Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect
Transport of anthropogenic aerosol into the Arctic in the spring months has the potential to affect regional climate; however, modeling estimates of the aerosol direct radiative effect (DRE) are sensitive to uncertainties in the mixing state of black carbon (BC). A common approach in previous modeli...
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ftdoajarticles:oai:doaj.org/article:ae875df31e9b4fb1a5f7c9456951b33a 2023-05-15T13:15:49+02:00 Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect J. K. Kodros S. J. Hanna A. K. Bertram W. R. Leaitch H. Schulz A. B. Herber M. Zanatta J. Burkart M. D. Willis J. P. D. Abbatt J. R. Pierce 2018-08-01T00:00:00Z https://doi.org/10.5194/acp-18-11345-2018 https://doaj.org/article/ae875df31e9b4fb1a5f7c9456951b33a EN eng Copernicus Publications https://www.atmos-chem-phys.net/18/11345/2018/acp-18-11345-2018.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-18-11345-2018 1680-7316 1680-7324 https://doaj.org/article/ae875df31e9b4fb1a5f7c9456951b33a Atmospheric Chemistry and Physics, Vol 18, Pp 11345-11361 (2018) Physics QC1-999 Chemistry QD1-999 article 2018 ftdoajarticles https://doi.org/10.5194/acp-18-11345-2018 2022-12-31T11:35:45Z Transport of anthropogenic aerosol into the Arctic in the spring months has the potential to affect regional climate; however, modeling estimates of the aerosol direct radiative effect (DRE) are sensitive to uncertainties in the mixing state of black carbon (BC). A common approach in previous modeling studies is to assume an entirely external mixture (all primarily scattering species are in separate particles from BC) or internal mixture (all primarily scattering species are mixed in the same particles as BC). To provide constraints on the size-resolved mixing state of BC, we use airborne single-particle soot photometer (SP2) and ultrahigh-sensitivity aerosol spectrometer (UHSAS) measurements from the Alfred Wegener Institute (AWI) Polar 6 flights from the NETCARE/PAMARCMIP2015 campaign to estimate coating thickness as a function of refractory BC (rBC) core diameter and the fraction of particles containing rBC in the springtime Canadian high Arctic. For rBC core diameters in the range of 140 to 220 nm, we find average coating thicknesses of approximately 45 to 40 nm, respectively, resulting in ratios of total particle diameter to rBC core diameters ranging from 1.6 to 1.4. For total particle diameters ranging from 175 to 730 nm, rBC-containing particle number fractions range from 16 % to 3 %, respectively. We combine the observed mixing-state constraints with simulated size-resolved aerosol mass and number distributions from GEOS-Chem–TOMAS to estimate the DRE with observed bounds on mixing state as opposed to assuming an entirely external or internal mixture. We find that the pan-Arctic average springtime DRE ranges from −1.65 to −1.34 W m −2 when assuming entirely externally or internally mixed BC. This range in DRE is reduced by over a factor of 2 (−1.59 to −1.45 W m −2 ) when using the observed mixing-state constraints. The difference in DRE between the two observed mixing-state constraints is due to an underestimation of BC mass fraction in the springtime Arctic in GEOS-Chem–TOMAS compared to Polar 6 ... Article in Journal/Newspaper Alfred Wegener Institute Arctic black carbon Directory of Open Access Journals: DOAJ Articles Arctic Atmospheric Chemistry and Physics 18 15 11345 11361 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 J. K. Kodros S. J. Hanna A. K. Bertram W. R. Leaitch H. Schulz A. B. Herber M. Zanatta J. Burkart M. D. Willis J. P. D. Abbatt J. R. Pierce Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Transport of anthropogenic aerosol into the Arctic in the spring months has the potential to affect regional climate; however, modeling estimates of the aerosol direct radiative effect (DRE) are sensitive to uncertainties in the mixing state of black carbon (BC). A common approach in previous modeling studies is to assume an entirely external mixture (all primarily scattering species are in separate particles from BC) or internal mixture (all primarily scattering species are mixed in the same particles as BC). To provide constraints on the size-resolved mixing state of BC, we use airborne single-particle soot photometer (SP2) and ultrahigh-sensitivity aerosol spectrometer (UHSAS) measurements from the Alfred Wegener Institute (AWI) Polar 6 flights from the NETCARE/PAMARCMIP2015 campaign to estimate coating thickness as a function of refractory BC (rBC) core diameter and the fraction of particles containing rBC in the springtime Canadian high Arctic. For rBC core diameters in the range of 140 to 220 nm, we find average coating thicknesses of approximately 45 to 40 nm, respectively, resulting in ratios of total particle diameter to rBC core diameters ranging from 1.6 to 1.4. For total particle diameters ranging from 175 to 730 nm, rBC-containing particle number fractions range from 16 % to 3 %, respectively. We combine the observed mixing-state constraints with simulated size-resolved aerosol mass and number distributions from GEOS-Chem–TOMAS to estimate the DRE with observed bounds on mixing state as opposed to assuming an entirely external or internal mixture. We find that the pan-Arctic average springtime DRE ranges from −1.65 to −1.34 W m −2 when assuming entirely externally or internally mixed BC. This range in DRE is reduced by over a factor of 2 (−1.59 to −1.45 W m −2 ) when using the observed mixing-state constraints. The difference in DRE between the two observed mixing-state constraints is due to an underestimation of BC mass fraction in the springtime Arctic in GEOS-Chem–TOMAS compared to Polar 6 ... |
format |
Article in Journal/Newspaper |
author |
J. K. Kodros S. J. Hanna A. K. Bertram W. R. Leaitch H. Schulz A. B. Herber M. Zanatta J. Burkart M. D. Willis J. P. D. Abbatt J. R. Pierce |
author_facet |
J. K. Kodros S. J. Hanna A. K. Bertram W. R. Leaitch H. Schulz A. B. Herber M. Zanatta J. Burkart M. D. Willis J. P. D. Abbatt J. R. Pierce |
author_sort |
J. K. Kodros |
title |
Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
title_short |
Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
title_full |
Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
title_fullStr |
Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
title_full_unstemmed |
Size-resolved mixing state of black carbon in the Canadian high Arctic and implications for simulated direct radiative effect |
title_sort |
size-resolved mixing state of black carbon in the canadian high arctic and implications for simulated direct radiative effect |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-18-11345-2018 https://doaj.org/article/ae875df31e9b4fb1a5f7c9456951b33a |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Alfred Wegener Institute Arctic black carbon |
genre_facet |
Alfred Wegener Institute Arctic black carbon |
op_source |
Atmospheric Chemistry and Physics, Vol 18, Pp 11345-11361 (2018) |
op_relation |
https://www.atmos-chem-phys.net/18/11345/2018/acp-18-11345-2018.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-18-11345-2018 1680-7316 1680-7324 https://doaj.org/article/ae875df31e9b4fb1a5f7c9456951b33a |
op_doi |
https://doi.org/10.5194/acp-18-11345-2018 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
18 |
container_issue |
15 |
container_start_page |
11345 |
op_container_end_page |
11361 |
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1766271221881634816 |