File : D2.11
Authors : Audrey Fortems-Cheiney and Grégoire Broquet(CEA)
We have developed an atmospheric inversion configuration to quantify monthly to annual budgets of the national emissions of FFCO2 in Europe over 10 years from 2008 to 2017. These FFCO2 emission estimates are based on the assimilation of the long-term series of NO2 OMI spaceborne observations. In a first step, variational regional inversions are performed to estimate the daily European NOx emissions at 0.5° horizontal resolution, using the TNO-GHGco-v2 inventory as prior, the NO2 OMI data, the CIF and the CHIMERE regional CTM. In a second step, these maps are converted into estimates of the correction to be applied to monthly budget of sectoral anthropogenic NOx and then FFCO2 emissions per country.
Results mainly indicate an increase of the estimates of NOx anthropogenic emissions by the inversion compared to the TNO-GHGco-v2 inventory, mainly due to positive corrections during spring and summer, in particular over polluted areas. The annual budget of European NOx anthropogenic emissions is increased by about 5% compared to the TNO-GHGco-v2 inventory. The corresponding estimate of FFCO2 emissions is also slightly larger than those of the TNO-GHGco-v2 inventory. Overall, this shows a general consistency between our estimates based on NO2 satellite data and the inventory which is a positive indication regarding the potential of the atmospheric inversion approach to support the estimate FFCO2 emissions at the national scale. However, the uncertainties in the FFCO2 inversions presented here are still too high to attempt at using these inversions to improve the current knowledge on the FFCO2 national scale emission budgets in Europe, although further progresses are expected.
Figure 1 : Monthly estimates of German (in grey), French (in cyan), Polish (in magenta) and Dutch (in blue) FFCO2 emissions from the TNO-GHGco-v2 inventory (in thin line) and from the inversions (in bold line), in ktCO2, from January 2008 to December 2017
