The shelfbreak jet of the Beaufort Sea is the main conduit of Pacific water progressing eastward from the Chukchi shelf, delivering heat, freshwater, and nutrients that impact the hydrographic state and ecosystem of the western Arctic Ocean. A mooring has been maintained in the center of the jet since 2002 (with a few gaps). Here we use this unique timeseries to quantify the seasonal signal in water mass properties and transport of the jet and explore the interannual variability. Seasonally, the volume transport of the jet is greatest from July to October. Early in the record there is a single transport peak in July, but in recent years a second peak occurs in October. Warm water first appears at the mooring site in July and lasts until December, at which point winter water is the prevalent water mass advected by the jet. However, there are pronounced year-to-year variations in this timing. The strength of the shelfbreak jet displays striking interannual variability, with greater than five-fold changes in transport over the two-decade period. The driving factors behind these changes in hydrography and transport of the jet are investigated.
 

Arcitc,Beaufort Sea,shelfbreak jet,water mass