Comparison between ozone column depths and methane lifetimes computed by 1-D and 3-D models at different atmospheric O2 Levels

Recently, Cooke et al. (2022) used a 3-D coupled chemistry-climate model (WACCM6) to calculate ozone column depths at varied atmospheric O2 levels. They argued that previous 1-D photochemical model studies, e.g., Segura et al. (2003), may have overestimated the ozone column depth at low pO2, and hence also overestimated the lifetime of methane. We have compared new simulations from an updated version of the Segura et al. model with those from WACCM6, together with some results from another 1-D and 3-D model. The discrepancy in ozone column depths is likely due to multiple interacting parameters, including lower boundary conditions, vertical and meridional transport rates, and different chemical mechanisms, especially the treatment of O2 photolysis in the Schumann-Runge (SR) bands (175-205 nm). The discrepancy in tropospheric OH concentrations and methane lifetime between WACCM6 and the 1-D model at low pO2 is reduced when absorption from CO2 and H2O in this wavelength region is included..., We have data from three different models: 1-D photochemical model, WACCM6 3D model, and ROCKE-3D model. All models have been run with 4 different atmospheric O2 levels: 1 PAL, 0.1 PAL, 0.01 PAL, and 0.001 PAL. The source code for the 1-D photochemical model from Kasting group is available on Github: https://github.com/AoshuangJi/1-D-photochemical-model. The specific release for WACCM6 used in this paper is CESM2.1.3, which can be downloaded from the following: https://escomp.github.io/CESM/versions/cesm2.1/html/downloading_cesm. The source code for ROCKE-3D model is available through: https://simplex.giss.nasa.gov/gcm/ROCKE-3D/.
The data for generating Figure 1 are saved in Table 1 in our manuscript.
All the data from the 1D photochemical model are in Standard 1DnoCL.zip and seperate files with '1D' in the filename. Especially, the dataset 'Figure5_1D.csv' is from the 1D photochemical model by running one step from standard run with different solar zenith angles at the present atmospher..., The data can be downloaded and processed using MatLab. The MatLab code 'plotdata.m' to read data and plot all the figures is also uploaded here. The pathway to read data in the code should be adjusted to where readers save those data. More detailed information can be found in 'README.md'.
We have three different models. Files that contain '1D' in the file name are outputs from the 1-D photochemical model. The .zip file 'Standard1DnoCL.zip' includes outputs from Standard 1D model without chlorine at four different pO2 levels. To replicate those runs, one can adjust the chlorine Flag 'CLFLAG' in '/1DModelAoshuangJi/IO/input_atmchem.dat' to '1', and follow the instruction note on Github (see the link below). There are 'Converged' runs and 'ONESTEP' runs. All the important information can be found in files that contains 'outchem'. The data used for plotting are saved in /plot and have 'OUTPUT_PLOT' in the file name. 'NOS' indicates outputs from 1D runs without scattering, and 'NOSNOA' indic...