Space Weather - The Practice of Space Physics

Abstract

Public awareness of space weather effects on space and terrestrial systems will grow rapidly in the coming years. Evidence of this can be seen in the media response to the two magnetic cloud driven storms in January and April of 1997. On January 11, in the latter stages of the magnetic storm associated with the magnetic cloud event, an AT&T Telstar geosynchronous communication satellite failed, the exact cause of which is still under investigation and may never be known. The casual association of the failure with enhancements in the energetic particle fluxes at geosynchronous orbit during the storm is easy and attracts attention. As a result articles appeared 12 days later in at least eight countries all over the world in newspapers, on radio and on television. The uniqueness of this event was that the SOHO spacecraft of the International Solar Terrestrial Physics (ISTP) Program, located in orbit about the libration point approximately 240 Earth radii in front of the Earth, was able to track the progress from the sun of the coronal mass ejection (CME) and resulting magnetic cloud responsible for the storm. SOHO scientists privately predicted the magnetic activity a day ahead at an ISTP scientific meeting at NASA. When SOHO observed another magnetic cloud approaching Earth in April, a press conference was held by NASA predicting a storm. Because the January event and the satellite failure was fresh in peoples minds, page 1 media articles were written, not about what was likely to happen, but emphasizing worst case effects. A significant storm happened as predicted on April 10, but the results of course did not match the worst case scenario. A subsequent article in a Boston Globe article on April 10, 1997, with the headline “Not much flare to this solar event experts say” presented a more realistic report. Most events will not be ‘killer’ events, but all will produce space weather. The frequency of major events will increase as we approach the next solar cycle maximum.