Abstract :
Ten balloon flights were conducted from Hyderabad, India to measure polar conductivity. Measurements were carried out during balloon ascent as well as at float altitude. At float altitude, i.e. 32–36 km, the measurements were carried out for a period ranging from 5 hrs to 10 hrs. At sunrise the conductivity always decreases. At around 1000 hrs local time the conductivity is maximum and again decreases at around 1400 hrs. This variation shows that at float altitude, 32–36 km the conductivity shows semi-diurnal variations. We suggest that this is due to semidiurnal tide.
