Underway and quality-controlled surface fCO2 data collected from voyage 1 of RSV Nuyina, September to November 2026

Published: 2026-09-28

Delayed-mode quality-controlled surface underway fCO2 data collected on RSV Nuyina, Voyage 1 of the 2025_26 field season. Data collected on RSV Nuyina contributes to Australian Antarctic Division (AAD) Project 4652 (PI: P. Miloslavich) and is a is part of an AAD-CSIRO collaborative effort. The CSIRO contribution is supported by the Integrated Marine Observing System (IMOS) Biogeochemical Sensors Sub-Facility (PI: B. Tilbrook). IMOS is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). Raw CO2 data were measured as mole fractions with a General Oceanics pCO2 system equipped with a LI-COR 7000 CO2 sensor. The CO2 sensor response was calibrated at 3-4 hour intervals using CO2-in-air reference gases on the WMO X2019 scale with the zero and span set daily using the low and high reference gas standards. Expocode: 09NX20250926 Variables Information: Variable Name: Organization Description of Variable: participating institutions. Variable Name: Vessel Description of Variable: Ship name. Variable Name: CruiseID Description of Variable: Cruise designation. Variable Name: Day_GMT Description of Variable: UTC (ddd.hhhh). Variable Name: Date Description of Variable: Observation date UTC (yyyy/mm/dd). Variable Name: Time Description of Variable: Observation time UTC (hh:mm:ss). Variable Name: Lat Description of Variable: Latitude (decimal degrees). Variable Name: Long Description of Variable: Longitude (decimal degrees). Variable Name: xCO2EQ_PPM Description of Variable: Mole fraction of CO2 (dry) in the equilibrator head space at equilibrator temperature (ppm). Variable Name: xCO2ATM_PPM Description of Variable: Mole fraction of CO2 in the atmosphere (dry), measured every 3-4 hours after standard gas measurements. These values are linearly interpolated with times between good atmospheric CO2 measurements. There was no air intake for the 2025_26 field season and atmospheric values are set to -999 (missing). Variable Name: Press_Equil Description of Variable: Equilibrator head space pressure (hectopascal). Variable Name: Press_ATM Description of Variable: Barometric pressure at sea level(hectopascal). Variable Name: TEQ Description of Variable: Equilibrator water temperature (degrees Celsius). Variable Name: SST Description of Variable: Sea surface temperature (degrees Celsius). Variable Name: SAL Description of Variable: Sea surface salinity. Variable Name: fCO2SW_UATM Description of Variable: Fugacity of carbon dioxide at surface water salinity and temperature and 100% humidity (microatmosphers). Variable Name: fCO2ATM_UATM _INTERPOLATED Description of Variable: Fugacity of CO2 in the atmosphere from xCO2ATM_PPM at sea surface salinity and temperature and 100% humidity (microatmospheres). Variable Name: DfCO2_UATM Description of Variable: Sea water fCO2 minus interpolated air fCO2 (microatmospheres). Variable Name: WindSpd_True Description of Variable: Wind speed (knots). Variable Name: WindDirn_True Description of Variable: Wind direction, where 0 is North and 90 is East (degrees). Variable Name: Type Description of Variable: Measurement type (EQU = equilibrator head space, ATM = atmosphere). Variable Name: WOCE_QC_FLAG Description of Variable: WOCE quality control flag (2=good, 3=questionable, -999=missing).