Divergence-driven upscale energy transfer in the high-order surface geostrophic turbulence

A finite Rossby number induces cyclone--anticyclone asymmetry in surface quasi-geostrophic turbulence under thermal wind balance. Using freely decaying simulations, we demonstrate that this asymmetry systematically enhances large-scale frontolysis. By extending energy-transfer theory to incorporate horizontal divergence, we further reveal that divergence during frontolysis drives a dominant inverse energy cascade in the balanced submesoscale flows.