Tropical-extratropical interactions and arctic-extratropical interactions conducive to intraseasonal variability of the North Pacific jet stream

The autumnal spin up of the Northern Hemisphere (NH) general circulation is characterized by intraseasonal variability in the structure of the North Pacific jet stream (NPJ). The variability in the structure of the NPJ is often associated with large-scale flow reconfigurations over the North Pacific and North America and changes in the NH zonal available potential energy (AZ). This dissertation investigates variability in the structure of the NPJ and the NH AZ in conjunction with tropical-extratropical interactions (TEIs) and arctic-extratropical interactions (AEIs). The former are investigated in association with the El Niño-Southern Oscillation, the Madden-Julian Oscillation, and western North Pacific tropical cyclones (TCs), whereas the latter are investigated in association with upper-tropospheric potential vorticity (PV) disturbances (PVDs).