Eos, Transactions American Geophysical Union

Alfvén waves and the aurora



Magnetic storms at Earth are associated with radio communication disturbances and brilliant auroral displays that are seen at unusually low latitudes, often as far south as southern California. Two researchers, Bruce T. Tsurutani (Jet Propulsion Laboratory, Pasadena, Calif.) and Walter D. Gonzalez (Brazilian Institute for Space Research (INPE), San Jose dos Campos), by using data from the joint National Aeronautics and Space Administration/European Space Agency International Sun-Earth Explorer 3 interplanetary satellite (ISEE 3) have recently been studying the causes of magnetic storms. In a recent presentation at the 1987 AGU Spring Meeting at Baltimore, Md., they demonstrated a quantitative requirement for the minimum intensity of the interplanetary electric field necessary to create large magnetic storms. Furthermore, their study shows that the long-held belief that the very intense aurora seen days to weeks after the s t o rm onset are part of the decay of the storm is incorrect.