What is Space Weather?
Space Weather is a term which has become accepted over the past few years to refer to a collection of physical processes, beginning at the Sun and ultimately affecting human activities on Earth and in space. The Sun emits energy, as flares of electromagnetic radiation (radio waves, infra-red, light, ultraviolet, X-rays), and as energetic electrically charged particles through coronal mass ejections (CME) and plasma streams. The particles travel outwards as the solar wind, carrying parts of the Sun's magnetic field with them. The electromagnetic radiation travels at the speed of light and takes about 8 minutes to move from Sun to Earth, whereas the charged particles travel more slowly, taking from a few hours to several days to move from Sun to Earth. The radiation and particles interact with the Earth's (geo)magnetic field and outer atmosphere in complex ways, causing concentrations of energetic particles to collect and electric currents to flow in regions of the outer atmosphere (magnetosphere and ionosphere). These can result in geomagnetic variations, aurora, and can affect a number of technologies. For more information, see below.
Table of Contents
- Solar storms and the Sun
- Geomagnetic storms
- Space weather effects
- What are the effects of space weather?
- How are power systems protected from space weather?
- How does space weather affects pipelines?
- How does space weather affect HF radio communications?
- How does space weather affect GPS?
- How does space weather affect satellites?
- How do we prepare for the affects of space weather?
- How can damage from space weather be prevented?
- What caused the March 1989 blackout?
- Space weather forecasting
What causes space weather?
The source of space weather is the Sun. The Sun is a million times larger than Earth and so distant that its light takes eight minutes to reach us. When violent solar phenomena occur, they create space weather effects on Earth, which can pose a hazard for human activities. The effects range from mild (aurora borealis - the northern lights often seen across Canada) to extreme (electric power grids may experience blackouts or collapse).
How does the sun influence the Earth?
The Sun releases a continuous stream of charged particles made up of energized electrons and protons. This is called the solar wind, and it travels at speeds of more than 1.5 million km/hour and carries parts of the Sun's magnetic field toward Earth. As the solar wind gets close to our planet, it is deflected by the Earth's magnetic field.
Three kinds of solar phenomena can have major impacts on Earth by disturbing our space environment. The first is a coronal mass ejection (CME), a large explosion that hurls superheated plasma (electrified gas) into interplanetary space. The second is coronal holes that release high-speed streams of plasma that boost the solar wind. The third is a solar flare, an intense burst of radiation coming from the release of magnetic energy. CMEs and coronal holes can trigger geomagnetic storms in our magnetosphere (the region surrounding a planet where its magnetic field dominates).
What is the aurora?
Aurora, often called northern lights, are coloured patterns of light seen dancing in the night sky. They are driven by the energy coming from the Sun. When the Sun is active, it often produces mass ejections of charged particles that get trapped by the Earth's magnetic field. Guided by the magnetic field, the particles flow toward the Earth's poles where they collide with nitrogen and oxygen in the upper atmosphere. As a result of this interaction, green, blue and red light is emitted, producing the aurora borealis (northern hemisphere) and aurora australis (southern hemisphere).
Will I see the aurora tonight?
Whether or not the aurora might be visible depends on the forecast of geomagnetic activity in your area. The 'Review and Forecast (observatories)' webpage provides forecasts of the geomagnetic activity expected at a number of different locations in Canada. If the station closest to your location has predicted conditions that are 'stormy' or higher around the time of local midnight, and the sky is clear and dark, there's a possibility of seeing the aurora tonight! To figure out how to convert your Local Time (LT) to the Universal Time (UT) shown in the plot, use this simple formula:
|Newfoundland Standard Time||LT = UT - 3:30|
|Atlantic Standard Time||LT = UT - 4:00|
|Eastern Standard Time||LT = UT - 5:00|
|Central Standard Time||LT = UT - 6:00|
|Mountain Standard Time||LT = UT - 7:00|
|Pacific Standard Time||LT = UT - 8:00|
|Newfoundland Daylight Time||LT = UT - 2:30|
|Atlantic Daylight Time||LT = UT - 3:00|
|Eastern Daylight Time||LT = UT - 4:00|
|Central Daylight Time||LT = UT - 5:00|
|Mountain Daylight Time||LT = UT - 6:00|
|Pacific Daylight Time||LT = UT - 7:00|
Is the north magnetic pole moving? Where is it now?
