Recent research has suggested that energetic particles entering the Earth's atmosphere at the poles can lead to 5-10 K changes in the surface tempertaures in polar regions during the wintertime. This is thought to be as a result of chemical changes driven by energetic particles enering the Earth's atmosphere at high altitudes (50-90 km) affecting the radiation balance of the atmosphere as a whole. However the exact nature of the particles is unknown, and further analysis/confirmation of the effect on surface temperature variability is limited by this knowledge gap. We propose to fill this knowledge gap by deploying low-powered narrow band radio receivers south of the Antarctic Peninsula in order to monitor energetic particle precipitation coming from the radiation belts that surround the Earth. Only then will the study of the impact of the particles in driving atmospheric chemical changes be possible with any degree of certainty. Being able to site our experiments in the Antarctic is critical because: 1) the geomagnetic latitudes of the sites chosen for this project are associated with processes occuring at the heart of the outer radiation belt - allowing us to determine the maximum radiation belt particle influence on the atmosphere; 2) the effect of energetic particle precipitation on the experimental radiowave observations that we will make is enhanced over thick ice-sheet regions - this condition only occurs south of the Antarctic Peninsula at the geomagentic latitudes that are needed to make the best observations; 3) the region south of the Antarctic Peninsula is where most of the particle precipitation from the outer radiation belt will occur, because of the influence of the nearby South Atlantic Magnetic Anomaly in knocking the energetic particles out of their orbits and into the atmosphere. The data collected, analysed and interpreted by the project partners brought together by this proposal, will allow us to model the chemical changes in the Antarctic atmosphere due to energetic particle precipitation. As a result we will be able to determine the impact of complex radiation belt processes on the global atmosphere. Our Investigation of the effects on polar surface temperatures is part of international efforts to understand climate variability and the links to the upper atmosphere (e.g. the NERC Science Themes, the Climate and Weather of the Sun-Earth System programme, phase II, and the International Living with a Star programme - ILWS) . Our proposal is also timely in that there will be extensive supporting measurements made during the lifetime of our proposal by x-ray balloons funded by NASA, and by new NASA and CSA radiation belt satellites, all supported by the ILWS programme. Extensive collaboration between this proposal and the balloon/satellite mission scientific teams has been initiated and will continue throughout the project lifetime.

The greenhouse gases carbon dioxide (CO2) and methane (CH4) are by far the biggest contributors to recent and ongoing climate change. Of all the known greenhouse gases (excluding water vapour), CO2 and CH4 have the highest concentrations in the atmosphere and they are rising rapidly. CO2 is particularly problematic because there is so much of it (about 200 times more than CH4) and because once emitted to the atmosphere, much of it will stay there for several hundred years. Whereas, by comparison, CH4 has a lifetime in the atmosphere of about a decade, but it is a much more potent greenhouse gas than CO2 - that is, for equal amounts of CO2 and CH4 in the atmosphere, CH4 will trap heat radiation about 70 times more effectively than CO2 (over a 20-year time period). With the ratification of the Paris Agreement, the world has committed to avoiding dangerous climate change and the most obvious way to do this is by reducing emissions of CO2 and CH4. How will we know if emission mitigation policies are effective? Which nations or regions are meeting their emissions reduction targets? How will natural CO2 and CH4 fluxes respond to extreme weather events? And which aspects of the carbon cycle remain unsolved? For example, despite decades of study, scientists are still not sure why CH4 emissions are currently rising. To answer these questions we need to be able to measure and quantify CO2 and CH4 emissions and concentrations, and have the ability to separately quantify natural and manmade sources. Our current abilities to do so are severely limited, especially for CH4, which has a diverse array of natural and manmade sources. If we cannot determine the effectiveness of mitigation policies, then our ability to predict climate change impacts will be compromised by large uncertainties. 'Polyisotopologues' are one very promising new tool for distinguishing between different source emissions. The chemical elements that make up CO2 and CH4 molecules (carbon (C), oxygen (O) and hydrogen (H)) can have different masses, called isotopes. Different sources can have different isotopic 'fingerprints' or 'signatures' (because source reaction processes may favour a lighter or heavier molecule), thus measuring isotopic signatures is a useful way to gain insight into sources. Isotopic measurements have been made routinely for several decades; whereas the state-of-the-art technology developed in this project would allow us to measure molecules with more than one rare isotope. For example, most C has a relative atomic mass of 12 and H a mass of 1. The rarer isotopes of C and H have masses of 13 and 2, respectively. Isotopologues of CH4, which are measured routinely, include 12CH4, 13CH4 and 12CH3D (where 'D' represents the heavy H atom with mass 2). Whereas polyisotopologues of CH4 include 13CH3D and 12CH2D2 - these are far more challenging to measure, yet could provide invaluable insight into source emissions and sinks. POLYGRAM (POLYisotopologues of GReenhouse gases: Analysis and Modelling) will push the frontiers for both CO2 and CH4 polyisotopologue measurement capability using the latest advances in laser spectroscopic analysis and very high-resolution isotope ratio mass spectrometry. In addition to these challenging technological developments, we will establish a small global atmospheric sampling network to examine latitudinal and longitudinal variations in polyisotopologues, which will help us to constrain overall global budgets of CO2 and CH4. We will carry out field campaigns to determine polyisotopologue source signatures, for example, of CH4 from wetlands, cattle and landfills, and of CO2 from plant photosynthesis and respiration, and from fossil fuel burning. We will conduct laboratory experiments to estimate the reaction rates for CH4 isotopologues when they are oxidised and destroyed in the atmosphere. Finally, we will carry out atmospheric transport modelling for both gases to better interpret and understand the measurements.

