The Variation of Thermospheric Meridional Neutral Winds Deduced from F2 Layer Heights

Abstract:

Ionospheric layer heights (h_mF₂) are sensitive to the motion of neutral winds along magnetic field lines. Techniques have been developed to derive the magnetic meridional component of neutral winds in the thermosphere using values of h_mF₂ derived from ionosonde measurements. The winds obtained from h_mF₂ are termed ‘equivalent’ neutral winds because they comprise both neutral wind and electric field contributions to any changes in h_mF₂. The method has been shown to provide winds that agree well with winds from other techniques and it has the advantage of being able to provide diurnal winds at the large number of mid-latitude ionosonde sites. Equivalent neutral winds are currently being generated using a vast global ionosonde database of mid-latitude ionosonde measurements that spans the years 1961-1990 with the aim to develop a new empirical wind model. In the database, there are nearly 100 ionosonde sites in the mid-latitudes and the wind values being generated at each site have a one-hour time resolution. This paper presents comparisons of the derived equivalent neutral winds with other observations and wind models. The paper will also examine the wind behavior with solar activity at different locations.