Earth's magnetic field is produced by electrical currents that originate in the hot, liquid, outer core of the Earth. The flow of electric currents in that core is slowly changing, so the magnetic field produced by those currents also changes. This means that at the surface of the Earth, both the strength and direction of the magnetic field will vary over the years.
The north magnetic pole is not located in the same place as the north geographic pole. In the past, the pole was located within Canadian territory. However, the most recent survey in 2007 places the pole north of Canada, about 1100 km from Resolute Bay.
Is the Earth's magnetic field going to flip?
The Earth's magnetic field regularly reverses with the north and south pole trading places. Such flips seem to come at regular intervals averaging about 300 000 years. However, the last one occurred about 780 000 years ago, and we don't know whether or not we're due for another one. We do know that such a reversal takes a few thousand years to complete. During that time the Earth's magnetic field doesn't vanish, it just gets more complicated; magnetic field lines become twisted and tangled but will still continue to protect us from solar radiation and space weather.
Why is space weather important to Canadians?
The Earth's northern magnetic pole is located in the Arctic Ocean near the Canadian Arctic Archipelago. Geomagnetic activity is especially strong in the surrounding auroral zones. Given its close proximity to the north magnetic pole and the auroral zone, Canada is among the countries most affected by space weather.
Solar storms and the Sun
How active is the Sun?
The Sun follows a regular cycle of activity. Over the last 300 years the Sun has consistently alternated through periods of maximum and minimum activity on a roughly 11-year cycle. During solar maximum (expected in 2013), geomagnetic storms are predicted to be more frequent.
What is a solar flare?
A solar flare is a release of electromagnetic energy from the sun in the form of light and X-rays. The X-rays and gamma rays reach the Earth in about 8-minutes and can cause disruptions to radio communications. These events are typically short-lived, lasting about 1/2 hour. Long duration flares can last for more than 3 hours.
There are different classes of solar flares:
- CMEs associated with class C flares are the smallest and have little effect on the Earth.
- CMEs associated with class M flares are of medium strength and can cause minor geomagnetic storms.
- CMEs associated with class X flares are the strongest and can lead to major geomagnetic storms.
What is a coronal hole?
Coronal holes are regions of open magnetic field lines where high-speed streams of plasma can flow out from the Sun. If conditions are right, when these particles reach the Earth, geomagnetic storms can occur. High speed streams interacting with the Earth are the cause of long lasting (3 or 4 days) periods of geomagnetic activity, particularly in the auroral zone.
What is a Coronal Mass Ejection (CME)?
Coronal Mass Ejections (CMEs) are gigantic amounts of electrified gas or plasma hurled into interplanetary space that can have a major influence if directed toward the Earth. CMEs can have a number of effects on the Earth.
The shock wave from the fast moving mass can accelerate protons so that they reach the Earth in about an hour causing problems with radio communications at high latitudes.
The CME reaches the Earth after 1-3 days. The impact can deform the Earth's geomagnetic field changing the direction of compass needles and causing currents to be induced in long conductors like pipelines and power lines. The massive influx of particles can also effect HF radio communication, and damage satellites. Not all effects are bad though, because a CME also effects where and how often the aurora can be seen.
What are geomagnetic storms?
A geomagnetic storm refers to disturbances of the Earth's magnetosphere, caused by sudden strong variations in the speed, density and magnetic properties of the solar wind. The resulting magnetic field variations generate electric currents in long conductors such as power lines and pipelines. The effects of geomagnetic storms range from mild (interference with aeromagnetic surveys) to extreme (electric power grids may experience blackouts or collapse).
Are there geomagnetic storms in Canada?
Yes. Canada has three zones of geomagnetic activity: the polar cap; the auroral zone; and the subauroral zone. The highest geomagnetic activity and greatest disturbances are observed in the auroral zone.
What causes a geomagnetic storm?
