Dataset abstract This dataset contains quality-checked meteorological observations of air temperature, relative humidity, dew point, barometric pressure and observations of downwelling solar radiation and ultraviolet radiation. Further it contains the wind speed and direction relative to the ship but not corrected for air-flow distortion, and translated into the earth reference frame. For each of these variables observations are available from a portside and starboard side sensor. The dataset also contains, cloud base height and sky cover at three levels measured with a Ceilometer. As additional information the solar azimuth and altitude angle have been calculated for the ship’s position every five minutes and have been added as a one-minute time series using the nearest value. The ship’s position, heading, course and speed over ground are also provided. The wind speed measurements were made at a height of approximately 30.5 meters above sea level. The measurement height of the temperature and humidity probes is 23.7 meters above sea level. The barometric pressure was measured at 20 meters above sea level. The observations have been screened for implausible values and on some occasions despiking based on visual inspection and a rolling interquartile range filter have been applied. Solar radiation measurements are affected by shadowing of the ship, and the air temperature and humidity by the heating of air that passes over the ship. Masks are provided to flag affected observations. The wind speed readings are affected by airflow distortion and should be used with consideration until a dataset of corrected wind speeds is published. More details on airflow distortion can be requested from the contact person. Dataset contents ACE_filtered_meteorological_data_1min.csv, data file, comma-separated values diff_TA1_TA3_WDR2_5min_1.png, metadata, portable network graphics ratio_SR1_SR3_solangle_5min_1.png, metadata, portable network graphics data_file_header.txt, metadata, text README.txt, metadata, text ace_filtered_meteorological_data_change_log.txt, metadata, text Change log v1.1 - The range check for skycover (SC) and cloudlevel (CL) was added to the quality-checking routines. 53 data points violated the range check for these variables: these have now been marked as NaN. v1.0 - Initial release of verified meteorological data. Dataset license This meteorological dataset is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full description can be found at https://creativecommons.org/licenses/by/4.0/

{"references": ["Smith, Shawn R., Mark A. Bourassa, and Ryan J. Sharp. Establishing More Truth in True Winds. JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY 16 (1999): 14.", "Stull, Roland. Wet-Bulb Temperature from Relative Humidity and Air Temperature. 2011. Journal of Applied Meteorology and Climatology 50, no. 11 (9 September 2011): 2267\u201369. https://doi.org/10.1175/JAMC-D-11-0143.1."]}

The Antarctic Circumnavigation Expedition was made possible by funding from the Swiss Polar Institute and Ferring Pharmaceuticals. Antarctic Circumnavigation Expedition – Delivering Added value To Antarctica (ACE-DATA) is funded by the Swiss Data Science Center as Project number 17-02.