Multiparameter measurement of biogeochemical properties of the sea surface microlayer (SML), 0.5-meter depth, underlying water (ULW) at 1-meter depth and near surface ocean at 1.5-meter depth during cruise FK1911120 onboard RV Falkor. The pH, temperature and conductivity were measured both in the SML and ULW with two VWR model MU 6100H. The salinity values were calculated from the conductivity and corrected with discrete water samples measured with a salinometer in the lab. The temperature reported comes from the conductivity sensors. The pH (0m) and pH (1m) were measured in surface and bulk water (approximated 0.5 and 1.5 m depth) with a flowthrough sensor manufactured by SubCtech and with two AMT pH sensors. Fluorescent dissolved organic matter (fDOM) in SML and ULW was measured with two TriOs MicroFlu sensors. All the meteorological data comes from a Davis Instrument Vantage Pro2 located on the top of the sea surface scanner (S3) mast. Discrete samples for surfactants analysis were taken with the S3 and analysed in the laboratory with voltammetry. More details about the S3 and the sensors on it are described in Ribas-Ribas et al., 2017 (https://doi.org/10.1175/JTECH-D-17-0017.1). The S3 was deployed during 17 stations between the 20 November 2019 and the 17 December 2019 in the Pacific Ocean.

Bulk = underlying bulk water (1 m depth)SML = sea surface microlayerQuality flags: 0/no entry=not checked, 2=good, 4=badTeq = Titron equivalent