Equivalent black carbon concentration in- and outside low-level Arctic clouds at Zeppelin Observatory, Svalbard, 2015⁠ – ⁠2019

Linn Karlsson, Radovan Krejci, Paul Zieger

We have measured the concentration of black carbon concentrations in air and within particles that served as cloud nuclei for the course of four years, from November 2015 until November 2019, at the Zeppelin Observatory (485 m a.s.l.) on Svalbard.

An optical method was used to determine the (equivalent) black carbon concentrations of both whole-air and cloud residuals, respectively. This data set allows to determine the degree on how much black carbon is potentially taken up by low-level Arctic clouds. The unique long data coverage makes the data suitable for the evaluation of black carbon concentrations as well as black carbon scavenging within Earth system models.

Black carbon particles originate from incomplete combustion such as emissions from cars, ships, industry or forest fires. These particles can be transported to the Arctic atmosphere, where they can have an impact on climate by e.g. scattering and absorbing solar radiation or by influencing clouds through acting as nuclei for the formation of cloud droplets.

Citation

Linn Karlsson, Radovan Krejci, Paul Zieger (2023) Equivalent black carbon concentration in- and outside low-level Arctic clouds at Zeppelin Observatory, Svalbard, 2015⁠ – ⁠2019. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/zeppelin-ebc-2015-2019-1

References

Zieger P, Heslin-Rees, D, Karlsson, L, Koike, M, Modini, R, Krejci, R (2023) Black carbon scavenging by low-level Arctic clouds. Nature Comm. (in review)

Karlsson L, Krejci R, Koike M, Ebell K, Zieger P (2021) A long-term study of cloud residuals from low-level Arctic clouds, Atmos Chem Phys 21:8933–8959. https://doi.org/10.5194/acp-21-8933-2021

Petzold A, Schönlinner M (2004) Multi-angle absorption photometry—a new method for the measurement of aerosol light absorption and atmospheric black carbon. Journal of Aerosol Science 35(4):421-441. https://doi.org/10.1016/j.jaerosci.2003.09.005

Platt SM, Hov Ø, Berg T, Breivik K, Eckhardt S, Eleftheriadis K, Evangeliou N, Fiebig M, Fisher R, Hansen G, Hansson H-C, et al (2022) Atmospheric composition in the European Arctic and 30 years of the Zeppelin Observatory, Ny-Ålesund. Atmos Chem Phys 22:3321–3369. https://doi.org/10.5194/acp-22-3321-2022

Data description

Equivalent black carbon (eBC) concentrations were measured behind a whole-air and a counterflow virtual impactor (CVI) inlet using two identical Multi-Angle Absorption Photometer instruments (MAAP, Thermo Fisher Scientific, Germany, Model 5012) . The data was recorded from November 2015 until November 2019 at the Zeppelin Observatory, Svalbard, located at 485 m above sea level. More details on the observatory can be found in Platt et al. (2022).

Within the MAAP, particles are deposited on a filter and the attenuation and scattering of monochromatic light is measured simultaneously. The instrument delivers eBC concentrations (see Petzold and Schönlinner, 2004, for more technical details).

The whole-air inlet measures eBC of interstitial aerosol and cloud particles, while the CVI only samples the cloud particles. Within the CVI, the particles are then dried and the eBC concentration is measured. The CVI data is corrected for enrichment and sampling efficiency as described by Karlsson et al. (2021).

The data are provided in one comma-separated values (csv) file with the following content:

• time: Date and time (UTC) in the format yyyy-mm-dd HH:MM:SS
• CVI_status: Status of CVI (on, off or switching)
• BC_cvi: Equivalent black carbon concentration (unit: microgram per cubic meter) measured by MAAP1 (during clouds it measures behind the CVI, during non-cloudy periods it measured behind the whole-air inlet)
• z: Updraft velocity (unit: meter per second) measured by an ultra-sonic anemometer (Metek GmbH, Germany, Model Sonic-3 Omni)
• BC_tot: Equivalent black carbon concentration (unit: microgram per cubic meter) measured by MAAP2 measured behind whole-air inlet
• flag: Data quality (good or bad). Bad data should not be used (e.g. due to inlet switching)
• visibility: Visibility (unit: meter) measured by the CVI inlet's visibility sensor

The time resolution is 1-min. The eBC concentrations are given at ambient conditions and are stated as outputted by the instrument (no corrections due to differences in wavelengths applied). Please note that the eBC-concentrations during cloudy periods (CVI on) are corrected by the CVI sampling enrichment factor and sampling efficiency.

File size: 114.5 MB
Number of rows, including header: 2107356

Comments

More info can be found in Zieger et al. (2023, in review).

Please cite and consult Zieger et al. (2023) when using these data.