Differences between the North Pacific and ENSO modes

The low-frequency mid latitude atmospheric circulation divergence between North Pacific and El Nino-Southern oscillation were analyzed. The coherent patterns between the tropical and North Pacific SST and North Pacific 500-hPa geopotential height anomolies were idenetified as intrinsic midlatitude mode, the North Pacific mode and a tropical ocean-atmosphere coupled mode and the ENSO mode. The atmospheric variation leads changes in SST in NP mode, and opposite in SST mode. The results state that the intrinsic coupled mode in the midlatitude North Pacific might be distinguished from the forced mode by remote ENSO, on the interannual time scale.