Polarization electric fields in the nighttime F layer at Arecibo

Abstract

Incoherent scatter radar measure-neutral velocity vectors have equal components in ,, ments made in 1981 and 1982 are used to determine both directions perpendicular to B. the polarization field is fully developed with a well-developed polarization field so long as Ep ---uxB and j--0. At this stage the ion and electrostatic fields originating in the conjugate hemisphere are taken into account.

The summer evening anomaly and conjugate effects

“…They conjectured that, "a southern hemisphere ' battery' had lower internal resistance than the local F layer dynamo and hence controlled the electric field." Other investigators have also discussed this effect including Burnside et al [1983], Buonsanto et al [1993], and Takami et al [1996]. Fejer [1991Fejer [ , 1993 also included discussion of it in two summary papers.…”

“…If it assumed that the E region dynamo electric field is a polarization one in this situation, then there should be a strong upward and poleward drift in the evening when the polarization electric field is eastward and a downward and equatorward one in the hours near dawn when the polarization electric field is westward. Both theory and observations [Behnke and Hagfors, 1974;Behnke et al, 1985;Burnside et al, 1983;Buonsanto et al, 1993;Takami et al, 1996;Fejer, 1991Fejer, , 1993 have indicated that downward drifts possessing these characteristics occur in the morning when one end of the flux tube is illuminated and the other is in darkness. The current NCAR-TIEGCM and CTIPe assume that the conductivity is halved in this situation, rather than imposing the full electrodynamic solution in which a polarization electric field is connected to a very weakly conducting F region in the other hemisphere.…”

“…Among other results, they found that when there is a polarization field in the westward direction on the dayside (as there is near dawn), there was a downward drift in both hemispheres, just as we infer from the observations presented here. Burnside et al [1983] expanded this work to investigate the case when the conjugate footprint of the flux tube occurred in the F region. This work is of less relevance to the results described here, but Burnside et al did also demonstrate that the F region neutral winds measured by a Fabry-Perot Interferometer moved separately from the ion drifts measured by the Arecibo Incoherent Scatter Radar, suggesting that the electric field was being driven by something other than the neutral wind dynamo.…”

C/NOFS observations of electromagnetic coupling between magnetically conjugate MSTID structures

“…Otsuka et al [] first used ASI data to confirm the conjugacy of MSTIDs. One‐to‐one correspondences between conjugate dark/bright bands [ Shiokawa et al , ] confirmed the need for interhemispheric coupling [ Burnside et al , ]. Soon thereafter combined airglow and radar experiments demonstrated that MSTID‐related bright and dark 630.0 nm bands are associated with downward and upward plasma drifts [ Ogawa et al , ], indicating the presence of polarization electric fields with westward and eastward components, respectively.…”

Effects of the midnight temperature maximum observed in the thermosphere–ionosphere over the northeast of Brazil

“…It is often observed at low latitudes, such as in Arecibo (Nelson and Cogger, 1971;Behnke and Harper, 1973;Burnside et al, 1981Burnside et al, , 1983) and the Indian sector . Similar characteristics were also observed in the present study.…”