Fig. 8: Difference in energy conversion efficiency between coupled and uncoupled simulations.

KE and APE (a; J), and efficiency of energy conversion terms (b; day−1) associated with the PNA in the C-run (purple) and A-run (orange). All variables are integrated over the extratropical Northern Hemisphere (0°–360°E, 20°–90°N) and vertically from the surface to 200hPa. The vertical integrals from the surface to 500hPa are indicated with filled boxes and the remaining are shown in open boxes. CK and CP denote barotropic and baroclinic energy conversions from the climatological-mean fields, CKHF and CPHF barotropic and baroclinic feedbacks, respectively, from transient eddies, CQ diabatic APE generation, and CPK conversion from APE to KE. c, d, Same as (a, b), but for NAO.