An explosion of activity on the Sun causes charged particles to be released, which can eventually result in disturbances in the magnitude and direction of the Earth's magnetic field. Geomagnetic storms can last hours or days, and they can directly affect operations that rely on the Earth's magnetic field, such as magnetic surveys done by mineral exploration companies, compass use for navigation and directional drilling.
Why are Geomagnetic storms a problem?
Geomagnetic storms can cause unexpected electric currents in long conductors like power lines. The effect of geomagnetic storms on power systems is illustrated by the Hydro-Quebec blackout in 1989. In 90 seconds the entire Hydro-Quebec power grid collapsed. The blackout left over six million people in Quebec and northeast United States without power for nine hours.
What happened? A geomagnetic storm generated electrical currents in the Hydro-Quebec power lines, causing protective devices to take sections of the grid off-line. This tripped other protective devices and, in a quick succession of events, the entire system went down.
How do you characterize the strength of geomagnetic storms?
The strength of the geomagnetic storm that can result from a solar storm depends on the size of the coronal mass ejection, and the magnetic field associated with it. When that field points southward, it's able to have a stronger interaction with the Earth's magnetic field, increasing the influence on the Earth. When that storm will impact the Earth depends on the speed of the CME. All of these parameters can be measured by satellite before the CME reaches the Earth.
At the Earth, magnetic storms are characterised by a K-level index that ranges from 0-9. Storms having little effect range from K=0-3, mid level effects would be K=4-7, and strong storms with lots of impact would occur for K > 7.
Space weather effects
What are the effects of space weather?
Effects from solar activity include (but are not limited to) geomagnetically induced currents in power systems and pipelines, azimuthal errors in directional drilling, disruptions to HF radio communication and GPS navigation, and failure or misoperation of satellites:
- Magnetic disturbances induce electric currents in long conductors such as power lines and pipelines causing power system outages or interfere with pipeline corrosion systems.
- Magnetic disturbances directly affect operations that use the magnetic field, such as magnetic surveys, directional drilling, or compass use.
- Radio waves used for satellite communications or GPS navigation are affected by the increased ionization with disruption of the communication or navigation systems.
- Effects on satellites including radiation damage, memory upsets, phantom commands, surface charging and internal charging.
How does space weather affect power systems?
Geomagnetic storms can cause unexpected electric currents in long conductors like power lines. Natural Resources Canada conducts specific research related to power systems. Power utility companies use this research to continually improve their operating procedures so the impact of geomagnetic disturbances on power grids is minimized. Power companies can also use space weather forecasts from Natural Resources Canada to closely monitor geomagnetic storms.
How does space weather affects pipelines?
Pipelines are another type of long conductor affected by electrical currents produced by geomagnetic storms. Pipelines are coated and fitted with corrosion protection devices that keep the pipeline in a safe voltage range, so that corrosion is prevented or at least minimized. A geomagnetic storm will boost voltages on the pipeline and compromise operation of corrosion protection devices. The effect on the pipeline is cumulative and can significantly shorten its lifespan. Monitoring of the pipeline and the performance of the protective devices helps to reduce the risk of corrosion leading to a leak and environmental damage.
How does space weather affect HF radio communication?
Streams of energetic particles produced during a geomagnetic storm enter the ionosphere (the upper part of the atmosphere made up of ions and electrons) around the magnetic poles and ionize molecules to form electrons and positive ions. The increased number of electrons at lower altitudes causes the ionosphere to absorb, instead of reflect, radio signals near the poles - so radio signals are weak. Radio communications in the Arctic can be disrupted from days to weeks at a time, causing aircraft flying over the North Pole to have limited radio contact. Airlines use forecasts and monitoring of geomagnetic storms to determine whether their pilots should take alternate routes during these events.
How does space weather affect GPS?
When charged particles ejected from the Sun arrive at the Earth, they can cause perturbations in the geomagnetic field. Another effect is that in the ionosphere the electron density (number of electrons in a given volume) can vary considerably, both in time and space. Disturbances in the ionosphere can decrease the precision of locations determined by Global Positioning Systems (GPS) used for navigation in ships, aircraft and vehicles.
How does space weather affect satellites?
