RV Investigator Voyage IN2026_T02 Triaxus (undulating CTD) Data

Updated: 2026-09-30

This record describes the data (CTD, Dissolved Oxygen, Transmissometer, PAR, ECO Triplet, Nitrate, Fluorescence and LOPC) collected using the towed TRIAXUS platform on Investigator voyage IN2026_T02, titled: "CAPSTAN IN2026_T02." The voyage took place between April 23, 2026 and May 05, 2026 (AEST), departing from Fremantle and returning to Hobart. 1 Triaxus tow was conducted for CAPSTAN voyage objectives. Pressure, conductivity, temperature, and dissolved oxygen data were gathered from duplicate sensors using a Seabird SBE9plus CTD. Also carried on the Triaxus hull were a cosine Photosynthetically Active Radiation (PAR) sensor, a transmissometer, an ECO Triplet (optical backscatter, CDOM fluorometer and chlorophyll fluorometer) and a Laser Optical Plankton Counter (LOPC). On each tow, data from legs where the Triaxus was vertically undulating regularly were processed. Data from deployment into the water, turns, and retrieval were also gathered and processed. Typically, only undulation legs and full tows are processed, but as there was only one tow in this voyage, deployment and retrieval legs were also processed. See Appendix A.1 for definitions and example usage of common terms employed here and throughout this report to describe Triaxus tow components and their associated data. Pressure, conductivity, temperature, and dissolved oxygen sensor data were converted to calibrated units. Spikes and out-of-range values were removed, and primary sensor data were compared to secondary sensor data. PAR, transmissometer and ECO Triplet data were combined into the dataset. LOPC data was gathered but are not processed or published with this report. Published data have been grouped into 1-decibar bins. Both primary and secondary CTD sensors were reliable, so the final dataset uses the primary CTD sensor values in the default data variables (i.e., variables without “_2” appended). On this voyage all tows were made up of legs that were sufficiently short to be recorded in single files. As such, a “leg” is the same as a “section” for all tows in this voyage. The published data consist of: • along-track time-series data for each leg • synthetic interpolated vertical casts for each undulation peak and trough of each leg • interpolated sectional plots of various sensor data taken from along-track time-series data for each leg The collected data were processed (quality-controlled), and subsequently archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC). Additional information regarding this dataset may be contained in the Voyage Summary and the Data Processing Report.