Dataset: Two decibar averaged CTD profiles collected during BATS Validation (BVAL) cruises from April 1991 through July 2025

Data Collection

Data were collected on BVAL cruises from April 1991 (BVAL cruise #50001) through July 2025 (BVAL cruise #50063). Research was conducted on many research vessels including R/V Weatherbird II, R/V Cape Henlopen, R/V Cape Hatteras and R/V Atlantic Explorer. Numerous Chief Scientists: Rachel Dow, Anthony Michaels, Kjell Gundersen, Rodney Johnson,  Michael Lomas, Ann Close, Paul Lethaby, Vivienne Lochhead, Steven Bell, Gwyn Evans, Samuel Stevens, Claire Medley, and Dominic Smith.

Profiles were collected using a standard Sea-Bird SBE-09 plus CTD. Data are processed following the methods of Knap et al., 1997 with the final product being reported as two decibar averages and all profiles. It should be noted that the two decibar profiles are reported for the downcast only and bottle marker data collected on the upcast are presented with the bottle data.

CTD Protocol

CTD profiles for BATS validation cruises have been collected since April 1991 and although there have been some changes during this period as a result of new instrumentation or methodologies, the general sampling procedures have been consistent with those detailed in the BATS method manual version #4 (Knap et al., 1997).

In summary, the CTD is operated as per SeaBird's suggested methods with data collection at the full scan rate of 24 Hz. The CTD is powered up and allowed to stabilize at 12 m prior to profiling and once stable  (typically 4 minutes) the CTD is brought back to the surface from which point the profile begins with typical descent rates of 0.7-1.0 m/s, depending on weather conditions. Water samples are collected on the upcast and prior to triggering bottles the CTD is kept at the desired depth for a minimum of 60 seconds to ensure that entrainment from the following wake has subsided. Once the water sample is taken the CTD immediately continues with the upcast at an ascent rate of 0.7-1.0 m/s.