Sounding the Sun

摘要

The long term goal of this project is to help ensure the safe and continued operation of DoD communication systems, both earth-based and those involving satellite links, by providing early detection of solar events known as coronal mass ejections (CMEs) and enabling early warning to be given of CMEs that appear likely to impact the earth. It has already been demonstrated, in January of 1997, that communication satellites can be disabled as a result of these CMEs. More such events, and possibly many more such events, can be expected as we approach the solar maximum projected for the years 1999-2000 (see solar cycle figure below). In addition, there may be more extensive blackouts in the US, Canada, and other countries than have occurred during earlier solar maximums due to the recent trend of deregulation and consequent merger of many electric utilities into larger units. Note also that, while emphasis is given here to the impact of CMEs on communication systems, operation of the GPS navigation system has never been tested during a solar maximum period, and it is conceivable that the strong CMEs expected during the solar maximum of 1999-2000 will affect the GPS satellites and their communication links to the earth as well.