Comment on acp-2020-1195

Abstract

The study presents an inversion analysis with a well-established modelling system using both in situ measurements from the ECCC network and GOSAT satellite measurements. The targeted region for analysis is Canada, and only fluxes in this domain are adjusted and only measurements over this domain are assimilated, which may be problematic (see discussion below). Various state vector setups are presented, where the anthropogenic and biogenic fluxes are scaled separately in time (annually or monthly, respectively) and based on anthropogenic sector or province. Due to the limited number of measurements, these latter approaches are rightly judged to be less robust. The study is interesting and relevant, although I have some concerns about the approach.