Mesoscale spatio-temporal variability of airborne lidar-derived aerosol properties in the Barbados region during EUREC<sup>4</sup>A
<p>From 23 January to 13 February 2020, 20 ATR-42 scientific flights were conducted in the framework of the EUREC4A field campaign over the tropical Atlantic, off the coast of Barbados (13<span class="inline-formula"><sup>∘</sup></span>30<span class="i...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/1271/2022/acp-22-1271-2022.pdf |
| Summary: | <p>From 23 January to 13 February 2020, 20 ATR-42 scientific flights were conducted in the framework of the EUREC4A field campaign over the
tropical Atlantic, off the coast of Barbados (13<span class="inline-formula"><sup>∘</sup></span>30<span class="inline-formula"><sup>′</sup></span> N, <span class="inline-formula">−</span>58<span class="inline-formula"><sup>∘</sup></span>30<span class="inline-formula"><sup>′</sup></span> W). By means of a sideway-pointing lidar,
these flights allowed us to retrieve the optical properties of the aerosols found in the sub-cloud layer and below the trade wind inversion. Two
distinct periods with significant aerosol contents were identified in relationship with the so-called trade wind and tropical regimes,
respectively. For these two regimes, mixings of two air mass types encompassing dust and carbonaceous aerosols have been highlighted. Both were
mainly from West Africa with similar optical contributions and linked to dust uptake above Sahara and biomass burning between Guinea-Bissau and
Côte d'Ivoire. In the tropical transport regime, the wind within the planetary boundary layer is stronger and favours a contribution of marine
aerosols (sulfate and sea salt aerosol components) in shallower aerosol layers than for the trade wind transport regime. The latter is responsible
for advecting dust–biomass-burning-aerosol mixtures in the deeper, well-mixed layer, in part due to the complex interactions of the easterly flow from
West Africa with mid-latitude dynamics. The aerosol vertical structures appear to be well reproduced using atmospheric composition reanalyses from
CAMS when comparing with lidar-derived vertical profiles. The competition between the two types of transport regimes leads to strong heterogeneity
in the optical properties of the horizontal aerosol field. Our study highlights the transport regime under which a significant mixture of dust and
biomass burning aerosols from West Africa can be observed over the Caribbean and Barbados in particular, namely the trade wind regime.</p> |
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| ISSN: | 1680-7316 1680-7324 |