text: Between 1998 and 2013, research conducted at BATS has generated over 450 peer-reviewed articles.  Among the findings are measurements showing the gradual acidification of the surface ocean, where surface water pH, carbonate ion concentration, and the saturation state for calcium carbonate minerals, such as aragonite, have all decreased since 1998.  Additionally, studies at BATS have shown changes in the Revelle factor, suggesting that the capacity of North Atlantic Ocean surface waters to absorb carbon dioxide has diminished, even as seawater pCO has kept pace with increasing atmospheric pCO.