Iodic acid, sulfuric acid and methanesulfonic acid collected during the Arctic Ocean 2018 expedition

Andrea Baccarini, Julia Schmale, Josef Dommen

Measurements of iodic acid, sulfuric acid and methanesulfonic acid concentration in the gas phase obtained with a nitrate chemical ionization mass spectrometer (we used an APi-TOF mass spectrometer produced by Tofwerk AG coupled with a Chemical ionization inlet A70 produced by Airmodus).

These three species are of fundamental importance in the atmosphere because they participate in both new particle formation and growth affecting the Earth radiative balance and cloud properties. Iodic acid is mainly produced from the oxidation of the iodine molecule whereas both sulfuric and methanesulfonic acid are produced from the oxidation of dimethyl sulfide.

Measurements were performed on the 4th deck of icebreaker Oden during August and September 2018 along the track of the expedition. Concentrations are reported as molecules per cubic centimeter in ten minutes averages.

Citation

Andrea Baccarini, Julia Schmale, Josef Dommen (2020) Iodic acid, sulfuric acid and methanesulfonic acid collected during the Arctic Ocean 2018 expedition. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-ao-2018-aerosol-cims-1

References

Baccarini A, Karlsson L, Dommen J, Duplessis P, Vüllers J, Brooks IM, Saiz-Lopez A, Salter M, Tjernström M, Baltensperger U, Zieger P, Schmale J (2020) Frequent new particle formation over the high Arctic pack ice by enhanced iodine emissions. Nature Communications 11:4924. https://doi.org/10.1038/s41467-020-18551-0

Junninen H et al. (2010) A high-resolution mass spectrometer to measure atmospheric ion composition. Atmos. Meas. Tech. 3:1039⁠ – ⁠1053. https://doi.org/10.5194/amt-3-1039-2010

Jokinen T et al. (2012) Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOF. Atmos. Chem. Phys. 12:4117⁠ – ⁠4125. https://doi.org/10.5194/acp-12-4117-2012

Kürten A, Rondo L, Ehrhart S, Curtius J (2012) Calibration of a chemical ionization mass spectrometer for the measurement of gaseous sulfuric acid. J. Phys. Chem. A. 116:6375⁠ – ⁠6386. https://doi.org/10.1021/jp212123n

Data description

Raw data were collected at 0.5 Hz frequency and then the spectra were integrated for 10 minutes in order to improve the signal to noise ratio. The datetime is reported in the UTC timezone as yyyy-mm-dd HH:MM:SS.

The measurement uncertainty is estimated to be to -50%/+100%. The lower limit of detection (LOD) based on three standard deviations of the background noise was estimated to be lower than 5×10³ molecules cm⁻³; values below the LOD were replaced by LOD/√(2).

The last column in the dataset is a flag to separate between clean data and data that are potentially influenced by the ship exhaust: 1 indicates clean data and 2 contaminated data.

The mass spectrometer is described in Junninen et al. (2010) and the chemical ionization inlet in Jokinen et al. (2012). The instrument was calibrated after the campaign using sulfuric acid (Kürten et al. 2012) and the concentration is corrected for diffusional losses in the inlet.

Comments

The ship track with latitude and longitude information can be found in the Navigation, meteorological and surface seawater data from the Arctic Ocean 2018 expedition data set.

The data creator ORCIDs are the following:

• Andrea Baccarini: https://orcid.org/0000-0003-4614-247X
• Julia Schmale: https://orcid.org/0000-0002-1048-7962
• Josef Dommen: https://orcid.org/0000-0002-0006-0009

Data were collected during the Arctic Ocean 2018 expedition on board the Swedish icebreaker (I/B) Oden, which was organized by the Swedish Polar Research Secretariat. The observations were part of the project ‘Aerosol-cloud interactions in the High Arctic’ (PI Paul Zieger, Department of Environmental Science, Stockholm University; see MOCCHA project website with updates).