Aluminum in the northwestern Indian-Ocean (Arabian Sea)

Abstract

The distribution of Al has been studied along two transects (approximately 15-degrees and 18-degrees-N) in the Arabian Sea. The waters of the Arabian Sea along the Indian coast are relatively enriched in Al (approximately 55-74 nM) over the offshore surface waters (approximately 37-52 nM). A pronounced maximum in the surface mixed layer suggests the dissolution of Al from atmospherically derived particles to be the source of excess Al in the offshore waters of the Arabian Sea, compared to other oceanic regions. The characteristic Al decrease in the deeper waters of the Arabian Sea indicates its intense scavenging in the water column. A residence time of approximately 8.4 yr for Al in the Arabian Sea, with respect to the combined input of Al from fluvial and atmospheric sources, corroborates the high reactivity of Al in the oceans.