9530285 DeMenocal Did tropical atmosphere-ocean circulation change near 2.8 Ma? African precipitation and Atlantic upwelling are linked at annual and orbital time scales through insolation forcing of West African monsoon. ODP site 662, off west Africa, will be studied for winter dust input within equatorial Atlantic upwelling system. Freshwater diatoms and nannofossils will be used to monitor variations in African precipitation and tropical upwelling. The study will help answer the question about circulation changes in the mild Pliocene.
