Empirical microwave surface emissivity

ARTS provides the TESSEM2 and TELSEM2 empirical microwave emissivity models through the Tessem and Telsem options of spectral_surf_refl_agendaSet(). Load their model data with TessemNN or TelsemAtlas, or with the corresponding workspace ASCII reader methods.

TESSEM2

TESSEM reads the following local values from surf_field:

• "t": surface skin temperature [K];

• "wind speed": 10-m wind speed [m/s]; and

• "salinity": salinity [kg/kg].

Each value can use any normal SurfaceData representation, including a constant, a latitude/longitude field, or a function. Surface Jacobian targets for all three inputs are evaluated by finite differences using the target perturbation.

TELSEM2

TELSEM obtains its spatial variation from its monthly atlas. It uses surf_field only for the local surface geometry and evaluates the atlas for the ray point and local surface normal.

Surface-boundary behavior

Both agenda options return polarized specular reflectance. Thermal emission is supplied by the closed-surface agenda, which applies Kirchhoff consistency.