Projects

VENI (Venusian Electricity, Nephology, and Ionisation) (2018 – present)

Dr. Martin Airey, Prof. Giles Harrison

The clouds of Venus seem likely to be affected by Galactic Cosmic Rays (GCRs), as is seen to occur elsewhere in the Solar system such as at Neptune and Uranus. The most energetic GCRs cause ionisation (the creation of charge) via a cascade of interactions in our atmosphere. This affects our atmosphere in a variety of ways, including allowing current to flow in a Global Electric Circuit (GEC). On Earth, the peak altitude for ion production in this way is at around 15-26 km, high above the clouds. However, on Venus, this maximum occurs at around 60 km, which coincides with Venus’ permanent, thick, sulphuric acid cloud deck. Charge is known to influence cloud droplet properties, including the range of conditions in which they can grow, and for how long they are stable. In a series of experiments, droplets of sulphuric acid are levitated in a sound wave so that their properties can be observed in isolation. A carbon dioxide atmosphere is used in some of the experiments to accurately portray the actual conditions on Venus. Charging through ionisation around the droplet is created and the effects on the droplets are monitored in an electric field. The findings of this study will help us to determine how important the effects induced by GCRs are on Venus, in particular in the formation and persistence of the clouds and may also help us to find out whether or not there is a GEC on Venus.

SWIGS (Space Weather Impact on Ground-based Systems) (2017 – present)

As part of the NERC-funded national SWIGS consortium, we are studying downscaling from annual mean data to high time resolution magnetometer data with the aim of generating a climatology of GICs (induced currents in long powerlines and pipelines that cause degradation and, potentially, catastrophic failures) and to developing proxies to monitor their accumulated effect. National Environment Research Council (NERC) grant numbers NE/P016928/1 and NE/P017231/1

Rad-Sat (2017 – present)

We are part of the NERC funded Rad-Sat consortium, modelling the acceleration, transport and loss of radiation belt electrons to protect satellites from space weather. Over the last 10 years the number of operational satellites in orbit has grown from 450 to more than 1300. We rely on these satellites more than ever before for a wide range of applications such as mobile phones, TV signals, internet, navigation and financial services. All these satellites must be designed to withstand the harsh radiation environment in space for a design life that can be as long as 15 years or more. Space weather events can increase electron radiation levels by five orders of magnitude in the Earth’s Van Allen radiation belts causing satellite charging, disruption to satellite operations and sometimes satellite loss. For example, in 2003 it was estimated that at least 10% of all operational satellites suffered anomalies (malfunctions) during a large space weather event known as the Halloween storm. It is therefore important to understand how and why radiation levels vary so much so that engineers and business can assess impact and develop mitigation measures. New results from the NASA Van Allen Probes and THEMIS satellite missions show that wave-particle interactions play the major role in the acceleration, transport and loss of high energy electrons and hence the variability of the radiation belts. This consortium brings together scientists from across the UK (BAS, Reading, UCL/MSSL, Imperial and Sheffield) with stakeholders from the insurance and satellite services sector to improve upon the current state-of-the-art in Radiation Belt models. Reading’s role is to harness powerful first-principles simulations to test whether nonlinear effects result in more particle acceleration and loss compared to standard theoretical treatments currently used in Radiation Belt models. We will construct new descriptions of diffusion for times and locations in the model where the current theoretical treatment is insufficient.

VolcLab

VolcLab is an instrument package designed for deployment into volcanic plumes with a standard radiosonde on a weather balloon. The instruments included record ash mass concentration, backscatter, SO2, charge, and turbulence. These measurements provide in situ plume characteristics for airspace risk management planning as well as providing valuable scientific information on plume dynamics.

GLOCAEM (Global Coordination of Atmospheric Electricity) (2016 – 2018)

GLOCAEM is a NERC funded International Opportunities project which will create the first online database of near real time atmospheric electric field from around the world. PI – Dr Keri Nicoll (contact k.a.nicoll@reading.ac.uk).

Reading Solar System Science STFC consolidated grant (2015 – present)

The heliosphere under space climate change (Mathew Owens, Mike Lockwood):

Investigation of how coronal and heliospheric structures evolve under space climate change, using a both the available observational and proxy records of solar magnetic activity and numerical modelling of the solar corona and heliosphere.

Whistler-mode wave-particle interactions in the magnetosphere

Clare Watt

High-energy electrons are trapped in a torus region surrounding the Earth to form the Outer Radiation Belt. The Earth’s magnetic field constrains the electrons to perform gyrating, bounce and drift motions. These motions are disrupted by wave-particle interactions that behave, in the collisionless environment of space, a little like collisions in an ideal gas. Wave-particle interactions result in both particle precipitation into the ionosphere, and particle energisation to high energies. Electromagnetic waves therefore mediate the transfer of energy to relativistic electrons, and an outstanding question in Radiation Belt physics is to determine the efficiency of this mechanism in different magnetospheric conditions. We are using powerful first-principle particle-in-cell plasma simulations to study this important interaction.