Observed Ocean Variability in the Mindanao Dome Region

• DOI: 10.1175/2010jpo4329.1
• Publication Date: 2010-10-22T21:57:37Z
• Authors: Yuji Kashino; Akio Ishida; Shigeki Hosoda
• Keywords: Downwelling; Buoy; Ekman transport

Abstract Ocean variations at semiannual, annual, and interannual time scales in the Mindanao Dome (MD) region of southern Philippine Sea were examined using data derived from underwater sensors on Triangle Trans-Ocean Buoy Network (TRITON) buoys 8°N, 137°E; 5°N, 130°E. Annual signal dominated above 300-m depth MD region. At 137°E, saline water exceeding 35 psu was observed 100–200-m boreal winter to spring, seemingly associated with meridional migration North Equatorial Countercurrent during these seasons. Thermocline ascent, probably related MD, also spring. An important mechanism annual variation 5°N seems be variability local wind, as mentioned past studies. However, 8°N due Rossby waves originating west 150°W rather than wind effects. Semiannual observed, its amplitude reaching 40%–70% signal. With regard variability, ocean scale El Niño–Southern Oscillation (ENSO) seen; upper heat content (above depth) decreased 2002–03 2006–07 Niño periods increased between those periods. Increasing this after 2005 large negative anomalies Ekman pumping (downwelling) that appeared 2006 east 150°E north 5°N.