Insulation effect: Decoupling of soil from atmosphere

• Insulation effect: Decoupling of soil from atmosphere (30%-90% of the snow mantle is air)

• Albedo Effect: Higher albedo than any other natural surface (0.4-0.85 for bare ground/low vegetation, 0.2-0.33 for snow in forests)

• Snow melting prevents rise of surface temperature above 0°C for a long period in spring – impact on hydrological cycle and energy budget at surface

• Snow Model

• One layer – prognostic variables : snow temperature, snow water equivalent, snow density, snow albedo

• Multi-layer – Vertical profiles in snow pack; considers equations for the snow albedo, snow temperature, density, total water content and content of liquid water. Therefore phase transitions in the snow pack are included.

Link between atmosphere and soil by exchange of fluxes of heat, moisture, and momentum – New: with TILE approach

• Link between atmosphere and soil by exchange of fluxes of heat, moisture, and momentum – New: with TILE approach

• Demand for realistic surface and soil characteristics – external parameters

• Flexible ICON interface structure offers several coupling options: TERRA-ICON into COSMO, Offline SVAT-Mode, 3rd party SVAT