 1. The study examines typical features of ionospheric plasma regularities at altitudes of CHAMP, 300 to 400 km, and GRACE, 500 km, focusing on equatorial plasma bubbles, EPBs. 2. Peak EPB occurrence rates decrease from high to low solar flux periods, with an average linear increase in occurrence rate at both altitudes for high flux levels. 3. Results show that EPBs form regions of depleted plasma along geomagnetic flux tubes and are associated with flux tubes reaching greater apex heights in regions of high occurrence rates. This article was authored by Xi Xiong, Xi Xiong, Jay Park, and others.