Abstract
A theoretical thermospheric circulation model is introduced in this paper. In the model, the Navier-Stokes equations have been solved to derive horizontal neutral winds based on the atmospheric temperature and densities of neutral species, which at present are taken from the latest atmospheric model (NRLMSISE-00). In this work, the zonal and meridional neutral winds are obtained from our model for seasons at moderate solar activity, mainly in East Asia. The zonal winds generally flow westward from around midnight to afternoon and reverse their direction for the rest of the day in equinox, while the phases have some differences in summer and winter. The main daily variation pattern of meridional winds is daytime poleward and nighttime equatorward in equinox. It is also found that the meridional winds blow almost southward in summer and northward in winter. In the meanwhile, comparisons of winds calculated from our model with those of the HWM93 model are carried out to see whether the models are consistent or not. For zonal winds, the results show good agreement in phases and some discrepancy in magnitudes. Our meridional winds present significant differences with the HWM93 model during solstices, while they remarkably agree in equinoxes. Finally, our model meridional winds are compared with the equivalent winds derived from the ionospheric data in Wuhan (30.6°N, 114.4°E). The results show much better agreement than with HWM93 model winds at the height of F2 peak.
Highlights
Considerable experimental and theoretical evidences show that the thermosphere and iono-TAO, Vol 14, No 1, March 2003 sphere are closely coupled
The neutral winds deduced from incoherent scatter and Fabry-Perot optical interferometers (FPI) measurements have been re ported by Roble et al (1974), Yagi and Dyson (1985), and so on
Based on the sim plified servo equations given by Rishbeth (1967) and Rishbeth et al (1978), two major ap proaches to deriving the neutral winds have been developed by Buonsanto (1986), Buonsanto et al (1989) and Miller et al (1986) respectively
Summary
Considerable experimental and theoretical evidences show that the thermosphere and iono-. Buonsanto et al (1989) applied the method suggested by Rishbeth et al (1978), and assumed the F2 peak appeared at a balance height in the absence of vertical drift and an applied drift consisting of diffusive drift and the neutral wind along magnetic field line carried the peak to a new level, where the production and loss processes determined the change rate of the electron density In this approach, besides the ionospheric parameters (hmF2 and foF2), the neutral density, temperature and o+-o colli sion frequency are required. Due to some particular features of the equatorial region, such as the equato rial anomaly and so on, we are aiming to develop a self-consistent thermosphere-circulation ionosphere model to study the close coupling between thermosphere and ionosphere at mid and low latitudes and the ionosphere model has been described recently by Liu et al (2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
