Why does the Indonesian throughflow appear to originate from the North Pacific?

Abstract

The outputs of two recent ocean general circulation models are examined; in both models, the Indonesian throughflow is supplied by Mindanao Current water because the South Equatorial Current (SEC) retroflects into the nearby North Equatorial Countercurrent-Equatorial Undercurrent system. It is shown that although the throughflow does originate in the South Equatorial Current, the high-salinity signal of the SEC is probably obliterated by rainfall along this long path so that the throughflow appears to originate from the North Pacific. These results suggest that retroflection processes may play an important role in controlling the supply of fresh water from the Pacific to the Indian Ocean. -Authors