Aircraft-based measurements of High Arctic springtime aerosol show evidence for vertically varying sources, transport and composition
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Published:2019-01-03
Issue:1
Volume:19
Page:57-76
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ISSN:1680-7324
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Container-title:Atmospheric Chemistry and Physics
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language:en
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Short-container-title:Atmos. Chem. Phys.
Author:
Willis Megan D.ORCID, Bozem HeikoORCID, Kunkel DanielORCID, Lee Alex K. Y., Schulz HannesORCID, Burkart Julia, Aliabadi Amir A., Herber Andreas B., Leaitch W. Richard, Abbatt Jonathan P. D.ORCID
Abstract
Abstract. The sources, chemical transformations and removal mechanisms of aerosol
transported to the Arctic are key factors that control Arctic
aerosol–climate interactions. Our understanding of sources and processes is
limited by a lack of vertically resolved observations in remote Arctic
regions. We present vertically resolved observations of trace gases and
aerosol composition in High Arctic springtime, made largely north of
80∘ N, during the NETCARE campaign. Trace gas gradients observed on
these flights defined the polar dome as north of 66–68∘ 30′ N
and below potential temperatures of 283.5–287.5 K. In the polar dome, we
observe evidence for vertically varying source regions and chemical
processing. These vertical changes in sources and chemistry lead to
systematic variation in aerosol composition as a function of potential
temperature. We show evidence for sources of aerosol with higher organic
aerosol (OA), ammonium and refractory black carbon (rBC) content in the upper
polar dome. Based on FLEXPART-ECMWF calculations, air masses sampled at all
levels inside the polar dome (i.e., potential temperature <280.5 K, altitude <∼3.5 km) subsided during transport
over transport times of at least 10 days. Air masses at the lowest potential
temperatures, in the lower polar dome, had spent long periods (>10 days)
in the Arctic, while air masses in the upper polar dome had entered the
Arctic more recently. Variations in aerosol composition were closely related
to transport history. In the lower polar dome, the measured sub-micron
aerosol mass was dominated by sulfate (mean 74 %), with lower contributions from rBC (1 %), ammonium (4 %) and OA
(20 %). At higher altitudes and higher potential temperatures, OA,
ammonium and rBC contributed 42 %, 8 % and 2 % of aerosol mass,
respectively. A qualitative indication for the presence of sea salt showed
that sodium chloride contributed to sub-micron aerosol in the lower polar
dome, but was not detectable in the upper polar dome. Our observations
highlight the differences in Arctic aerosol chemistry observed at
surface-based sites and the aerosol transported throughout the depth of the
Arctic troposphere in spring.
Funder
Natural Sciences and Engineering Research Council of Canada
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference135 articles.
1. Abbatt, J. P. D., Benz, S., Cziczo, D. J., Kanji, Z., Lohmann, U., and Moehler,
O.: Solid ammonium sulfate aerosols as ice nuclei: A pathway for cirrus
cloud formation, Science, 313, 1770–1773, https://doi.org/10.1126/science.1129726,
2006. a, b 2. Abbatt, J. P. D., Thomas, J. L., Abrahamsson, K., Boxe, C., Granfors, A.,
Jones, A. E., King, M. D., Saiz-Lopez, A., Shepson, P. B., Sodeau, J.,
Toohey, D. W., Toubin, C., von Glasow, R., Wren, S. N., and Yang, X.: Halogen
activation via interactions with environmental ice and snow in the polar
lower troposphere and other regions, Atmos. Chem. Phys., 12, 6237–6271,
https://doi.org/10.5194/acp-12-6237-2012, 2012. a, b 3. Abbatt, J. P. D., Leaitch, W. R., Herber, A. B., Bertram, A. K., Blanchet, J.
P., Korolev, A., Burkart, J., Bozem, H., Willis, M. D., Lee, A. K. Y.,
Schulz, H., Hanna, S., Aliabadi, A. A., and Staebler, R.: NETCARE 2015 POLAR6
aircraft campaign, available at:
https://open.canada.ca/data/dataset/efe0e41c-890d-404d-bb1b-421456022d51,
last access: 20 December 2018. a 4. Arnold, S. R., Law, K. S., Brock, C. A., Thomas, J. L., Starkweather, S. M.,
von Salzen, K., Stohl, A., Sharma, S., Lund, M. T., Flanner, M. G.,
Petäjä, T., Tanimoto, H., Gamble, J., Dibb, J. E., Melamed, M., Johnson,
N., Fidel, M., Tynkkynen, V. P., Baklanov, A., Eckhardt, S., Monks, S. A.,
Browse, J., and Bozem, H.: Arctic air pollution: Challenges and
opportunities for the next decade, Elementa, 4,
000104, https://doi.org/10.12952/journal.elementa.000104, 2016. a, b, c, d, e, f 5. Asmi, E., Kondratyev, V., Brus, D., Laurila, T., Lihavainen, H., Backman, J.,
Vakkari, V., Aurela, M., Hatakka, J., Viisanen, Y., Uttal, T., Ivakhov, V.,
and Makshtas, A.: Aerosol size distribution seasonal characteristics measured
in Tiksi, Russian Arctic, Atmos. Chem. Phys., 16, 1271–1287,
https://doi.org/10.5194/acp-16-1271-2016, 2016. a
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