The atmospheric bridge communicated the <i>δ</i><sup>13</sup>C decline during the last deglaciation to the global upper ocean

Abstract. During the early part of last glacial termination (17.2–15 ka) and coincident with a ∼35 ppm rise in atmospheric CO2, sharp 0.3‰–0.4‰ decline δ13CO2 occurred, potentially constraining key processes that account for deglacial CO2 rise. A comparable δ13C has also been documented numerous marine proxy records from surface thermocline-dwelling planktic foraminifera. The recorded foraminifera previously attributed to release respired carbon deep ocean was subsequently transported within upper sites where signal (and then ultimately transferred atmosphere). Benthic global ocean, including new record presented here tropical Pacific, document this distinct decline. Here we present modeling evidence show rather than propagating directly prior reaching atmosphere, would have first upwelled Southern Ocean it entered atmosphere. In way transmission isotopically light analogous ongoing invasion fossil fuel CO2. model results suggest thermocline waters throughout 500–2000 m water depths were affected by bridge during deglaciation.