ARTS built-in documentation server

Workspace Method AtmFieldsCalc

Description

Interpolation of raw atmospheric T, z, VMR, and NLTE T/r fields to
calculation grids.

An atmospheric scenario includes the following data for each
position (pressure, latitude, longitude) in the atmosphere:
   1. temperature field
   2. the corresponding altitude field
   3. vmr fields for the gaseous species
This method interpolates the fields of raw data (t_field_raw,
z_field_raw, vmr_field_raw) which can be stored on arbitrary
grids to the calculation grids (p_grid, lat_grid, lon_grid).
If nlte_field_raw is empty, it is assumed to be so because LTE is
assumed by the user and nlte_field will be empty.

Internally, AtmFieldsCalc applies GriddedFieldPRegrid and
GriddedFieldLatLonRegrid. Generally, 'half-grid-step' extrapolation
is allowed and applied. However, if *vmr_zeropadding*=1 then VMRs at
p_grid levels exceeding the raw VMRs' pressure grid are set to 0
(applying the *vmr_zeropadding* option of GriddedFieldPRegrid).

Default is to just accept obtained VMRs. If you want to enforce
that all VMR created are >= 0, set *vmr_nonegative* to 1. Negative
values are then set 0. Beside being present in input data, negative
VMR can be generated from the interpolation if *interp_order* is
above 1.

Authors: Claudia Emde, Stefan Buehler

Synopsis

AtmFieldsCalc(

t_field, z_field, vmr_field, nlte_field, p_grid, lat_grid, lon_grid, t_field_raw, z_field_raw, vmr_field_raw, nlte_field_raw, nlte_level_identifiers, nlte_vibrational_energies, atmosphere_dim, interp_order, vmr_zeropadding, vmr_nonegative, nlte_when_negative )

Variables

OUT	t_field	(Tensor3)	The field of atmospheric temperatures.
OUT	z_field	(Tensor3)	The field of geometrical altitudes.
OUT	vmr_field	(Tensor4)	VMR field.
OUT	nlte_field	(EnergyLevelMap)	The field of NLTE temperatures and/or ratios.
IN	p_grid	(Vector)	The pressure grid.
IN	lat_grid	(Vector)	The latitude grid.
IN	lon_grid	(Vector)	The longitude grid.
IN	t_field_raw	(GriddedField3)	Raw data for atmospheric temperatures.
IN	z_field_raw	(GriddedField3)	Raw data for geometrical altitudes.
IN	vmr_field_raw	(ArrayOfGriddedField3)	VMR data for the chosen gaseous species.
IN	nlte_field_raw	(ArrayOfGriddedField3)	Raw data for NLTE temperatures and/or ratios.
IN	nlte_level_identifiers	(ArrayOfQuantumIdentifier)	An array of non-lte quantum identifiers for levels matching nlte_field_raw and on request nlte_vibrational_energies.
IN	nlte_vibrational_energies	(Vector)	An list of vibrational energies matching nlte_level_identifiers and nlte_field_raw or being 0.
IN	atmosphere_dim	(Index)	The atmospheric dimensionality (1-3).
GIN	interp_order	(Index, Default: 1)	Interpolation order (1=linear interpolation).
GIN	vmr_zeropadding	(Index, Default: 0)	Pad VMRs with zeroes to fit the pressure grid if necessary.
GIN	vmr_nonegative	(Index, Default: 0)	If set to 1, negative VMRs are set to 0.
GIN	nlte_when_negative	(Index, Default: 0)	-1: Skip step. 0: Negative is 0. Else: Negative is t.