GEMINI-UK

GEMINI-UK (Greenhouse gas Emissions Monitoring network to Inform Net-zero Initiatives for the UK) is the National Centre for Earth Observation’s main contribution towards the Greenhouse gas Emissions Measurement and Modelling Advancement programme, or GEMMA for short

GEMMA aims to produce data and model driven estimates of the UK’s greenhouse gas emissions at a regional level, on a regular basis. Through GEMMA, the Natural Environment Research Council has invested over £5 million in improving and expanding the UK’s greenhouse gas observing network. As part of this investment, GEMINI-UK represents a new capability for measuring column concentrations of greenhouse gases around the country using ground-based remote sensing technology. NCEO are responsible for the planning and deployment of GEMINI-UK, and will play a lead role in understanding the measurements made by the network. 

Once established in 2024, GEMINI-UK will comprise 10 new Bruker EM27/SUN spectrometers operated at locations all around the UK. These instruments, which are sensitive to the shortwave infrared part of the electromagnetic spectrum, measure direct sunlight using a solar tracker. By analysing the measured spectrum at wavelengths absorbed by carbon dioxide, methane, and carbon monoxide, we are able to determine how much light is absorbed by these gases as it passes through the atmosphere, and in turn extract their concentrations in the atmosphere above each of our measurement sites. 

To operate these instruments continuously, remotely, and autonomously over a long period of time, we have developed an automated weatherproof enclosure that ensures the instrument remains within its safe operating temperatures and humidity. A mini-PC within the enclosure controls the spectrometer and solar tracker, automatically starting operations at the beginning of each day once the Sun is high enough above the horizon, whilst also allowing remote access, control, and data upload via the internet. An optical glass dome lets light through to the solar tracker whilst allowing us to maintain a stable environment within the enclosure, and is protected by an automated cover which moves into place when triggered by a rain sensor. 

The measurements collected at each of the sites will be processed centrally, producing time series of greenhouse gas column concentration data. Through the GEMMA programme, this data will then be included in the atmospheric inversions operated by colleagues at the UK Met Office, University of Bristol and University of Edinburgh, resulting in improved carbon emissions estimates for the UK.