In-Seong Han

Supply of Heat by Tsushima Warm Current in the East Sea (Japan Sea)

A significant surface net heat loss appears around the Kuroshio and the Tsushima Warm Current regions. The area where the surface heat loss occurs should require heat to be supplied by the current to maintain the long-term annual heat balance. Oceanic heat advection in these regions plays an important role in the heat budget. The spatial distribution of the heat supply by the Tsushima Warm Current near the surface was examined by calculating the horizontal heat supply in the surface layer of the East Sea (the Japan Sea) (ESJS), directly from historical sea surface temperature and current data. We have also found a simple estimation of the effective vertical scale of heat supply by the current to compensate net heat loss using the heat supplied by the current in the surface 10 m layer. The heat supplied by the current for the annual heat balance was large in the Korea/Tsushima Strait and along the Japanese Coast, and was small in the northwestern part of the ESJS. The amount of heat supplied by the current was large in the northwestern part and small in the south-eastern part of the ESJS. These features suggest that the heat supplied by the Tsushima Warm Current is restricted to near the surface around the northeastern part and extends to a deeper layer around the southeastern part of the ESJS.

Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study

In the summer rainy season, the Korean Peninsula is frequently influenced by severe weather phenomena such as floods and rain-induced landslides. A band-shaped precipitation system associated with unstable atmospheric conditions occurred over northwest Korea on 27 July 2011. This precipitation system produced heavy rainfall over the Seoul metropolitan area, which received over 80 mm h−1 of rainfall and suffered 70 weather-related fatalities. To investigate the precipitation system, we used diverse meteorological data of environmental condition and estimated three-dimensional wind field from dual-Doppler radar measurements of vertical air motion. Environmental conditions included high equivalent potential temperature (θ e ) of over 355 K at low levels, and low θ e of under 330 K at middle levels, causing vertical instability. Furthermore, a pressure trough was located to the northwest of Korea, favouring the development of the band-shaped precipitation system. The tip of the band-shaped precipitation system was made up of line-shaped convective systems (LSCSs) that caused flooding and landslides, and the LSCSs were continuously enhanced by merging between new cells and the pre-existing cell. The position of merging moved from the coast to offshore areas and influenced the positioning of the regions of enhanced convection. In turn, this affected the roughness of the convective cell and the internal structure of the enhanced convective regions. Onshore, the convective area was higher than in offshore areas because of strong convergence (≤−4×10−4 s−1) at low levels caused by friction over land. The strong convergence generated strong updraft (≥4 m s−1) that influenced the height of the convective area. The convective region offshore was wider than that onshore because of weak convergence (≥−2.2×10−4 s−1) at low levels. Updraft in offshore areas was weak (≤3 m s−1) compared with onshore, resulting in a lower and wider convective area. Spatial variations in surface roughness result in different structural features and profiles of divergence within LSCSs, even if they originate in the same convective region.

Species Composition and Community Structure of Demersal Organisms Caught by Shrimp Beam Trawl in the Coastal Waters of Gunsan of West Sea

Abstract Species composition of aquatic organism in the marine ranching area of Gunsan, Korea were investigated using shrimp beam trawl from May to December in 2010. A total of 91 species, 98,127 ind./ ㎢ and 877.6 ㎏/㎢ of aquatic organism were collected. Among them, species were included 60 species in Pisces, 21 in Crustacea and 10 in Mollusca. The individual dominant species, occupying over 10% of total individuals, were Latreutes anoplonyx(47,327 ind/㎢, 48.23%), Crangon hakodatei(11,578 ind./㎢, 11.80%) and Trachysalambria curvirostris(10,237 ind./㎢, 10.40%). And the biomass dominant species, occupying over 9% of total biomass, were Paralichthys olivaceus(135 ㎏/㎢, 15.4%), Okamejei kenojei(98.2 ㎏/㎢, 11.2%) and Portunus tribuberculatus(84.8 ㎏/㎢, 9.6%). From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed data of number of species and individuals per unit area collected more than two times during this survey by each month and station was divided into three different groups. Group A showed seasonal similarity of characteristic of distribution in August and November, Group B in December and Group C in May. Key words : Species composition, Community structure, Dermersal organisms, Gunsan, Shrimp beam trawlCorresponding author : 051-626-9895, bluejuve@gmail.com 2016 (R2016051) .

Analysis of Long-term Oceanic Data for the Prediction of Undaria pinnatifida Aquaculture Production off the Coast of Busan

미역(Undaria pinnatifida)은 갈조식물문 다시마목 미역과에 속하는 해조류로서 동아시아지역의 주요 양식 종으로 활성화 되어 있는 해조류이다. 우리나라에서는 1970년대부터 미역 양 식산업이 활발히 이루어지고 있으며, 총 해조류 양식의 약 48% 정도를 차지하고 있다(Park et al., 2008). 부산연안에서도 해조 류 양식이 활발히 이루어지고 있으며 주요 양식종인 김, 미역, 다시마 양식의 생산량은 국내 총 생산량의 5.9%를 차지하고 있 으며, 품종 별로는 미역 7.1%, 김 6.7%, 다시마 3.1%를 차지하 고 있다(Gijang Gun Office, 2012). 각 해조류 양식종별 생산액 의 국내 비율을 살펴보면, 김은 6.0%, 미역은 18.7%, 다시마는 13.1%를 차지하고 있어, 특히 미역양식은 생산량에 비하여 생 산액이 전국 비율의 2.5배 이상 높아 품질 좋은 미역생산이 이 루어지고 있음을 시사하고 있다. 부산연안에서 이루어지고 있 는 미역생산의 시기를 살펴보면 일반적으로 조기산 미역양식에 서 후기산 건조용 미역까지 주로 9월 중순 이후에서 이듬해 4월 까지 미역양식이 활발히 이루어지고 있으며, 9월 중순-12월까 지는 조기산 물미역을 양성하여 10-12월에 수확을 하며, 11월 에서 이듬해 3월까지는 후기산 물미역 및 건조용 미역을 양성 하여 주로 이듬해 1-3월 사이에 수확을 한다. 또한 12월에서 이 듬해 4월까지 양성하는 후기산 건조용 미역의 경우 수확은 이 듬해 1-4월 사이에 이루어지고 있다(Gijang Gun Office, 2012). 해조류의 성장 및 생육에는 다양한 해양, 기상 요소가 작용 을 하는 것으로 알려져 있으며(Lobban and Harrison, 1994; Dring, 1982, Dawes, 1981), 우리나라의 다양한 연구에서도 수 온, 광도, 파고 등이 중요한 원인으로 알려져 있다(Nam, 1986; Koh et al., 1989; Koh and Sung, 1983; Nam et al., 1996). 특 히, 수온과 해조류 양식과는 밀접한 관련이 있는 것으로 알려져 있으며 김 생산량과 수온 등 환경과의 해역 별 상관성에 관한 연구는 다양하게 수행되어 왔다(Lee, 1988; Hong et al., 1987; Jang et al., 1983). 부산연안에서 미역 생산량과 수온과의 상관