Water Quality and Bio-optical Properties Measured from the Geostationary and Polar-Orbiting Ocean Color Sensors in the Northwestern Pacific Region

The first geostationary ocean color satellite sensor, the Korean Geostationary Ocean Color Imager (GOCI), has the unique capability with hourly measurements during daytime (from 9:00 to 14:00 local time) to provide short- and long-term environmental monitoring such as water optical, biological, and biogeochemical properties in the marine ecosystem. GOCI covers the western Pacific region, including some open oceans and turbid coastal/inland waters. In this presentation, we show results of GOCI-derived ocean color products from 2012 to 2019 using the Multi-Sensor Level-1 to Level-2 (MSL12) ocean color data processing system to characterize diurnal, seasonal, and interannual variations in water property. In addition, water quality and bio-optical products from the polar-orbiting ocean color satellite sensors, e.g., the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) and the Ocean and Land Colour Instrument (OLCI) on the Sentinel-3A, derived using the same MSL12 ocean color data processing system are compared with those from GOCI. Satellite ocean color products are also compared with the in-situ measurements from the two AERONET-OC sites located in the Yellow Sea. Results show that over open oceans ocean color products are quite accurate and highly stable, and reasonable water property data can be derived over turbid coastal and inland waters. Furthermore, we show that GOCI measurements provide important diurnal (temporal) information, while the polar-orbit satellites (VIIRS and OLCI) provide large scale spatial coverages. Thus, measurements from the geo and polar-orbiting satellites are complementary to provide more complete picture/information of water optical, biological, and biogeochemical variations over open ocean and coastal/inland waters. Some detailed data analyses and discussions for satellite results derived from GOCI, VIIRS, and OLCI are provided.