Mid-latitude E-region bulk motions inferred from digital ionosonde and HF radar measurements

G. C. Hussey (1) , Christos Haldoupis (2) , Alain Bourdillon (3) , J. Delloue (4) , J. T. Wiensz (1)

1 Department of Physics and Engineering Physics
2 Department of Physics [Heraklion]
3 IETR - Institut d'Électronique et des Technologies du numéRique
4 UPMC - Université Pierre et Marie Curie - Paris 6

In the mid-latitude E-region there is now evidence suggesting that neutral winds play a significant role in driving the local plasma instabilities and electrodynamics inside sporadicE layers. Neutral winds can be inferred from coherent radar backscatter measurements of the range-/azimuth-time-intensity (RTI/ATI) striations of quasi-periodic (QP) echoes, or from radar interferometer/imaging observations. In addition, neutral winds in the E-region can be estimated from angle-of-arrival ionosonde measurements of sporadic-E layers. In the present paper we analyse concurrent ionosonde and HF coherent backscatter observations obtained when a Canadian Advanced Digital Ionosonde (CADI) was operated under a portion of the field-of-view of the Valensole high frequency (HF) radar. The Valensole radar, a mid-latitude radar located in the south of France with a large azimuthal scanning capability of 82° (24° E to 58° W), was used to deduce zonal bulk motions of QP echoing regions using ATI analysis. The CADI was used to measure angle-of-arrival information in two orthogonal horizontal directions and thus derive the motion of sporadic-E patches drifting with the neutral wind. This paper compares the neutral wind drifts of the unstable sporadic-E patches as determined by the two instruments. The CADI measurements show a predominantly westward aligned motion, but the measured zonal drifts are underestimated relative to those observed with the Valensole radar.

Domaines: Océan, Atmosphère; Sciences de la Terre

G. C. Hussey, Christos Haldoupis, Alain Bourdillon, J. Delloue, J. T. Wiensz. Mid-latitude E-region bulk motions inferred from digital ionosonde and HF radar measurements. Annales Geophysicae, 2004, 22 (11), pp.3789-3798. ⟨hal-00329400⟩