Objective estimates of mantle 3He in the ocean and implications for constraining the deep ocean circulation

a Department of Applied Mathematics, School of Mathematics and Statistics, University of New South Wales, Sydney, NSW 2052, Australia b Department of Geography/Earth Research Institute, University of California, Santa Barbara, CA 93106-4060, USA c Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095-1565, USA d Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA