Impact assessment of continental and marine air-mass on size-resolved aerosol chemical composition over coastal atmosphere: Significant organic contribution in coarse mode fraction

Size-segregated aerosols (five stages from <1.1 to >7 μm in diameter) collected a coastal location south-west peninsular India were analysed for water-soluble ionic species, carbonaceous and metallic species on seasonal basis two years (2017–19). The annual mean concentration of the components Na+, Ca2+, Mg2+, Cl−, NO3−, Al, Fe exhibited coarse mode (> 2 μm) enhancement; while NH4+, K+, SO42−, MSA−, oxalate, Organic carbon (OC), Elemental (EC) peaked fine (< μm). contribution dominated under influence continental air-mass relative shift towards size regime with respect marine was observed. showed dominance sea-salt fraction during monsoon, anthropogenic ions post-monsoon, crustal pre-monsoon winter. While nss-SO42− found be major component aerosol fraction, OC contributed significantly both mode. Distinct variation size-distribution Fine post-monsoon winter indicating its multiple sources formation pathways. predominantly existed modulated by changing synoptic air-masses. water insoluble modified sea-land breeze activities nature. significant over this atmosphere has been attributed to; condensation gaseous precursors pre-existing particles leading WSOC primary emission natural terrestrial organic matter resulting WIOC.