D, E, and Sporadic E with Arecibo
A few weeks ago, we ran some experiments with the specific intention of getting a very good D- and E-region incoherent scatter radar measurement. We were specifically interested in the E-region autocorrelation function shape at the 100 km altitude, where different collisional models provide very different results. The idea was to compare the Bhatnagar–Gross–Krook, Brownian motion, and hard sphere collision models, and to see which one fits best.
As a by-product of this measurement, we have a relatively sensitive and high resolution mode for investigating the D- and E-region of the ionosphere. Here's what the electron density looks like with this mode:
|The D-region is approximately 70 km to 90 km. The E-region is 90 to 150 km.|
Sporadic E can reflect radio waves of a higher frequency than the normal background E-region. They are often used by radio amateurs and DXers to make serendipitous long distance radio links.