title: Larger CO₂ source at the equatorial Pacific during the last deglaciation.
abstract: While biogeochemical and physical processes in the Southern Ocean are thought to be central to atmospheric CO₂ rise during the last deglaciation, the role of the equatorial Pacific, where the largest CO₂ source exists at present, remains largely unconstrained. Here we present seawater pH and pCO₂ variations from fossil Porites corals in the mid equatorial Pacific offshore Tahiti based on a newly calibrated boron isotope paleo-pH proxy. Our new data, together with recalibrated existing data, indicate that a significant pCO₂ increase (pH decrease), accompanied by anomalously large marine (14)C reservoir ages, occurred following not only the Younger Dryas, but also Heinrich Stadial 1. These findings indicate an expanded zone of equatorial upwelling and resultant CO₂ emission, which may be derived from higher subsurface dissolved inorganic carbon concentration.
authors.affiliation: Atmosphere and Ocean Research Institute (AORI), the University of Tokyo, 5-1-5 Kashiwa, Chiba 277-8564, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Atmosphere and Ocean Research Institute (AORI), the University of Tokyo, 5-1-5 Kashiwa, Chiba 277-8564, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 200 Monobe-otsu, Nankoku, Kochi 783-8502, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Atmosphere and Ocean Research Institute (AORI), the University of Tokyo, 5-1-5 Kashiwa, Chiba 277-8564, Japan.
authors.forename: Stephen
authors.initials: S
authors.lastname: Obrochta
authors.affiliation: Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba 305-8567, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki