A series of 12 daily aerosol samples was collected during March 1985 at Alert, Canada. Trace elemental composition and ion analysis was performed on the samples employing the techniques of instrumental neutron activation analysis and ion chromatography. Current knowledge, enrichment factor calculations, and regression analysis suggest four main constituent sources for the Arctic aerosol in this period: crustal, oceanic, anthropogenic, and photochemical reactions of marine Br compounds. Elements derived mainly from crustal sources are Al, Ca, Ce, Co, Fe, K, La, Mn, Sc, Sm, Th, and Ti. Oceanic-derived elements include Cl, I, and Na, while anthropogenic sources include As, In, NO-3, NH+4, Sb, Se, SO4=, and V. The source of zinc remains ambiguous. Elemental ratios give supporting evidence that anthropogenic sources have their origin in Eurasia. Calculations of excess bromine in the late winter confirm results of previous experiments done in the Arctic. ¿ American Geophysical Union 1990