Seek S310‐25: Quasi‐periodic echoes and polarization electric fields

Abstract

We have reexamined data collected during the flight of the SEEK S310‐25 sounding rocket, together with a second set of radar measurements, to determine whether a more consistent interpretation could be derived, if we allowed for the possibility that sporadic E (Es) was configured as a sequence of elongated strips in the form of a frontal structure. We show that the features found in the plasma density, electric field ( ) and the so‐called quasi‐periodic (QP) echoes are consistent with a polarization process acting on the Es strips that is driven by a Hall and not a Pedersen current. Specifically, we show that three large spikes, measured in situ, appeared at intervals of ground distance that were nearly identical to those of the QP echoes. The vector relationship between the spikes and the background was also consistent with this type of polarization process. We also briefly discuss a counterclockwise rotation of , which could be related with a process responsible for the existence of frontal structures.