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.

The restoration of vast tracts of peatlands is a key UK government strategy aiming to help achieve net zero by 2050 and tackle climate change. Peatlands are important global carbon (C) stores accumulating around 30% of the world's soil C in only 3% of its land surface. The UK contains substantial peatland ecosystems, covering more than 12% of the total land area, of which less than a quarter are in near-natural condition. Natural intact peatlands can act as a significant net sink of greenhouse gases (GHGs), removing carbon dioxide (CO2) from our atmosphere and storing it longer term in bog and fen wetlands. Unfortunately, UK peatlands overall represent a significant net source of GHGs to the atmosphere, with 60% of emissions originating from lowland peats drained for agriculture. Widespread peat management and restoration projects, such as rewetting drained, or 'wasted' peatland areas, could therefore aid in mitigating climate change by reducing emissions, as well as by providing wider societal benefits such as promoting biodiversity, minimising flood risks, and helping to provide safe drinking waters. Measuring the effectiveness of landscape peatland recovery efforts is however extremely challenging. Regular measurements of GHG emissions (hourly/ daily) currently require sophisticated and expensive tower infrastructure, limiting the number we can deploy, and the area directly measured to monitor changes in GHGs our landscapes are releasing. We, therefore, require new innovative and low-cost solutions for environmental GHG monitoring instrumentation. The GEMINI project will address these challenges by developing robust, low-cost, and open-access GHG sensor platforms, capable of monitoring CO2 and methane (CH4) emissions from our landscapes and providing information suitable for supplementing current UK observational networks. These sensor systems will have low power requirements making them capable of working remotely, unsupervised for months without mains power. Individual sensors will be capable of measuring regularly (every 30 minutes) and sending their results directly to a shared network.

The aim of this proof-of-concept study is to determine the feasibility of new remote sensing observations that will capture, for the first time, detailed changes in the chemistry of the Earth's stratosphere, mesosphere, and lower thermosphere on short timescales that cannot be measured using other techniques. Such observations would address major gaps in our understanding of the links between solar variability & space weather, atmospheric chemistry, and the global climate system. The importance of the areas targeted by this project are highlighted by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) which states the need to 'assess climate change impact on - and the role of the mesosphere in radiative forcing of the atmosphere'. Ozone and hydroxyl radical (OH) are important trace gases in the middle and upper atmosphere that respond strongly to solar forcing and, at high latitudes, geomagnetic activity associated with space weather. Energetic particles from space are guided by the Earth's magnetic field into the atmosphere at high latitudes. Important questions about this energetic particle precipitation remain unresolved. These include what are the key chemical changes in the middle and upper atmosphere and how are these changes are coupled to the atmospheric layers below? Following geomagnetic storms, energetic electron precipitation (EEP) into the polar middle atmosphere causes ionisation reactions that generate odd nitrogen and odd hydrogen species, in particular OH. These reactive chemicals take part in both short-duration and long-term catalytic destruction of ozone that modifies the radiative and thermal structure of the atmosphere, affecting temperatures down to the Earth's surface. EEP occurs very frequently and potentially has a more significant impact on the atmosphere than the impulsive but highly sporadic and well-studied effects of powerful solar proton storms. It has been difficult to estimate the effect of EEP on the atmosphere because of the challenge of making measurements of rapidly-evolving atmospheric chemical composition, in particular ozone and OH, at altitudes of 20-100 km. Commercial satellite TV broadcasting is possible due to remarkable advances in microwave electronics, enabling weak signals transmitted over 36,000 km from geostationary orbit to be received by inexpensive rooftop dishes. We propose incorporating the highly-sensitive Ku-band satellite receiver technology in ground-based microwave radiometers to measure ozone and OH. The microwave spectrum of the atmosphere contains information about ozone from an emission line at 11.072 GHz and from OH at 13.44 GHz. Ku-band microwave radiometry will allow precise, quantitative characterisation of these atmospheric signals using the sensitive heterodyne detection technique combined with high-resolution radiofrequency analysis. We will use computer-based algorithms to investigate how ten-fold improvements in receiver sensitivity will allow detailed measurements of the spatial and temporal distributions of ozone and OH. The proposed instruments would be robust, semi-autonomous, and operate continuously making observations that are highly applicable to studies of EEP, atmospheric dynamics, planetary scale circulation, chemical transport, and the representation of these processes in global climate models, ultimately leading to advances in numerical weather prediction. They would provide a low cost, reliable alternative to increasingly sparse satellite measurements, extending long-term data records and also providing "ground truth" data for calibrating and validating scientific satellite data. The work is relevant to three NERC research subjects (Atmospheric physics and chemistry; Climate and climate change; Tools, technology & methods) and will build UK expertise in microwave remote sensing and atmospheric information retrieval.

