Aerosol measurements during COPE: composition, size, and sources of CCN and INPs at the interface between marine and terrestrial influences
Heavy rainfall from convective clouds can lead to devastating flash flooding, and observations of aerosols and clouds are required to improve cloud parameterisations used in precipitation forecasts. We present measurements of boundary layer aerosol concentration, size, and composition from a seri...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/11687/2016/acp-16-11687-2016.pdf |
| _version_ | 1818147793424875520 |
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| author | J. W. Taylor T. W. Choularton A. M. Blyth M. J. Flynn P. I. Williams P. I. Williams G. Young K. N. Bower J. Crosier J. Crosier M. W. Gallagher J. R. Dorsey J. R. Dorsey Z. Liu P. D. Rosenberg |
| author_facet | J. W. Taylor T. W. Choularton A. M. Blyth M. J. Flynn P. I. Williams P. I. Williams G. Young K. N. Bower J. Crosier J. Crosier M. W. Gallagher J. R. Dorsey J. R. Dorsey Z. Liu P. D. Rosenberg |
| author_sort | J. W. Taylor |
| collection | DOAJ |
| description | Heavy rainfall from convective clouds can lead to devastating flash flooding,
and observations of aerosols and clouds are required to improve cloud
parameterisations used in precipitation forecasts. We present measurements of
boundary layer aerosol concentration, size, and composition from a series of
research flights performed over the southwest peninsula of the UK during the
COnvective Precipitation Experiment (COPE) of summer 2013. We place emphasis
on periods of southwesterly winds, which locally are most conducive to
convective cloud formation, when marine air from the Atlantic reached the
peninsula. Accumulation-mode aerosol mass loadings were typically
2–3 µg m<sup>−3</sup> (corrected to standard cubic metres at 1013.25 hPa
and 273.15 K), the majority of which was sulfuric acid over the sea, or
ammonium sulfate inland, as terrestrial ammonia sources neutralised the
aerosol. The cloud condensation nuclei (CCN) concentrations in these
conditions were ∼ 150–280 cm<sup>−3</sup> at 0.1 % and
400–500 cm<sup>−3</sup> at 0.9 % supersaturation (SST), which are in good
agreement with previous Atlantic measurements, and the cloud drop
concentrations at cloud base ranged from 100 to 500 cm<sup>−3</sup>. The
concentration of CCN at 0.1 % SST was well correlated with non-sea-salt
sulfate, meaning marine sulfate formation was likely the main source of
CCN. Marine organic aerosol (OA) had a similar mass spectrum to previous
measurements of sea spray OA and was poorly correlated with CCN.
<br><br>
In one case study that was significantly different to the rest, polluted
anthropogenic emissions from the southern and central UK advected to the
peninsula, with significant enhancements of OA, ammonium nitrate and
sulfate, and black carbon. The CCN concentrations here were around 6 times
higher than in the clean cases, and the cloud drop number concentrations were
3–4 times higher.
<br><br>
Sources of ice-nucleating particles (INPs) were assessed by comparing
different parameterisations used to predict INP concentrations, using
measured aerosol concentrations as input. The parameterisations based on
total aerosol produced INP concentrations that agreed within an order of magnitude
with measured first ice concentrations at cloud temperatures as low as
−12 °C. Composition-specific parameterisations for mineral dust,
fluorescent particles, and sea spray OA were 3–4 orders of magnitude lower
than the measured first ice concentrations, meaning a source of INPs
was present that was not characterised by our measurements and/or one or
more of the composition-specific parameterisations greatly underestimated
INPs in this environment. |
| first_indexed | 2024-12-11T12:40:54Z |
| format | Article |
| id | doaj.art-e30aa0d7f6a9403fa5f27184feb89268 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-11T12:40:54Z |
