Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects
Low clouds persist in the summer Arctic with important consequences for the radiation budget. In this study, we simulate the linear relationship between liquid water content (LWC) and cloud droplet number concentration (CDNC) observed during an aircraft campaign based out of Resolute Bay, Canada con...
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ftcopernicus:oai:publications.copernicus.org:acpd75422 2023-05-15T14:58:32+02:00 Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects Dionne, Joelle von~Salzen, Knut Cole, Jason Mahmood, Rashed Leaitch, W.~Richard Lesins, Glen Folkins, Ian Chang 2019-04-09 application/pdf https://doi.org/10.5194/acp-2019-290 https://www.atmos-chem-phys-discuss.net/acp-2019-290/ eng eng doi:10.5194/acp-2019-290 https://www.atmos-chem-phys-discuss.net/acp-2019-290/ eISSN: 1680-7324 Text 2019 ftcopernicus https://doi.org/10.5194/acp-2019-290 2019-12-24T09:49:20Z Low clouds persist in the summer Arctic with important consequences for the radiation budget. In this study, we simulate the linear relationship between liquid water content (LWC) and cloud droplet number concentration (CDNC) observed during an aircraft campaign based out of Resolute Bay, Canada conducted as part of the NETCARE study in July 2014. Using a single column model, we find that autoconversion can explain the observed linear relationship between LWC and CDNC. Of the three schemes we examined, the autoconversion scheme using continuous drizzle (Khairoutdinov and Kogan, 2000) appears to best reproduce the observed linearity in the tenuous-cloud regime (Mauritsen et al., 2011), while a scheme with a threshold for rain (Liu and Daum, 2004) best reproduces the linearity at higher CDNC. An offline version of the radiative transfer model used in the Canadian Atmospheric Model version 4.3 is used to compare the radiative effects of the modelled and observed clouds. We find that there is no significant difference in the upward longwave fluxes at the top of the atmosphere from the three autoconversion schemes (p = 0.05), but that all three schemes differ at p = 0.05 from the calculations based on observations. In contrast, the downward longwave and shortwave fluxes at the surface for all three schemes do not differ significantly (p = 0.01) from the observation-based radiative calculations. Text Arctic Resolute Bay Copernicus Publications: E-Journals Arctic Canada Resolute Bay ENVELOPE(-94.842,-94.842,74.677,74.677) |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Low clouds persist in the summer Arctic with important consequences for the radiation budget. In this study, we simulate the linear relationship between liquid water content (LWC) and cloud droplet number concentration (CDNC) observed during an aircraft campaign based out of Resolute Bay, Canada conducted as part of the NETCARE study in July 2014. Using a single column model, we find that autoconversion can explain the observed linear relationship between LWC and CDNC. Of the three schemes we examined, the autoconversion scheme using continuous drizzle (Khairoutdinov and Kogan, 2000) appears to best reproduce the observed linearity in the tenuous-cloud regime (Mauritsen et al., 2011), while a scheme with a threshold for rain (Liu and Daum, 2004) best reproduces the linearity at higher CDNC. An offline version of the radiative transfer model used in the Canadian Atmospheric Model version 4.3 is used to compare the radiative effects of the modelled and observed clouds. We find that there is no significant difference in the upward longwave fluxes at the top of the atmosphere from the three autoconversion schemes (p = 0.05), but that all three schemes differ at p = 0.05 from the calculations based on observations. In contrast, the downward longwave and shortwave fluxes at the surface for all three schemes do not differ significantly (p = 0.01) from the observation-based radiative calculations. |
format |
Text |
author |
Dionne, Joelle von~Salzen, Knut Cole, Jason Mahmood, Rashed Leaitch, W.~Richard Lesins, Glen Folkins, Ian Chang |
spellingShingle |
Dionne, Joelle von~Salzen, Knut Cole, Jason Mahmood, Rashed Leaitch, W.~Richard Lesins, Glen Folkins, Ian Chang Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
author_facet |
Dionne, Joelle von~Salzen, Knut Cole, Jason Mahmood, Rashed Leaitch, W.~Richard Lesins, Glen Folkins, Ian Chang |
author_sort |
Dionne, Joelle |
title |
Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
title_short |
Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
title_full |
Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
title_fullStr |
Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
title_full_unstemmed |
Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects |
title_sort |
modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer arctic and its radiative effects |
publishDate |
2019 |
url |
https://doi.org/10.5194/acp-2019-290 https://www.atmos-chem-phys-discuss.net/acp-2019-290/ |
long_lat |
ENVELOPE(-94.842,-94.842,74.677,74.677) |
geographic |
Arctic Canada Resolute Bay |
geographic_facet |
Arctic Canada Resolute Bay |
genre |
Arctic Resolute Bay |
genre_facet |
Arctic Resolute Bay |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-2019-290 https://www.atmos-chem-phys-discuss.net/acp-2019-290/ |
op_doi |
https://doi.org/10.5194/acp-2019-290 |
_version_ |
1766330673171267584 |