ATLAS-1.0

Atmospheric Lagrangian Dispersion Model for tephra transport and deposition

Reckziegel Florencia, Folch Arnau & Viramonte José.

Introduction

ATLAS (Atmospheric Lagrangian dispersion) is an atmospheric dispersion model tailored to volcanic tephra/ash particles.

Using the Advection-Diiffusion-Sedimentation equation, ATLAS describes the plume dispersion and sedimentation, and calculates load and concentrations isopach. The model can be run in differnt scales (regional to global), with different off-line numerical weather prediction models. ATLAS can be used in forward mode (to forecast the ash dispersal from a volcano or to describe a past eruption) or backward mode(to constrain unknown source term characteristics). Multiple source terms can be defined, with different granulometric characteritics, in the same simulation.

Dependencies

ATLAS requires:

• An MPI implementation(OpenMPI, mpich)
• An MPI-compatible F90 compiler
• The entire NCO toolkit
• NetCDF-Fortran (Not a part of NCO tools)
• Python3

Compiling

From the top level you can run

	make

to compile ATLAS. This will generate an executable called P_ATLAS.1.0.x under the Runs/ folder

Running

ATLAS can be run by doing

	mpirun -n X ../P_ATLAS.1.0.x <simulation>

Where mpirun is the executable in your chosen MPI-implementation that runs an MPI executable, simulation is the name of your simulation (See Manual for more details on folder structure and input files), and X is the number of concurrent instances you wish to run. For testing purposes, an example is provided along with the necessary Data files, and can be run from Runs/pexample by doing

	mpirun -n X ../P_ATLAS_1.0.x pexample