Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds

During the CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) campaign, the interaction between aerosol particles and cloud microphysical properties was investigated in detail, which also includes the influence of clouds on the aerosol formation. During two int...

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Main Authors: B. Wehner, F. Werner, F. Ditas, R. A. Shaw, M. Kulmala, H. Siebert
Format: Article
Language:English
Published: Copernicus Publications 2015-10-01
Series:Atmospheric Chemistry and Physics
Online Access:http://www.atmos-chem-phys.net/15/11701/2015/acp-15-11701-2015.pdf
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author B. Wehner
F. Werner
F. Ditas
R. A. Shaw
M. Kulmala
H. Siebert
author_facet B. Wehner
F. Werner
F. Ditas
R. A. Shaw
M. Kulmala
H. Siebert
author_sort B. Wehner
collection DOAJ
description During the CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) campaign, the interaction between aerosol particles and cloud microphysical properties was investigated in detail, which also includes the influence of clouds on the aerosol formation. During two intensive campaigns in 2010 and 2011, helicopter-borne measurement flights were performed to investigate the thermodynamic, turbulent, microphysical, and radiative properties of trade-wind cumuli over Barbados. During these flights, 91 cases with increased aerosol particle number concentrations near clouds were detected. The majority of these cases are also correlated with enhanced irradiance in the ultraviolet (UV) spectral wavelength range. This enhancement reaches values up to a factor of 3.3 greater compared to background values. Thus, cloud boundaries provide a perfect environment for the production of precursor gases for new particle formation. Another feature of cloud edges is an increased turbulence, which may also enhance nucleation and particle growth. The observed events have a mean length of 100 m, corresponding to a lifetime of less than 300 s. This implies that particles with diameters of at least 7 nm grew several nanometers per minute, which corresponds to the upper end of values in the literature (Kulmala et al., 2004). Such high values cannot be explained by sulfuric acid alone; thus extremely low volatility organic compounds (ELVOCs) are probably involved here.
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spelling doaj.art-9c34d6914d9849028f40b7f38fcaa84a2022-12-22T02:49:21ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242015-10-011520117011171110.5194/acp-15-11701-2015Observations of new particle formation in enhanced UV irradiance zones near cumulus cloudsB. Wehner0F. Werner1F. Ditas2R. A. Shaw3M. Kulmala4H. Siebert5Leibniz Institute for Tropospheric Research (TROPOS), 04318 Leipzig, GermanyLeipzig Institute for Meteorology, 04103 Leipzig, GermanyLeibniz Institute for Tropospheric Research (TROPOS), 04318 Leipzig, GermanyDepartment of Physics, Michigan Technological University, Houghton, Michigan, USADepartment of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, FinlandLeibniz Institute for Tropospheric Research (TROPOS), 04318 Leipzig, GermanyDuring the CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados) campaign, the interaction between aerosol particles and cloud microphysical properties was investigated in detail, which also includes the influence of clouds on the aerosol formation. During two intensive campaigns in 2010 and 2011, helicopter-borne measurement flights were performed to investigate the thermodynamic, turbulent, microphysical, and radiative properties of trade-wind cumuli over Barbados. During these flights, 91 cases with increased aerosol particle number concentrations near clouds were detected. The majority of these cases are also correlated with enhanced irradiance in the ultraviolet (UV) spectral wavelength range. This enhancement reaches values up to a factor of 3.3 greater compared to background values. Thus, cloud boundaries provide a perfect environment for the production of precursor gases for new particle formation. Another feature of cloud edges is an increased turbulence, which may also enhance nucleation and particle growth. The observed events have a mean length of 100 m, corresponding to a lifetime of less than 300 s. This implies that particles with diameters of at least 7 nm grew several nanometers per minute, which corresponds to the upper end of values in the literature (Kulmala et al., 2004). Such high values cannot be explained by sulfuric acid alone; thus extremely low volatility organic compounds (ELVOCs) are probably involved here.http://www.atmos-chem-phys.net/15/11701/2015/acp-15-11701-2015.pdf
spellingShingle B. Wehner
F. Werner
F. Ditas
R. A. Shaw
M. Kulmala
H. Siebert
Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
Atmospheric Chemistry and Physics
title Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
title_full Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
title_fullStr Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
title_full_unstemmed Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
title_short Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
title_sort observations of new particle formation in enhanced uv irradiance zones near cumulus clouds
url http://www.atmos-chem-phys.net/15/11701/2015/acp-15-11701-2015.pdf
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