Abstract
The continental United States is well instrumented with facilities for
mid-latitude upper atmosphere research that operate on a continuous
basis. In addition, citizen scientists provide a wealth of information
when unusual events occur. We combine ionospheric total electron content
(TEC) data from distributed arrays of GNSS receivers, magnetometer
chains, and auroral observations obtained by citizen scientists, to
provide a detailed view of the intense auroral breakup and westward
surge occurring at the peak of the 10-11 May 2024 extreme geomagnetic
storm. Over a 20-min interval, vertical TEC (vTEC) increased at
unusually low latitude (~45°) and rapidly expanded
azimuthally across the continent. Individual receiver/satellite data
sets indicate sharp bursts of greatly elevated of vTEC
(~50 TECu). Intense red aurora was co-located with the
leading edge of the equatorward and westward TEC enhancements,
indicating that the large TEC enhancement was created by extremely
intense low-energy precipitation during the rapid substorm breakup.