Jia Geng KK2003 (GPpr15)
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | Jia Geng (7672) |
| Cruise identifier | KK2003 (GPpr15) |
| Cruise period | 2020-07-03 — 2020-08-20 |
| Status | Completed |
| Port of departure | Xiamen, China |
| Port of return | Xiamen, China |
| Purpose | Research |
| Objectives | Objectives
1. To determines the distribution of macro- and micro-nutrients, fingerprint their sources, and estimate their fluxes into the NPSG 2. To constrain the spatial-temporal variability of biological N2 fixation and its limiting factors in the NDL 3. To quantify the carbon fixation and associated planktonic community structure 4. To constrain the export production from both the NDL and NRL 5. To simulate the biological pump and carbon sinks in the NPSG During the 51 days cruise, seawater samples were collected with a conventional CTD and a trace metal clean CTD, respectively, and near-surface underway seawater samples were collected from a towed fish sampling system for TEIs, nutrients, pigments, and on-deck incubations. The cruise also conducted trace metal clean in situ pump for trace metal concentrations on particles in 9 stations by McLane In-Situ Pumps with a SBE37IM CTD attached to each pump. Seawater, particles, and aerosol samples were collected in this cruise for the determination of TEIs. GEOTRACES key trace elements and isotopes in collected samples, including some other elements and isotopes REEs, 234Th, 210Pb-210Po and silicon and barium isotopes, will be analyzed after the cruise in shore-based laboratories. Regular CTD casts in 17 stations with the others physical (salinity, currents, turbulence, etc), chemical (DO, DIC, POC, macro-nutrients, etc), and biological (chlorophyll a, pigments, flow cytometry and molecular samples etc.) parameters. Turbulence dissipation rate, hydrological parameters and meteorological parameters were measured at stations and/or underway. Nutrient profiles, including nanomolar level phosphate and nitrate in shallow water column, were analyzed aboard for each station. A series of on-deck incubation experiments were also conducted with emphases on the interactions between ecosystem functions and macro- and micro-nutrient supply. These incubation experiments were conducted for phytoplankton primary production, nitrogen fixation, bacterial production and respiration, zooplankton grazing rates, etc. In addition, Lagrange observations were conducted at 3 Mega stations by surface floating drifts and 3 sediment traps in both the NDL and NR. This project can substantially improve our understandings to fundamental biogeochemistry in these climatically and ecologically important oligotrophic ocean systems. |
| Chief scientist | Weifang Chen (Xiamen University State Key Laboratory of Marine Environmental Science), Xin Liu (Xiamen University State Key Laboratory of Marine Environmental Science), Yongming Huang (Xiamen University State Key Laboratory of Marine Environmental Science) |
| Project | GEOTRACES -Trace elements and their isotopes in the water column |
| Cruise report |  (1.17 MB) |
| Ocean/sea areas | |
| General | North West Pacific Ocean (limit 180W) Philippine Sea |
