Dataset: Trace metal CTD bottle sensor data from the Hydrothermal Estuaries expedition to the Juan de Fuca hydrothermal plume, Northeast Pacific Ocean, aboard R/V Atlantis (AT50-15) in August and September 2023

This dataset includes the processed bottle-CTD sensor data collected with depth profiles of a trace metal clean CTD owned by the Fitzsimmons lab and deployed on the Hydrothermal Estuaries cruise to the Endeavour hydrothermal plume, Juan de Fuca Ridge, Northeast Pacific Ocean aboard R/V Atlantis (AT50-15) from August-September 2023. Data are only shown for the depths on which Niskin-X bottles were closed. Bottles were closed on the upcast only, and every depth has duplicate bottles fired to satisfy our water budget requirements. Station locations were selected using modeling estimates and sensor data from the AUV Sentry; a station upstream of the hydrothermal plume was also sampled as a background. Each station (except for the background) targeted the most concentrated plume at sequential distances aimed to represent increasing plume age.

Data were collected using a Sea-bird SBE 19+v2 CTD instrument package designed to continuously measure conductivity, temperature, and pressure, and all titanium housings were used to satisfy trace metal clean conditions. The CTD includes two components, the deck unit (SBE 33) and underwater unit (SBE 19+v2) for real-time monitoring. The SBE 19+v2 comes with the standard three sensors and can hold up to six additional sensors. Here we chose to supplement the CTD data with oxygen (SBE 43), transmissometry (C-Star), and turbidity (Seapoint Turbidity Meter and a 100x gain cable).

Profiles were taken at each of the five main vent sites at the Main Endeavour Field (between 48°00 N and 47°54 N) and stations up to 20 kilometers west from these sites. Stations were selected based on modeling and AUV Sentry surveys to target the hydrothermal plume. An upstream background station was also sampled north of the vent site. All samples taken were deeper than 1700 meters.