How Do Space Hurricanes Disturb the Polar Thermosphere: A Statistical Survey

The space hurricane is a polar cap auroral structure with strong flow shears and intense particle precipitation that can disturb the thermosphere under quiet geomagnetic conditions. Here the statistical characteristics of this interaction are surveyed using data from the Defense Meteorological Satellite Program and Gravity Field and Steady-State Ocean Circulation Explorer satellites. The results confirm that space hurricanes modify the ion and neutral circulation in the polar cap through enhanced electric fields. Local precipitation, particularly >500 eV electrons, which raises the Pedersen conductance, leads to enhanced Joule heating and the generation of gravity waves. Electric fields play a leading role on the dawn side of the space hurricane. Gravity waves are also mainly located on the dawnside of the space hurricane, with a maximum vertical wind of 37 m/s and a 17% neutral density disturbance. These findings augment our awareness of magnetosphere-polar ionosphere-thermosphere coupling under quiet northward IMF conditions.