Ships generally burn low quality fuel and emit large quantities of sulfur dioxide and particulates, or aerosols (harmful at high concentrations), into the atmosphere above the ocean. In the presence of clouds the sulfur dioxide is rapidly converted into more particle mass growing them to sizes where they act as sites for cloud droplet formation. Given that about 70% of shipping activities occur within 400 km of the coast, ships are a large source of air pollution in coastal regions, causing 400k premature mortalities per year globally. In the UK, air pollution (including ship emissions) is responsible for 40,000 premature mortalities each year. In an effort to reduce air pollution from shipping activity, the United Nation's International Maritime Organization (IMO) is introducing new regulations from January 2020 that will require ships in international waters to reduce their maximum sulfur emissions from 3.5% by mass of fuel to 0.5%. Particulates emitted by ships may enhance the number of cloud droplets and potentially form regions of brighter clouds known as ship tracks. Largely because of this effect, some global models predict that ship emissions of particulates currently have a significant cooling influence on the global climate, masking a fraction of the warming caused by greenhouse gas emissions. So whilst a reduction in ship sulfur emission is predicted to almost halve the number of premature deaths globally via a reduction in sulfate aerosols, a lack of similar reductions in greenhouse gases from shipping (e.g. CO2) could lead to an overall climate warming. However, the magnitude of the cooling caused by particulates is very uncertain, with large discrepancies between global model and satellite-based estimates. This may be due to imprecise representations of the effects of aerosols on clouds in global models or biases in satellite detections of ship tracks. Furthermore, how shipping companies respond to the 2020 regulation (i.e. degree and method of compliance), in international waters where surveillance is challenging, is largely unknown and requires observational verification. We will take advantage of this unique and drastic "inverse geoengineering" event in 2020. By combining aircraft observations, long-term surface observations, satellite remote sensing, and process-level modelling, we will investigate the impact of the 2020 ship sulfur emission regulation on atmospheric composition, radiative forcing and climate in the North Atlantic. Results of this project will improve our understanding of the impact of ship emissions on air quality and climate.

This proposal will combine the expertise and data sets provided by Lancaster University and the British Antarctic Survey to answer a series of important questions regarding the significance of charged particle precipitation into the atmosphere on atmospheric chemistry. This will advance the debate on how solar activity affects tropospheric and stratospheric variability by establishing a key link in the chain. Two inter-hemispheric, ground-based networks of instruments will be used to provide estimates of energetic electron precipitation. Lancaster is the PI institute for the Global Riometer Array (GLORIA) and BAS is the co-PI institute of the Antarctic-Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Konsortia (AARDDVARK). This project aims to provide a global picture of the fluxes of energetic electrons entering the atmosphere in order to answer the key question: what is the significance of energetic electron precipitation to atmospheric chemistry and dynamics? The primary aim of this proposal will be to utilise the riometer (relative ionospheric opacity meter) and VLF (very low frequency) radio wave observations together with advanced modelling of the electron distributions in the magnetosphere, in order to determine the characteristics of energetic electron precipitation in the atmosphere and the polar regions in particular. These instruments respond to different electron energies and by combining the observations with suitable modelling of the electrons in the magnetosphere it is possible to make estimates of the location, energy spectrum and flux of electron precipitation events, particularly in the polar regions, and at energies that have implications for atmospheric chemistry in the stratosphere and mesosphere. The data product will be of particular use for coupled-climate models as an input to represent the coupling between geomagnetic activity and the atmosphere, instead of broad geomagnetic indexes such as Ap or Kp. Although the key aim is to produce electron flux spectra, this can be easily converted into ion-pair production rates or even NOx profiles to suit the model input requirements. This data product will be employed in an ion and neutral chemistry model to determine the corresponding level of NOx production. We will use this to answer the following key questions: 1. How does the NOx profile vary during substorms and storms? 2. How does NOx production vary between hemispheres? We will determine the role of solar wind driving of atmospheric chemistry rather than solar irradiance. The inter-hemispheric nature of GLORIA and AARDDVARK means that we will be able to determine NOx production in both polar regions simultaneously and determine differences and similarities from season to season. These are important questions concerning the importance of atmospheric chemistry in the upper atmosphere and how it is influenced by geomagnetic activity. We will therefore be able to answer what is the significance of energetic electron precipitation to atmospheric chemistry and dynamics?