Showing papers by "Peter Bergamaschi published in 2022"
••
TL;DR: In this article , a novel high-resolution inverse modeling system (FLEXVAR) based on FLEXPART-COSMO back trajectories driven by COSMO-7 domain and the four-dimensional variational (4DVAR)-based dataimilation technique is presented.
Abstract: Abstract. We present a novel high-resolution inverse modelling
system (“FLEXVAR”) based on FLEXPART-COSMO back trajectories driven by COSMO
meteorological fields at 7 km×7 km resolution over the European
COSMO-7 domain and the four-dimensional variational (4DVAR) data
assimilation technique. FLEXVAR is coupled offline with the global inverse
modelling system TM5-4DVAR to provide background mole fractions
(“baselines”) consistent with the global observations assimilated in
TM5-4DVAR. We have applied the FLEXVAR system for the inverse modelling of
European CH4 emissions in 2018 using 24 stations with in situ
measurements, complemented with data from five stations with discrete air
sampling (and additional stations outside the European COSMO-7 domain used
for the global TM5-4DVAR inversions). The sensitivity of the FLEXVAR
inversions to different approaches to calculate the baselines, different
parameterizations of the model representation error, different settings of
the prior error covariance parameters, different prior inventories, and
different observation data sets are investigated in detail. Furthermore, the
FLEXVAR inversions are compared to inversions with the FLEXPART extended
Kalman filter (“FLExKF”) system and with TM5-4DVAR inversions at 1∘×1∘ resolution over Europe. The three inverse modelling
systems show overall good consistency of the major spatial patterns of the
derived inversion increments and in general only relatively small
differences in the derived annual total emissions of larger country regions.
At the same time, the FLEXVAR inversions at 7 km×7 km resolution
allow the observations to be better reproduced than the TM5-4DVAR simulations
at 1∘×1∘. The three inverse models derive
higher annual total CH4 emissions in 2018 for Germany, France, and
BENELUX compared to the sum of anthropogenic emissions reported to UNFCCC
and natural emissions estimated from the Global Carbon Project CH4
inventory, but the uncertainty ranges of top-down and bottom-up total
emission estimates overlap for all three country regions. In contrast, the
top-down estimates for the sum of emissions from the UK and
Ireland agree relatively well with the total of anthropogenic and natural
bottom-up inventories.
4 citations