Impact of geothermal heating on the global ocean circulation

Abstract

The response of a global circulation model to a uniform geothermal heat flux of 50 mW m −2 through the sea floor is examined. If the geothermal heat input were transported upward purely by diffusion, the deep ocean would warm by 1.2°C. However, geothermal heating induces a substantial change in the deep circulation which is larger than previously assumed and subsequently the warming of the deep ocean is only a quarter of that suggested by the diffusive limit. The numerical ocean model responds most strongly in the Indo‐Pacific with an increase in meridional overturning of 1.8 Sv, enhancing the existing overturning by approximately 25%.