10.27.2003 12:00 AM
Solar Storm Threatens Communications
Solar activity was high over the weekend. Two large (Jupiter size) sunspots of sufficient size to be visible without a telescope (although with suitable eye protection!) are responsible for the increased activity. Two "X-class" solar flares erupted 12 hours apart from the sunspots Sunday. At least one of these eruptions has hurled a coronal mass ejection (CME) towards Earth. It is predicted to sweep past Earth Tuesday and trigger geomagnetic storms. The most visible effect will be auroras. An earlier flare created auroras visible as far south as Payson, Arizona.

Why am I reporting this? In addition to interesting lights in the sky, if the CME triggers geomagnetic storms, communications could be affected. Ham radio operators know how geomagnetic storms disrupt high frequency communications and provide an opportunity to bounce VHF and higher signals off the aurora. The main concern for broadcasters will be the effect it will have on satellites in space and power lines on the ground. I found two articles describing what could happen.

One from 1996 titled Solar Storms Linked to Magnetic Disturbances on Earth. The article focuses on new technology that allows predicting when the disturbances will hit, giving power and utility companies time to prepare. John Kappenman, an engineer at Minnesota Power, said North America is the most vulnerable to magnetic fluctuations due to the landmass being closest to the Earth's magnetic north pole and due to its complex power grid. He added, "rock geologies in North America are extremely vulnerable to these magnetic storms because they complicate or add coupling effects to power systems. The failures are occurring in fairly large numbers and we see patterns in failure rates in different parts of the country." He explained that the duration of an outage could be several hours and perhaps extend into days.

A more recent article released by NASA last week was titled, NASA Scientist Dives Into Perfect Space Storm and focuses on research by Dr. Bruce Tsurutani, a plasma physicist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. It describes a solar storm that took place Sept. 1-2, 1859. Dr Tsurutani described it: "With the flare came this explosive release of a massive cloud of magnetically charged plasma called a coronal mass ejection. These things actually fire out from the Sun radially, so not all of them head toward the Earth. But those that do usually take three to four days to reach Earth. This one took all of 17 hours and 40 minutes." This storm overwhelmed Earth's own magnetic field, allowing charged particles to penetrate into Earth's upper atmosphere. In 1859, communication was by telegraph and there wasn't much of an electrical grid. The article pointed out that a storm in 1994 caused major malfunctions to two satellites and a storm much less intense than the 1859 storm "caused the Hydro-Quebec (Canada) power grid to go down for over nine hours."

Dr. Tsurutani commented, "The question I get asked most often is, 'Could a perfect space storm happen again, and when?'" "I tell people it could, and it could very well be even more intense than what transpired in 1859. As for when, we simply do not know."

It may be a good time to make sure that your emergency generator is working properly and backup plans are in place in case the satellite delivering your programming is disrupted Tuesday. With these two sunspots still active, there is a threat of a "perfect space storm." I've found some links that will help you stay informed of what is happening in space:

- Space Weather Now - a NOAA Space Environment Center (SEC) site with real time information, including an aurora map showing where auroras may be visible.
- NOAA Space Weather Scales - This page shows the effects of different categories of geomagnetic storms, solar radiation storms and radio blackouts. This is perhaps the best site to visit to see what you should be prepared for.
- Today's Space Weather - Official Geophysical Forecasts, including the Satellite Environment Plot that focuses on conditions at the location of geosynchronous satellites.
- SEC's Radio User's Page - Another SEC site with links to reports of interest to radio operators.
- SpaceWeather.com - This unofficial site by Dr. Tony Phillip provides an excellent view of current conditions, including text, graphs and amazing telescope images. There are also many links to other sites for more information.


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