Sources of PM 10 ionic species in the South-West Mediterranean (Algeria)

The contents of water-soluble major's ions (MSA, Cl , NO , SO , Na , NH , K , Mg , and Ca ) in the PM particle fraction were investigated thanks to detailed measurements of the main chemical constituents of PM in remote coastal areas in Bou-Ismail; in the South-West of the Mediterranean Sea (Algeria), during a 2-year period; from July 2011 to August 2013, under the framework of the ChArMEx project (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr ). The total water-soluble ion concentrations in PM at the Bou-Ismail measurement station varied from 3.3 µg/m (July 2011) to 49.6 µg/m (March 2012). The annual mean mass concentrations of ions in the PM particulate fraction were Cl > Na > SO > Mg > NO > Ca > K > NH > Oxalate. The change in potassium nss-K + concentrations in PM over the course of a year reveals that biomass burning (BB) has an effect on three separate seasons: the beginning of winter (February and March), the end of summer (August), and the autumn (September and October). The origin periods of biomass burning BB identified employing the mapping of hotspots and fires during periods of August and September 2011, 2012, and 2013 underlined the important fires in the surrounding areas of the Mediterranean Sea (Sardinia Islands from Italy, Corsica from France).