This record describes the Acoustic Doppler Current Profiler (ADCP) data collected from the Marine National Facility RV Investigator voyage IN2023_V01, titled: "Antarctic Bottom Water production in the past: Records from marine sediments, Cape Darnley, East Antarctica." The voyage took place between January 25, 2023 and March 2, 2023 (AEST), departing from Fremantle and returning to Hobart.
This voyage had two main scientific objectives. First, to understand past changes in Antarctic Bottom Water (AABW) production using long sediment cores from the continental slope over multiple warm periods during the Pleistocene. Second, to develop an improved bathymetry model to support oceanographic modelling of AABW pathways. Sediment core records of previous warmer interglacial will provide an analogue for understanding the impact of any future changes in bottom water production associated with a warming climate.
This report describes the production of quality-controlled ADCP data from RV Investigator voyage IN2023_V01.
The OS150 unit was run for the majority part of the voyage whilst the OS75 was run for parts of the voyage.
The OS75 showed unusual behaviour where the data depth was half the expected value at around 350m with low data quality. On-board investigation discovered that beams 1 and 2 of the OS75 unit were severely degraded and the fault was attributed to the likely failure of the ceramic arrays.
ADCP data were collected using the University of Hawaii Data Acquisition System (UHDAS) and post-processed using the Common Ocean Data Access System (CODAS). Documentation for these systems can be found in (Hummon, 2009-2021).
Both the RDI Ocean Surveyor 150kHz ADCP and the RDI Ocean Surveyor 75kHz ADCP were run in narrowband mode.
Internal triggering was used.
The drop keel (port) extension was set at below the waterline as detailed:
2m from the voyage start until 11-Feb-2023 09:20:05 UTC,
0m (Zero) from 11-Feb-2023 09:21:30 to 21-Feb-2023 23:24:15 UTC and
2m from 21-Feb-2023 23:25:05UTC to the end of the voyage.
There were several gaps in the OS75 ADCP data due to the investigation on board related to the fault discussed above and the reduction in the usual data quality resulted in extra processing effort being required. Apart from the usual data cleaning, there were no significant ADCP processing-related issues in relation to the OS150 data.
To access the full voyage plan and other reports and data associated with this voyage, please see the contact information at the end of this report.
This dataset was processed (quality-controlled), and then archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).
