Impact of the Galápagos Islands on the equatorial Pacific

The existence of the Galápagos Archipelago directly on the Equator presents the opportunity for physical interaction with the equatorial current system and other processes related to the cold tongue. Using an ocean general circulation model of the tropical Pacific Ocean, it has been found that inclusion of the Galálagos leads to improvements in the sea surface temperature (SST) field. Obstruction of the equatorial undercurrent (EUC) by the Galápagos is critical to the improved SST, ultimately leading to a more diffuse thermocline, reduced entrainment mixing and reduced transport in the meridional-vertical cells. The pattern of SST warming due to the inclusion of the Galápagos is similar to that of the known cold bias in current ocean models and the NOAAA CFS. Such an improvement in SST would have a positive impact on the ability of coupled models to produce realistic clouds, precipitation, biological activity and carbon cycling.