Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity
Atmospheric particles can affect climate directly, by scattering solar radiation, or indirectly, by acting as the seed upon which cloud droplets form. These clouds can then cool the earth's surface by reflecting incoming sunlight. In order to constrain the large uncertainties in predicting the...
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ftcanadathes:oai:collectionscanada.gc.ca:OTU.1807/29679 2023-05-15T14:53:06+02:00 Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity Chang, Rachel Ying-Wen Abbatt, Jonathan P. D. 2011-06 http://hdl.handle.net/1807/29679 en_ca eng http://hdl.handle.net/1807/29679 Arctic aerosol cloud condensation nuclei aerosol-cloud interactions aerosol nucleation 0725 0768 Thesis 2011 ftcanadathes 2013-11-23T23:26:27Z Atmospheric particles can affect climate directly, by scattering solar radiation, or indirectly, by acting as the seed upon which cloud droplets form. These clouds can then cool the earth's surface by reflecting incoming sunlight. In order to constrain the large uncertainties in predicting the ultimate effect of aerosol on climate, the sources of atmospheric particles and their subsequent ability to turn into cloud droplets needs to be better understood. This thesis addresses two parts of this issue: the sources of Arctic aerosol and the hygroscopicity of continental organic aerosol. Small particles were observed in Baffin Bay during September 2008 that coincided with high atmospheric and ocean surface dimethyl sulphide (DMS) concentrations suggesting that the aerosol formed from oceanic sources. An aerosol microphysics box model confirmed that local DMS could have produced the observed particles. In addition, the particle chemical composition was measured using aerosol mass spectrometry in the central Arctic Ocean in August 2008 and particles were found to be 43% organic and 46% sulphate. Factor analysis further apportioned the aerosol mass to marine biogenic and continental sources 33% and 36% of the time, respectively, with the source of the remaining mass unidentified. The second part of the study parameterises the hygroscopicity of the ambient organic aerosol fraction (κorg) at Egbert, Ontario and Whistler, British Columbia. This was done using two methods: 1) by assuming that the oxygenated organic component was hygroscopic and that the unoxygenated organic component was non-hygroscopic, κ of the oxygenated component was found to be 0.22 ± 0.04, and 2) by assuming that κorg varied linearly with the atomic oxygen to atomic carbon ratio, it could be parameterised as κorg = (0.29 ± 0.05) × (O/C). Calculations predict that knowing κorg is important in urban, semi-urban, and remote locations whenever the inorganic mass fraction is low. Thesis Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Theses Canada/Thèses Canada (Library and Archives Canada) Arctic Arctic Ocean Baffin Bay Egbert ENVELOPE(-69.649,-69.649,-69.951,-69.951) |
institution |
Open Polar |
collection |
Theses Canada/Thèses Canada (Library and Archives Canada) |
op_collection_id |
ftcanadathes |
language |
English |
topic |
Arctic aerosol cloud condensation nuclei aerosol-cloud interactions aerosol nucleation 0725 0768 |
spellingShingle |
Arctic aerosol cloud condensation nuclei aerosol-cloud interactions aerosol nucleation 0725 0768 Chang, Rachel Ying-Wen Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
topic_facet |
Arctic aerosol cloud condensation nuclei aerosol-cloud interactions aerosol nucleation 0725 0768 |
description |
Atmospheric particles can affect climate directly, by scattering solar radiation, or indirectly, by acting as the seed upon which cloud droplets form. These clouds can then cool the earth's surface by reflecting incoming sunlight. In order to constrain the large uncertainties in predicting the ultimate effect of aerosol on climate, the sources of atmospheric particles and their subsequent ability to turn into cloud droplets needs to be better understood. This thesis addresses two parts of this issue: the sources of Arctic aerosol and the hygroscopicity of continental organic aerosol. Small particles were observed in Baffin Bay during September 2008 that coincided with high atmospheric and ocean surface dimethyl sulphide (DMS) concentrations suggesting that the aerosol formed from oceanic sources. An aerosol microphysics box model confirmed that local DMS could have produced the observed particles. In addition, the particle chemical composition was measured using aerosol mass spectrometry in the central Arctic Ocean in August 2008 and particles were found to be 43% organic and 46% sulphate. Factor analysis further apportioned the aerosol mass to marine biogenic and continental sources 33% and 36% of the time, respectively, with the source of the remaining mass unidentified. The second part of the study parameterises the hygroscopicity of the ambient organic aerosol fraction (κorg) at Egbert, Ontario and Whistler, British Columbia. This was done using two methods: 1) by assuming that the oxygenated organic component was hygroscopic and that the unoxygenated organic component was non-hygroscopic, κ of the oxygenated component was found to be 0.22 ± 0.04, and 2) by assuming that κorg varied linearly with the atomic oxygen to atomic carbon ratio, it could be parameterised as κorg = (0.29 ± 0.05) × (O/C). Calculations predict that knowing κorg is important in urban, semi-urban, and remote locations whenever the inorganic mass fraction is low. |
author2 |
Abbatt, Jonathan P. D. |
format |
Thesis |
author |
Chang, Rachel Ying-Wen |
author_facet |
Chang, Rachel Ying-Wen |
author_sort |
Chang, Rachel Ying-Wen |
title |
Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
title_short |
Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
title_full |
Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
title_fullStr |
Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
title_full_unstemmed |
Arctic Aerosol Sources and Continental Organic Aerosol Hygroscopicity |
title_sort |
arctic aerosol sources and continental organic aerosol hygroscopicity |
publishDate |
2011 |
url |
http://hdl.handle.net/1807/29679 |
long_lat |
ENVELOPE(-69.649,-69.649,-69.951,-69.951) |
geographic |
Arctic Arctic Ocean Baffin Bay Egbert |
geographic_facet |
Arctic Arctic Ocean Baffin Bay Egbert |
genre |
Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin |
genre_facet |
Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin |
op_relation |
http://hdl.handle.net/1807/29679 |
_version_ |
1766324515718037504 |