HR: 0800h
AN: A41C-0053    [Abstracts]
TI: On the effect of spatial aggregation of source regions on the stability of greenhouse gas emission estimates calculated by an inverse Lagrangian box model
AU: * Pieterse, G
EM: G.Pieterse@ecn.nl
AF: Energy Research Institute of the Netherlands, Westderduinweg 3, Petten, 1755 ZG Netherlands
AU: Vermeulen, A
EM: A.Vermeulen@ecn.nl
AF: Energy Research Institute of the Netherlands, Westderduinweg 3, Petten, 1755 ZG Netherlands
AB: Estimation of emission rates from atmospheric concentration observations has proven to remain a big challenge. In this paper, a new approach is chosen for the source strength estimation algorithm based on Source Receptor Matrices (SRM's) as derived for the COMET trajectory model for methane (Vermeulen et al., 2001). In the new approach, source regions are identified automatically by calculation of the Potential Source Region Contribution (PSRC) to measurements performed at multiple sites and spatial aggregation of these regions to achieve uniform PSRC in the aggregated Source-Receptor Matrix (aSRM). The emission strengths are then estimated using Singular Value Decomposition (SVD) of the aSRM. The SVD procedure also yields a Covariance Matrix (CM), which describes the statistical accuracies and mutual dependencies of the solutions. A recursive algorithm is implemented to further accumulate source regions in order to improve covariance and accuracy for the source strength estimates. The aSRM of Europe was constructed using the influence functions for the year 2002 for the locations of the CHIOTTO Tall Tower sites. Measurement data was not available for all sites. The results indicate that the new approach will enable accurate and stable methane budget calculations for the monitored region. As expected, the spatial distribution of the aggregated source regions will not be uniform, because the individual sources are not represented uniformly in the measured signals. Currently, the method is also evaluated for estimation of other greenhouse gas budgets of Europe, like CO₂, SF₆ and N₂O. In principle, the aSRM method can be applied to SRM's of any transport model and component, provided that the forward performance of the model is adequate and that matching observations exist.
DE: 0545 Modeling (4255)
DE: 1218 Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005