Types of Storms or Events

Space weather drivers may cause one or more of the following space weather storms or events:

• geomagnetic storms,
• solar radiation storms,
• radio blackouts,
• and ionospheric disturbances.

Instructions: Click the the tabs above to learn more about each category.

Geomagnetic storms occur when CMEs or fast solar wind streams cause strong disturbances to Earth’s magnetic field. The Earth’s magnetic field changes in the course of a storm as the near-Earth system attempts to adjust to the jolt of energy from the Sun carried in the solar wind.

Frequency: Geomagnetic storms can occur at any time in the solar cycle, but are most common near solar maximum. These storms are also common in the declining phase of the solar cycle due to high-speed solar wind streams.

Duration: Geomagnetic storms usually last a few hours to days - The strongest storms may persist for up to a week. A string of CMEs may cause prolonged disturbed periods related to the additional energy being pumped into the system.

Special: Geomagnetic storms pose problems for many activities, technological systems, and critical infrastructure; however one positive attribute of a geomagnetic storm is the aurora, which becomes brighter and moves closer to the equator. This heightened aurora signals the vigorous electrodynamic processes at play to accommodate the burst of energy.

Industries Impacted: Geomagnetic storms induce currents that can have significant impact on electrical transmission equipment. Electric power companies have procedures in place to mitigate the impact of geomagnetic storms.

Solar radiation storms occur when large quantities of charged particles, protons, electrons, and heavy ions, are accelerated by processes at or near the Sun and by shock waves in the solar wind driven by CMEs. When these processes occur, the near-Earth environment is bathed with high energy particles.

Solar radiation storms can occur at any time during the solar cycle but tend to be most common around solar maximum.

Speed: Energetic protons reach Earth a half hour to several hours after a solar eruption.

Duration: Solar radiation storms can last from a few hours to days, depending on the magnitude of the eruption.

Earth’s magnetic field and atmosphere offer some protection from this radiation, but the amount of protection is a function of altitude, latitude, and magnetic field strength. The polar regions are most affected by energetic particles because the magnetic field lines at the poles are connected to interplanetary space where the particles originate.

Industries Impacted: Solar radiation storm impacts include loss of HF radio communications throughout the polar regions, elevated radiation exposure to astronauts and to passengers and crew in aircraft at high altitudes and latitudes, and damage to satellite systems.

Radio blackouts occur when bursts of X-ray and Extreme Ultra Violet radiation emitted from solar flares increase the ionization of the upper atmosphere on the sunlit side of Earth. The additional ionization causes radio waves to be absorbed when they pass through this region.

Frequency: Solar flares resulting in radio blackouts are among the most common space weather events to affect Earth - Minor events occur, on average, 2000 times each solar cycle.

General Impact: Radio blackouts primarily affect High Frequency (HF) (3-30 MHz) communication, although fading and diminished reception may spill over to Very High Frequency (VHF) (30-300 MHz) and higher frequencies.

Speed: Radio blackouts are by far the fastest to impact our planet. The X-rays creating radio blackouts arrive at the speed of light - 8 minutes from Sun to Earth, making advance warnings difficult. Forecasts on durations, however, are possible.

Duration: Radio blackouts can last from minutes to hours.

Industries Impacted: The impacts of radio blackouts are felt by industries relying on HF radio communication and low frequency signals, primarily the aviation and marine industries.

Disturbances in the ionosphere and upper atmosphere have important impacts on radio communication, satellite navigation systems and atmospheric drag experienced by Low Earth Orbit (LEO) satellites, including the International Space Station. The conditions in the ionosphere are controlled by the solar and magnetospheric energy inputs coming from above, as well as by atmospheric energy coming from below, including tidal and gravity waves.

Frequency: Ionospheric disturbances can occur at any time during the solar cycle. Some disturbances are caused by large geomagnetic storms, whereas others result from a combination of solar and atmospheric conditions.

General Impact: Global Navigation Satellite Systems (GNSS) signals, which are used for a growing number of precision positioning, navigation, and timing applications, as well as for atmospheric radio-occultation, are affected by the ionosphere. Strong spatial irregularities in the ionosphere (ionospheric scintillations) can cause loss of lock between a receiver and the satellites and result in a total disruption of service. Variability in the total electron content (TEC) between the receiver and the satellite degrades the positioning accuracy.

Duration: Ionospheric disturbances can last from minutes to days.

Industries Impacted: Ionospheric disturbances impact industries that rely on precision navigation, such as surveying, mining, agriculture, construction, and aviation.