Studies of equatorial spread-F using LISN VIPIR

Abstract

LISN, the Low Latitude Ionospheric Sensor Network, is a distributed observatory. LISN represents a closely coordinated geophysical instrument set, comprised of GPS receivers providing TEC values and scintillation measurements, magnetometers providing daytime ionospheric electric fields and Vertical Incidence Pulsed Ionospheric Radar (VIPIR) providing ionograms. The LISN Observatory was designed to do continuous measurements using GPS receivers, VIPIR ionosondes and flux gate magnetometers; provide a nowcast of TEC, S4 index, and other derived parameters of the low-latitude ionosphere. The LISN-GPS network of 70 GPS receivers (planned, about 45+ connected now) and 5 VIPIR ionosondes planned in the same field line, will make it possible to address science questions regarding: the effect of E and Es layers on inhibiting ESF, the role of Gravity Waves on seeding plasma bubbles. It will also provide clues to understand the causes of day-to-day variability of the low-latitude ionosphere. The first VIPIR ionosonde has been installed and working temporarily in Jicamarca since October 2008. The VIPIR is able to operate in different modes; we have used high temporal and spatial resolution modes to measure the E and F regions. We carried out a campaign during March 2009 that aimed to measure the effect of gravity waves on the ionospheric densities and to observe the means of gravity waves as a seeding mechanism for spread F. This poster describes the preliminary results on the characteristics of ionospheric density structures, velocities during spread-F conditions from the VIPIR data.