Dependence of the evening prereversal enhancement of the vertical plasma drift on geophysical parameters

作者：Kil Hyosub^*; Oh Seung Jun

来源：Journal of Geophysical Research, 2011, 116: A05311.

DOI：10.1029/2010JA016352

The variability of the evening prereversal enhancement (PRE) of the vertical plasma drift has been investigated by using the average velocity at a fixed local time range, but this method does not provide a clear distinction between the PRE occurrence frequency and magnitude. In this study, we examine the dependence of the occurrence frequency, occurrence local time, and magnitude of the PRE on geophysical parameters by using the retrievals of the individual PRE from the first Republic of China satellite data. Our result shows that the seasonal-longitudinal variation of the average vertical velocity in the evening that has been identified in previous studies is associated with both the PRE occurrence frequency and PRE magnitude. The magnitude of the PRE shows an increasing trend with an increase of the solar flux and with a decrease of the conjugate E region sunset time lag. The seasonal-longitudinal variation of the occurrence local time of the peak PRE shows a dependence on the E region sunset time at the magnetic equator rather than on the magnetic declination or the sunset time lag in the conjugate E regions. This observation indicates that the optimum time for the creation of the peak PRE is when the sunset terminator at the E region height and the magnetic meridian intersect near the magnetic equator.

• 出版日期2011-5-14