Articles | Volume 9, issue 8
Research article
09 Aug 2016
Research article |  | 09 Aug 2016

LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights

Jean-Baptiste Renard, François Dulac, Gwenaël Berthet, Thibaut Lurton, Damien Vignelles, Fabrice Jégou, Thierry Tonnelier, Matthieu Jeannot, Benoit Couté, Rony Akiki, Nicolas Verdier, Marc Mallet, François Gensdarmes, Patrick Charpentier, Samuel Mesmin, Vincent Duverger, Jean-Charles Dupont, Thierry Elias, Vincent Crenn, Jean Sciare, Paul Zieger, Matthew Salter, Tjarda Roberts, Jérôme Giacomoni, Matthieu Gobbi, Eric Hamonou, Haraldur Olafsson, Pavla Dagsson-Waldhauserova, Claude Camy-Peyret, Christophe Mazel, Thierry Décamps, Martin Piringer, Jérémy Surcin, and Daniel Daugeron

Abstract. In the companion (Part I) paper, we have described and evaluated a new versatile optical particle counter/sizer named LOAC (Light Optical Aerosol Counter), based on scattering measurements at angles of 12 and 60°. That allows for some typology identification of particles (droplets, carbonaceous, salts, and mineral dust) in addition to size-segregated counting in a large diameter range from 0.2 µm up to possibly more than 100 µm depending on sampling conditions (Renard et al., 2016). Its capabilities overpass those of preceding optical particle counters (OPCs) allowing the characterization of all kind of aerosols from submicronic-sized absorbing carbonaceous particles in polluted air to very coarse particles (> 10–20 µm in diameter) in desert dust plumes or fog and clouds. LOAC's light and compact design allows measurements under all kinds of balloons, on-board unmanned aerial vehicles (UAVs) and at ground level. We illustrate here the first LOAC airborne results obtained from a UAV and a variety of scientific balloons. The UAV was deployed in a peri-urban environment near Bordeaux in France. Balloon operations include (i) tethered balloons deployed in urban environments in Vienna (Austria) and Paris (France), (ii) pressurized balloons drifting in the lower troposphere over the western Mediterranean (during the Chemistry-Aerosol Mediterranean Experiment – ChArMEx campaigns), (iii) meteorological sounding balloons launched in the western Mediterranean region (ChArMEx) and from Aire-sur-l'Adour in south-western France (VOLTAIRE-LOAC campaign). More focus is put on measurements performed in the Mediterranean during (ChArMEx) and especially during African dust transport events to illustrate the original capability of balloon-borne LOAC to monitor in situ coarse mineral dust particles. In particular, LOAC has detected unexpected large particles in desert sand plumes.

Short summary
We illustrate the first Light Optical Aerosol Counter (LOAC) airborne results obtained from an unmanned aerial vehicle (UAV) and a variety of scientific balloons: tethered balloons deployed in urban environments, pressurized balloons drifting in the lower troposphere over the western Mediterranean during the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), and meteorological sounding balloons launched in the western Mediterranean region and in the south-west of France.