UK-South Africa Partnership : EO for Atmospheric Composition Science

Climate change mitigation, and air quality (AQ) improvement are two inter-related pressing global challenges for which high quality, trustable Earth Observation (EO) data are essential. Particularly, quantitative knowledge of atmospheric composition is required to understand the gases and particulates emitted into the atmosphere (processes and quantities), their fate (transport and chemistry), and their impact on the Earth system and ultimately on the present and the future health of the biosphere (including people). To that end, both for the quantification of greenhouse gases (GHG) and pollutants, complex EO systems combining satellite-borne, airborne, and ground-based instrument networks, together with models and data analytics, have been and are being developed nationally and globally.

EO data of the atmosphere’s composition obtained remotely from the satellite infrastructure are inherently global. However, the quality of the satellite data sets is dependent upon a network of ground-based instruments for validation, which are overwhelmingly located in the northern hemisphere, and operated by the most industrialized countries. For example, there is no such validation site anywhere in Africa as far as GHG data are concerned. This introduces some significant geographical biases, associated to the local specificity of the land (albedo) and gas transport, affecting the global dataset quality and therefore its use for accurate monitoring and understanding of GHG- and AQ-related atmospheric processes. This is particularly detrimental to the global effort to transparently reduce GHG emission and improve AQ.

The aim of the project is to establish a UK/South Africa long term collaboration towards augmenting the global EO ground-based capabilities, essential to maintaining and validating the accuracy of GHG and AQ measurements made remotely from satellites and to relate local measurements to global datasets. By leveraging the expertise of STFC RAL Space and NRF South African Environmental Observation Network, the primary objective is to establish a first validation site in South Africa with ground-based remote sensing instrumentation relevant to GHG and AQ, collect a dataset over a season, analyse the data using advanced algorithms, and demonstrate their added value to the EO and atmospheric composition sciences. In addition, a novel, machine-learning approach to use satellite observations to extend surface network measurements of pollutants across South Africa will be demonstrated.

Through this seminal project, the project team intends to produce evidence in support of the establishment of a permanent ground-based reference EO validation site in an under-sampled region of the world; ultimately to be integrated into the international satellite validation networks and to contribute to addressing global environmental issues. Such an ‘EO super-site’ is ideal for capacity building, strengthening UK/South Africa collaborative links, improving both infrastructure and skills, training the next generation of EO scientists and technologists, and growing knowledge and understanding in atmospheric composition, with a relation to land GHG emission and AQ that can inform policy and possible actions.