Summary
Vertical geoelectric eld measurements at Vostok,Antarctica (78:5ºS ;107ºE;corrected geomagnetic latitude,83:4ºS) made during 1998 are compared with both Weimer (1996)and IZMEM (1994)model calculations of the solar-wind-induced, polar-cap potential di erences with respect to the station.By investigating the correlations between these parameters for individual UT hours,we con rm and extend the diurnal range over which signi cant correlations have been obtained.Nineteen individual UT hours are signi cantly correlated with the Weimer model predictions and nine with the IZMEM model predictions.Diurnal variation in the slopes of the linear regressions allows us to comment on each model,demonstrating that Antarctic polar plateau geoelectric eld measurements can be used to investigate polar convection.Seasonal variations in the diurnal electric eld variations at Vostok are compared with the Carnegie global electric circuit diurnal curves,after allowance is made for the solar-wind-induced,polar-cap potential di erence patterns.