An analysis of the occurrence of equatorial plasma bubbles (EPBs) around the world during the 2015 St. Patrick's Day geomagnetic storm is presented. A network of 12 Global Positioning System receivers spanning from South America to Southeast Asia was used, in addition to colocated VHF receivers at three stations and four nearby ionosondes. The suppression of postsunset EPBs was observed across most longitudes over 2 days. The EPB observations were compared to calculations of the linear Rayleigh‐Taylor growth rate using coupled thermosphere‐ionosphere modeling, which successfully modeled the transition of favorable EPB growth from postsunset to postmidnight hours during the storm. The mechanisms behind the growth of postmidnight EPBs during this storm were investigated. While the latter stages of postmidnight EPB growth were found to be dominated by disturbance dynamo effects, the ini...

The response of equatorial ionosphere to the magnetospheric origin DP 2 current system fluctuations is examined using ground‐based multiinstrument observations. The interaction between the solar wind and magnetosphere generates a convection electric field that can penetrate to the ionosphere and cause the DP 2 current system. The quasiperiodic DP 2 current system, which fluctuates coherently with fluctuations of the interplanetary magnetic field (IMF) Bz, penetrates nearly instantaneously to the dayside equatorial region at all longitudes and modulates the electrodynamics that governs the equatorial density distributions. In this paper, using magnetometers at high and equatorial latitudes, we demonstrate that the quasiperiodic DP 2 current system penetrates to the equator and causes the dayside equatorial electrojet (EEJ) and the independently measured ionospheric drift velocity to flu...