EGU21-2729
https://doi.org/10.5194/egusphere-egu21-2729
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Aerosol characterization in an oceanic context around Reunion island (AEROMARINE field campaign)

Faustine Mascaut1, Olivier Pujol1, Jérôme Brioude2, Bert Verreyken2,3,4, Raphaël Peroni1, Luc Blarel1, Thierry Podvin1, Jean-Marc metzger5, Karine Sellegri6, and Philippe Goloub1
Faustine Mascaut et al.
  • 1Université de Lille, Département de Physique, Laboratoire d'Optique Atmosphérique (LOA), 59655, Villeneuve d'Ascq, France
  • 2Laboratoire de l'Atmosphère et des Cyclones (LACy), UMR 8105, Météo France/CNRS/Université de La Réunion, Saint Denis de La Réunion, France
  • 3Royal Belgian Institute for Space Aeronomy, 1180 Brussels, Belgium
  • 4Department of Chemistry, Ghent University, 9000 Ghent, Belgium
  • 5Observatoire des Science de l'Univers de La Réunion, UMS3365, 97744 Saint-Denis, France
  • 6Laboratoire de Météorologie Physique, UMR6016, CNRS, Université Clermont Auvergne, 63178 Aubière, France

We present the results of the AEROMARINE field campaign which took place in the boreal spring 2019 off the coast of Reunion island in the South West Indian Ocean basin. The southern Indian Ocean is of major interest for the study of marine aerosols, their distribution and variability [1]. Nine instrumented light plane flights and a ground-based microwave radiometer were used during the AEROMARINE field campaign. These measurements were compared with the long-term measurements of the AERONET sun-photometer (based in Saint Denis, Reunion Island) and various instruments of the high altitude Maido Observatory (2200m above sea level, Reunion island). These results were analyzed using different model outputs: (i) the AROME mesoscale weather forecast model to work on the thermodynamics of the boundary layer, (ii) the FLEXPART-AROME Lagrangian particle dispersion model to assess the geographical and vertical origin of air masses, and (iii) the chemical transport model CAMS (Copernicus Atmosphere Monitoring Service) to work on the aerosol chemical composition of air masses. These measurements allowed us to determine the background concentration of natural marine aerosols and to highlight that (1) the atmospheric layers above 1500m are in the free troposphere and are mainly composed of aerosols from the regional background and (2) that the local environment (ocean or island) has little impact on the measured concentrations. Marine aerosols emitted locally are mostly measured in the lower atmospheric layers (below 500m). The daytime marine aerosol distributions in the free troposphere measured by the aircraft were compared to the aerosol distribution measured at the high altitude Maido observatory at night when the observatory is located in the free troposphere.  We also found that the CAMS reanalyses overestimated the aerosol optical depth in this region. Finally, our study confirms, with no ambiguity, that the AERONET station in Saint Denis (Reunion island) can be considered as a representative marine station in the tropics [2]



References
[1]  I.  Koren,  G.  Dagan,  and  O.  Altaratz.   From  aerosol-limited  to  invigoration  of  warm  convective clouds. Science, 344 (6188) : 1143–1146, 2014.
[2]  P. Hamill, M. Giordano, C. Ward, D. Giles, and B. Holben.  An aeronet-based aerosol classification using the mahalanobis distance. Atmospheric Environment, 140 : 213–233,2016.

How to cite: Mascaut, F., Pujol, O., Brioude, J., Verreyken, B., Peroni, R., Blarel, L., Podvin, T., metzger, J.-M., Sellegri, K., and Goloub, P.: Aerosol characterization in an oceanic context around Reunion island (AEROMARINE field campaign), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2729, https://doi.org/10.5194/egusphere-egu21-2729, 2021.

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