|
|
 |
|
|
Ann. Geophys., 21, 2185-2191, 2003
www.ann-geophys.net/21/2185/2003/
© European Geosciences Union 2003
A new approach to the derivation of dynamic information from ionosonde measurements
L. Liu, X. Luan, W. Wan, B. Ning, and J. Lei
Wuhan Ionospheric Observatory, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences, Wuhan, 430071, P. R. China
Abstract. A new approach is
developed to derive dynamic information near the peak of the ionospheric
F-layer from ionosonde measurements. This approach avoids deducing equivalent
winds from the displacement of the observed peak height from a no-wind
equilibrium height, so it need not determine the no-wind equilibrium height
which may limit the accuracy of the deduced winds, as did the traditional servo
theory. This approach is preliminarily validated with comparisons of deduced
equivalent winds with the measurements from the Fabry-Perot interferometer, the
Millstone Hill incoherent scatter radar and with previous works. Examples of
vertical components of equivalent winds (VEWs), over Wuhan (114.4° E, 30.6°
N, 45.2° dip), China in December 2000 are derived from Wuhan DGS-256 Digisonde
data. The deduced VEWs show large day-to-day variations during the winter, even
in low magnetic activity conditions. The diurnal pattern of average VEWs is
more complicated than that predicted by the empirical Horizontal Wind Model (HWM).
Using an empirical electric field model based on the observations from
Jicamarca radar and satellites, we investigate the contributions to VEWs from
neutral winds and from electric fields at the F-layer peak. If the electric
field model is reasonable for Wuhan during this period, the neutral winds
contribute mostly to the VEWs, and the contribution from the E × B
drifts is insignificant.
Key words. Meteorology and
atmospheric dynamics (thermospheric dynamics) – Ionosphere
(ionosphere-atmosphere interaction; instrument and techniques)
Full Article in PDF (1160 KB) |
|
|
