  The annular eclipse of Jan 15, 2010 over southern India was studied with a
network of multi-instrumental observations consisting magnetometer, ionosonde
and GPS receivers. By selecting the day before and the normal EEJ days as the
control days, it is intrinsically proved that the regular eastward electric
field for the whole day at the equator was not just weakened but actually was
flipped for several hours by the influence of tides related to the spectacular
Sun-Moon-Earth alignment near the middle of the day. The effect of flipping the
electric field was clearly seen in the equatorial ionosonde data and through
the large array of GPS receivers that accomplished the TEC data. The main
impact of the change in the electric field was the reduced EIA at all
latitudes, with the anomaly crest that shifted towards the equator. The
equatorial F-region density profile was also showing an enhanced F region peak
in spite of a reduced VTEC. By comparison to the plasma density depletion
associated with the temporary lack of photo-ionization during the episode of
eclipse, the electrodynamical consequences of the eclipse were far more
important and influenced the plasma density over a wide range of latitudes.