Satellites are particularly sensitive to space weather effects and may experience radiation damage, memory upsets, phantom commands, surface charging and internal charging. One example is a space weather disturbance on January 20, 1994, that caused the failure of the Anik E1 and E2 satellites, Canada's main communications satellites. The failure caused loss of cable television service, failed transmission between media outlets and a loss of telephone service in northern Canada.
How do we prepare for the affects of space weather?
Space weather forecasts from Natural Resources Canada provide crucial information for anyone who might be impacted by geomagnetic storms. Pipeline, power and communication companies can prepare their systems to be more robust and resilient to the effects of space weather. Individuals can prepare themselves for the inconvenience of a power outage or communication breakdown by having an emergency plan and kit prepared. The Public Safety Canada website Is Your Family Prepared has excellent advice on what to include in an emergency plan and an emergency kit, both of which can be put to good use in any natural disaster or emergency.
How can damage from space weather be prevented?
Scientists in the Canadian Space Weather Forecast Centre both monitor and research space weather and its impacts on a variety of technologies. Their goal is to reduce the risk of interruptions to the safe operation of critical infrastructure, such as power grids, pipelines, satellites, communication and navigation. In collaboration with other government departments, universities and industrial partners, Natural Resources Canada researchers have provided many important contributions to reduce the vulnerability of critical technology to space weather hazards. These include modeling and monitoring geomagnetic effects on power systems and pipelines. NRCan researchers continue to investigate new and emerging topics to improve space weather forecasts.
What caused the March 1989 blackout?
The effect of geomagnetic storms on power systems is illustrated by the Hydro-Quebec blackout in 1989. A CME erupted on March 10 1989, and reached the Earth on the evening of Monday March 12, 1989 causing a geomagnetic storm that persisted through March 13 and 14. The geomagnetic storm generated electrical currents in the Hydro-Quebec power lines, causing protective devices to take sections of the grid off-line. This tripped other protective devices and, in a quick succession of events, the entire system shut down. The blackout left over six million people in Quebec without power for nine hours.
Space weather forecasting
Why is space weather forecasting important?
Space weather forecasts provide crucial information for anyone who might be impacted by space weather: airline pilots, astronauts, power utility engineers, mineral exploration geophysicists and even tourists hoping to catch a glimpse of the northern lights.
Space weather can also have significant impacts on the technological infrastructure we've come to rely on, including:
- Interference with radio-wave signals (navigation systems and radio communications)
- Electric power grid disturbances
- Pipeline corrosion
- Satellite operational problems
- Radiation hazard for astronauts and pilots flying at high altitudes
How is space weather forecast in Canada?
The Geomagnetic Laboratory of Natural Resources Canada is the Government of Canada's headquarters for the Geomagnetic Monitoring Service and the Canadian Space Weather Forecast Centre.
The Canadian Space Weather Forecast Centre monitors, analyzes and forecasts space weather and dispatches warnings and alerts across Canada. This includes tracking solar disturbances from the Sun to the Earth and monitoring the Earth's magnetic field on the ground using a network of magnetometers distributed throughout Canada. The centre also contributes to the International Space Environment Service by providing geomagnetic data and space weather forecasts.
How is the forecast created?
Geomagnetic activity is forecast using data from instruments that monitor the Sun. The Advanced Composition Explorer and Solar and Heliospheric Observatory Satellites (funded and operated by the U.S. National Aeronautics and Space Administration and European Space Agency), located 1.5 million kilometres above the Earth, are good examples of instruments for solar monitoring. Magnetometers and charged particle detectors are used to give advanced notice of potentially harmful space weather periods. Scientists look at patterns and clues in the data collected to produce a forecast.
How far in advance can you forecast space weather?
Thanks to satellite observations we're able to detect solar storms within a matter of minutes-to-hours. Depending on the rate at which they are ejected, it takes between 1 and 3 days for particles ejected during these storms to reach the Earth. Based on observations of the solar eruptions, we can predict when they will reach the Earth, and forecast the expected geomagnetic activity that will result. This 1-3 day delay allows sufficient time for critical infrastructure to protect itself from the effects of the solar storm. Additional measurements are made at the ACE satellite which provides information on solar wind plasma 30-90 minutes before reaching the Earth. We can't always predict when a solar storm will erupt on the sun, but once it does, we can predict when it will affect the Earth.
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