Equivalent black carbon concentration measured with an aethalometer AE33 during the Arctic Ocean 2018 expedition

Benjamin Heutte, Andrea Baccarini, Paul Zieger, Julia Schmale

Equivalent black carbon (eBC) mass concentration was measured with a commercial aethalometer (model AE33, Magee Scientific, Berkeley, USA). Measurements were performed onboard of the Swedish icebreaker (I/B) Oden from August to September 2018 as part of the expedition Arctic Ocean 2018.

Black carbon is an anthropogenic aerosol resulting from incomplete combustion (e.g. traffic or ship exhaust or industrial emissions). It is relevant for various atmospheric processes such as its influence on radiative transfer within the Earth's atmosphere.

The instrument was located on the 4th deck of I/B Oden, switching hourly between a total and interstitial air inlet, with cutoff sizes of 40 and 1 µm respectively. Optical absorption was measured at 7 different wavelengths simultaneously, with a 1 second time resolution. We used the absorption at 880 nm (channel 6) to derive eBC, using a mass absorption cross-section value of 7.77 m² g⁻¹.

Citation

Benjamin Heutte, Andrea Baccarini, Paul Zieger, Julia Schmale (2024) Equivalent black carbon concentration measured with an aethalometer AE33 during the Arctic Ocean 2018 expedition. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-ao-2018-aerosol-ebc-ae33-1

References

Karlsson, L., Baccarini, A., Duplessis, P., Baumgardner, D., Brooks, I. M., Chang, R. Y.-W., Dada, L., Dällenbach, K. R., Heikkinen, L., Krejci, R., Leaitch, W. R., Leck, C., Partridge, D. G., Salter, M. E., Wernli, H., Wheeler, M. J., Schmale, J., & Zieger, P. (2022). Physical and chemical properties of cloud droplet residuals and aerosol particles during the Arctic Ocean 2018 expedition. Journal of Geophysical Research Atmospheres, 127(11). https://doi.org/10.1029/2021jd036383

Zieger, P. and Karlsson, L. (2022) Equivalent black carbon concentration measured during the Arctic Ocean 2018 expedition. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-ao-2018-aerosol-ebc-1

Data description

The data is provided in one comma-separated values (.csv) file (185 KB). Columns:

• Date/Time_(UTC): Date and time (DD-mm-YYYY HH:MM:SS) in UTC
• eBC (ng/m3): eBC mass concentrations in units of ng/m³
• Pollution_flag_(1=polluted): Pollution flag to identify periods influenced by the local ship pollution. 1 corresponds to polluted data, 0 to clean data.

The equivalent black carbon measurements were collected with a commercial aethalometer (model AE33, Magee Scientific, Berkeley, USA). The raw dataset was first averaged to a time resolution of 1 min. Outliers of more than 3 times the median absolute deviation from an hourly moving window were removed and data were finally averaged to 10 min time resolution. We converted the ‘Mask to identify polluted periods during the Arctic Ocean 2018 expedition’ from a 1 min to a 10 min time resolution, by setting the condition that if more than 1 data point is polluted in a 10 min moving window, the entire 10 minutes period is defined as polluted. This flag identifies periods which are likely influenced by the local ship pollution.

Comments

Data were collected during the Arctic Ocean 2018 expedition on board the Swedish icebreaker 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). 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.