The Advanced Regional
Prediction System
ARPS 3.0 Characteristics
Below are listed the basic functional features of ARPS 3.0.
- Equations - Fully compressible, nonhydrostatic advective-form.
- Geometry - Options for 1-D, 2-D, 3-D geometries.
- Prognostic Variables - Zonal wind, meridional wind, vertical wind, perturbation
potential temperature, perturbation pressure, water vapor specific humidity,
cloud water mixing ratio, rainwater mixing ratio.
- Diagnostic Variables - Subgrid-scale mixing coefficients for momentum
and scalars based on Smagorinsky-Lilly closure scheme.
- Spatial Discretization - Second-order quadratically-conservative.
- Temporal Discretization - Second-order leapfrog with Asselin time filter
option.
- Grid System - Arakawa C-grid with terrain-following vertical coordinate.
- Solution Technique - Split explicit (mode-splitting) with fully explicit
small time step for acoustic modes. The model provides an option for changing
the sound speed.
- Lateral Boundary Conditions - Options for combining periodic, rigid,
zero-gradient, and two types of wave-radiating boundary conditions.
- Top & Bottom Boundary Conditions - Options for rigid or periodic.
Rayleigh sponge option.
- Spatial Computational Mixing - Options for 2nd- and 4th-order mixing
with constant mixing coefficient.
- Divergence Damping - The model provides an option for divergence damping
to suppress acoustic oscillations.
- Subgrid Scale Mixing - Options for no mixing, constant eddy mixing coefficient,
Smagorinsky-Lilly diagnostic first-order closure, and a combination of the
latter two.
- Cloud Physics - Kessler warm-rain bulk parameterization (provision has
been made for ice, though the associated source/sink terms have not been
added).
- Surface Fluxes - Bulk aerodynamic drag laws for surface momentum, heat,
and moisture fluxes.
- Reference Frame Rotation - Options for a non-rotating reference frame,
standard Coriolis force terms, or the complete set of terms involving the
Earth's rotation.
- Domain Translation - Option for translating the domain at a constant
velocity.
- Base State - The model base state can be defined analytically, or from
a vertical sounding using a variety of temperature and moisture variables
at equally- or unequally-spaced levels.
- Restart Option - Full restart capability at intervals selected by the
user.
- History Data - The model provides options for writing data in binary,
ASCII, packed binary, NCSA HDF, or Savi3D formats. These data can then be
read through a graphics package provided with the model, or through user-
created routines based on templates provided.
- Post-Processing - Savi3D visualization system (CAPS only) and ZXPLOT
vector graphics package (provided).
- Validation - Code has been validated against several exact solutions
to the Navier-Stokes equations.
- Execution Mode - Interactive (command-line interface) and batch execution
supported.