earthkit.climate.atmos.temperature.chill_units

earthkit.climate.atmos.temperature.chill_units(tas: xarray.DataArray | str = 'tas', ds: xarray.Dataset | Any = None, *, positive_only: bool = False, freq: str = 'YS', **kwargs: Any) → Any

Chill units.

Chill units are a measure to estimate the bud breaking potential of different crop based on Richardson et al. (1974). The Utah model assigns a weight to each hour depending on the temperature recognising that high temperatures can actual decrease, the potential for bud breaking. Providing positive_only=True will ignore days with negative chill units.

Units:

• cu: dimensionless

This function wraps xclim.indicators.atmos.chill_units.

Parameters:

• tas (xarray.DataArray | str) – Hourly temperature.

• positive_only (bool) – If True, only positive daily chill units are aggregated.

• freq (str) – Resampling frequency.

• ds (xarray.Dataset | Any) – Input dataset.

• **kwargs (Any) – Additional keyword arguments.

Returns:

The computed index.

Return type:

Any