Zdroj.pdf

Sea level rise in the tropical western Pacific Ocean from 1993-2009 was 3 times faster than the global average, at a rate of 10 mm yr^-1. This regional enhancement is thermosteric in nature and confined to the upper ocean above the 12°C isotherm. The North Equatorial Current (NEC) and North Equatorial Countercurrent (NECC) have migrated southward and strengthened over this period, with the NEC bifurcation latitude shifting southward by 2° latitude over 18 years. A 1½-layer reduced-gravity model forced by ECMWF reanalysis wind stress data suggests that these changes are largely attributable to upper-ocean water mass redistribution caused by strengthened atmospheric Walker circulation. The model simulation indicates that the NEC and NECC trends began in the early 1990s, following a period of weakening and northward migration in the two decades prior to 1993.