Abstract: The surface seawater sampling system is a basic component of scientific research equipment on a scientific research vessel, providing continuous surface seawater sampling for instruments such as FerryBox, laboratory instruments and incubators. It can provide continuous monitoring of pCO₂, pH, dissolved oxygen, temperature, salinity, chlorophyll, turbidity, nutrients (NH₄⁺, NO₂⁻, NO₃⁻, PO₄³⁻ and SiO₃²⁻) and methane in surface seawater. To obtain accurate data, a real-time, high-fidelity and continuous surface sea water supply is needed for monitoring and research. Because of the particularity of the operation area, the sampling system faces common problems in polar regions; for example, the suction mouth is often blocked by broken ice in the pack-ice zone, marine organisms adhere to the pipeline wall and cause pollution, the seawater temperature rises rapidly during transportation, and pipeline rust contaminates seawater samples. To solve the above problems, the Xuelong 2 was designed with regard to several key points such as anti-icing, high-fidelity seawater sampling, real-time collection, and prevention of biological pollution. We successfully designed a surface seawater sampling system that can operate continuously in the pack-ice zone during the 36^th CHINARE (Chinese National Antarctic Research Expedition), markedly reduce the occurrence of ice blockage with a high probability, and obtain a large amount of valuable data for scientific research.

Key words: Xuelong 2, surface seawater sampling, FerryBox, polar, icebreaker