COSMIC-2, GOLD, and ICON Observations of Plasma Bubbles and Vertical Ion Drifts

Abstract:

COSMIC-2, GOLD, and ICON are now providing unprecedented coverage of the equatorial ionosphere. COSMIC-2 GNSS observations provide information on the vertical structure of the ionosphere electron density as well as scintillation. GOLD gives the morphology of the ionosphere and plasma bubbles in the American sector with continuous UV images from geostationary orbit. At the same time, COSMIC-2 and ICON IVM observations provide vertical ion drifts, which is a direct measure of the equatorial dynamo. In addition, ICON measures the thermospheric winds, which drive the dynamo. By combining all these observations, we can have a better understanding of the equatorial ionosphere and the ionospheric condition under which the plasma bubbles occur. The vertical ion drift during the pre-reversal enhancement is directly related to the growth rate of the Rayleigh Taylor instability (R-T), which is responsible in large part for the occurrence of plasma bubbles. GOLD observes plasma bubbles regularly and the vertical ion drifts from ICON and COSMIC-2 can shed more light on the occurrence of the plasma bubbles. The GOLD bubble observations are also useful for validation of the geolocation of irregularities from the COSMIC-2 GNSS signal scintillation observations. We will give an overview of recent progress on this equatorial ionosphere study using these three missions and, on the effort, to validate the localization of irregularities with GNSS using the GOLD data.