The Relationship between Radiance of the Tiny Ionospheric Photometer and Geomagnetic Indices

The Tiny Ionospheric Photometer (TIP) on FORMOSAT-3/COSMIC measures the radiance due to the emission at 135.6 nm with high spatial resolution of the horizontal structure of the ionosphere. This radiance is closely related to the ionospheric electron density. In this research, we use both the nighttime data of TIP measurements and geomagnetic indices including AE, AU, AL and Dst indices to calculate their correlations at different magnetic latitudes and magnetic local time globally during 2006-2009. We also investigate such correlations by considering the factor of time lead/lag. The correlations are different at different magnetic latitudes and magnetic local time. The various reasons that affect the correlations at different locations, such as magnetic storms, substorms, and seasons, are discussed in this study.