Pacific Winter Water (PWW) enters the western Arctic Ocean from the Chukchi Sea; however, the physical mechanisms that regulate its circulation are still not clear. Here, we investigate the interannual variability of PWW with a comprehensive dataset over a decade. We quantify the thickening and expansion of PWW during 2002-2016, as well as its changing pathway. The total volume of PWW in the Beaufort Gyre (BG) region is estimated to have increased from 3.48±0.04×1014m3 during 2002-2006 to 4.11±0.02×1014m3 during 2011-2016, an increase of 18%. We find a redistribution of PWW in recent years toward the Chukchi Borderland associated with the spin up of the BG. We also find that the deepening rate of the lower bound of PWW is almost double that of its upper bound in the northern Canada Basin, a result of lateral PWW intrusion in addition to the vertical Ekman pumping. Of the 70 m of deepening of the lower bound of PWW observed over 2003-2011 in the northwestern basin, 43% resulted from lateral PWW intrusion from the Chukchi Borderland. The different partition of freshwater budgets in the Ekman layer versus in the PWW layer also suggests that the redistribution of PWW is largely a result of the westward shift of the overlying wind-driven BG. We hypothesize that a recently observed increase of lower halocline eddies in the BG might be explained by this redistribution through a compression mechanism of PWW over the Chukchi Borderland.