Results from simulations with the coarse-resolution version of MPI-ESM performed by the RETRO team at DKRZ. The left side shows a normal (prograde) rotating earth. The right side shows a backwards (retrograde) rotating earth. The simulations are forced with pre-industrial boundary conditions. For the full description see the Earth System Dynamics manuscript "The climate of a retrograde rotating earth". In upwelling zones, nutrients are brought from the deep to the surface, leading to high biological activity, and the production of large amounts of organic matter. This organic matter is remineralized while sinking to greater water depths. Remineralization requires oxygen, so in regions with high organic matter fluxes oxygen minimum zones (OMZs) develop. In the retrograde experiment (right), a massive OMZ forms in the Indian ocean.