Equatorial zonal electric fields inferred from a 3-Delectrostatic potential model and ground-basedmagnetic field measurements

摘要

We present a new technique to infer quiet time zonal electric fields in thedaytime equatorial ionosphere. The electric field inference technique utilizes a three-dimensional (3-D) electrostatic potential model of the low-latitude ionosphere constrainedby ground-based magnetic field measurements. To test this technique, inferred zonalelectric fields for the Peruvian sector in Jicamarca (11.95°S, 283.13°E, 0.6°N dip latitude)were compared with zonal electric field (vertical drift) measurements made by theJicamarca Incoherent Scatter Radar. The comparison shows a good agreement between theinferred and measured electric fields. An example of electric field estimation for Davao(7.4°N, 125.4°E, 0.58°S dip latitude) in the Philippines sector is also presented in thisreport. Inferred electric fields for Davao are in good agreement with F region verticalplasma drifts measured by drift sensors onboard the AE-E and ROCSAT-1 satellites onthat longitude sector. Our results suggest that realistic estimates of quiet time zonal electricfields for the equatorial ionosphere can be obtained from the 3-D potential modelwhenever observatory magnetic field measurements are available.