Trace element solubility in wet deposition: Investigating the evolution at the intra-event scale

Abstract

Understanding the solubility dynamics of elements during wet deposition is crucial for assessing their environmental impacts. In this study, we investigated the solubility behaviour of various elements originating from natural and anthropogenic sources using a dataset of 106 samples describing the sequential collections of 8 rainfall events. Our results reveal distinct solubility patterns depending on the type of event, with mineral-dust events exhibiting lower solubility and anthropogenic events displaying higher solubility, in relation with dust content and pH. The study of intra-event solubility reveals variations over short periods during a rain event, which evolve differently according to the chemical elements and depend mainly on the origin of the aerosols scavenged by the rain. In the case where the aerosol origin is the same during a rain event, the precipitation characteristics and in-cloud scavenging mechanisms play a role on the elemental solubility as the rainfall progresses.

Keywords: In-cloud scavenging; Rain sequential sampling; Trace elements solubility; Wet deposition.