Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008
We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC...
Published in: | Atmospheric Chemistry and Physics |
---|---|
Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/acp-17-9697-2017 https://www.atmos-chem-phys.net/17/9697/2017/ |
id |
ftcopernicus:oai:publications.copernicus.org:acp56305 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:acp56305 2023-05-15T14:48:41+02:00 Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 Qi, Ling Li, Qinbin Henze, Daven K. Tseng, Hsien-Liang He, Cenlin 2018-09-18 application/pdf https://doi.org/10.5194/acp-17-9697-2017 https://www.atmos-chem-phys.net/17/9697/2017/ eng eng doi:10.5194/acp-17-9697-2017 https://www.atmos-chem-phys.net/17/9697/2017/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-17-9697-2017 2019-12-24T09:51:14Z We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before 18 April and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (20–25 April) to global emissions from 1 March to 25 April. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 % of total anthropogenic contributions), and natural gas flaring emissions in the western extreme north of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing–Tianjin–Hebei (also known as Jing–Jin–Ji), the biggest urbanized region in northern China, contribute significantly (∼ 10 %) to surface BC across the Arctic. On average, it takes ∼ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach the Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic transport events dominate BC at Denali (87 %), a site outside the Arctic front, which is a strong transport barrier. The relative contribution of these events to surface BC within the polar dome is much smaller (∼ 50 % at Barrow and Zeppelin and ∼ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of <q>chronic</q> pollution (∼ 40 % at Barrow, 65 % at Alert, and 57 % at Zeppelin) on about a 1-month timescale. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Text Arctic Barrow black carbon Extreme North of Russia Alaska Copernicus Publications: E-Journals Arctic Atmospheric Chemistry and Physics 17 15 9697 9716 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before 18 April and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (20–25 April) to global emissions from 1 March to 25 April. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 % of total anthropogenic contributions), and natural gas flaring emissions in the western extreme north of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing–Tianjin–Hebei (also known as Jing–Jin–Ji), the biggest urbanized region in northern China, contribute significantly (∼ 10 %) to surface BC across the Arctic. On average, it takes ∼ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach the Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic transport events dominate BC at Denali (87 %), a site outside the Arctic front, which is a strong transport barrier. The relative contribution of these events to surface BC within the polar dome is much smaller (∼ 50 % at Barrow and Zeppelin and ∼ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of <q>chronic</q> pollution (∼ 40 % at Barrow, 65 % at Alert, and 57 % at Zeppelin) on about a 1-month timescale. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. |
format |
Text |
author |
Qi, Ling Li, Qinbin Henze, Daven K. Tseng, Hsien-Liang He, Cenlin |
spellingShingle |
Qi, Ling Li, Qinbin Henze, Daven K. Tseng, Hsien-Liang He, Cenlin Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
author_facet |
Qi, Ling Li, Qinbin Henze, Daven K. Tseng, Hsien-Liang He, Cenlin |
author_sort |
Qi, Ling |
title |
Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
title_short |
Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
title_full |
Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
title_fullStr |
Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
title_full_unstemmed |
Sources of springtime surface black carbon in the Arctic: an adjoint analysis for April 2008 |
title_sort |
sources of springtime surface black carbon in the arctic: an adjoint analysis for april 2008 |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-17-9697-2017 https://www.atmos-chem-phys.net/17/9697/2017/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Barrow black carbon Extreme North of Russia Alaska |
genre_facet |
Arctic Barrow black carbon Extreme North of Russia Alaska |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-17-9697-2017 https://www.atmos-chem-phys.net/17/9697/2017/ |
op_doi |
https://doi.org/10.5194/acp-17-9697-2017 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
17 |
container_issue |
15 |
container_start_page |
9697 |
op_container_end_page |
9716 |
_version_ |
1766319775651201024 |