Carbon Atmospheric Tracer Research to Improve Numerics and Evaluation

Project Information

CATRINE

Grant agreement ID: 101135000

DOI

10.3030/101135000

EC signature date 21 November 2023

Start date 1 January 2024

End date 31 December 2026

Funded under

• Digital, Industry and Space

Total cost

No data

EU contribution

€ 2 996 289,69

Coordinated by

EUROPEAN CENTRE FOR MEDIUM-RANGE WEATHER FORECASTS
United Kingdom

Periodic Reporting for period 1 - CATRINE (Carbon Atmospheric Tracer Research to Improve Numerics and Evaluation)

Reporting period: 2024-01-01 to 2025-06-30

Summary of the context and overall objectives of the project

The CATRINE project will focus on the atmospheric tracer transport research areas identified by the EU's CO2 Task Force, the CO2 Human Emissions (CHE) project, and the Copernicus CO2 service (CoCO2) projects. The accuracy and mass conservation of the tracer transport model is of utmost importance in the design of the CO2MVS. Any unaccounted systematic errors in the tracer transport model can lead to inaccuracies in the estimation of CO2 and other tracer emissions. Therefore, CATRINE aims to improve the methods used to represent resolved tracer transport by the winds, with a particular focus on mass conservation, and to identify other systematic errors associated with unresolved processes represented by parametrizations. The project will define protocols for evaluating tracer transport models at both global and local scales. Test beds based on field campaign case studies will be developed, along with suitable metrics for tracer transport evaluation, utilising a range of tracers and observations at both global and local scales.
These metrics will be employed in the operational CO2MVS to evaluate the implementation of new transport model developments, characterise transport accuracy and representativity in data assimilation, and provide a quality control stamp of tracer transport accuracy. Lastly, CATRINE will provide clear recommendations to the CO2MVS and the Carbon Cycle Community which works with atmospheric inversion models for the evaluation and quality assessment of tracer transport models.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Significant progress has been made in understanding the origins and evolution of mass conservation errors in the global CO2MVS IFS advection scheme, particularly in relation to various atmospheric tracers relevant to CO2MVS. Such findings have enabled the identification of areas for improvements within the core algorithms of the IFS advection scheme, leading to a noticeable reduction in mass conservation errors. Furthermore, analysis across a wide range of case studies— from academic case studies to comprehensive greenhouse simulations under accurate emission protocols developed in WP7 — has demonstrated that the optimized configuration of the IFS advection scheme developed by CATRINE can accurately transport atmospheric tracers, when mass errors are controlled by the mass fixer.
• Two Large Eddy Simulation (LES) protocols for modelling transport in plumes from emission hotspots have been delivered. The implementation of various configurations for the coupling of boundary conditions and various plume rise models have been completed with recommendations provided for the protocol.
• Test beds for parametrizations of convection and turbulent mixing have been designed focusing on the boundary layer and upper-troposphere and lower stratosphere. These use a comprehensive set of observations from field campaigns, very high-resolution LES simulations, as well as modelling protocols based on the CAMS IFS forecast and analysis of greenhouse gases and a new TransCom protocol for the evaluation of global atmospheric transport models. An initial evaluation of the IFS and ICON-ART simulations with the test beds has also been performed. The results show an overall good agreement with observations, but highlight sensitivities with model resolution and physical parametrizations which will be further investigated in the next half of the project using the Stochastic Perturbation of Parametrizations approach.
• A new protocol to evaluate global transport models has been designed for the TransCom model inter-comparison exercise to be led by the CATRINE project. It includes the four CATRINE global models (IFS, ICON-ART, LMDz, TM5), and 5 additional modelling groups outside CATRINE have also been invited after a successful TransCom international workshop organized by CATRINE. A preliminary evaluation of the CATRINE global model simulations shows the fit to the observations at background sites is generally good, although there are significant systematic differences in the inter-hemispheric gradient between the transport models, as well as a large spread near the surface and in the upper troposphere. New diagnostics are proposed to assess atmospheric transport processes based on vertically integrated mass fluxes which will help to elucidate the systematic errors and differences detected in the transport models during the TransCom intercomparison exercise. These diagnostics are commonly used in the evaluation of the hydrological cycle in Numerical Weather Prediction (NWP) re-analysis products and have the potential of improving atmospheric transport evaluation in inversion models.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Although much of the work is still in progress our first results move beyond the state of the art. Significant advances have been made in understanding the origin of mass conservation errors in the global CO2MVS IFS advection scheme, leading to refinements in core algorithms. Two Large Eddy Simulation (LES) protocols are being drafted, with advances in boundary condition coupling and the implementation of a plume rise model. Testbeds for convection and turbulent mixing parametrizations have also been developed and used to evaluate the IFS and ICON-ART models, leveraging field observations and high-resolution LES. Finally, a new TransCom protocol has been presented to the international community of atmospheric inversion modellers focusing for the first time on the impact of high resolution on the transport of anthropogenic CO2 in global models. The evaluation of the transport model intercomparison will include new mass budget diagnostics to quantify the relative contribution of transport and surface fluxes on the observed atmospheric variability of CO2 and other tracers. A new tracer transport evaluation strategy based on a range of tracer indices built upon a multi-tracer and multi-scale approach has also been proposed.

Large Eddy Simulation of CO2 plumes at 10m height from the Rotterdam area using MicroHH model