High Frequency Radar Detection of Coronal Mass Ejections
Abstract
Coronal mass ejections are now recognized to be one of the main causes of disruptive geomagnetic storms at the Earth. The detection of coronal mass ejections that are directed at the Earth therefore would be a significant step in space weather forecasting ability. Currently, such ejections are detectable with coronagraph imaging primarily as solar limb events; thus the ejections are mostly directed away from the Earth. High frequency radars of sufficient effective radiated power are now becoming available that can directly detect Earthward-directed coronal mass ejections. Solar atmosphere sounding experiments in the early 1960s demonstrated this capability. It should be possible to reflect radar signals from the electron density enhancements in coronal mass ejections using high power radars in the 10 to 80 MHz range. The reflected signal will have a Doppler shift resulting from the Earthward-directed velocity of the coronal mass ejection. This measurement will provide an estimated travel time to the Earth of possible geomagnetic disturbances.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1996
- Accession Number
- ADA530618
Entities
People
- Paúl Rodríguez
Organizations
- United States Naval Research Laboratory