The Satellite-Observed Linkages Between Large-Scale Climate Fluctuations and Mesoscale Eddy Movements in the North Pacific

The North Pacific Gyre Oscillation (NPGO), Pacific Decadal Oscillation, and El Nino-Southern Oscillation are climate fluctuations in the Pacific. Mesoscale eddies dominate the ocean kinetic energy spectrum. By analyzing the altimetry data, a close linkage between these climate fluctuations and eddy propagation speed is found. Propagation speeds of both cyclonic and anticyclonic eddies in the regions of 10 & DEG; & SIM; 20 & DEG;N, 120 & DEG;-180 & DEG;E and 35 & DEG; & SIM; 45 & DEG;N, 160 & DEG;E-160 & DEG;W are faster in the NPGO negative phase than positive phase, while those in the area of 25 & DEG; & SIM; 35 & DEG;N, 150 & DEG;E-170 & DEG;W are opposite. These differences between positive and negative phases are the response of large-scale circulation modulated by NPGO. When these climate fluctuations support the same westward/eastward anomaly of circulation, the eddies can propagate much faster/slower than that only considering NPGO. Causality analysis verifies that climate fluctuations can have strong influences on eddy movement. These climate fluctuations can affect the water mass, heat and salt transport by eddy advection.