Determining and understanding substorm energy loss and partitioning

Lead Research Organisation: University College London
Department Name: Mullard Space Science Laboratory

Abstract

The substorm is a repeatable earthquake-like disturbance to near-Earth Space, which, apparently unpredictably, recurs after anything from 2 hours to a day or more and dumps typically one thousand million million Joules of energy into the upper atmosphere equivalent to ten Oklahoma tornados or the largest nuclear weapon in the US arsenal. The substorm's intermittency and variable size makes it arguably the greatest source of uncertainty in predicting the state of the upper atmosphere. Its most obvious effect is the aurora, which would be nice to know when its happening so that we could plan our Arctic holidays, but substorm prediction is also important for mitigating the effects of natural changes in the upper atmosphere on geostationary satellite communications and navigation, low-altitude satellite orbits and remote sensing, electricity power grids, and oil and mineral prospecting. Prediction is also the ultimate test for our scientific understanding. Progress requires measuring and analysing substorm variability in order to test and develop models based on maths and physics. We already know the statistics of substorm timing and have explained this with a simple mathematical model (that has also been used for understanding neuron firing in the brain!). However, knowing and understanding the variability of substorm size is much harder because it requires to measure simultaneously over large regions of the polar upper atmosphere and out into Space.

In this project, we propose to attempt this by examining lots of substorms over more than a decade using spacecraft together with networks of magnetometers (sophisticated scientific compasses) and radars in both the Arctic and Antarctic. The resulting stats will be compared with what we already know from much more limited observations and with the predictions of new and existing substorm theories and models. The outcomes will be knowing things like how likely a really big substorm is that could mess things up, as well as models to explain why and hopefully when that might occur.

Planned Impact

As discussed in the Academic Beneficiaries section, there are numerous institutions that will benefit from this research. The overarching objective, to determine the energy partitioning within the substorm, and thus what quantity of energy is deposited into the Earth's ionosphere in the form of particle precipitation and Joule heating, is of paramount importance to those interested in the effects of Space Weather on our everyday lives.

Modern society is increasingly reliant on space-based technologies for their everyday lives and substorms have consequences on modern technological infrastructure in the Space and Energy sectors. These include damage to satellites, especially from surface charging, and disruptions to satellite communications and navigation due to ionospheric absorption and scintillation, to electricity supply due to electrical currents induced in the ground from ionospheric currents, and to oil and mineral prospecting due to geomagnetic field fluctuations.

Such so-called 'space weather' hazards are now considered to be sufficiently important to have been included in the latest UK Government National Risk Register. Providing information directly relevant to predictive space weather modelling efforts is the first step towards providing advance warning for low-frequency, but high-consequence events such as those identified by the top UK and US Science Advisors Holdren and Beddington who warn "The potential total cost of an extreme Space Weather event is estimated as $2 Trillion in year 1 in the U.S. alone, with a 4-10 year recovery period".

The Meteorological Office is responsible for providing space weather predictive capability and will directly benefit from the improved knowledge of the radiation belts that this project will provide. The Global Positioning System (GPS), and their European counterparts in Galileo, may be a primary benefactor of our research. The loss of particles into the ionosphere leads to large and currently unpredictable changes in the density of the ionosphere. The accuracy of location information provided by GNSS is significantly degraded during periods of rapid ionospheric change that result from the direct action of substorm and radiation belt dynamics. Many industries rely upon GNSS/GPS for their remarkable precision timing to 100 billionths of a second, synchronizing networks, computers or instruments. GPS technology is also used heavily in precision farming, including spraying and harvest, for snow removal in the US, and for vessels to determine their location precisely at sea anywhere on the globe. More generally, the effects of space weather can be felt in all activities that use space-related assets. For example, during the October-November 2003 geomagnetic storms the effects of space weather were included in a US National Weather Service report for the first time.

The research and professional skills that the two PDRAs will develop during this project will be in computational programming, the processing large datasets and clear scientific reasoning, written skills in the form of reports and publications, which are all applicable to many employment sectors.

