Anthropogenic and natural contributions to the rainfall chemistry of a mountainous area in the Cevennes National Park (Mont-Lozere, southern France)

Nine years of bulk precipitation chemistry data for a mountainous site in southern France are presented. The mean rainwater is of moderate acidity (pH 4.63, alkalinity ?4 μEql^?1) even though there is high, non-marine, deposition of sulphur (near 20 kg ha^?1 year^?1). Based on the statistical characteristics of the data set, three major sources of elements are identified: long range pollution, Mediterranean sea salt aerosols and aeolian erosion dust, mainly from the Sahara. Most of the sulphur in the rainfall is present as neutral sulphate salts, owing to the latter being rich in alkaline minerals; this counteracts the strong acid input.