Global storm time plasma redistribution imaged from the ground and space

The bulk redistribution of plasma in the near‐Earth space environment during the onset and main phase of a magnetic storm has been observed on a global scale with 2‐minute resolution using Far‐Ultraviolet images from the NASA‐IMAGE satellite and ground‐based total electron content (TEC) maps using Global Positioning Satellite (GPS) receivers. The dynamic variations under the storm conditions show a redistribution of plasma away from the nominal low‐latitude location of the equatorial ionospheric anomalies, resulting in peak nightside ionospheric densities at middle latitudes. A zonal redistribution of plasma is also evident, as the plasma is depleted across the Atlantic sector, while TEC values grow in the Caribbean sector to the largest values on the nightside. The ground‐based GPS measurements provide 24‐hour observations of TEC, while the FUV measurements provide nightside observation with greater spatial resolution, continuous over land and sea. The complimentary observations are shown to have a very good correspondence, promising new analyses of storm time plasma redistribution with high temporal and spatial resolution and greatly improved global coverage.