Space-Based Ultraviolet Images of Low Latitude Ionospheric Structures: A Preliminary Model-Data Comparison

Satellite ultraviolet imaging has been shown to be a technique for producing global maps of ionospheric electron density and thermospheric neutral density. The ionosphere can be structured over a large range of scales from the global macroscale (hundreds to thousands of kilometers) to the mesoscale (tens to hundreds of kilometers) down to the microscale (centimeters to tens of kilometers). The characterization and description of ionospheric dynamics and structure are important issues in space weather research. Recently the Global Ultraviolet Imager (GUVI) on board the Thermospheric Ionospheric Mesospheric Energetics and Dynamics (TIMED) satellite has detected far ultraviolet (FUV) images of structures in the low latitude and equatorial ionosphere. In addition we have developed a nonlinear three-dimensional time-dependent dynamical-radiative numerical simulation model applicable to the low latitude and equatorial ionosphere. We have used this code to generate UV signatures of simulated Rayleigh-Taylor bubbles. Preliminary comparison of the simulation model with the TIMED data indicate that the FUV images are consistent with the nonlinear evolution of Rayleigh-Taylor bubbles. In this talk we will present further comparisons between TIMED observations and the nonlinear dynamical model. In addition we will attempt to relate characteristics of the UV images with ionospheric physical dynamical processes.