Splines of reconstructed deep ocean 14C ages over that last 25 kyr and simulation results of the carbon and radiocarbon cycle across the last 55 kyr

Carbon cycle models used to interpret the IntCal20 compilation of atmospheric ∆14C have so far neglected a key aspect of the millennial-scale variability connected with the thermal bipolar seesaw: changes in the strength of the Atlantic meridional overturning circulation (AMOC) related to Dansgaard/Oeschger and Heinrich events. Here we implement such AMOC changes in the carbon cycle box model BICYCLE-SE to investigate how model performance over the last 55,000 years is affected, in particular with respect to available 14C and CO2 data. Thus, this data set contains: (a) Carbon cycle simulation output of the BICYCLE-SE model covering the last 55,000 years consisting of changes in marine reservoir age (MRA) of the whole ocean, or of the deep ocean in different basins (Atlantic, Southern Ocean, Indo-Pacific), non-polar surface ocean MRA, atmospheric CO2, atmospheric D14C, 14C production rates in 18 scenarios, which differ in boundary conditions (prescription of atmospheric carbon inventories) and changes in the strength of the AMOC in order to meet changes in marine 14C age as provided by data. (b) Six splines of intermediate (0.2-2.0 km) and deep (>2km) ocean marine reservoir age in Atlantic, Southern Ocean, Indo-Pacificof the past 25,000 years based on benthic 14C data as compiled in Skinner et al., 2023 (doi: 10.5194/cp-19-2177-2023), related to data set doi:10.1594/PANGAEA.960693.