简介：Icenucleatingparticle（INP）measurementsweremadeattwohigh-altitudestationsinIndia.AerosolscollectedonfilterpaperatGirawaliObservatory,InterUniversityCenterforAstronomy&Astrophysics（IGO）,andattheRadioAstronomyCenter,Ooty（RAC）,wereactivatedindepositionmodeusingathermalgradientdiffusionchambertodeterminetheINPconcentrations.ThemeasurementcampaignsatIGOwereconductedduring2011,2013and2014,andatRACduring2013and2014.Whentheaerosolsampleswereexposedtoanicesupersaturationofbetween5%and23%inthetemperaturerange-17.6?Cto-22?C,themaximumINPnumberconcentrationatIGOandRACwas1.0L-1and1.6L-1,respectively.Amaximumcorrelationcoefficientof0.76wasobservedbetweentheINPnumberconcentrationandicesupersaturation.TheairmasstrajectoriesanalyzedforthemeasurementcampaignsshowedthattheArabianDesertandaridregionswerethemainINPcontributors.ElementalanalysisofparticlesshowedthepresenceofNa,Cl,Si,Al,Fe,Cu,Co,Cd,S,MnandK,aswellassomerare-EarthelementslikeMo,Ru,La,Ce,VandZr.Whenaerosolsinthesizerange0.5–20μmwereconsidered,thefractionthatactedasINPswas1:104to1:106atIGO,and1:103to1:104atRAC.ThehigherratioofINPstoaerosolsatRACthanIGOmaybeattributabletothepresenceofrare-EarthelementsobservedintheaerosolsamplesatRAC,whichwereabsentatIGO.