What question did this study set out to answer?

To assess the impact of abrupt changes in Atlantic meridional overturning circulation on marine reservoir ages using various Earth system models.

January 20, 2026Open Access

A model intercomparison of radiocarbon-based marine reservoir ages during the last 55 kyr including abrupt changes in the Atlantic Meridional Overturning Circulation

Key Points

To assess the impact of abrupt changes in Atlantic meridional overturning circulation on marine reservoir ages using various Earth system models.
Conducted transient simulations for the last 55 kyr using two Earth System Models of Intermediate Complexity (EMICs): LOVECLIM and Bern3D.
Compared results to the BICYCLE-SE box model and previous LSG ocean general circulation model outputs.
Analyzed changes in marine reservoir ages during abrupt AMOC reductions across different stadials.
Abrupt AMOC reductions led to increases in marine reservoir age in the northern and deep Atlantic by 300–1300 14C years during some stadials.
The change in mean non-polar surface marine reservoir age during abrupt AMOC changes was around ±100 to ±200 14C years depending on the model used.
Spatial results showed a radiocarbon bipolar seesaw, indicating older surface water in the high northern latitudes and younger in the southern regions.

Abstract

Abstract. Changes in the marine reservoir age (MRA) of the surface ocean are important information used for radiocarbon dating of marine sediment cores or archaeological artifacts. MRA changes are expressed relative to the atmosphere, and as such are dependent on the prevailing atmospheric radiocarbon calibration curve. The most recent estimate for evolving global average MRA for latitudes approximately 50° N) and the deep Atlantic, for example during Heinrich stadial 1 of 300–1250 and 500–1300 14C yr, respectively, roughly in agreement with their reconstructed rises by about 1200–1300 14C yr. We find that the changes in the mean non-polar surface MRA ( 50° S) are extremely model-dependent and for most times between 18 and 43 kyr BP the changes in the multi-model mean MRA are larger than the 95 % confidence interval of the non-polar MRA depicted in Marine20, making the construction of a similarly numerical model-based calibration curve for this region a challenging task.

Read Full Paperexternally

Mark Helpful

Bookmark

Relay

View Full Paper