage from Korea; Northern Middle Shelf Biofacies is related to the Coastal Waters and Yellow Sea Cold Water, Central Middle Shelf Biofacies is related to the Yellow Sea Warm Current; and Southern Outer Shelf and Upper Slope Biofacies is related to the Tsushima Warm Current.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.267-274
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• 2017

The natural disasters such as typhoon, earthquake, flood, heavy rain, drought, sweltering heat, wind wave, tsunami and so on, are difficult to estimate the scale of damage and spot. Also, these disasters were being damaged to human life. However, if based on the disaster statistics the past damage cases are analyzed and the estimated damages can be calculated, the initial damage action can be taken immediately and based on the estimated damage scale the damage can be mitigated. In the present study, therefore, we proposed the functions of wind wave damage estimation for the southern coast. The functions are developed based on Disaster Report('91~'14) for wind wave and typhoon disaster statistics, regional characteristics and observed sea weather.

• Asian Journal of Atmospheric Environment
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• v.7 no.3
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• pp.139-151
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• 2013

The purpose of this study is to understand distributional characteristics in the atmospheric concentrations of $O_3$ and its precursors based on data taken at the southern Korean coast. The average $O_3$ concentration in the high altitude was found to range from 32.3 to 90.8 ppb with a maximum concentration of 132 ppb. The ambient $O_3$ concentration was high at altitudes of 1000 m and 500 m above the southern sea near Gwangyang Bay and an industrial area containing emission sources. The daily mean concentrations of $NO_y$ and CO were 6.7-24.2 ppb and 0.152-0.487 ppm, respectively. During the aerial measurement period, the highest mean concentration of $O_3$ was observed on June 1. The aerial measurement results showed that the maximum ozone concentration was observed to be 132 ppb in the high altitude the southernmost part of Yeosu. The measurement of vertical wind fields in the air indicated that $O_3$ formed in the southernmost part of Yeosu was transported by strong southwesterly winds to the northeast of Gwangyang Bay. This led to a ground $O_3$ concentration of over 100 ppb in Jinju, the northeastern part of Gwangyang Bay. On August 9, when the maximum $O_3$ concentration was 50 ppb, the measurement results showed that $O_3$ concentrations were relatively low compared to other days. In particular, low $NO_2$ and TVOC concentrations were observed, both of which serve to form $O_3$ in photochemical reactions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.65-69
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• 1981

The oceanic effect on the climate of the southern coast of Korea was analysed based on the sea surface temperature and in order to study relationships between the fluctuation of the sea surface temperature and that of climatic elements. Meteolorogical data from 1960 to 1979 were used. In the year when difference between the air and water temperature was maximum, the air temperature in southern coast was higher than normal year. A fluctuation of the sea surface temperature plays an important influence to determine the variation of the air temperature in the coastal area. Humidity of the coastal climate depends upon the oceanic effect in summer, but not in winter. This results may be due to prevailing wind effect. The oceanic effect on the precipitation in the coastal area is not found.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1067-1079
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• 2021

The coastal water is a space where salmon (Oncorhynchus keta), critical energy-conveying mediator, stay to adapt to different environments while traveling between ocean and river ecosystems for spawning and growth. The mid-eastern coast of Korea (MECW) is the southern limit of salmon distributed in the North Pacific Ocean. Understanding the distribution and migration characteristics of salmon in the MECW is important for the prediction of changes in the amount and distribution of salmon related to changes in the future marine environment. We analyzed the relationship between the salmon migratory timing ascending the Wangpi river and change in vertical seawater temperature and tidal elevation. Overall results highlight that (1) Salmon began to ascend the river when the sea surface water temperature (SST) decreased below 20℃; (2) The number of salmon ascending the river increased when the temperature difference between the upper and lower layers decreased, but decreased when the temperature difference was higher than 5℃; (3) The number of salmon ascending the river peaked, when the SST was 18℃-19℃ and sea levels rose at high tide. This study provide important insight into predicting changes in the ecosystem energy circulation through climate change at its southern distribution limit.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.166-178
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• 2015

