Because oceans contain over 50 times as much CO2 as the atmosphere, surface pH is more sensitive to changes in the rates of upwelling of low - pH, carbon - rich deep waters. (landscapesandcycles.net)
The water here is fairly cold, due to a cold upwelling from a deep ocean through south of Bali. (aquamarinediving.com)
It is thought that the poor representation of ocean upwelling in current models has larger scale impacts reducing the accuracy of model projections on a global scale. (embrace-project.eu)