Processed CTD data acquired from 15-18°S along the Southern East Pacific Rise (SEPR) during R/V Roger Revelle cruise RR2106 (2021)

This data set was acquired during cruise RR2106 using 3 separate CTD systems (referred to as "Hydrothermal", "Trace Metal", and "Pump") that all utilized Seabird 911plus CTD systems with various integrated analog sensors (see the associated documentation that identifies the instrument configuration of each system). The data files are in ASCII format and column headers define the fields. Navigation is included in the files. The aim of the study was to evaluate the contribution of low-temperature hydrothermal venting as an important, but overlooked, source of stabilized dissolved iron to the ocean. Operations included near-bottom (20-40 m above the seafloor) CTD tows (using the "Hydrothermal" CTD only) along with vertical casts that were completed using all 3 systems. The CTD data has been processed using Seabird Data Processing modules and averaged to 5-second intervals. Navigation for the tows was calculated using a lay-back method. Primary plume tracers are potential temperature anomaly (ΔTheta, °C), turbidity anomaly (optical backscatter, ΔNTU), and oxidation-reduction potential anomaly (ΔE, mV). Users should refer to the continuous CTD data files (i.e., those with "CTDdata" in the file names) for ΔTheta and ΔE values at the time the bottle samples were obtained; ΔNTU values are included in the "BottleFile" files, which are subsets of the continuous data from the times each bottle sample was obtained (generated by Seabird Data Processing "Bottle Summary" module). The data set was generated as part of the projects called "Are Low-Temperature Hydrothermal Vents an Important but Overlooked Source of Stabilized Dissolved Iron to the Ocean?" and "Low temperature hydrothermal vent fluxes as traced by radium isotopes". Funding was provided by NSF awards OCE17-56402 and OCE18-29431.