| publishDate | 2016-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-e30aa0d7f6a9403fa5f27184feb892682022-12-22T01:07:00ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-09-0116116871170910.5194/acp-16-11687-2016Aerosol measurements during COPE: composition, size, and sources of CCN and INPs at the interface between marine and terrestrial influencesJ. W. Taylor0T. W. Choularton1A. M. Blyth2M. J. Flynn3P. I. Williams4P. I. Williams5G. Young6K. N. Bower7J. Crosier8J. Crosier9M. W. Gallagher10J. R. Dorsey11J. R. Dorsey12Z. Liu13P. D. Rosenberg14Centre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKNational Centre for Atmospheric Science, University of Leeds, Leeds, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKNational Centre for Atmospheric Science, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKNational Centre for Atmospheric Science, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKNational Centre for Atmospheric Science, University of Manchester, Manchester, UKCentre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, UKSchool of Earth and Environment, University of Leeds, Leeds, UKHeavy rainfall from convective clouds can lead to devastating flash flooding, and observations of aerosols and clouds are required to improve cloud parameterisations used in precipitation forecasts. We present measurements of boundary layer aerosol concentration, size, and composition from a series of research flights performed over the southwest peninsula of the UK during the COnvective Precipitation Experiment (COPE) of summer 2013. We place emphasis on periods of southwesterly winds, which locally are most conducive to convective cloud formation, when marine air from the Atlantic reached the peninsula. Accumulation-mode aerosol mass loadings were typically 2–3 µg m<sup>−3</sup> (corrected to standard cubic metres at 1013.25 hPa and 273.15 K), the majority of which was sulfuric acid over the sea, or ammonium sulfate inland, as terrestrial ammonia sources neutralised the aerosol. The cloud condensation nuclei (CCN) concentrations in these conditions were ∼ 150–280 cm<sup>−3</sup> at 0.1 % and 400–500 cm<sup>−3</sup> at 0.9 % supersaturation (SST), which are in good agreement with previous Atlantic measurements, and the cloud drop concentrations at cloud base ranged from 100 to 500 cm<sup>−3</sup>. The concentration of CCN at 0.1 % SST was well correlated with non-sea-salt sulfate, meaning marine sulfate formation was likely the main source of CCN. Marine organic aerosol (OA) had a similar mass spectrum to previous measurements of sea spray OA and was poorly correlated with CCN. <br><br> In one case study that was significantly different to the rest, polluted anthropogenic emissions from the southern and central UK advected to the peninsula, with significant enhancements of OA, ammonium nitrate and sulfate, and black carbon. The CCN concentrations here were around 6 times higher than in the clean cases, and the cloud drop number concentrations were 3–4 times higher. <br><br> Sources of ice-nucleating particles (INPs) were assessed by comparing different parameterisations used to predict INP concentrations, using measured aerosol concentrations as input. The parameterisations based on total aerosol produced INP concentrations that agreed within an order of magnitude with measured first ice concentrations at cloud temperatures as low as −12 °C. Composition-specific parameterisations for mineral dust, fluorescent particles, and sea spray OA were 3–4 orders of magnitude lower than the measured first ice concentrations, meaning a source of INPs was present that was not characterised by our measurements and/or one or more of the composition-specific parameterisations greatly underestimated INPs in this environment.https://www.atmos-chem-phys.net/16/11687/2016/acp-16-11687-2016.pdf |
| spellingShingle | J. W. Taylor T. W. Choularton A. M. Blyth M. J. Flynn P. I. Williams P. I. Williams G. Young K. N. Bower J. Crosier J. Crosier M. W. Gallagher J. R. Dorsey J. R. Dorsey Z. Liu P. D. Rosenberg Aerosol measurements during COPE: composition, size, and sources of CCN and INPs at the interface between marine and terrestrial influences Atmospheric Chemistry and Physics |
| title | Aerosol measurements during COPE: composition, size, and sources of CCN and
INPs at the interface between marine and terrestrial influences |
| title_full | Aerosol measurements during COPE: composition, size, and sources of CCN and
INPs at the interface between marine and terrestrial influences |
| title_fullStr | Aerosol measurements during COPE: composition, size, and sources of CCN and
INPs at the interface between marine and terrestrial influences |
| title_full_unstemmed | Aerosol measurements during COPE: composition, size, and sources of CCN and
INPs at the interface between marine and terrestrial influences |
| title_short | Aerosol measurements during COPE: composition, size, and sources of CCN and
INPs at the interface between marine and terrestrial influences |
| title_sort | aerosol measurements during cope composition size and sources of ccn and inps at the interface between marine and terrestrial influences |
| url | https://www.atmos-chem-phys.net/16/11687/2016/acp-16-11687-2016.pdf |
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