pyPDAF.PDAF.prepost

pyPDAF.PDAF.prepost()

This function does not perform any DA. It is used to perform a preprocess and postprocess of the ensemble. Compared to pyPDAF.PDAF.assimilate_prepost, this function does not set assimilation flag. The function is a combination of pyPDAF.PDAF.put_state_prepost and pyPDAF.PDAF.get_state, and executes the user-supplied function in the following sequence: 1. py__collect_state_pdaf 2. py__prepoststep_state_pdaf 3. py__prepoststep_state_pdaf 4. py__distribute_state_pdaf 5. py__next_observation_pdaf

Parameters:

• py__collect_state_pdaf (Callable[dim_p:int, state_p : ndarray[tuple[dim_p], np.float64]]) –

  Collect state vector from model/any arrays to pdaf arrays

  Callback Parameters

  • dim_pint

    • pe-local state dimension

  • state_pndarray[tuple[dim_p], np.float64]

    • local state vector

  Callback Returns

  • state_pndarray[tuple[dim_p], np.float64]

    • local state vector

• py__distribute_state_pdaf (Callable[dim_p:int, state_p : ndarray[tuple[dim_p], np.float64]]) –

  distribute a state vector from pdaf to the model/any arrays

  Callback Parameters

  • dim_pint

    • PE-local state dimension

  • state_pndarray[tuple[dim_p], np.float64]

    • PE-local state vector

  Callback Returns

  • state_pndarray[tuple[dim_p], np.float64]

    • PE-local state vector

• py__prepoststep_pdaf (Callable[step:int, dim_p:int, dim_ens:int, dim_ens_l:int, dim_obs_p:int, state_p : ndarray[tuple[dim_p], np.float64], uinv : ndarray[tuple[dim_ens-1, dim_ens-1], np.float64], ens_p : ndarray[tuple[dim_p, dim_ens], np.float64], flag:int]) –

  Preprocesse the ensemble before analysis and postprocess the ensemble before distributing to the model for next forecast

  Callback Parameters

  • stepint

    • current time step (negative for call before analysis/preprocessing)

  • dim_pint

    • PE-local state vector dimension

  • dim_ensint

    • number of ensemble members

  • dim_ens_lint

    • number of ensemble members run serially on each model task

  • dim_obs_pint

    • PE-local dimension of observation vector

  • state_pndarray[tuple[dim_p], np.float64]

    • pe-local forecast/analysis state (the array ‘state_p’ is generally not initialised in the case of ESTKF/ETKF/EnKF/SEIK, so it can be used freely here.)

  • uinvndarray[tuple[dim_ens-1, dim_ens-1], np.float64]

    • Inverse of the transformation matrix in ETKF and ESKTF; inverse of matrix formed by right singular vectors of error covariance matrix of ensemble perturbations in SEIK/SEEK. not used in EnKF.

  • ens_pndarray[tuple[dim_p, dim_ens], np.float64]

    • PE-local ensemble

  • flagint

    • pdaf status flag

  Callback Returns

  • state_pndarray[tuple[dim_p], np.float64]

    • pe-local forecast/analysis state (the array ‘state_p’ is generally not initialised in the case of ESTKF/ETKF/EnKF/SEIK, so it can be used freely here.)

  • uinvndarray[tuple[dim_ens-1, dim_ens-1], np.float64]

    • Inverse of the transformation matrix in ETKF and ESKTF; inverse of matrix formed by right singular vectors of error covariance matrix of ensemble perturbations in SEIK/SEEK. not used in EnKF.

  • ens_pndarray[tuple[dim_p, dim_ens], np.float64]

    • PE-local ensemble

• py__next_observation_pdaf (Callable[stepnow:int, nsteps:int, doexit:int, time:float]) –

  Routine to provide number of forecast time steps until next assimilations, model physical time and end of assimilation cycles

  Callback Parameters

  • stepnowint

    • the current time step given by PDAF

  • nstepsint

    • number of forecast time steps until next assimilation; this can also be interpreted as number of assimilation function calls to perform a new assimilation

  • doexitint

    • whether to exit forecasting (1 for exit)

  • timefloat

    • current model (physical) time

  Callback Returns

  • nstepsint

    • number of forecast time steps until next assimilation; this can also be interpreted as number of assimilation function calls to perform a new assimilation

  • doexitint

    • whether to exit forecasting (1 for exit)

  • timefloat

    • current model (physical) time

Returns:

outflag – Status flag

Return type:

int