Investigation of the sensitivity of global oceans to continental runoff using the PCM parallel climate model

The location, magnitude, and timing of continental runoff have a significant impact on the spatial-temporal distribution of the global freshwater flux. A series of simulations was conducted using the high resolution parallel climate model PCM to determine the sensitivity of the global oceans to variations in the freshwater flux due to continental runoff. A half degree observed runoff data set was used to force the ocean component of the model in uncoupled mode. Three cases of the continental runoff flux were examined: annual average values at the continental margins, monthly average values and more realistic hydrographs output from a river routing model. The effects that changing the runoff regime had on sea surface temperature, sea surface salinity, mixed layer depth, ocean circulation, and meridional overturning were examined with implications for the role of river fluxes in the fully coupled land-ocean-atmosphere system.