Injection of High Chlorophyll-a Waters by a Branch of Kuroshio Current into the Nutrient-Poor North Pacific Subtropical Gyre

An unusual eastward flow was observed branching out from the Kuroshio Current near island of Taiwan in western North Pacific during period June–July 2010. The branch meandered approximately 21°N, carrying high chlorophyll-a (Chla) waters for over 1000 km 125°E into nutrient-poor subtropical gyre (NPSG). warmer and fresher than surrounding waters, with temperature–salinity properties resembling those Current. Thus, we called it cross-shore (ECKB). Injecting far central NPSG, ECKB flowed at a mean surface speed 0.5 m per second, as shown satellite altimeters, Lagrangian drifter, Japan-Meteorological-Agency (JMA) 137°E-meridian cruise transect. mechanism linked to cyclonic wind anomaly north 22–24°N. cooled ocean beneath via Ekman suction then enhanced front its south 21°N strengthened subsequently induced an that bifurcated main stream northward-flowing