Miniature autonomous LHR for CO2 column measurements

Globally rising and accelerating levels of CO2 in the atmosphere, most likely due to human activity and anthropogenic emissions , are believed to be the main driver of climate change . Within the global carbon biogeochemical cycle, the regional quantification of terrestrial (and to a lesser extent, oceanic) sources, sinks and feedbacks remains uncertain, particularly in the tropics . Likewise, geographical patterns of CO2 emissions from fossil sources are needed to improve upon the regional land flux estimates . Reducing uncertainties on the carbon cycle quantification is currently one of the most challenging tasks within climate research. Therefore improved instrumentation to be part of a carbon observing system is urgently needed, either to produce new dataset beyond what commercial systems are currently capable of, or to participate in the validation and constraining of flux estimation algorithms along the next generation of space-based remote sounders.

We propose the demonstration of an instrument concept anticipated to enable for the first time the deployment of dense, autonomous, ground-based sounder networks for atmospheric CO2 profiling and column measurements. The concept of ultra-miniaturized thermal infrared laser heterodyne spectro-radiometer (TIR-LHR) offers significant advantages: high column measurement precision (<0.5% in 90s), high temporal resolution (~1 measurement/minute), unprecedented compact and deployable package ultimately suitable to operate autonomously as part of large networks, and moderate cost of purchase and maintenance. We believe the benefits of the proposed technology enable a significant qualitative step in greenhouse gas (GHG) measurement and associated scientific investigations. The instrument concept combines the benefits of TIR-LHR, and those of the latest miniaturization advances in laser based systems we have developed. Even though intrinsically flexible, the demonstrator will target CO2 (and H2O and SF6) as one of the most important GHG whose fluxes needs accurate characterization and monitoring.

The proposed project combines thermal infrared laser heterodyne spectro-radiometry (TIR-LHR) with unique miniaturization and ruggedization technologies to develop the smallest-ever system for accurate column and profile measurements of atmospheric constituents. When fully mature, the concept will be widely applicable, with a corresponding range of impacts.
1) Impact relevant to the specific case of atmospheric CO2
The proposed technology will contribute to the understanding and characterization of climate change and as such also contribute to the socio-economical benefits of mitigation. In addition, the proposed technology, driven by the demand for CO2 emission monitoring, is relevant for the development of a environmental sensing product, hence benefiting the UK in innovation, and job creation. The technology is foreseen to be of importance as part of a green house gas observing system, which could provide the data for an emission service creation for industries, governments, local authorities.
2) Wider applications of the proposed technology
The proposed project targets CO2 as one of the most important green house gas. However, the technology is generic and can be used for any atmospheric or gas phase molecule. Therefore the impact is much wider and spans into the entire environmental analysis sector, with perhaps air quality as the most pressing one. Beyond the TIR-LHR remote sounding concept, the miniaturization to be implemented in the project is a technology platform relevant to a large spectrum of optical technologies. This would contribute to field sensor miniaturization and cost reduction to enable wide spread use of new sensing technologies in the field.

The impact will be realized through close interaction with the Rutherford Appleton Lab technology transfer office (SIL). IP will be secured and business approached to license the technology and develop a business case. At the same time, end users will be approached to develop application and deployment of the technology with early adopters.