Understanding energetic particle effects on atmospheric processes

Lead Research Organisation: University of Reading
Department Name: Meteorology

Abstract

Our moderate climate makes life on Earth possible. In order to predict how our climate will change in future, it is necessary to understand all of the processes, both natural and man made, which can contribute to climate change. Climate scientists have a fairly good grasp of the anthropogenic factors, but there are gaps in our knowledge about the contribution to climate change from natural variability. One of the major sources of uncertainty is the variability caused by our sun. The brightness of the sun influences Earth's climate directly by heating, and varies mainly on an 11 year timescale. This direct effect is relatively well understood, however there are other indirect effects (which are linked to solar output, but require another physical process in between) which are thought to influence Earth's climate, and are not at all well understood. It is essential that these indirect effects are better understood if we are to accurately account for solar effects in predicting future climate change.

My research will investigate one of the potential indirect effects of solar variability on atmospheric processes, which is the effect of electrical charge on clouds. Charge is created in the atmosphere by ionisation from Galactic Cosmic Rays (GCRs) (highly energetic particles from outside our solar system). When GCRs approach Earth, they are deflected by both the Solar and Earth's magnetic field, which act as a selective energy barrier to GCRs. The sun's magnetic field varies mainly on an 11 year timescale, therefore GCR fluxes, and thus charge in the atmosphere is controlled by solar activity. Due to constant vertical flow of charge in the atmosphere, charge accumulates at the upper and lower boundaries of layer clouds (the very common sort of clouds that you see on an overcast day). The charge sticks to the cloud droplets, which is thought to influence the behaviour of the droplets, such as how they grow and stick together, which can be seen in large scale cloud properties like cloud height. Since such clouds control heating and cooling in the atmosphere, and cover around 40% of the Earth's surface at one time, charge effects on clouds may have implications for climate. My research will investigate the factors that control charge in the atmosphere, determine whether charge plays a role in cloud processes, and ultimately determine whether this is important for climate.

In order to characterise the factors controlling charge in the atmosphere, and the typical charge present inside layer clouds, measurements will be made using a suite of newly developed sensors which have been designed to fly alongside conventional weather balloons. These lightweight, disposable sensors provide a cost effective method of obtaining extra science data above the surface, from weather balloons which are already being launched around the world by global meteorological services. These airborne measurements will be combined with surface measurements of charge and atmospheric electricity at various sites around the world to understand the global response of charge to changes in solar variability. Such measurements are rare and are vital to understand the physical mechanisms responsible for modulating vertical charge flow and therefore coupling between Space Weather and the lower atmosphere.

This topic sits at the intersection of physics and meteorology and presents an opportunity to investigate processes that we are still very much in our infancy of understanding. There is a great deal of exciting and potentially very important fundamental research to be done in this field, which will ultimately help us to understand whether these new processes are relevant to climate.

Planned Impact

The research proposed by this fellowship application is relevant to a number of non-academic beneficiaries:

Policy makers and general public
There is a wide interest from the general public and policy makers in natural sources of climate variability. Suggestions that cosmic rays can provide an unexpectedly large natural influence on climate have been used to refute the need to curb carbon dioxide emissions. In order to challenge such assertions, new quantitative knowledge about the affect of cosmic rays on climate is necessary, which this fellowship aims to address. Once the natural sources of climate variability have been accounted for, both the general public and policy makers will benefit from the improved and more accurate climate modelling that will result.

Commercial
The special science sensors developed as part of this fellowship use novel instrumentation techniques which can extend the usefulness of the pre-established measurement infrastructure of the global radiosonde network. Such an approach is cost effective and can permit measurements to be made in dangerous or remote marine areas. So far, the UK Met Office, British Antarctic Survey, Icelandic Met Office, The Royal Navy and instrument manufacturers Vaisala, Meteomodem and Biral have all expressed interest in the use of novel sensors on radiosondes. Previous commercial work with the UK Met Office resulted in the manufacture and sale of a number of radiosonde sensors for volcanic ash detection. Such interest therefore offers the potential for future spin-out.

Government
The UK Met Office now have an increased interest in Space Weather and its hazards through Space Weather forecasting. A possible destination for the instrumentation used in this Fellowship is in permitting the radiosonde network of the UK Met Office, in which there is long-established substantial investment maintaining the network for routine meteorological observations, to undertake regular measurements of upper atmosphere high energy particles. Interest in the radiosonde sensors has also been expressed by the Icelandic Met Office, for vertical profiling of ash during periods of future volcanic eruptions.

