Seasonal variation of water-soluble inorganic components in aerosol size-segregated at the puy de Dôme station (1,465 m a.s.l.), France

The size-segregated chemical composition of aerosol particles was investigated during 1 year at the puy de Dôme (1,465 m a.s.l.), France. These measurements aimed to a better understanding of the influence of the air mass origin on the size-segregated chemical composition of the aerosol at an altitude site. Mountain site measurements are important because they are representative of long range transport and useful for model validation. PM 1 mass concentration exhibits a seasonal variability with a summer maximum. The composition of PM 1 did not change significantly in terms of relative contribution of water soluble inorganic ions but is rather variable in term of total mass concentrations. For the PM 10-1 , a different seasonal behaviour was found with maxima concentrations in autumn-winter. Aerosols were classified into four different categories according to their air mass origin: marine, marine modified, continental and Mediterranean. The PM 10 aerosol mass at 50 % relative humidity was close to 2.5 μg m −3 in the marine, 4.3 μg m −3 in the marine modified, 10.3 μg m −3 in the continental and 7.7 μg m −3 in the Mediterranean sectors. We noted that the influence of the air mass origin (on the chemical properties) could be seen especially on the PM 10-1 . A significant PM 10-1 mode was found in marine, modified marine, and Mediterranean air masses, and PM 1 dominated in the continental air masses samples. As a result, the aerosol chemical composition variability at the puy de Dôme is a function of both the season and air mass type and we provide a chemical composition of the aerosol as a function of each of these environmental factors.