geostrophic

The polaris.ocean.tasks.geostrophic.Geostrophic test performs a series of 5-day runs starting from an initial condition in geostrophic balance. The resolution of the sphere varies (by default, between 60 and 240 km). The results after 5 days are compared with the exact solution used to produce the initial condition to determine the rate of convergence.

framework

The config options for the geostrophic tests are described in geostrophic in the User’s Guide.

Additionally, the test uses a forward.yaml file with a few common model config options related to drag and default horizontal and vertical momentum and tracer diffusion, as well as defining mesh, input, restart, and output streams.

base_mesh

Geostrophic tasks use shared base_mesh steps for creating Quasi-uniform and Icosahedral Spherical Meshes at a sequence of resolutions.

init

The class polaris.ocean.tasks.geostrophic.init.Init defines a step for setting up the initial state at each resolution with a velocity field and water-column thickness in geostrophic balance, as described in initial conditions in the User’s Guide.

forward

The class polaris.ocean.tasks.geostrophic.forward.Forward descends from polaris.ocean.convergence.spherical.SphericalConvergenceForward, and defines a step for running MPAS-Ocean from an initial condition produced in an init step. See Convergence Tests for some relevant discussion of the parent class. The time step is determined from the resolution based on the dt_per_km config option in the [spherical_convergences] section. Other model config options are taken from forward.yaml.

analysis

The class polaris.ocean.tasks.geostrophic.analysis.Analysis descends from polaris.ocean.convergence.ConvergenceAnalysis, and defines a step for computing the error norm (L2) for the water-column thickness and normal velocity at each resolution, saving them in convergence_h.csv and convergence_normalVelocity.csv, and plotting them in convergence_h.png and convergence_normalVelocity.png.

viz

The visualization step is available only in the geostrophic/with_viz tasks. It is not included in the geostrophic in order to keep regression as fast as possible when visualization isn’t needed.

The class polaris.ocean.tasks.geostrophic.viz.Viz is a step for plotting the initial and final states of the advection test for each resolution. The colormap is controlled by the config options discussed in config options.

See global lat/lon plots for more details on the global lat-lon plots.