REPLY TO THE "COMMENT BY DELMELLE ET AL. (2013)ON 'SCAVENGING OF SULFUR, HALOGENS AND TRACE METALS BY VOLCANIC ASH: THE 2010 EYJAFJALLAJOKULL ERUPTION' BY BAGNATO ET AL. (2013)"

Abstract

With this short communication we address the principal issues raised by Delmelle et al. (2014) in relation to the work of Bagnato et al. (2013) concerning the 2010 eruption of Eyjafjallajökull, Iceland. The principal conclusions of the work of Bagnato et al. (2013) include the observation that protracted gas-aerosol interaction in the plume promotes selective leaching of cation species from ash, with alkalis and Ca (and, among trace elements, Zn and Cu) being more rapidly re-mobilized (and transferred to soluble surface salts) relative to more inert elements (Mg, Ti). They also observed that adsorption onto ash surfaces is a major atmospheric sink of volcanic acidic gases, with 282tons of elemental sulfur and 605-691tons of halogens being daily ground deposited via ash over Iceland in early May 2010. Acidic gas adsorption onto ash increases almost linearly with plume aging (e.g., upon increasing in-plume residence times of ash and gases), and is seen to proceed at about 3 time faster r...