What is Space Weather?
Space weather refers to the variable conditions in the space environment between the Sun and Earth, primarily influenced by activity on the Sun’s surface. The Sun constantly emits a stream of charged particles known as the solar wind, which carries the Sun’s magnetic field out into the solar system.
Space weather phenomena originate from the Sun’s hot outer atmosphere, called the corona. Solar activity such as solar flares and coronal mass ejections can significantly enhance the solar wind and cause disturbances in Earth’s magnetic field, leading to geomagnetic storms. While Earth’s magnetic field and atmosphere shield us from most of the effects, intense space weather events can impact modern technologies.
Top 10 Space Weather Impacts on Earth
- Power Grids: Strong electrical currents driven along the Earth’s surface during geomagnetic storms can disrupt electric power grids and cause widespread blackouts. In extreme cases, this can damage transformers and knock them offline, reducing grid capacity.
- Satellite Communications: Changes in the ionosphere during geomagnetic storms can interfere with high-frequency radio communications and satellite communication links. Solar energetic particles can also penetrate satellite electronics and cause electrical failure.
- GPS Navigation: Space weather storms can modify signals from radio navigation systems like GPS, causing degraded accuracy. Ionospheric disturbances may also produce signal fluctuations (scintillation) that affect GPS applications.
- Astronaut Health: Astronauts exposed to increased radiation from solar particle events can quickly reach their permissible exposure limits, posing health risks. During radiation storms, astronauts may need to seek shelter in better shielded areas.
- Aviation: During solar radiation storms, radio communications can be compromised for commercial airliners on transpolar routes. Aircraft electronics may also be damaged and flight crews can receive increased radiation doses during large events.
- Radio Communications: Solar flares can cause radio blackouts on the sunlit side of Earth, degrading HF radio communications. Low-frequency radio signals may experience phase shifts and fading.
- Pipelines: Geomagnetic disturbances can induce electric currents in long conductors like pipelines, contributing to corrosion. This requires pipeline operators to take precautions.
- Spacecraft Operations: Satellites can experience temporary anomalies, damage to critical electronics, solar array degradation, and blinding of optical systems like star trackers due to energetic particle exposure.
- Aurora: While not a direct impact, geomagnetic storms can trigger aurora at lower latitudes than normal. The 1859 Carrington Event produced aurora visible as far south as Cuba and Hawaii.
- Magnetic Surveys: Magnetic disturbances from space weather directly affect operations that use Earth’s magnetic field, such as magnetic surveys, directional drilling, and compass navigation.
While major space weather events are low-probability, they are high-impact, with potential to significantly disrupt modern technologies. Monitoring, forecasting and preparing for space weather is therefore important to mitigate the risks.
