SNOW_BLOW

Case description

Idealized blowing snow case simulating snow transport by wind in polar boundary layer conditions. The case uses a column setup for local testing and a 30x30km domain at 50m resolution for HPC simulations.

Configuration

Parameter

Local (BLOWSNOW_c1b1D)

HPC (SNOW_BLOW)

Category

Idealized cases

HPC cases

Grid type

Cartesian (1D column)

Cartesian (2D)

Horizontal resolution

Variable (wind 11-16 m/s)

50m

Domain size

1 column

30x30km (600x600 grid)

Vertical levels

Variable

70

Initial condition

RSOU (radiosounding)

RSOU (radiosounding 2011-03-18)

Surface

Flat (FLAT)

External (EXTE)

Equation system

LHE (liquid-ice)

DUR (dry)

Lateral boundaries

CYCL (cyclic)

OPEN

Turbulence

TKEL (TKE-length)

TKEL (TKE-length)

Time step

0.5s (local)

1.5s (HPC)

Segment length

1200s (20min)

10800s (3h)

Physics

Blowing snow (no sublimation)

Blowing snow + sublimation

Declination

Configuration

Description

BLOWSNOW_c1b1D_U11

Column with 11 m/s wind speed

BLOWSNOW_c1b1D_U16

Column with 16 m/s wind speed

SNOW_BLOW_0100_UnifSnw

Initial condition with uniform snow

SNOW_BLOW_0200

Time 2h - evolving state

SNOW_BLOW_0300

Time 4h - evolving state

SNOW_BLOW_0400

Time 6h - evolving state

Steps

Step

Script

001_prep_ideal

run_prep_ideal_case_xyz

002_run

run_mesonh_xyz

HPC_prep_ideal

run_prep_ideal_case

HPC_run

run_mesonh

Specificities

Scientific specificities - Blowing snow parameterization (LBLOWSNOW=T) - Snow saltation and suspension (CSNOW_SALT=’TSOR’) - Snow sedimentation (CSNOW_SEDIM=’TABC’) - Snow sublimation (only HPC: LSNOWSUBL=T) - Canopy snow processes (LBLOWSNW_CANOSUBL on HPC) - WENO advection scheme (5th order) - Ice phase microphysics (ICE3)

Technical specificities - Multiple wind speed variants (local) - Four sequential time steps (HPC: 0100-0400) - 20-layer snow scheme (CRO) - ISBA-Canopy (LISBA_CANOPY=T) - SLEVE vertical coordinate

Validation

  • Snow mass balance

  • Vertical profiles of snow concentration

  • Surface snow mass evolution

  • Saltation flux comparison

Numerical ressources

Local: Single CPU (1 node, 1 core) HPC: 1 node, 128 cores (MPI parallel)

References

  • Gordon et al. (2007): Blowing snow parameterization

  • Vignon et al. (2021): Blowing snow at Antarctic station

  • Box et al. (2022): Arctic snow transport modeling