Underway Seawater System

Surface CTD Thermosalinograph (SCT) system is a real-time ocean observation setup installed on research vessels, primarily used to continuously measure surface seawater temperature and conductivity along the ship’s navigation path. From these data, important hydrographic parameters such as salinity, density, and sound velocity are derived. The system pumps surface seawater from beneath the vessel and is equipped with the SEA-BIRD SBE 21 SeaCAT Thermosalinograph sensor, ensuring high-precision and stable data collection.

Additionally, the SCT system can be expanded with various sensors, such as WET Labs’ fluorescence and transmissometry probes, enabling simultaneous measurements of chlorophyll-a concentration and light penetration (or derived attenuation coefficients). This supports marine biology and water quality studies. The collected data can be compared with satellite remote sensing results to enhance spatiotemporal resolution in ocean monitoring, making it widely used in marine science research, fisheries resource assessment, and climate change observation.