COLD BUBBLE

Case description

The COLD BUBBLE case simulates a density current (cold air outbreak) in the atmosphere. This is a classic test case for non-hydrostatic dynamics and validates the model ability to reproduce propagating gravity currents.

Configuration

Parameter

Value

Category

Idealized cases

Dynamics

Non-hydrostatic

Horizontal grid spacing

50 m (1024x1 grid)

Integration length

900 s (15 minutes)

Time step

0.5 s

Coriolis effect

disabled

Turbulence

NONE

Cloud scheme

NONE

Deep convection

NONE

Radiation

NONE

Steps

Step

Script

001_prep_ideal

run_prep_ideal_case

002_mesonh

run_mesonh

Specificities

Scientific specificities

  • Cold pool perturbation with temperature anomaly of -16.2 K

  • Perturbation centered at 3000m with radius 4000x4000x2000m (x,y,z)

  • Open lateral boundary conditions on x-axis, cyclic on y-axis

  • No physics (DNS-like configuration)

  • Resolution: 1024 x 1 x 128 grid points

Technical specificities

  • Cartesian domain with 1024x1 horizontal points

  • 128 vertical levels with 50m spacing

  • Stretched vertical grid (2.5x factor above 5000m)

  • Boussinesq approximation disabled

Validation

  • Vertical velocity evolution (W)

  • Temperature perturbation propagation

  • Cloud visualization

Numerical ressources

Single CPU (1 node, 1 core)