Measurements of pCO2 from an autonomous drifting buoy in 2019 during FALKOR cruise FK191120, station 4

Data from autonomous, drifting buoy with a floating chamber to measure insitu air-sea carbon dioxide (CO2) fluxes during RV Falkor cruise FK191120 in the southern Pacific during November-December 2019. The technique is described in detail in Ribas-Ribas et al. (2018) (https://doi.org/10.1525/elementa.275). The buoy is equipped with a sensor to measure aqueous and atmospheric partial pressure of CO2 (pCO2), and to monitor the increase or loss of CO2 inside the chamber. One complete cycle including two chamber measurements last 70 minutes. The buoy can be deployed for more than 15 hours, and at wind speeds of up to 10 m/s. Floating chambers are known to overestimate fluxes due to the creation of additional turbulence at the water surface. We check that by measuring turbulence with two Acoustic Doppler Velocimeter (ADV), one directly underneath the center of the floating chamber (equipped with an inertial motion unit) and the other one positioned sideways to measure turbulence outside the perimeter of the buoy.