Space Weather Impact on Ground-based Systems

Space weather describes the changing properties of near-Earth space, which influences the flow of electrical currents in this region, particularly within the ionosphere and magnetosphere. Space weather results from solar magnetic activity, which waxes and wanes over the Sunspot cycle of 11 years, due to eruptions of electrically charged material from the Sun's outer atmosphere. Particularly severe space weather can affect ground-based, electrically conducting infrastructures such as power transmission systems (National Grid), pipelines and railways. Ground based networks are at risk because rapidly changing electrical currents in space, driven by space weather, cause rapid geomagnetic field changes on the ground. These magnetic changes give rise to electric fields in the Earth that act as a 'battery' across conducting infrastructures. This 'battery' causes geomagnetically induced currents (GIC) to flow to or from the Earth, through conducting networks, instead of in the more resistive ground. These GIC upset the safe operation of transformers, risking damage and blackouts. GIC also cause enhanced corrosion in long metal pipeline networks and interfere with railway signalling systems.

Severe space weather in March 1989 damaged power transformers in the UK and caused a long blackout across Quebec, Canada. The most extreme space weather event known - the 'Carrington Event' of 1859 - caused widespread failures and instabilities in telegraph networks, fires in telegraph offices and auroral displays to low latitudes. The likelihood of another such extreme event is estimated to be around 10% per decade. Severe space weather is therefore recognised in the UK government's National Risk Register as a one-in-two to one-in-twenty year event, for which industry and government needs to plan to mitigate the risk. Some studies have estimated the economic consequence of space weather and GIC to run to billions of dollars per day in the major advanced economies, through the prolonged loss of electrical power.

There are mathematical models of how GIC are caused by space weather and where in the UK National Grid they may appear (there are no models of GIC flow in UK pipelines or railway networks). However these models are quite limited in what they can do and may therefore not provide a true picture of GIC risk in grounded systems, for example highlighting some locations as being at risk, when in fact any problems lie elsewhere. The electrical model that has been developed to represent GIC at transformer substations in the National Grid misses key features, such as a model of the 132kV transmission system of England and Wales, or any model for Northern Ireland. The conductivity of the subsurface of the UK is known only partly and in some areas not at all well. (We need to know the conductivity in order to compute the electric field that acts as the 'battery' for GIC.) The UK GIC models only 'now-cast', at best, and they have no forecast capability, even though this is a stated need of industry and government. We do not have tried and tested now-cast models, or even forecast models, of magnetic variations on the ground. This is because of our under-developed understanding of how currents flow in the ionosphere and magnetosphere, how these interconnect and how they relate to conditions in the solar wind.

In this project we will therefore upgrade existing or create new models that relate GIC in power, pipe and railway networks to ionospheric, magnetospheric and solar wind conditions. These models will address the issues we have identified with the current generation of models and their capabilities and provide accurate data for industry and governments to assess our risk from space weather. In making progress on these issues we will also radically improve on our physical understanding of the way electrical currents and electromagnetic fields interact near and in the Earth and how they affect the important technologies we rely on.

There are three main interest groups where the proposed research will have impact.

Industry - Geohazard Impact & Assessment
Geomagnetically Induced Currents (GIC) impact the National Grid, pipelines and railways. We will therefore have representation on our stakeholder advisory group from organisations such as National Grid plc (power and pipelines), Scottish Power (power) and Atkins (railways), as well as UK Space Agency (international space weather initiatives and measurements), MunichRe (natural hazard insurance) and the Met Office Space Weather Operations Centre (MOSWOC). By interacting with this stakeholder group the investigators' scientific research into coupled ground-ionospheric-magnetospheric processes will be better tailored to their (and other) end-user needs, for example in terms of forecasts, surface electric fields or GIC model accuracy. For the National Grid our developments will add functionality and improved accuracy in GIC models already in service with them, as part of the real-time 'Monitoring and Analysis of GIC' (MAGIC) project that BGS is contracted to provide. National Grid uses MAGIC to determine where GIC is impacting their network during storms and to help inform their decision-making about the system state and operation. Our world-leading GIC and physical models of near-Earth processes will be adapted and used in other countries, and add to the international influence of the investigators. Understanding of space weather impact on pipelines and railways is a particularly under-developed area with very little in the published literature. We therefore foresee that our research will be world-leading here, likely acting as a stimulus to similar activities in other countries. We plan UK 'firsts' in terms of models of GIC flow in UK pipelines (with National Grid) and railways (with Atkins). Both National Grid and Atkins are keen to investigate the UK exposure to space weather.

Government - Geohazard Impact & Assessment
Space weather is recognised on the UK National Risk Register. Cabinet Office, BEIS, Go Science and other government departments have worked with some of the investigators, industry and industry regulators in the area of impacts on ground-based systems. Cabinet Office established the 'Space Environment Impact Expert Group' (SEIEG) to advise the government Chief Scientist through SAGE during space weather emergencies. Several SAGE 'table top' rehearsals have already been held, involving investigators from this proposal. The UK government, regional governments and assemblies, local authorities and emergency responders will therefore benefit from the quantified accuracy we will deliver from our new and improved GIC-related models. We will use our research outputs to inform discussion papers within the SEIEG group intended for government decision makers. We will also hold two 'information briefing events' to target scientifically aware lay-people from government and other agencies. This should aid information flow and decision making during severe space weather events and emergency planning in general and this will be integrated with MOSWOC daily operations.

Public - Engagement, Public Awareness, Natural Hazard Preparedness, Aurora Observation
Space weather is a topic that has had high prominence in the media over the last few years, prompting public interest in the aurora (what is it, where is it, and when to see it?). The investigators already have a strong track record in outreach activities, including the highly successful AuroraWatch website (Lancaster), public demonstrations (e.g. BGS 'Open Days'), talks and regular media activity in response to alerts of major space weather. We plan to tap into this interest and communicate what we are doing and why it matters by further investigator activities in these areas, including through a Royal Society Summer Science exhibit, where we will showcase our research and demonstrate our significantly improved GIC-related models.