EarthMesh is a mesh generation tool for land surface, ocean, and atmospheric models. It generates unstructured meshes with adaptive refinement based on various surface characteristics.

• Generates well-centered Delaunay triangle and dual hexagonal meshes
• Performs adaptive mesh refinement based on configurable thresholds
• Supports refinement criteria like land type heterogeneity, topography, LAI, soil properties, etc.
• Supports generation of land surface, ocean and atmospheric meshes for global/limited-area modeling
• Outputs mesh files compatible with CoLM2024, FVCOM, MPAS, OLAM and other models

• NetCDF library
• Fortran compiler (Intel Fortran or gfortran)

EarthMesh/
├── src/                    # Source code directory
│   ├── mkgrd.F90          # Main program for mesh generation
│   ├── MOD_*.F90          # Module files for preprocessing and refinement
│   ├── blas.F90           # BLAS routines
│   ├── lapack.F90         # LAPACK routines
│   ├── consts_coms.F90    # Constants and common variables
│   └── icosahedron.F90    # Icosahedral mesh generation
├── examples/               # Example configuration files
│   ├── *.nml              # Namelist configuration files
│   └── mask_refine_filelist.txt
├── Makefile                # Build configuration
├── Makeoptions*            # Compiler-specific options
├── make.sh                 # Intel compiler build script
├── make_gnu.sh             # GNU compiler build script
├── switch_compiler.sh      # Compiler switching utility
├── .gitignore              # Git ignore rules
└── README.md               # This file

make

Or use the build script:

./make.sh

./make_gnu.sh

Or manually:

cp Makeoptions.gnu Makeoptions
make

Use the switch_compiler.sh script to switch between Intel and GNU compilers:

./switch_compiler.sh

After compilation, the executable mkgrd.x will be created in the root directory.

To clean compiled files:

make clean

Run the executable with a namelist file from the examples directory:

./mkgrd.x examples/Atmos_hex_NXP64_refine2_Global_251027.nml

Edit the namelist file in the examples/ directory (e.g., Atmos_hex_NXP64_refine2_Global_251027.nml) to configure:

• Mesh resolution
• Refinement criteria and thresholds
• Input/output file paths
• Domain specifications

• examples/Atmos_hex_NXP64_refine2_Global_251027.nml - Global atmospheric mesh with refinement
• examples/Atmos_hex_NXP64_refine2_Global_Simple_251027.nml - Simplified global atmospheric mesh

Output directories are created based on the configuration in the namelist file. Typical output includes:

• meshfile/ - Main mesh definition files (cell vertices, connectivity)
• result/ - Final mesh files from the last refinement iteration
• contain/ - Containment relationship files
• threshold/ - Threshold files for adaptive refinement
• tmpfile/ - Intermediate output files during refinement

All source modules are located in the src/ directory:

• mkgrd.F90 - Main program
• MOD_grid_preprocess.F90 - Grid preprocessing and initialization
• MOD_refine.F90 - Mesh refinement algorithms
• MOD_Area_judge.F90 - Area and region determination
• MOD_GetContain.F90 - Cell containment calculations
• MOD_GetRef.F90 - Reference data processing
• MOD_data_preprocess.F90 - Input data preprocessing
• MOD_file_preprocess.F90 - File I/O operations
• MOD_mask_postproc.F90 - Post-processing of mask data
• consts_coms.F90 - Constants and common variables
• icosahedron.F90 - Icosahedral mesh generation
• blas.F90, lapack.F90 - Linear algebra routines

• Rui Zhang (V2)
• Hanwen Fan (V1)
• Zhongwang Wei @ SYSU

If you use this tool in your research, please cite:

Fan, H., Xu, Q., Bai, F., Wei, Z., Zhang, Y., Lu, X., Wei, N., Zhang, S., Yuan, H., Liu, S. and Li, X., 2024. An unstructured mesh generation tool for efficient high-resolution representation of spatial heterogeneity in land surface models. Geophysical Research Letters, 51(6), p.e2023GL107059.

This project is licensed under the GNU General Public License v2.0.

For questions or support, please contact:

• Zhongwang Wei (zhongwang007@gmail.com)

• 2025.10.28 - Reorganized code structure with src/ and examples/ directories
• 2025.01.09 - V2 initial version developed by Rui Zhang
• 2024.07.19 - Updates by Zhongwang Wei
• 2023.10.28 - Development by Hanwen Fan and Zhongwang Wei @ SYSU
• 2023.02.21 - Updates by Zhongwang Wei @ SYSU
• 2021.12.02 - Initial development by Zhongwang Wei @ SYSU