MPAS Ocean User's Guide V6

The Model for Prediction Across Scales-Ocean (MPAS-Ocean) is an unstructured-mesh ocean model

capable of using enhanced horizontal resolution in selected regions of the ocean domain. Model

domains may be spherical with bottom topography to simulate the earth's oceans, or on Cartesian

domains for idealized experiments. The global meshes, created using Spherical Centroidal Voronoi

Tesselations (Ringler et al., 2008, 2011) consist of gridcells that vary smoothly from low to high

resolution regions. Numerical algorithms specially designed for these grids guarantee that mass,

tracers, potential vorticity (in isopycnal mode) and energy are conserved (Thuburn et al., 2009;

Ringler et al., 2010). MPAS-Ocean high-resolution and variable-resolution global simulations, as

well as descriptions of mesh generation, model capabilities, and algorithms, are presented in Ringler

et al. (2013a). The vertical grid is detailed in Petersen et al. (2014), including the Arbitrary

Lagrangian Eulerian method, a variety of vertical coordinates, and results from five test cases.

MPAS-Ocean is one component within the MPAS framework of climate models that is devel-

oped in cooperation between Los Alamos National Laboratory (LANL) and the National Center

for Atmospheric Research (NCAR). Functionality that is required by all cores, such as i/o, time

management, block decomposition, etc, is developed collaboratively, and this code is shared across

cores within the same repository. Each core then solves its own differential equations and physical

parameterizations within this framework. This user's guide reflects the spirit of this collaborative

process, where Part I, "The MPAS Framework", applies to all cores, and the remaining parts apply

to MPAS-Ocean.

This release of the ocean model corresponds with the initial release of the Energy Exascale

Earth System Model (E3SM) by the U.S. Department of Energy (see https://e3sm.org/). E3SM

includes MPAS components for ocean, sea ice, and land ice. Each component may be run as a

stand-alone model, or coupled within E3SM. MPAS-Ocean now includes biogeochemistry modules,

and the ability to control groups of tracers.

Information about MPAS-Ocean, including the most recent code, user's guide, and test cases,

may be found at http://mpas-dev.github.com. This user's guide refers to MPAS-Ocean version 6.