Aluminium in the northwestern Indian Ocean (Arabian Sea)

The distribution of Al has been studied along two transects ( 15° and 18°N) in the Arabian Sea. The waters of the Arabian Sea along the Indian coast are relatively enriched in Al ( 55–74 nM) over the offshore surface waters ( 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 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.