argopy.utils.optical_modeling.Z_iPAR_threshold

Z_iPAR_threshold(axis: ndarray, par: ndarray, threshold: float = 15.0, tolerance: float = 5.0) → float

Depth where unlabelled array of PAR reaches some threshold value (closest point)

The closest level in the vertical axis for which PAR is about a threshold value, with some tolerance.

See xarray.Dataset.argo.optic.Z_iPAR_threshold for more details on the methodology.

Parameters:

• axis (array_like, 1 dimensional) – Vertical axis values, pressure or depth, positive, increasing downward, typically from the PRES parameter of an Argo float.

• par (array_like, 1 dimensional) – Photosynthetically available radiation, typically from the DOWNWELLING_PAR parameter of an Argo float.

• threshold (float, optional, default: 15.) – Target value for par. We use 15 as the default because it is the theoretical value below which the Fchla is no longer quenched (For correction of NPQ purposes).

• tolerance (float, optional, default: 5.) – PAR value tolerance with regard to the target threshold. If the closest PAR value to threshold is distant by more than tolerance, consider result invalid and return NaN.

Return type:

float

See also

xarray.Dataset.argo.optic.Z_iPAR_threshold