We investigated marine environmental characteristics of Goheung coastal areas in August where is known to be the first outbreak site of Cochlodinium polykrikoides (hereafter C. polykrikoides) blooms, based on the oceanographic data observed from 1993 to 2013 around the Korean southern coastal waters including Eastern China Sea by National Fisheries Research and Development Institute (NFRDI). The data of NOAA/NGSST satellite images as well as numerical simulation results by Seo et al. [2013] were also used for analysis. Water temperatures at the surface and bottom layers in Goheung coast, i.e. Narodo, were $25.0^{\circ}C$ and $23.7^{\circ}C$ so that they were higher than $23.8^{\circ}C$ and $19.4^{\circ}C$ in Geoje coast where is a reference site, respectively. In addition, salinities at the surface and bottom layers in Goheung coast were 31.78 psu and 31.98 psu so that they were a little higher than 31.54 psu at the surface but a little lower than 32.79 psu at the bottom in Geoje coast, respectively. That is, the differences in water temperature or salinity between the surface and bottom layers in Goheung coast in August were not large compared to Geoje coast. This suggests that stratification in Goheung coast in August is fairly weak or may not be established. In addition, the concentrations of DIN and DIP at the surface layer were 0.068 mg/L ($4.86{\mu}M$) and 0.015 mg/L ($5.14{\mu}M$) in Goheung coast while 0.072 mg/L ($5.14{\mu}M$) and 0.01 mg/L ($0.32{\mu}M$) in Geoje coast, so they did not indicate a meaningful difference. On the other hand, when C. polykrikoides blooms, water temperature and salinity in August at the station 317-22 ($31.5^{\circ}N$, $124^{\circ}E$) of the East China Sea, where is near the mouth of Yangtze River, were $27.8^{\circ}C$ and 31.61 psu, respectively. Thus, water temperature was much higher whereas salinity was almost similar compared to Goheung coast. Furthermore, concentrations of $NO_3-N$ and $PO_4-P$ in the East China Sea in August were remarkably high compared to Goheung coast. When C. polykrikoides blooms, according to not only the image data of satellites NOAA/NGSST but also numerical experiment results by Seo et al.[2013], the freshwater out of Yangtze River was judged to clearly affect the Korean southern coastal waters. Therefore, the supply of nutrients in terms of Yangtze River may greatly contribute to the outbreak of C. polykrikoides blooms in Goheung coast in summer.

• 한국해양학회지
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• v.29 no.1
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• pp.28-41
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• 1994

The hourly sea level data are analyzed in order to find the general characteristics of the storm surges at the coasts of Korea, Japan and Russia. the surges are calculated by removing the predicted tides from the observed sea level at 44 tidal stations. In korea, positive and negative surges of the west coast are larger than those of the south and east coasts. The magnitudes of negative surges are larger than those of positive surges at the west of Japan. The surges of the northern Russian coast are relatively larger than those of the southern west coast of japan. The yearly maximum positive surges at the west coast of Korea, are found to be caused by extratropical storm, but the maximum positive surges at the south or the east coast of Korea are due to the summer typhoon. Mostly the yearly maximum negative surges occur at the west coast of Korea (particularly Inchon), and they are caused by extratropical storm.

• Journal of Environmental Science International
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• v.31 no.1
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• pp.87-97
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• 2022

In this study, type analysis was conducted along with the advancement of basic data to calculate the maximum damage caused by strong winds during the typhoon period. The result of the damage by region showed that in 2012, the difference in damage was clearly distinguished as the region was classified in detail. In addition, the result of the annual damage in 2011 was strong on the west coast, and in 2016, the damage to the southeast coast was significant. In 2012, the 3-second gust was relatively stronger on the west and southeast coasts than in 2011, and the winds blew stronger along the southeast coast in 2016. Monthly damage data showed that the damage to the west coast was high in August, and the damage to the southeast coast was high in October from 2002 to 2019. The 3-second gust showed the result of wide expansion throughout the southern coast of the Korean Peninsula in October. As a result, the damage differs for type bacause the intensities and paths of typhoons vary depending on their characteristics, the 3-second gust blows differently by region based on regional characteristics, and the sale price is considered in metropolitan cities.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.4
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• pp.296-304
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• 2010

The shoreline change caused by the construction of shore protection structures are discussed based on the example of Youngrang coast, Sokcho where the coastal erosion control system(CECS), three artificial headlands and two submerged breakwaters are being constructed. The study qualitatively analyzed the shoreline changes of Youngrang coast using available satellite/aerial photographs and camera photographs taken during the construction period of 6 years since 2002 for the artificial headlands construction. The main results from the study are as following. (1) Before the installation of the middle artificial headland, longshore drifts along Youngrang coast are transported in the NW-SE direction according to the seasonally different wave characteristics. (2) During the CECS construction the shoreline is continuously changed by altering the local longshore drift budget. Especially, the middle artificial headland induces considerable change of shoreline by blocking the sediment supply from the southern pocket beach to the northern pocket beach and by accelerating the sediment accretion at the wave shadow zone behind its head. It induces the asymmetry on the net longshore drift causing the significant erosion at the center of the southern pocket beach. (3) The study demonstrates that serious unintended erosion/accretion problem are possibly occurred due to local changes on the wave transformation and the sediment transport by the construction of coastal erosion control system.