Publications

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Bai S (2018) Spatial Distribution and Semiannual Variation of Cold-Dense Plasma Sheet in Journal of Geophysical Research: Space Physics

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Coxon J (2016) Identifying the magnetotail lobes with Cluster magnetometer data in Journal of Geophysical Research: Space Physics

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Forsyth C (2016) What effect do substorms have on the content of the radiation belts? in Journal of geophysical research. Space physics

 
Description The substorm is arguably the greatest source of uncertainty in predicting the state of the upper atmosphere due to its intermittency and varying magnitude. Prediction is important for mitigating the effects of the upper atmosphere on geostationary satellite communications and navigation, low-altitude satellite orbits and remote sensing, electricity power grids, and oil and mineral prospecting. It is also the ultimate test for our scientific understanding. Progress requires quantitative analysis of substorm variability in order to motivate and test predictive physical models and is the subject of at least one, if not two successful NERC Highlight Topics that have recently been awarded.
We have
Exploitation Route Quantitative substorm onset databases are the single biggest problem facing our field. We are typically not able to do this, which means deternining key physical processes relative to this unknown time is impossible. As we have determined a fully quantitative and statistically robust estimate of substorm onset time, and made this available to the community without reservation, we believe that this will be a huge community resource for many years to come. In terms of energy budget for the inner magnetosphere, those that require knowledge of substorm onset will use this technique and database to quantify the resultant energisation and loss of relativistic electrons. Space weather is an increasingly important national requirement to understand, as shown by the Government's National Risk Register priority list.
Sectors Aerospace, Defence and Marine,Energy,Environment,Government, Democracy and Justice

 
Description public dialogue
Geographic Reach National 
Policy Influence Type Participation in a national consultation
 
Description AGU
Amount $1,000 (USD)
Organisation American Geophysical Union 
Sector Charity/Non Profit
Country United States
Start 09/2014 
End 09/2014
 
Description NERC Highlight Topic
Amount £3,000,000 (GBP)
Funding ID NE/P017150/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 05/2017 
End 05/2021
 
Description ics
Amount $1,000 (USD)
Organisation International Conference on Substorms 
Sector Academic/University
Country Japan
Start 11/2014 
End 11/2014
 
Title New database on substorm onset, duration 
Description A new technique to define the three phases of a substorm 
Type Of Material Data analysis technique 
Year Produced 2016 
Provided To Others? Yes  
Impact many other papers resulted 
URL https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JA021343
 
Title New model for calculating pedersen conductance 
Description New model for calculating pedersen conductance from all-sky imager data 
Type Of Material Data analysis technique 
Year Produced 2019 
Provided To Others? Yes  
Impact too early to tell 
 
Description Collaboration with Atkins 
Organisation Severn Trent Water
Country United Kingdom 
Sector Private 
PI Contribution Working with Atkins and partners, engaged with water sector to understand their level of preparedness for space weather
Collaborator Contribution Briefings and discussion with water and power companies
Impact No substantive outcomes were generated from this 6 month project
Start Year 2014
 
Description Collaboration with Atkins 
Organisation Thames Water Utilities Limited
Country United Kingdom 
Sector Private 
PI Contribution Working with Atkins and partners, engaged with water sector to understand their level of preparedness for space weather
Collaborator Contribution Briefings and discussion with water and power companies
Impact No substantive outcomes were generated from this 6 month project
Start Year 2014
 
Description Collaboration with Atkins 
Organisation WS Atkins
Country United Kingdom 
Sector Private 
PI Contribution Working with Atkins and partners, engaged with water sector to understand their level of preparedness for space weather
Collaborator Contribution Briefings and discussion with water and power companies
Impact No substantive outcomes were generated from this 6 month project
Start Year 2014
 
Description A press release, press conference or response to a media enquiry/interview - Interview on Independent online 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interview on space weather in Independent
Year(s) Of Engagement Activity 2018
 
Description Space Weather Public Dialogue Stakeholder Summit 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact The purpose of the public dialogue is to inform the policy of both governments and companies in respect of space weather and the potential consequences on people and infrastructure. This has been done through a series of workshops over the summer with members of the public in urban and rural locations. The aim has been to develop and gauge public understanding of space weather and its impacts and scenarios for resilience (both civil society and individuals), and consider the roles and responsibilities of the Government, companies, communities and individuals to mitigate against and/or respond to space weather impacts

The purpose of the Stakeholder Summit is to bring together representatives from Government, local authorities, academic institutions and corporations who all have an interest in space weather and its potential impacts. The morning will be spent discussing the outputs of the public dialogue and the afternoon will be used to explore actions and recommendations for the future.

Develop a final report that will be circulated to all those who have been involved in the dialogue project and posted on the website.

The project team and STFC will discuss how to keep members of public involved in the longer term.
Year(s) Of Engagement Activity 2014