Publications

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Harrison R (2015) Focus on high energy particles and atmospheric processes in Environmental Research Letters

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Harrison R (2015) On the microphysical effects of observed cloud edge charging Layer Cloud Electricity in Quarterly Journal of the Royal Meteorological Society

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Harrison R (2018) Saharan dust plume charging observed over the UK in Environmental Research Letters

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Harrison RG (2017) Note: A self-calibrating wide range electrometer for in-cloud measurements. in The Review of scientific instruments

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Harrison RG (2016) Coordinated weather balloon solar radiation measurements during a solar eclipse. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Lorenz R (2016) Point discharge current measurements beneath dust devils in Journal of Atmospheric and Solar-Terrestrial Physics

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/L011514/1 01/09/2014 29/02/2016 £440,600
NE/L011514/2 Transfer NE/L011514/1 01/03/2016 30/09/2020 £311,115
 
Description I have demonstrated robustly that on average, the electrical charge present in stratiform layer clouds agrees with that predicted by theory. However, on an individual cloud-to-cloud basis the situation is much more complex. I have also shown that there is an asymmetry between the electrical charge present at the top and bottom of stratiform layer clouds, due to dynamical reasons, which may mean that charge effects on cloud droplets are larger at cloud top than cloud base.
Exploitation Route The measurements I have made so far can be used by others in the meteorological modelling community to inform modelling studies on the effect of charge on cloud processes, and therefore potentially on climate.
Sectors Environment

 
Description International Exchanges 2017 Cost Share
Amount £10,000 (GBP)
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 03/2018 
End 10/2019
 
Description United Arab Emirates Rain Enhancement Programme
Amount $1,500,000 (USD)
Funding ID Electrical aspects of rain generation 
Organisation United Arab Emirates Government 
Sector Public
Country United Arab Emirates
Start 03/2017 
End 10/2019
 
Description COST action on Atmospheric Electricity CA15211 
Organisation Democritus University of Thrace
Country Greece 
Sector Academic/University 
PI Contribution I am one of the UK Management Committee representatives for this COST action network.
Collaborator Contribution This is an international network with over 40 countries involved.
Impact None as yet as the action has just started.
Start Year 2016
 
Description Collaborative gearing scheme award 
Organisation British Antarctic Survey
Country United Kingdom 
Sector Academic/University 
PI Contribution This collaboration resulted in the successful award of a NERC Collaborative Gearing Scheme Award which enabled me to travel to Antarctica to setup/install and test atmospheric electric field instrumentation. This collaboration has now resulted in a full year's worth of rare electric field data which is being analysed at present.
Collaborator Contribution BAS provided the travel and infrastructure costs for transportation to Antarctica, as well as the personnel responsible for maintenance of the equipment whilst there .
Impact - invited talk at George Watson's College, April 2015 - Oral presentation at Royal Met Soc Atmospheric Electricity Wilson meeting, November 2015
Start Year 2014
 
Description Bath Science Cafe talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact In February 2016 I was invited to give a talk at the Bath Science Cafe in the Raven pub. This was received with great enthusiasm with lots of questioning from the general public afterwards.
Year(s) Of Engagement Activity 2016
 
Description Feature length segment on BBC radio4 (The curious cases of Rutherford and Fry) 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I recorded a feature length segment for BBC radio 4 as part of their programme "The curious cases of Rutherford and Fry". For this I provided advice, interviews on radio as well as perfomed a balloon launch experiment which was recorded for radio. Radio 4 have received feedback on this from several interested members of the public.
Year(s) Of Engagement Activity 2017
URL http://www.bbc.co.uk/programmes/w3cswd1s
 
Description Physics Review article 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact I have written an article on atmospheric electricity for Physics Review. This is a magazine which supports the studies of physics students, who are studying for A-levels, AS-levels, GNVQ, Irish or Scottish Highers, or Scottish CSYS. The article will be published in the March 2016 edition of the magazine therefore as yet there has been no opportunity for impact.
Year(s) Of Engagement Activity 2016
 
Description Public lecture RMetS Scottish centre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public lecture to the Scottish Centre of the Royal Meteorological Society on "Electricity in the atmosphere: airborne measurements from balloons and drones".
Year(s) Of Engagement Activity 2016
URL https://www.rmets.org/events/measuring-electricity-atmosphere-balloons-and-drones
 
Description Public lecture RMetS south east centre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public lecture at the South East centre of the Royal Meteorological Society entitled "Atmospheric electricity research at Halley, Antarctica". I have since had several queries from interested members of the general public on atmospheric electricity and instrumentation.
Year(s) Of Engagement Activity 2016
URL https://www.rmets.org/events/atmospheric-electricity-research-halley-antarctica
 
Description Public lecture for the Institution of Engineering and Technology (IET) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact 50 members of the general public (including all ages from school children to retired people) attended a public lecture which I gave for the IET in December 2017. Feedback from the members of the audience was excellent, with many saying it was the best talk they'd heard in years. I have since had several emails from members of the public asking for more information about the subject.
Year(s) Of Engagement Activity 2017
URL https://localevents.theiet.org/4efac2
 
Description Radio interview for BBC radio Berkshire 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I performed an interview on BBC Radio Berkshire in reponse to media queries about new cloud charging research which I am involved with.
Year(s) Of Engagement Activity 2017
 
Description School visit - George Watsons 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact I attended George Watson's college in April 2015 to give an invited talk to students and staff entitled "Measuring atmospheric electricity in Antarctica". Feedback after the talk was very positive with staff encouraging me to write an article to more widely publicise atmospheric electricity to school children. I have since done this - see "Physics Review article" in the engagement activities section.
Year(s) Of Engagement Activity 2015
 
Description Sky news interview 
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 Public/other audiences
Results and Impact In November I was interviewed in a Sky News piece on monitoring CO2. This was broadcast on international TV and therefore reached a potentially very large audience.
Year(s) Of Engagement Activity 2015