Abstract
Inaccurate representation of atmospheric processes by transport
models is a dominant source of uncertainty in inverse analyses and can lead
to large discrepancies in the retrieved flux estimates. We investigate the
impact of uncertainties in vertical transport as simulated by atmospheric
transport models on fluxes retrieved using vertical profiles from aircraft
as an observational constraint. Our numerical experiments are based on
synthetic data with realistic spatial and temporal sampling of aircraft
measurements. The impact of such uncertainties on the flux retrieved using
the ground-based network and those retrieved using the aircraft profiles
are compared. We find that the posterior flux retrieved using aircraft
profiles is less susceptible to errors in boundary layer height, compared
to the ground-based network. This finding highlights a benefit of utilizing
atmospheric observations made onboard aircraft over surface measurements for
flux estimation using inverse methods. We further use synthetic vertical
profiles of CO2 in an inversion to estimate the potential of these
measurements, which will be made available through the IAGOS (In-service
Aircraft for a Global Observing System) project in the future, in constraining
the regional carbon budget. Our results show that the regions of tropical
Africa and temperate Eurasia, that are under-constrained by the existing
surface-based network, will benefit the most from these measurements, with
a reduction of posterior flux uncertainty of about 7 to 10 %.
Citation
ID:
166997
Ref Key:
verma2017atmosphericthe