Global Coordination of Atmospheric Electricity Measurements (GloCAEM)

It is well established that Earth has a "Global atmospheric Electric Circuit" (GEC), through which charge separation in thunderstorms sustains large scale current flow around the planet. The GEC generates an atmospheric electric field which is present globally, and is typically 100V/m near the surface in fair weather conditions. Measurements of electric field have been shown to include information about global thunderstorm activity, local aerosol concentrations and cloud cover, as well as changes in the space weather environment. Recent work has also suggested that atmospheric electrical changes may be effective as earthquake precursors, as well as being sensitive to release of radioactivity, as evidenced by the Fukushima disaster in 2011. A current NERC Independent Research Fellowship entitled "Understanding energetic particle effects on atmospheric processes" also investigates a mechanism by which vertical current flow in the GEC can affect layer cloud microphysics, thereby providing a route by which space weather changes can alter tropospheric weather processes through atmospheric electricity.

The global nature of the GEC means that in order that truly global signals are considered in understanding the processes within the circuit, many validating measurements must be made at different locations around the world. To date, no genuinely global network of FW atmospheric electricity measurements has ever existed, therefore, given the growing number of groups now involved in atmospheric electricity monitoring, such a proposal is timely. This project will bring these experts together to make the first steps towards an effective global network for FW atmospheric electricity monitoring. A specific objective of the project will be to establish the first modern archive of international FW atmospheric electric field data in close to real time to allow global studies of atmospheric electricity to be straightforwardly and robustly performed.

Direct communication between network members will be facilitated by two workshops, hosted by the University of Reading towards the beginning and end of the project. The first of these will facilitate discussion of measurement practises and instrumentation, as well as establish recording and archiving procedures to archive electric field data in a standardised, easily accessible format. CEDA-BADC have agreed to support the creation of a data repository and a data manager, employed by the University of Reading, who will be responsible for liasing between CEDA-BADC and the project partners to upload data.
In terms of scientific objectives, the PI will lead an investigation of space weather influences on the electric field measurements stored in the data repository. Evidence for influence from events such as solar flares, coronal mass ejections, and heliospheric current sheet crossings during the past three solar cycles will be examined using statistical techniques including super epoch analysis. During the second workshop, an outline for a peer reviewed publication describing the details of the network and data repository, as well as initial scientific findings will also be produced. This will form the basis for a joint publication from all the project partners and will help to advertise the network to the wider scientific community.

GloCAEM Impact Summary

The beneficiaries of the proposed research will be researchers interested in solar-terrestrial physics, high energy particle effects, atmospheric electricity, cloud microphysics and also the wider climate science community and the general public.

Beneficiaries from the scientific work:
There is a wide interest from the general public and policy makers in natural sources of climate variability. The effect of solar variability on climate has been identified by the Intergovernmental Panel on Climate Change in the Fourth Assessment report as an area having "low" levels of scientific understanding. Understanding how variability in the solar and space weather environment affects atmospheric processes relevant to climate (such as clouds) is a major challenge. This proposal aims to provide the necessary infrastructure, through the establishment of an atmospheric electricity network, to allow such challenges to be addressed. The scientific work that will result from the data deposited by this network will benefit the general public and policy makers by improving our understanding of space weather effects on global atmospheric electricity and clouds, eventually leading to a more complete understanding of natural sources of variability on climate.

Beneficiaries from the existence of an atmospheric electricity monitoring network:
The existence of a fair weather atmospheric electricity monitoring network will improve natural hazard monitoring in the case of earthquakes and volcanic eruptions, as well as monitoring of radioactive releases, be they accidental or deliberate. In 2011, electric field measurements in Japan showed an unprecedented sustained decrease immediately following the release of radioactivity from the Fukushima nuclear reactor, demonstrating the usefulness of electric field measurements as an indicator of increased ionisation in the atmosphere. A network of electric field monitors (such as the one suggested here) could therefore be used to track the spread of any radioactive release, providing valuable information for governments as well as the general public. The sensitivity of the electric field to volcanic ash also means that such a network would be useful for the detection of volcanic ash in the lower atmosphere, which is of major concern to the airline industries following large volcanic eruptions in busy flight corridors.