A Statistical Study of Space Hurricanes in the Southern Hemisphere.

The space hurricane is a large‐scale three‐dimensional magnetic vortex structure that can cause massive local energy injections in the polar cap. By analyzing Defense Meteorological Satellite Program (DMSP) F16–F19 satellite observations from 2005 to 2016, we found that the Southern Hemisphere space hurricane mainly occurs in summer under negative By dominated northward interplanetary magnetic field (IMF) conditions. In particular, the space hurricanes are more likely to occur in the dayside polar cap at magnetic latitude greater than 80°. The characteristics for the Southern Hemisphere are basically consistent with the characteristics of space hurricanes in the Northern Hemisphere. The different dependences of By component in different hemispheres supports the high‐latitude lobe reconnection as the formation mechanism. Plasma data from DMSP satellites in both hemispheres show that the appearance of the space hurricane greatly enhances the convection in the polar cap and the electron density on its dawn side. Within the space hurricane, electron temperatures typically increase significantly, accompanied by strong upward field‐aligned currents and electron precipitation. These results give us a better understanding of the solar wind‐magnetosphere‐polar ionosphere coupling process under northward IMF conditions. Plain Language Summary: The space hurricane is defined as a large three‐dimensional magnetic vortex structure that spans the polar ionosphere and magnetosphere. Previous research has pointed out that it often appears as an aurora spot near the north magnetic pole, which can greatly enhance the convection patterns and current systems in the polar ionosphere. To clarify its occurrence rate and characteristics in the Southern Hemisphere, we identified the 259 space hurricane events from the long‐term DMSP satellite observations in the Southern Hemisphere. The statistical results indicated that the Southern Hemisphere space hurricanes mainly occur in summer and dayside polar cap under negative By dominated and northward IMF conditions. In addition, we found that the electron temperatures within the space hurricane increased significantly and accompanied by strong upward field‐aligned field currents and electron precipitation. The appearance of the space hurricane greatly enhances the plasma velocity and the electron density on its dawn side. The characteristics in the Southern Hemisphere are basically consistent with the characteristics of space hurricanes in the Northern Hemisphere, and support high‐latitude lobe reconnection as the formation mechanism. This work helps us understand the spatial and temporal characteristics of the space hurricane and their impact on plasma parameters. Key Points: Space hurricanes in the Southern Hemisphere mainly occur in summer and afternoon sector with negative By dominated northward IMFPlasma data from DMSP satellites indicate that the space hurricane has enhanced Te, horizontal convection and Ne on its dawn sideStatistical properties of space hurricanes in the Southern Hemisphere are consistent with high‐latitude lobe reconnection [ABSTRACT FROM AUTHOR]