The identifi ed 30–50-day variation in the subthermocline current east of Mindanao

摘要

Based on nearly 4 year-long moored velocity measurements at 8°N/127°E and a high-resolution ocean model output,a signifi cant 30–50-day variation in the subthermocline current east of Mindanao was identifi ed for the fi rst time in addition to the 60–80-day variation reported in previous studies.The 30–50-day variation is an important component and it explains considerable variance same as that of the 60–80-day variation.The 30–50-day variation is vertically coherent in the subthermocline current.The standard deviations of the 30–50-day variation in zonal and meridional directions are of comparable,and is about 4.5–5 cm/s.Eddy-tracking analysis indicated that ocean eddies originating from the North Equatorial Current(10°N–11°N)contribute to the 30–50-day and the 60–80-day variations.The 30–50-day eddies propagate faster than the 60–80-day eddies.