Urban CO2 emissions from space: Sensitivity analysis and inter-comparison of light atmospheric inversion methods
Alexandre Danjou, Laboratoire des Sciences du Climat et de l'Environnement - IPSL, alexandre.danjou@lsce.ipsl.fr (Presenter)
Gregoire Broquet, Laboratoire des Sciences du Climat et de l'Environnement - IPSL, gregoire.broquet@lsce.ipsl.fr
Jinghui Lian, Origins, Suez, jinghui.lian@suez.com
François-Marie Bréon, Laboratoire des Sciences du Climat et de l'Environnement - IPSL, breon@lsce.ipsl.fr
Annmarie Eldering, Jet Propulsory Laboratory - NASA, annmarie.eldering@jpl.nasa.gov
Hervé Utard, Origins - Suez, herve.utard@origins.com
Thomas Lauvaux, Laboratoire des Sciences du Climat et de l'Environnement - IPSL, thomas.lauvaux@lsce.ipsl.fr
Several concepts of spaceborne instruments providing high resolution 2D views of atmospheric CO2 total column concentrations (XCO2) have been developed to monitor the CO2 anthropogenic emissions. Those concepts aim at collecting images of CO2 atmospheric plumes from cities and large power plants, whose analysis can lead, in principle, to the quantification of the corresponding emissions. However, there is still a need to develop and to asses emission estimation methods able to process rapidly a large number of XCO2 images.
In this study, the ability to quantify CO2 urban emissions from XCO2 2D images was examined using synthetic images at 1km resolution over the Paris area during the winter 2019/2020. The synthetic data were simulated using state-of-the-art mesoscale model simulations at 1km resolution coupled to a high-resolution inventory. We compared multiple direct flux calculation methods (Source Pixel, Integrated Mass Enhancement and Cross-sectional methods), further examined with various configurations, in addition to several formulations of Gaussian plume inversion techniques. These methods are computationally affordable compared to mesoscale inversions based on Eulerian or Lagrangian models, hence able to process rapidly a large amount of data over various cities in the future.
We quantified the uncertainties and accuracy of these methods using different combinations of assumptions to i) identify the plume from the city, ii) to determine the corresponding background concentrations from natural and anthropogenic sources outside the city, and iii) to estimate the effective wind speed and direction of the plume. From this large ensemble of approaches and configurations, we identified the most robust methods and parametrizations with their corresponding precisions under various meteorological conditions.
Starting with ideal cases without measurement noise and with perfectly known transport, we further increase the complexity of the experiments towards more realistic conditions. We show that the performances of most methods are similar in near steady state conditions and the observation conditions (wind variability, wind speed) impact their accuracy. However, the final uncertainty is mainly driven by some pre-processing steps (background, plume limits estimations).
Poster: Poster_Danjou__40_25.pdf
Presentation Type: Poster
Session: 4.2a Observations to quantify hot spots and local/urban emissions
Session Date: Thursday (6/17) 10:00 AM