Space Weather frequently asked questions

What is space weather?

Space weather describes changing environmental conditions in near-Earth space. Magnetic fields, radiation, particles, and matter, which have been ejected from the Sun, can interact with the Earths upper atmosphere and surrounding magnetic field to produce a variety of effects.

Space weather conditions constantly vary, with streams of particles from the Sun constantly hitting Earth via what is known as the solar wind. However, a greater impact to the Earth is felt during periods of high solar activity, when a large number (compared to quiet periods) of solar eruptions can occur in the form of flares and coronal mass ejections (CMEs).

Solar flares are sudden releases of energy in the form of particles, mass motions, and radiation across the entire electromagnetic spectrum. They are currently hard to predict, and radiation is detected in Earth's atmosphere as soon as 8 minutes after an eruption (travelling at the speed of light). CMEs often occur at a similar time to flares, and are ejections of large amounts of matter carrying the local magnetic field from the solar atmosphere. These can take days to reach Earth, and their arrival time is the focus of much space-weather forecasting.

What can it do / what are its impacts?

Space weather, such as Coronal Mass Ejections (CME's), affects many aspects of modern technology that we rely on every day - such as navigation and communication, power distribution, aircraft and the space based instrument operations.

What are the potential health impacts?

During high energy proton events passengers and crew on high flying aircraft may be exposed to elevated radiation levels, particularly on polar routes. Because of their exposure to radiation, aircrew on long-haul flights are classified as radiation workers by the European Union and frequent flyers and pregnant women are also at risk.

Why do we need this service?

The Government added solar storms to the National Risk Register of Civil Emergencies in 2011 and they have been classified as a serious threat to the UK over the last four years. Space weather is now ranked in the top four on the National Risk Register.

Space weather, such as coronal mass ejections (CME's), affects many aspects of modern technology that we rely on every day - such as navigation and communication, power distribution, aircraft and the space based instrument operations.

Who will benefit from this service?

The main direct beneficiaries of the space weather prediction service are the following sectors that have been identified as being both vulnerable to space weather and also provide key critical infrastructure;

  • energy
  • aviation
  • satellite operation
  • marine
  • communications
  • rail 
  • defence

Indirectly, we anticipate the UK space sector to benefit in terms of improved knowledge that can be translated into increased resilience. Also The UK has a strong heritage in the development of satellite instruments and know-how for space weather monitoring which will be enhanced by the UK taking a leading role in space weather prediction.

Is the Met Office doing this alone?

The Met Office is developing this capability in collaboration with a range of UK partners such as the British Geological Survey, Bath University and RAL Space as well as international partners such as the US National Oceanic and Atmospheric Administration (NOAA) Space Weather Prediction Centre.

How do you forecast space weather?

You can't predict when a particular event will occur on the Sun, but we can indicate periods of increased probability of events. The focus is on detecting events quickly to allow timely issuing of alerts and warnings for solar flares and radiation events. For coronal mass ejections (CME's) early detection to allow accurate analysis for input to models to predict arrival time of the CME at Earth.

Why did it take so long to set this service up when space weather has been on the national risk register since 2011?

Space Weather originally appeared on the National Risk Register as a provisional risk whilst assessment of the risk both from a science and an impact perspective was undertaken. The focus of assessing the impacts to the UK for an extreme event resulted in the publication in February 2013 of the Royal Academy of Engineering report on Extreme Space Weather. This report set out the potential impacts on engineered systems in the UK and also asserted that space weather forecasts provide a useful tool in the mitigation strategy. This made the case for space weather forecasting, building on development activities already underway in the Met Office.

Last updated: 7 October 2015