The Effects of the Onwumechillian Equatorial Electrojet Model on MT Soundings

The equatorial electrojet practically does not effect MT soundings at frequency higher than 10-2 Hz. However, below 10-2 Hz its influence can be very intense, increasing as frequencies decrease. Such influence can be felt at hundred of kilometers from either sides of the magnetic equator. The erratic behavior of the equatorial electro jet currents in the ionosphere and not its intensity seems to be the principal cause of such big effects. Since the electrojet currents are changing constant and erratically, the effects 011 the soundings can be very large and unforeseeable. To reach these conclutions we used in our numerical simulation the Onwumechillian model which is the simplest realistic model available for equatorial electrojet.