High- and Middle-Latitude Neutral Mesospheric Density Response to Geomagnetic Storms

We report the first observations of a highand middle-latitude neutral mesospheric density response to geomagnetic storms. Interhemisphere mesospheric densities are estimated using data from meteor radars at Davis Station (68.6 degrees S, 77.9 degrees E), Svalbard (78.3 degrees N, 16 degrees E) and Tromso (69.6 degrees N, 19.2 degrees E), which are located under the auroral zone; the Mohe (53.5 degrees N, 122.3 degrees E), and Beijing (40.3 degrees N, 116.2 degrees E) meteor radars, located in northern midlatitudes, and the Microwave Limb Sounder (MLS) on the Aura satellite. Both case studies and a superposed epoch analysis indicate that geomagnetic storms can significantly influence mesospheric density, causing a greater than similar to 10% decrease in the auroral zones and a similar to 5% decrease at higher midlatitudes. With such large changes, it is reasonable to suspect that geomagnetic storms influence the dynamics of the high and middle latitudes mesosphere.