Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region
<p>Aerosol particles are important for radiation effects, cloud formation, and therefore the climate system. A detailed understanding of the spatial distribution of aerosol particles within the atmospheric boundary layer, which depends on sources and sinks, as well as long-range transport and...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/10007/2022/acp-22-10007-2022.pdf |
| _version_ | 1811313478880722944 |
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| author | J. Lückerath J. Lückerath A. Held A. Held H. Siebert M. Michalkow B. Wehner |
| author_facet | J. Lückerath J. Lückerath A. Held A. Held H. Siebert M. Michalkow B. Wehner |
| author_sort | J. Lückerath |
| collection | DOAJ |
| description | <p>Aerosol particles are important for radiation effects, cloud formation, and therefore the climate system. A detailed understanding of the spatial distribution of aerosol particles within the atmospheric boundary layer, which depends on sources and sinks, as well as long-range transport and vertical exchange, is important. Especially in marine regions, where the climate effect of clouds is comparably high, long-range transport with subsequent vertical mixing dominates over local aerosol sources.</p>
<p>In this study, three different methods were applied to estimate the vertical aerosol particle flux in the marine boundary layer (MBL) and the vertical exchange between the MBL and the free troposphere (FT): eddy covariance (EC), flux–gradient similarity (<span class="inline-formula"><i>K</i></span> theory), and the mixed-layer gradient method (MLG). For the first time, MBL aerosol fluxes derived from these three methods were compared in the framework of the “Azores Stratocumulus Measurements of Radiation, Turbulence and Aerosols” (ACORES) field campaign in the Azores region in the northeastern Atlantic Ocean in July 2017. Meteorological parameters and aerosol and cloud properties were measured in the marine troposphere using the helicopter-borne measurement platform ACTOS (Airborne Cloud Turbulence Observation System).</p>
<p>All three methods were applied to estimate the net particle exchange between MBL and FT. In many cases, the entrainment fluxes of the MLG method agreed within the range of uncertainty with the EC and <span class="inline-formula"><i>K</i></span>-theory flux estimates close to the top of the MBL, while the surface flux estimates of the different methods diverged. It was not possible to measure directly above the surface with the helicopter-borne payload, which might be a source of uncertainty in the surface fluxes. The observed particle fluxes at the top of the MBL ranged from 0 to <span class="inline-formula">10×10<sup>6</sup></span> m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span> both in the upward and the downward direction, and the associated uncertainties were on the same order of magnitude. Even though the uncertainties of all three methods are considerable, the results of this study contribute to an improved understanding of the transport of particles between the MBL and FT and their distribution in the MBL.</p> |
| first_indexed | 2024-04-13T10:54:39Z |
| format | Article |
| id | doaj.art-897deb5dcc264b28899422b3707f96df |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-13T10:54:39Z |
| publishDate | 2022-08-01 |
| publisher | Copernicus Publications |
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| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-897deb5dcc264b28899422b3707f96df2022-12-22T02:49:33ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242022-08-0122100071002110.5194/acp-22-10007-2022Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores regionJ. Lückerath0J. Lückerath1A. Held2A. Held3H. Siebert4M. Michalkow5B. Wehner6Leibniz Institute for Tropospheric Research, Leipzig, Germanypreviously at: Atmospheric Chemistry, University of Bayreuth, Bayreuth, GermanyEnvironmental Chemistry and Air Research, Technische Universität Berlin, Berlin, Germanypreviously at: Atmospheric Chemistry, University of Bayreuth, Bayreuth, GermanyLeibniz Institute for Tropospheric Research, Leipzig, GermanyLeibniz Institute for Tropospheric Research, Leipzig, GermanyLeibniz Institute for Tropospheric Research, Leipzig, Germany<p>Aerosol particles are important for radiation effects, cloud formation, and therefore the climate system. A detailed understanding of the spatial distribution of aerosol particles within the atmospheric boundary layer, which depends on sources and sinks, as well as long-range transport and vertical exchange, is important. Especially in marine regions, where the climate effect of clouds is comparably high, long-range transport with subsequent vertical mixing dominates over local aerosol sources.</p> <p>In this study, three different methods were applied to estimate the vertical aerosol particle flux in the marine boundary layer (MBL) and the vertical exchange between the MBL and the free troposphere (FT): eddy covariance (EC), flux–gradient similarity (<span class="inline-formula"><i>K</i></span> theory), and the mixed-layer gradient method (MLG). For the first time, MBL aerosol fluxes derived from these three methods were compared in the framework of the “Azores Stratocumulus Measurements of Radiation, Turbulence and Aerosols” (ACORES) field campaign in the Azores region in the northeastern Atlantic Ocean in July 2017. Meteorological parameters and aerosol and cloud properties were measured in the marine troposphere using the helicopter-borne measurement platform ACTOS (Airborne Cloud Turbulence Observation System).</p> <p>All three methods were applied to estimate the net particle exchange between MBL and FT. In many cases, the entrainment fluxes of the MLG method agreed within the range of uncertainty with the EC and <span class="inline-formula"><i>K</i></span>-theory flux estimates close to the top of the MBL, while the surface flux estimates of the different methods diverged. It was not possible to measure directly above the surface with the helicopter-borne payload, which might be a source of uncertainty in the surface fluxes. The observed particle fluxes at the top of the MBL ranged from 0 to <span class="inline-formula">10×10<sup>6</sup></span> m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span> both in the upward and the downward direction, and the associated uncertainties were on the same order of magnitude. Even though the uncertainties of all three methods are considerable, the results of this study contribute to an improved understanding of the transport of particles between the MBL and FT and their distribution in the MBL.</p>https://acp.copernicus.org/articles/22/10007/2022/acp-22-10007-2022.pdf |
| spellingShingle | J. Lückerath J. Lückerath A. Held A. Held H. Siebert M. Michalkow B. Wehner Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region Atmospheric Chemistry and Physics |
| title | Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region |
| title_full | Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region |
| title_fullStr | Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region |
| title_full_unstemmed | Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region |
| title_short | Vertical aerosol particle exchange in the marine boundary layer estimated from helicopter-borne measurements in the Azores region |
| title_sort | vertical aerosol particle exchange in the marine boundary layer estimated from helicopter borne measurements in the azores region |
| url | https://acp.copernicus.org/articles/22/10007/2022/acp-22-10007-2022.pdf |
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