COASTAL SEAWATER QUALITY ASSESSMENT IN SOUTH KOREA USING GEOSTATIONARY OCEAN COLOR IMAGER (GOCI) SATELLITE DATA

Abstract

This study proposes a method to assess coastal seawater quality in South Korea using GeostationaryOcean Color Imager (GOCI) satellite data. GOCI, one of the three payloads of the COMS satellite launched in June 2010, is the first geostationary ocean color observation satellite sensor in the world. The GOCI sensor collects hourly data eight time a day at 6 visible and 2 nearinfrared bands at a 500 m resolution. Its spatial coverage is 2,500 x 2,500 km including Korea peninsula, Japan, East China, and portions of Mongolia and Russia. Coastal seawater quality in South Korea is operationally assessed using in situ measurements over five ocean divisions&#8212 East Sea, Korea StraitWestern Channel, Southwest Sea, Middle West Sea, and Jeju Sea&#8212 determined considering water depth, tide, and current. The water quality index consisting of five levels is also provided using five water quality-related measurements such as chlorophyll concentration (Chl-a), secchi disk depth (SD), bottom dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP). Since in situ data-based coastal water quality assessment does not provide spatially continuous information, satellite-based approaches can be used to assist the operationalcoastal seawater quality assessment. In this study, GOCI data were evaluated to assess coastal water quality considering the existing ocean water quality index systeonary ocean color observation satellite sensor in the world. The GOCI sensor collects hourly data eight time a day at 6 visible and 2 nearinfrared bands at a 500 m resolution. Its spatial coverage is 2,500 x 2,500 km including Korea peninsula, Japan, East China, and portions of Mongolia and Russia. Coastal seawater quality in South Korea is operationally assessed using in situ measurements over five ocean divisions&#8212 East Sea, Korea StraitWestern Channel, Southwest Sea, Middle West Sea, and Jeju Sea&#8212 determined considering water depth, tide, and current. The water quality index consisting of five levels is also provided using five water quality-related measurements such as chlorophyll concentration (Chl-a), secchi disk depth (SD), bottom dissolved oxygen (DO), dissolved inorganic nitrogen (DIN), and dissolved inorganic phosphorus (DIP). Since in situ data-based coastal water quality assessment does not provide spatially continuous information, satellite-based approaches can be used to assist the operationalcoastal seawater quality assessment. In this study, GOCI data were evaluated to assess coastal water quality considering the existing ocean water quality index syste