Data and scripts for "Antarctic Clouds: Evaluation of the LMDZ Atmospheric General Circulation Model Using CALIPSO Satellite Observations"

Repository for: Antarctic Clouds: Evaluation of the LMDZ Atmospheric General Circulation Model Using CALIPSO Satellite ObservationsAuthors: Justine Charrel, Jean-Baptiste Madeleine, Christophe Genthon, Hélène ChepferContact: [e-mail] This repository contains the complete dataset, simulation environment, and Python scripts required to fully reproduce the simulations and figures presented in the article cited above. The repository is structured into three main directories: Data/, Scripts/, and Figures/. --------------------------------------------------------------------------------------------------------------------------------------1. Model code and simulation environment (Data/LMDZ6A/Simulation/)This folder contains the exact configuration and source code used to run the LMDZ6A general circulation model coupled with the COSP simulator. 1.1 Modipsl environment and compilationmodipsl_IPSLCM7_COSP_2025-12-08/: This directory contains the complete modipsl environment necessary to run the simulations.- We highly recommend that users unfamiliar with the modipsl environment attend the official training sessions (https://ipsl.pages.in2p3.fr/icmc/plateforme/documentation/igcmg_doc/Training/) before attempting to replicate these runs.- The simulations presented in this study were executed on the Jean-Zay HPC cluster at IDRIS (http://www.idris.fr/docs/jean-zay/jean-zay/jean-zay-presentation/).- Source codes are located in modipsl/models and can be compiled using the appropriate compilation script compile_ipslcm7.sh, provided in the modipsl/config/IPSLCM7/ directory. 1.2 Global nudged simulation documentationLMDZOR-COSP-PROD_CMIP6_nudged_lat-lon_global_simulation.html: This html file is a detailed, step-by-step technical guide on how to install, compile, configure, and launch the global lat-lon nudged simulation on the Jean-Zay supercomputer. It covers the specific compilation flags for COSP, the parameter modifications for nudging (`guide.def`), the temporal management of boundary conditions, and job submission guidelines. 1.3 Initial states, boundary conditions and nudgingThe parameter files (e.g., lmdz.card, run.def, guide.def, config.def) used for this study are provided in the respective experiment folder in modipsl/config/IPSLCM7/LMDZOR-COSP-PROD/.Important note regarding heavy input files:Due to storage constraints, the heavy input NetCDF files required to run the model are not included in this archive.If you are running the model on Jean-Zay (IDRIS) or another IPSL-affiliated HPC, these files are generally available on the shared file systems (e.g., $R_IN).Otherwise, they must be downloaded or generated independently.You must update the paths in your .card files to point to your local directories for the following files:- Initial states: start.nc and startphy.nc.- Boundary & forcing files: limit.nc, aerosols, ozone climatology, solar forcing, and stratospheric aerosols.- GHG Files: .txt files for CO2, CH4, N2O, CFC11, and CFC12.- Nudging (ERA5): To run the simulations with wind nudging, you must provide the hourly ERA5 u.nc, v.nc, and T.nc files. The paths to these guiding files must be properly set in the [BoundaryFiles] section of lmdz.card. --------------------------------------------------------------------------------------------------------------------------------------2. Processed data and observations (Data/)This folder contains the observational datasets and the processed LMDZ6A outputs used for the analysis and plotting. - CALIPSO-GOCCP/: Contains the satellite observational data (daily and climatological means) interpolated to the LMDZ6A model grid (144x143) over the Antarctic domain (60°S–90°S).- LMDZ6A/Outputs/: Contains the relevant NetCDF outputs from our LMDZ6A simulations, including native variables (liquid/ice water content, cloud fraction) and COSP simulator outputs. It also includes the daily sea ice fraction (SICF) and surface geopotential (phis) files.- masks/: Contains NetCDF files defining the 5 primary surface categories over Antarctica (Open Water, Intermittent, Ice shelves & perennial sea ice, Margins, Plateau), generated directly from the model's topography and sea ice fraction. (A detailed README describing each specific NetCDF file can be found directly inside the Data/ folder). --------------------------------------------------------------------------------------------------------------------------------------3. Scripts and figures (Scripts/ & Figures/)The Scripts/ folder contains Jupyter Notebooks written in Python used to generate the figures for the publication. - script_fig02.ipynb: Generates the spatial maps of the surface category masks.- script_fig03_fig05.ipynb: Generates the daily spatial verification map and the monthly total cloud cover evolution.- script_fig04_fig06_fig07.ipynb: Generates the 2D spatial maps and the 3D latitudinal cross-sections of cloud fraction profiles and water contents.- script_fig08_fig09.ipynb: Generates the 2D and 3D density histograms (model vs. observations).- script_fig10.ipynb: Computes and plots the Probability Density Functions (PDFs) of daily cloud cover. All generated plots are automatically saved in the Figures/ directory. -------------------------------------------------------------------------------------------------------------------------------------- Environment RequirementsTo run the Jupyter notebooks, a standard scientific Python environment is required. The main dependencies are:numpy, xarray, matplotlib, cartopy, seaborn