Concentration of gaseous sulfuric acid measured over the Southern Ocean in the austral summer of 2016/2017, during the Antarctic Circumnavigation Expedition (ACE). Data files: gas_sulfuric_acid_concentration_data.csv File header date_time: start time of the five-minute averaging period in ISO 8601 format YYYY-MM-DDThh:mm:ss+00:00 [UTC] sulfuric_acid_concentration: Gaseous sulfuric acid concentration measured with a nitrate chemical ionization APi-TOF mass spectrometer (Tofwerk AG) [molecules per cubic centimetre] flag: data quality flag, 1 indicates good data whereas 0 indicates data contaminated by the ship exhaust latitude: median ship latitude during the five-minute averaging period as measured by the ship's GPS [decimal degrees N] longitude: median ship longitude during the five-minute averaging period as measured by the ship's GPS [decimal degrees E]