Results of coordinated measurements of thermosphere and F region parameters with an aim to study the extent of the prevailing coupling between these two regions at low latitudes (Mount Abu/Ahmedabad, India) are presented through individual case studies. Spectroscopically measured neutral temperature and meridional winds are used in the servo equations to estimate the balance height of the F region ionization maximum and compared with independently measured Hmax by means of ground-based ionosonde. The comparison reveals fairly good agreement, reproducing most of the observed features and providing direct experimental evidence for these two regions to behave as a closely coupled system. The electric fields, though they appear to be less significant at these latitudes, could still be inferred once the thermospheric data become available. The important conclusion is that the effect of the neutral temperature and its variabilities should be properly accounted for in the determination of meridional winds from the existing ground-based ionosonde data. ¿ American Geophysical Union 1993