Physical and chemical surface observations in the South Indian Ocean from two uncrewed sailing vehicles

This dataset collects a record of physical and chemical observations made by two uncrewed sailing vehicles (Saildrone 1038 and Saildrone 1039) in the South Indian Ocean during 2022 and 2023. SD1038 collected data near 15°E and between latitudes 35°S and 50°S during July 19-26, 2022. SD1039 made observations within the Subantarctic Zone (37-47°S, 20-45°E) between September 1, 2022 until February 24, 2023.

The local atmospheric and surface ocean parameters measured are listed below:
-- Atmospheric measurements: temperature, pressure, humidity.
-- Seawater measurements: temperature, pressure, conductivity, salinity.
-- Carbon measurements: fCO2, xCO2, and pCO2 in atmosphere and seawater.
-- Chlorophyll measurements: concentration.
-- Oxygen measurements: concentration, saturation, ratio of O2 in water to air.
-- Wind measurements: eastward, northward, and downward speed, plus gusts and direction.
-- Wave measurements: significant wave height and dominant wave period.
-- Irradiation measurements (SD1039 only): longwave, shortwave, and PAR.
-- Current velocity measurements (SD1039 only): eastwards, northwards, and upwards, down to 102m.
-- CCMP wind estimates (hourly only): collocated to Saildrone time and location.
-- Directions of large eddies transitted (SD1039 hourly only): based on AVISO eddy database.

Four files included:
-- SD1038_1min.nc (SD1038’s raw data at 1-minute timesteps with frequent gaps)
-- SD1039_1min.nc (SD1039’s raw data at 1-minute timesteps with frequent gaps)
-- SD1038_hrly.nc (SD1038’s hourly-averaged data, plus eddies and CCMP winds)
-- SD1039_hrly.nc (SD1039’s hourly-averaged data, plus eddies and CCMP winds)
1-minute files contain the “raw” data, at all times it was collected. Because many variables were only sampled once or a few times an hour, these files include frequent gaps. Hourly files were made from the 1-minute data, averaging whatever data exists within each hour, such that few gaps in the data exist for most variables.