A new algorithm to generate a priori trace gas profiles for the GGG2020 retrieval algorithm

Abstract. Optimal estimation retrievals of trace gas total columns require prior vertical profiles the gases retrieved to drive forward model and ensure retrieval problem is mathematically well posed. For well-mixed gases, it possible derive accurate using an algorithm that accounts for general patterns atmospheric transport coupled with measured time series in questions. Here we describe used generate GGG2020, a new version GGG analyze spectra from solar-viewing Fourier transform spectrometers, including Total Carbon Column Observing Network (TCCON). A particular focus this work improving accuracy CO2, CH4, N2O, HF, CO across tropopause into lower stratosphere. We show revised priors agree independent situ space-based measurements discuss impact on column retrievals.