Intensity Change and Zonal and Meridional Movements of the Aleutian Low and Their Associated Broad-Scale Atmospheric-Oceanic Characteristics

The changes in the intensity and position of the Aleutian Low (AL) exert significant effects on the ocean-land-atmosphere interactive processes and climate over East Asia, the North Pacific, and North America. In this study, the interannual variations of the AL intensity, meridional shift, and zonal shift, as well as their associated dynamical processes are investigated. The results show that the intensity, meridional shift, and zonal shift of the AL are well characterized by the three leading EOF modes of sea level pressure over the North Pacific, and are strongly correlated with the Pacific-North American pattern, the West Pacific pattern, and the Tropical/Northern Hemisphere pattern, respectively. The intensity variation of the winter AL seems to be closely associated with the ENSO-related atmosphere-ocean processes in the previous autumn, whereas the meridional shift is not associated any significant signal in the previous months, signifying a relatively higher predictability of the former. Besides, the eastward and westward movements of the AL show asymmetric features, attributed possibly to their asymmetric relationships with ENSO.