earthkit.meteo.vertical.fieldlist.height_on_hybrid_levels

earthkit.meteo.vertical.fieldlist.height_on_hybrid_levels(t, q, zs, sp, A=None, B=None, alpha_top='ifs', h_type='geometric', h_reference='ground')

Compute the height on hybrid (IFS model) full-levels.

Parameters:
  • t (FieldList) – Temperature on hybrid full-levels (K). Fields must correspond to a distinct set of hybrid full-levels in arbitrary order. Not all the levels must be present, but a contiguous level range including the bottom-most level must be used. E.g. if the vertical coordinate system has 137 model levels using only a subset of levels between e.g. 137-96 is allowed.

  • q (FieldList) – Specific humidity on hybrid full-levels (kg/kg). Must have the same number of fields and levels as t, the level ordering can be different.

  • zs (FieldList|Field) – Surface geopotential (m2/s2). Can be a single Field or a FieldList. If a FieldList is provided, it must contain exactly one Field. Not used when h_type is "geopotential" and h_reference is "ground".

  • sp (FieldList|Field) – Surface pressure (Pa). Can be a single Field or a FieldList. If a FieldList is provided, it must contain exactly one Field.

  • A (ArrayLike|None, optional) – A-coefficients defining the hybrid levels. Must contain all the half-levels in ascending order with respect to the model level number. When None, the A and B coefficients will be inferred from the metadata of the input fields sp, zs, t and q (tried in this order).

  • B (ArrayLike|None, optional) – B-coefficients defining the hybrid levels. Must contain all the half-levels in ascending order with respect to the model level number. Must be defined when A is provided and have the same size as A. When None, the A and B coefficients will be inferred from the metadata of the input fields sp, zs, t and q (tried in this order).

  • alpha_top ({"ifs", "arpege"}, default "ifs") – Option to initialise the alpha parameter on the top of the model atmosphere. See earthkit.meteo.vertical.array.pressure_on_hybrid_levels() for details.

  • h_type ({"geometric", "geopotential"}, default "geometric") –

    Type of height to compute. Default is "geometric". Possible values:

    • "geometric": geometric height (m)

    • "geopotential": geopotential height (m)

  • h_reference ({"ground", "sea"}, default "ground") –

    Reference level for the height calculation. Default is "ground". Possible values:

    • "ground": height with respect to the ground/surface level

    • "sea": height with respect to the sea level

Returns:

Height (m) on hybrid full-levels.

Return type:

FieldList

Notes

The height is calculated from the geopotential on hybrid levels, which is computed from the t, q, zs and the hybrid level definition (A, B or sp). The computations are described in [IFS-CY49R1-Dynamics] Chapter 2, Section 2.2.1.