Title: Inverse Modelling of European N2O Emissions: Assimilating Observations from Different Networks
Authors: CORAZZA MATTEOBERGAMASCHI PeterVERMEULEN A.t.AALTO A.HASZPRA L.MEINHARDT F.O'DOHERTY S.THOMPSON R.MONCRIEFF J.POPA E.STEINBACHER M.JORDAN A.DLUGOKENCKY E.BRÜHL C.KROL M.DENTENER Franciscus
Citation: ATMOSPHERIC CHEMISTRY AND PHYSICS vol. 11 no. 5 p. 2381-2398
Publisher: COPERNICUS GESELLSCHAFT MBH
Publication Year: 2011
JRC N°: JRC60421
ISSN: 1680-7316
URI: http://www.atmos-chem-phys.net/11/2381/2011/acp-11-2381-2011.html
http://publications.jrc.ec.europa.eu/repository/handle/JRC60421
DOI: 10.5194/acp-11-2381-2011
Type: Articles in Journals
Abstract: We describe the setup and first results of an inverse modelling system for atmospheric N2O, based on a four-dimensional variational (4DVAR) technique and the atmospheric transport zoom model TM5. We focus in this study on the European domain, utilizing a comprehensive set of quasi-continuous measurements over Europe, complemented by N2O measurements from the NOAA/ESRL cooperative global air sampling network. Despite ongoing measurement comparisons among networks parallel measurements at a limited number of stations show that significant offsets exist among the different laboratories. Since the spatial gradients of N2O mixing ratios are of the same order of magnitude as these biases, the direct use of these biased datasets would lead to significant errors in the derived emissions. Therefore, in order to also use measurements with unknown offsets, a new bias correction scheme has been implemented within the TM5-4DVAR inverse modelling system, thus allowing the simultaneous assimilation of observations from different networks. The N2O bias corrections determined in the TM5-4DVAR system agree within 0.1 ppb with the bias derived from the measurements at monitoring stations where parallel NOAA discrete air samples are available. The N2O emissions derived for the northwest European countries for 2006 show good agreement with the bottom-up emission inventories reported to UNFCCC. Moreover, the inverse model can significantly narrow the uncertainty range reported in N2O emission inventories, while the lack of measurements does not allow for better emission estimates in southern Europe. Several sensitivity experiments were performed to test the robustness of the results. It is shown that also inversions without detailed a priori spatio-temporal emission distributions are capable to reproduce major regional emission patterns within the footprint of the existing atmospheric network, demonstrating the strong constraints of the atmospheric observations on the derived emissions.
JRC Institute:Institute for Environment and Sustainability

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.