Experimental evidence of the rear capture of aerosol particles by raindrops
- 1Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, LPMA, Gif-sur-Yvette, France
- 2Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-CRI, SESUC, BMCA, Fontenay-aux-Roses, France
- 3Clermont Université, Université Blaise Pascal, Laboratoire de Météorologie Physique, Clermont-Ferrand, France
- 4CNRS, INSU, UMR6016, LaMP, Aubière, France
- 5CNRS UMR6614, CORIA Rouen, Site Universitaire du Madrillet, Saint-Étienne-du-Rouvray, France
- acurrently at: Strathom Energie, Paris, France
Abstract. This article presents new measurements of the efficiency with which aerosol particles of accumulation mode size are collected by a 1.25 mm sized raindrop. These laboratory measurements provide the link to reconcile the scavenging coefficients obtained from theoretical approaches with those from experimental studies. We provide here experimental proof of the rear capture mechanism in the flow around drops, which has a fundamental effect on submicroscopic particles. These experiments thus confirm the efficiencies theoretically simulated by Beard (1974). Finally, we propose a semi-analytical expression to take into account this essential mechanism to calculate the collection efficiency for drops within the rain size range.