Space Weather
space weather is the concept of changing environmental conditions in near-Earth space or Earth’s ionosphere caused by solar activity. It directly affects human-made objects in space as well as human activities on Earth. The study of space weather is relatively new, having only begun in the 1950s with the launch of artificial satellites. Space weather should not be confused with terrestrial weather; the two are separate phenomena.
There are three primary areas where space weather can impact humans and human activity: communications, navigation, and electrical power systems. In each of these areas, there are a number of sub-impacts that can occur (see below). These impacts range from annoying to deadly, depending on their severity.
Communications: Space weather can degrade or interrupt radio communications on Earth as well as in space. This includes everything from shortwave radio transmissions to satellite TV signals and GPS signals. The most common cause of communication disruptions is a phenomenon known as ionospheric scintillation, which is when charged particles from the Sun disrupt signal propagation within the ionosphere (the layer of Earth’s atmosphere that reflects radio waves back to Earth). Space weather can also cause auroral absorption, which is when aurora (northern/southern lights) absorb high-frequency radio signals passing through them.
Navigation: Similar to communications, navigation systems can also be impacted by space weather events. Most notably, GPS signals can be degraded or interrupted by solar storms causing position errors that could lead to crashes or collisions. Aircraft pilots and ship captains rely on GPS for positioning information, so this is a serious concern during large solar storms. Other navigation systems such as LORAN and eLoran are less affected by space weather but can still experience disruptions.
Electrical Power Systems: One of the most significant ways that space weather impacts humans is through its ability to disrupt electrical power grids on Earth. Solar storms release massive amounts of electromagnetic radiation and charged particles into our atmosphere which interact with our planet’s magnetic field causing geomagnetic storms . These storms induce electric currents in long metal pipelines (such as power lines) which then flow back into transformers at substations damaging them beyond repair . This process is called geomagnetic induction , and it typically takes days or weeks for repairs to be completed meaning widespread power outages could occur . Such an event happened in 1989 when a geomagnetic storm caused widespread blackouts across Canada lasting up 9 hours . In addition to damaging infrastructure , these sorts of events also pose a threat to human health due to increased exposure to EM radiation .
Solar Flares & CMEs: The Causes of Space Weather Events
Solar flares are sudden bursts of energy released by the Sun that typically last minutes to hours . They are often associated with coronal mass ejections (CMEs), which are clouds of plasma ejected from the Sun’s surface . Both solar flares and CMEs accelerate charged particles (protons and electrons) towards Earth where they interact with our planet’s magnetic field causing geomagnetic storms . The largest recorded flare occurred on August 4th , 1972 while the largest recorded CME was associated with the 1859 Carrington Event .