Impact of ocean data assimilation on the sub-polar North Atlantic in MPI-ESM

15 January 2025

Photo: UHH/Sebastian Brune

What is the added value of doing ocean data assimilation with respect to the simulated dynamics of the North Atlantic ocean? Do we actually need ocean data assimilation at all? In their recently published study, Sebastian Brune and Vimal Koul show that ocean data assimilation improves the representation of the sub-polar gyre and in particular the ocean heat transport across 51°N. Ocean data assimilation leads to a more realistic position of the North Atlantic Current (including a Northwest corner) and a more realistic representation of cooling and warming phases within the multi-decadal variation of sub-polar North Atlantic upper-ocean heat content. Thus, sub-surface oceanic observations play an important role in initialising successful decadal prediction of surface temperatures in the sub-polar North Atlantic.

Brune, S. and V. Koul, “Impact of ocean data assimilation on the sub-polar North Atlantic in MPI-ESM,” Quart. J. Roy. Meteorol. Soc., published online, pp. 1–12, 2025, doi: https://doi.org/10.1002/qj.4922.