VGRID

Vertical Hybrid-pressure grid generation

Components of the lib

This is composed of:

• A Fortran program (src/mkvgrid/main.F90) for generating hybrid-pressure grid.
• A Fortran library (src/stdatm/) containing routines for standard atmosphere computations of altitude and pressure on grid levels.
• A Python interface package pyvgrid (src/pyvgrid/) to the Fortran program and library, including also utilities to plot grids using bokeh.
• Examples of namelists (nam/) used to generate grids, including canonical ones.

Install

Using pip:

• pip install pyvgrid

To recompile:

• git clone https://github.com/ACCORD-NWP/vgrid.git
• cd vgrid
• for the python interface (incl. compilation):
  1. python -m build
  2. pip install dist/pyvgrid*.whl
• for the Fortran only: 0. BUILD_DIR=<where you want to build>; INSTALL_DIR=<where you want to install>
  1. cmake -B $BUILD_DIR -DCMAKE_INSTALL_PREFIX=$INSTALL_DIR
  2. cmake --build $BUILD_DIR
  3. cmake --install $BUILD_DIR

Examples of use

1. Generation of a new grid from namelist and command-line:

   • Prepare a namelist containing the parameters to tune, cf. examples in nam/
   • mkvgrid <my_nam> [optionally_a_second_one_for_comparison] this will compute the grid, generate namelist blocks for NAMVV1 and NAMFPG, and open a html figure in your default browser
   • Option -h to see other options of the command, especially to choose abscissa/ordinate among altitude, pressure, level number, level thickness (m or Pa).

2. Plot a grid from a FA file, and emulate its re-creation through mkvgrid: cf. doc/test_vgrid_from_epygram.py

Documentation

• Scientific documentation by P.Benard (2008) is available on: http://www.umr-cnrm.fr/gmapdoc/IMG/pdf/memoeta0.pdf
• Examples of namelists (in nam/) are auto-documented
• Python interface is auto-documented
• More to come...