Complex sentence: The latitude of this bifurcation is dependent on changes in the wind field, the primary forcing of circulation, from the large-scale atmospheric circulation which has seasonal (summer/winter), interannual (ENSO), and decadal (Pacific Decadal Oscillation) variability.
Split into simpler sentences: The latitude of bifurcation is dependent on changes in the large-scale atmospheric circulation. Changes in atmospheric circulation then changes the wind forcing which has seasonal (summer/winter), interannual (ENSO), and decadal (Pacific Decadal Oscillation) variability.