Award: OCE-1137812

The funding for the logistical support to participate in the replacement US GEOTRACES N Atlantic cruise in November, 2011, allowed us to mount our shipboard trace element program and fully participate in this cruise.  The results of this work are still in the process of being corrected by shore-based determinations of our co PI in Miami.  Initial results from the shipboard dissolved aluminium work that can be used to calculate mineral dust deposition to the ocean, show that there is greater amount of dust deposition in the western Atlantic compared to the eastern Atlantic.  This is somewhat surprising given that the major source of mineral dust to the Atlantic Ocean is the Saharan desert on the eastern border of the Atlantic Ocean.  It is believed that the cause of this apparent reversal in the expected gradient is because significant amounts of the dust that leave the African coast are carried across the Atlantic Ocean well above the marine boundary layer, and are thus not deposited in the ocean.  When this material reaches the western side of the Atlantic significant amounts of this dust descend into the marine boundary layer through atmospheric high pressure systems and are carried back across the Atlantic in the westerly winds.  During this reverse transect this dust, now in the marine boundary layer, is progressively deposited into the surface ocean resulting in a gradient of high deposition in the west, and lower deposition in the east.

Last Modified: 08/04/2012
Modified by: Christopher I Measures