F-region electric field and electrojet observations during the november 3, 1994, total eclipse

Abstract

On November 3, 1994, a total solar eclipse occurred at about 7:10 a.m. local time, with a maximum occultation path tangent to the southern coast of Peru. Occultation was not total at Jicamarca; it was 95%. The maximum occultation path touched tangencially the magnetic equator 700 km west of Jicamarca. Multiple instrument observations were made including incoherent scatter of the F-region, coherent backscatter of the Electrojet, Digisonde observations and a longitudinal chain of magnetograms. During a previous total eclipse which occurred on November 12, 1966, an interesting enhancement of the electric field occurred. This motivated us to run the Jicamarca radar in a vertical drift (E-W E-field) mode. Total backscattered power was also recorded, which also allowed simultaneous measurements of the electron density profiles. In addition to the I.S. measurements, a coherent radar was used with an antenna beam pointing 60 degrees west, sampling electrojet echoes up to 500 km west of Jicamarca. Apart of the radar data, the Jicamarca Digisonde was run, and a chain of magnetometers including points right under the maximum occultation were deployed. Preliminary results of these observations will be presented. Electron depletions are observed as expected, but no obvious electric field effects were noticed. The latter, if present, were obscured by the slight magnetic disturbance effects of magnetospheric origin occurring during the eclipse.