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The following Y2K material has been kept available by MITRE for historical purposes only and has not been updated unless noted.
| SOLAR STORMS COULD LOOK LIKE Y2K PROBLEMS |
As the final days and weeks of 1999 lead to the end of the century roll-over, Year 2000 Project leads have one more thing to keep in mind. When that critical communications link fails it may not be from Y2K. Space Weather could be the culprit. Space Weather refers to conditions on either the sun and its solar wind or the earth's magnetosphere, ionosphere, and thermosphere.
The reason Year 2000 focussed efforts should pay attention to Space Weather is that it could be the reason for failures that appear to be Y2K related and staff should be aware of that possibility when they go about figuring out what went wrong, why, and how to fix it.
Between November 1999 and April 2000 adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of problems on earth. Being aware of this other source of problem can help you manage your organizations response to problems that arise during the coming months.
The Sun is the ultimate driving force of the space environment. The Sun is also the reason the environment in space is not benign. The sun continuously emits electromagnetic energy and electrically charged particles (by-products of the nuclear fusion process in the Sun's core). Superimposed on these normal (or background) emissions are transitory increases in the electromagnetic radiation (particularly at X-ray, Extreme Ultra Violet (EUV), and Radio wavelengths) and in the energetic charged particle streams emitted by the sun. These increases will cause disturbances in the near-Earth environment.
The sun emits radiation over the entire electromagnetic spectrum. The distribution of solar energy is such that the most intense portion of it falls in the visible part of the energy spectrum. However, there are still substantial amounts of energy in the Near Ultraviolet and Infrared portions of the energy spectrum. While less than 1% of the sun's total emitted electromagnetic radiation lies in the EUV/X-ray and Radiowave bands, it is this type of energy that can vary widely and cause problems with radar, communications, and space systems. At different times in the solar weather seasons the emitted EUV & X-ray energy can increase by a factor of 100 over its normal level and radiowave energy can go up by a factor of tens of thousands.
Because the Sun is a large sphere of rotating gas with its equator rotating more rapidly than the poles there are constant changes and fluctuations as its gaseous contents mix and move. The rotation period is about 24 days at the equator and about 34 days at the poles. This differential rotation is frequently used to explain why the Sun displays changes in its solar activity.
One of the major visible features of the mixing action caused by the rotational differences is the sunspot. Sunspots are relatively cool regions within the visible surface of the sun. They appear dark against the hotter and brighter surrounding gas. The gas within a sunspot is relatively cool because it radiates more energy in the non-visible spectrum than it receives. The sunspot remains relatively cool because the strong magnetic field that accompanies it confines the gas within the sunspot so that it cannot mix with the hotter gases surrounding it. Solar flares usually occur in the vicinity of sunspots or sunspot pre-cursors, which are bright active regions called "Plage". The connection between solar flares and the sunspots/plage comes about because the energy released by a flare comes from the energy stored in the intense, complex magnetic fields which produce those plage and sunspots. Consequently, sunspots, their magnetic fields, flares, and solar activity in general are very closely related so to monitor and predict solar flares we should watch and study the activities of their companion phenomenon, sunspots. And, it turns out, sunspots are fairly easy to study and they are cyclic in nature. 
In addition to sunspots, flares, and phages, the Sun continuously emits a steady stream of charged particles in the form of the "solar wind". The solar wind is an extension of the corona, the outer atmosphere of the Sun. The solar wind consists of plasma, a roughly equal number of positively charged ions and negatively charged electrons. This plasma expands steadily to fill the solar system with protons and electrons.
At the Earth's surface, the atmosphere and the geomagnetic field provide ample protection from most of the solar electromagnetic radiation and charged particles. The protective boundary of the Earth's magnetic field is highly reactive to the onslaught of energy and pressure originating from the solar particles and fields. In a complex way, the Earth's magnetosphere redistributes its particle populations, often sending a rush of energetic particles along magnetic field lines into the atmosphere over the polar caps and creating the swirling red, green, and white auroras. Other particles pour into the Van Allen radiation belts and encircle the Earth in a ring of electric current. 
The Earth's magnetic field itself can distort to such an extent that compasses at the surface swing 10 degrees away from the magnetic pole. The ionosphere (80-1000 km above the Earth's surface) changes in ways that affect radio transmissions, absorbing some radio frequencies, distorting others, and creating electric currents on the ground that affect systems that can absorb the radiation, like power grids and pipeline systems.
Some of the charged particles that follow geomagnetic field lines into the atmosphere, reach the Earth at high northern and southern latitudes (i.e., in the auroral zones), but not right over the polar caps. As these particles penetrate into the Earth's upper atmosphere they collide with its atoms and molecules, causing them to become excited or ionized. When these atoms and molecules de-excite or recombine, they emit electromagnetic energy--from the Extreme Ultra Violet (EUV) to radiowaves.
During the enhanced particle bombardment associated with a Geomagnetic and Ionospheric Storm, the auroral zones intensify, broaden, and moves equatorward. The enhanced and very irregular degree of ionization caused by this variable particle bombardment will cause problems like: spacecraft charging, satellite drag, radar interference and clutter, and anomalous propagation of High Frequency (HF) and satellite communications radio signals.
There are three general types of space weather which occur at different times, or simultaneously, and cause different types of effects on communications, power, and navigation systems.
Examples of the Geomagnetic and Ionospheric Storm impacts include partial (or full) HF signals absorption for periods of minutes or hours. Another example is the random variations in signal amplitude, phase, and/or polarization of radiowave signals that can be caused by the storms which produce signal fading and data drop-outs on satellite and communication signals. Likewise, the rapid changes in geomagnetic fields can induce currents in electrically conductive items like power lines and pipelines. These induced currents can overload power transmission equipment and cause pipeline monitoring systems to incorrectly measure corrosion rates. In the last solar maximum, Hydro-Quebec spent 12 hours and $10 million restoring power to 6 million of its customers when a solar storm caused a cascade of circuit failures. Finally, there could be signal strength enhancements, fades, and phase changes induced by the storms that could cause a GPS receiver to lose signal lock with a particular satellite. Position calculation errors could be created by solar activity induced signal bending (which increases the signal path length) and the GPS radiowave's signal propagation speed could be retarded by changes in the ionosphere.
Since the use of the GPS constellation has only recently received wide-spread use, which has been during a quiet portion of the 11-year solar cycle, this will be the first Solar Maximum where the true environmental vulnerability of GPS is seen.
The near-Earth space environment is neither empty nor benign. Solar and geophysical activity can produce some quite significant and unpleasant impacts on earth-based systems and those which operate in the near-Earth environment. However, careful planning, accurate forecasts, and rapid notification of actual events, can allow you to work around unfavorable environmental conditions. They also allow one to avoid potentially harmful or ineffective actions, or to recover more quickly when adverse events occur.
Details on the current Space Weather are available from the Space Environment Center site including: Today's Space Weather, with the latest solar images, solar-geophysical data, and alerts & warnings. This site also has the current Solar X-Ray Flux as measured by the GOES satellite, a Satellite Environment Plot, and Solar Wind measurements.
Also see the Solar Terrestrial Activity Report by Jan Alvestad for ongoing reports on solar activity and comparisons of the current cycle with previous cycles.
Predictions about the current cycle (#23) are also available at the SEC site.