heyoka.model.f107a_center81p

heyoka.model.f107a_center81p#

heyoka.model.f107a_center81p(time_expr: expression = heyoka.time, sw_data: sw_data = sw_data()) → expression#

Derivative of the average of the 10.7-cm solar radio flux.

Added in version 7.12.0.

This function will return an expression representing the first-order derivative of f107a_center81() as a function of the input time expression time_expr. time_expr is expected to represent the number of Julian centuries elapsed since the epoch of J2000 in the terrestrial time scale (TT). sw_data is the space weather dataset to be used for the computation.

The derivative is modelled as a piecewise constant function of time, where the nodes are given by the dates in sw_data. Evaluation outside the dates range of sw_data will produce a value of NaN.

The derivative is returned in solar flux units per Julian century (TT).

Parameters:

  • time_expr – the input time expression.

  • sw_data – the SW data to be used for the computation.

Returns:

an expression representing the derivative of the 81-day running average of the observed 10.7-cm solar radio flux.