NOAA / Space Weather Prediction Center

A Primer on Space Weather

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Electric Power

When magnetic fields move about in the vicinity of a conductor such as a wire, an electric current is induced into the conductor. This happens on a grand scale during geomagnetic storms. Power companies transmit alternating current to their customers via long transmission lines. The nearly direct currents induced in these lines from geomagnetic storms are harmful to electrical transmission equipment. On March 13, 1989, in Montreal, Quebec, 6 million people were without commercial electric power for 9 hours as a result of a huge geomagnetic storm. Some areas in the northeastern

U.S. and in Sweden also lost power. By receiving geomagnetic storm alerts and warnings, power companies can minimize damage and power outages.

Rapidly fluctuating geomagnetic fields can induce currents into pipelines. During these times, several problems can arise for pipeline engineers. Flow meters in the pipeline can transmit erroneous flow information, and the corrosion rate of the pipeline is dramatically increased. If engineers unwittingly attempt to balance the current during a geomagnetic storm, corrosion rates may increase even more. Pipeline managers routinely receive alerts and warnings to help them provide an efficient and long-lived system.



The Sun is the heat engine that drives the circulation of our atmosphere. Although it has long been assumed to be a constant source of energy, recent measurements of this solar constant have shown that the base output of the Sun can have temporary decreases of up to one-half percent. Atmospheric scientists say that this variation is significant and that it can modify climate over time. Plant growth has been shown to vary over the 11-year sunspot and 22-year magnetic cycles of the Sun, as evidenced in tree-ring records.

While the solar cycle has been nearly regular during the last 300 years, there was a period of 70

years during the 17th and 18th centuries when very few sunspots were seen. This drop in sunspot number coincided with the timing of the Little Ice Age in Europe, implying a Sun-climate connection. Recently, a more direct link between climate and solar variability has been speculated. Stratospheric winds near the equator blow in different directions, depending on the time in the solar cycle. Studies are under way to determine how this wind reversal affects global circulation patterns and weather. During proton events, many more energetic particles reach the Earth’s middle atmosphere. There they cause molecular ionization, creating chemicals that destroy atmospheric ozone and allow increased amounts of harmful solar ultraviolet radiation to reach the surface of the Earth. A solar proton event in 1982 resulted in a temporary 70% decrease in ozone densities.

Geomagnetic Influence on People and Animals
There is a growing body of evidence indicating that changes in the geomagnetic field affect biological systems. Studies indicate that physically stressed human biological systems may respond to fluctuations in the geomagnetic field. Interest and concern in this subject have led the Union of Radio Science International to create a new commission entitled Electromagnetics in Biology and Medicine.

Possibly the most closely studied of the variable biological effects of the Sun has been the

degradation of homing pigeons’ navigational abilities during geomagnetic storms. Pigeons and other migratory animals, such as dolphins and whales, have internal biological compasses composed of the mineral magnetite wrapped in bundles of nerve cells. While this probably is not their primarily method of navigation, there have been many pigeon race smashes during a geomagnetic storm. A smash is a term used when only a small percentage of birds return home from a release site. Because these losses have occurred during geomagnetic storms, pigeon handlers have learned to ask for geomagnetic alerts and warnings as an aid to scheduling races.

Our Future
The list of consequences grows in proportion to our dependence on burgeoning technological systems. The subtleties of the interactions between the Sun and the Earth, and between solar particles and delicate instruments, have become factors that affect our well being. Thus there will be continued and intensified need for space environment services to address health, safety, and commercial needs. The Space Weather Predictions Center (SWPC) Forecast Center is jointly operated by NOAA and the U.S. Air Force and is the national and world warning center for disturbances that can affect people and equipment working in the space environment. SWPC
works with many national and international partners who contribute data and observations; we also share our data and products with them. We are pleased to support efforts worldwide to inform users of space weather.
Better understanding and better forecasts are keys to providing better services. SWPC conducts research in solar-terrestrial physics, develops techniques for forecasting solar and geophysical disturbances, and provides real-time monitoring and forecasting of solar and geophysical events.

The SWPC is one of the nine National Centers for Environmental Prediction, part of the NOAA National Weather Service.

Main Primer | Versión en Español | Effects of Space Weather Storms: Page 1 | Page 2 | Back to Education | Home