GOTHAM represents an ambitious research programme to gain robust, relevant and transferable knowledge of past and present day patterns and trends of regional climate extremes and variability of vulnerable areas identified by the IPCC, including the tropics and high-latitudes. It will achieve this by identifying the influence of remote drivers, or teleconnections, on regional climate variability, and assessing their relative impact. It will also assess the potential for improved season-decadal prediction using a combination of contemporary climate models, citizen-science computing and advanced statistical analysis tools. GOTHAM has the direct backing of many international weather and climate research centres, and will lead to the improved development of seasonal-decadal forecasts at the regional level. The improved knowledge and understanding of dynamical factors that influence regional weather and climate in the tropics/sub-tropics, and polar regions, will directly feed through to weather and climate forecast services to assist in their decisions on which priority areas of their model development to target in order to improve forecast skills. For example, GOTHAM will advise whether a model is missing or misrepresenting important global teleconnections that significantly influence regional climate in identified vulnerable regions. These impacts will be achieved through regular meetings with GOTHAM investigator groups and their extended collaborative networks, and extensive involvement in wider science and science-policy programmes with co-aligned strategies, such as the core projects within the WCRP. Improved seasonal to decadal scale forecasts will improve predictions of extreme events and natural hazard risks such as flooding that can have devastating impact on society. There is real potential for project results feeding through to impacts-related research, such as those involved in hydrological and flood forecast modeling, and these will be explored in liaison with identified partners in Asia and Europe.

Predicting future climate change is intimately linked to understanding what is happening to the climate system in the present, and in the recent past. Studies in the Polar Regions provide vital clues in our understanding of global climate, and early indications of changes arising from the coupling of natural processes, such as variability in the amount of energy from the Sun reaching the Earth, and man-made factors. For example, the polar winter provides the extreme cold, dark conditions in the atmosphere which, combined with chemicals released from man-made chlorofluorocarbon (CFC) gases, has led to destruction of the ozone layer 18-25 km above the ground every spring-time since the 1980's. The Southern hemisphere ozone 'hole' is now linked to observed changes in surface temperature and sea-ice across Antarctica, decreased uptake of carbon dioxide by the Southern Ocean, and perturbations to the atmospheric circulation that can affect weather patterns as far away as the Northern hemisphere. Ozone loss over the Arctic is generally lower and much more variable, but there is increasing evidence that different meteorology in this region can lead to interactions between regions of the atmosphere from the ground to over 100 km up, on the edge of space. Recovery of the ozone layer is expected now that CFC's are banned by international protocols, but this may be delayed by other greenhouse gases we are releasing into the atmosphere and natural processes such as changes in the Sun's output. Although the total amount of energy as sunlight changes by a small amount (~0.1%) over the typical 11-year solar cycle, the energetic particles - electrons and protons - streaming from the Sun changes dramatically on timescales from hours to years. These particles are guided by the Earth's magnetic field and can enter the upper atmosphere, most intensely over the Polar Regions. A visible effect is the aurora, but the particles can significantly modify the chemistry of the atmosphere down to the ozone layer. Powerful solar storms can also damage satellites and disrupt electrical power networks. However the mechanisms by which energetic particles generated by the Sun enter the Earth's atmosphere, and the complex, interacting processes that affect stratospheric ozone are not well understood, which limits our ability to accurately predict future ozone changes and impacts on climate. We propose answering major unresolved questions about energetic particle effects on ozone by making observations of the middle atmosphere from the prestigious ALOMAR facility in northern Norway. This location, close to the Arctic Circle, is directly under the main region where energetic particles enter the atmosphere, making it ideal to observe the resulting effects. We will install a state-of-the-art microwave radiometer there alongside other equipment run by scientists from all round the world. By analysing the microwaves naturally emitted by the atmosphere high above us we can work out how much ozone there is 30-90 km above the ground as well as measuring chemicals produced in the atmosphere by energetic particles. We will make observations throughout a complete Arctic winter (2011/12) and interpret them with the help of data from orbiting spacecraft measuring the energetic particles entering the atmosphere. We will use the Arctic observations and computer-based models to better understand the impact of energetic particles on the atmosphere. The ultimate goal is to further understanding of the processes that lead to climate variability in the Polar Regions and globally - highly relevant for UK environmental science, the BAS programme, and collaborative research at an international level in which BAS plays a key role.

The Earth's magnetosphere is the region of space close to Earth dominated by Earth's magnetic field. It is not empty, but contains plasma (charged particles) trapped by the magnetic field. In certain regions of the magnetosphere the trapped plasma can produce radio waves as the particles are accelerated along the Earth's magnetic field lines, known as Auroral Kilometric Radiation (AKR). This radio emission can be measured using instruments on board spacecraft, and can give us important information about the particle acceleration. The magnetosphere is highly dynamic and often undergoes a type of global reconfiguration know as a geomagnetic substorm. The onset of a substorm produces some of the most dynamic and spectacular aurora as energy is rapidly transferred from the magnetosphere to the upper atmosphere. In this project we will use observations of AKR made by the Wind spacecraft together with images of the aurora from Lapland to investigate the triggering of substorms and what happens in the minutes around substorm onset. There are several steps to the auroral dynamics in the lead up to a substorm, including the growth of a wave-like movement known as auroral beads. We will measure the energy of the accelerated particles producing the beads to learn more about the mechanism producing the acceleration, and we will investigate changes in the AKR through the different stages of the auroral dynamics. In particular, we will investigate a possible precursor signature of substorms which we found in a previous study of AKR, which could give important clues about the processes which make a substorm begin.