Determining the Longitude Dependence of Vertical E× B Drift Velocities Associated with the Four‐Cell, Nonmigrating Tidal Structure

摘要: Previous studies have established the existence of a four‐cell, longitude pattern in equatorial F‐region ionospheric parameters, such as TEC and electron densities and in daytime, equatorial E × B drift velocities. A recent paper, for the first time, quantified the longitude gradients in E × B drift velocities at the boundaries of four‐cell tidal structures and confirmed that these gradients exist on a day‐to‐day basis. Using the Ion Velocity Meter (IVM) on the Communication/Navigation Outage Forecast System (C/NOFS) satellite to obtain daytime, vertical E × B drift velocities, it was found, for example, that for 5, 6, and 7 October 2009 in the Atlantic sector, the E × B drift velocity gradient was about 1 m/sec/degree. For 23, 24, and 25 March 2009 in the Peruvian sector, it was about −4 m/sec/degree. In this chapter, we briefly review (1) observations and modeling studies of E × B drift velocities associated …