Evaluating BC and NO<sub><i>x</i></sub> emission inventories for the Paris region from MEGAPOLI aircraft measurements
High uncertainties affect black carbon (BC) emissions, and, despite its important impact on air pollution and climate, very few BC emissions evaluations are found in the literature. This paper presents a novel approach, based on airborne measurements across the Paris, France, plume, developed in ord...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/15/9799/2015/acp-15-9799-2015.pdf |
| Summary: | High uncertainties affect black carbon (BC) emissions, and, despite its
important impact on air pollution and climate, very few BC emissions
evaluations are found in the literature. This paper presents a novel
approach, based on airborne measurements across the Paris, France, plume,
developed in order to evaluate BC and NO<sub><i>x</i></sub> emissions at the scale of a
whole agglomeration. The methodology consists in integrating, for each
transect, across the plume observed and simulated concentrations above
background. This allows for several error sources (e.g., representativeness, chemistry, plume lateral dispersion) to be minimized in the model used. The
procedure is applied with the CHIMERE chemistry-transport model to three
inventories – the EMEP inventory and the so-called TNO and TNO-MP
inventories – over the month of July 2009. Various systematic uncertainty
sources both in the model (e.g., boundary layer height, vertical mixing,
deposition) and in observations (e.g., BC nature) are discussed and
quantified, notably through sensitivity tests. Large uncertainty values are
determined in our results, which limits the usefulness of the method to
rather strongly erroneous emission inventories. A statistically significant
(but moderate) overestimation is obtained for the TNO BC emissions and the
EMEP and TNO-MP NO<sub><i>x</i></sub> emissions, as well as for the BC / NO<sub><i>x</i></sub> emission ratio
in TNO-MP. The benefit of the airborne approach is discussed through a
comparison with the BC / NO<sub><i>x</i></sub> ratio at a ground site in Paris, which
additionally suggests a spatially heterogeneous error in BC emissions over
the agglomeration. |
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| ISSN: | 1680-7316 1680-7324 |