Rate of coastal temperature rise adjacent to a warming western boundary
current is non-uniform with latitude
Western boundary currents (WBCs) have intensified and become more
eddying in recent decades due to the spin-up of the ocean gyres,
resulting in warmer open ocean temperatures. However, relatively little
is known of how WBC intensification will affect temperatures in adjacent
continental shelf waters where societal impact is greatest. We use the
well-observed East Australian Current (EAC) to investigate WBC warming
impacts on shelf waters and show that temperature increases are
non-uniform in shelf waters along the latitudinal extent of the EAC.
Shelf waters poleward of 32S, are warming more than twice as fast as
those equatorward of 32S. We show that non-uniform shelf temperature
trends are driven by an increase in lateral heat advection poleward of
the WBC separation, along Australia’s most populous coastline. The large
scale nature of the process indicates that this is applicable to WBCs
broadly, with far-reaching biological implications.