Midlatitude total electron content and slab thickness: A summary of seasonal, solar cycle, and magnetically disturbed behavior

This paper is a summary of the results of nearly a full solar cycle of recordings of Total Electron Content, TEC, taken from Hamilton, Massachusetts, a northern midlatitude station. While many of the aspects of TEC behavior from this station have been published separately, the completion of a nearly full solar cycle of data recordings provides a convenient time to compile a summary of the conclusions drawn from this work. The major features of diurnal, seasonal, and solar-cycle dependence of TEC and equivalent slab thickness are described. The seasonal anomaly in daily maximum TEC has a pronounced peak during equinoxes, as does N(max) from a nearby ionosonde. Daytime equivalent slab thickness, however, has no seasonal anomaly and a negligible semiannual component. Slab thickness is also shown not to be a useful measure of daytime neutral temperature. Average changes in TEC, N(max) and slab thickness during magnetic storms are summarized as well.