Cruise Period:

2020/09/09-2020/10/05

Cruise: R/V Science

Investigation Region:

Regular CTD stationswere located along 130°E and over 8°-18°N with 0.5° interval.

Investigation Content and Instruments:

1) Skylightirradiance, upwelling radiance and downwelling irradiance were measuredsynchronously by profiler Ⅱ which is sea-bird scientific’s new generationoptical profiling instrument. We also gained particle size profile andchlorophyll fluorescence with turbidity profile by LISST 100X and ECOcombination fluorometer and turbidity sensor. In addition, water samples whichcollected within the depth of 200m for 7 layers were analyzed in the lab forthe absorption coefficient of suspend particulate matter, chlorophyll and CDOM (coloreddissolved organic matter).

2) Thefull-depth profiles of temperature, salinity oxygen and chlorophyll concentrationwere measured by the sea-bird 911 conductivity–temperature–depth (CTD)instrument on regular CTD stations. Some vertical distributions of biochemicalproperties such as dissolved oxygen and chlorophyll fluorescence were also analyzedwith water samples collected by CTD Rosette 10-liter Niskin bottles within thedepth of 5000 m. Furthermore, two lowered Acoustic Doppler Current Profilers(ADCPs) were equipped to explore the vertical structure of horizontal current velocitysynchronously.

3) We mainlyused the Vertical Microstructure Profiler (VMP) and Expandable microstructureprofiler (XMP) to gain the turbulence and mixing parameters above 800 m and overthe full depth, respectively.

4) Subsurfacemoorings were deployed to monitor the time variation of ocean currents,temperature and salinity. One upward- and one downward-looking TRDI 75 kHzADCPs were equipped at ~500 m to return hourly velocity profiles over 50-1000 mwith a vertical resolution of 8 m. Each mooring also supported Nortek Aquadoppor JFE INFINITY-Deep current meters at various depths for gaining currentvelocity data, and SBE37 conductivity–temperature–depth (CTD) instruments toobserve temperature and salinity data.

5) Shipboard RDI38KHz and 300KHz ADCPs are utilized to measure the real-time horizontal currentvelocity around the ship during the whole cruise. In addition, the KEXUE iscurrently equipped with a Seabeam3012 Multibeam Echosounder. We utilize thisequipment to perform seabed mapping to full ocean depth, with full resolution,coverage, and accuracy. KEXUE also supported the Vaisala MAWS420 automaticmeteorological station to monitor the meteorological factors such like localwind speed, temperature, pressure and humidity etc.