| | 1 | = PDAF_iau_reset = |
| | 2 | |
| | 3 | This page documents the routine `PDAF_iau_reset` of PDAF, which was introduced with PDAF V3.0. |
| | 4 | |
| | 5 | This routine is used to modify the IAU type and the number of IAU time steps during a run. While `PDAF_iau_init` set the IAU type and number of IAU steps initially, one can change these settings during a model run. |
| | 6 | |
| | 7 | The routine has to be called by all processes that are model processes. A common place is to call the routine in `assimilate_pdaf` after an analysis step or in `distribute_state_pdaf`. |
| | 8 | |
| | 9 | The interface is the following: |
| | 10 | {{{ |
| | 11 | SUBROUTINE PDAF_iau_reset(type_iau, nsteps_iau, flag) |
| | 12 | }}} |
| | 13 | with the following arguments: |
| | 14 | {{{ |
| | 15 | INTEGER, INTENT(in) :: type_iau !< Type of IAU |
| | 16 | !< (0) no IAU |
| | 17 | !< (1) constant increment weight 1/nsteps_iau |
| | 18 | !< (2) Linear IAU weight with maximum in middle of IAU period |
| | 19 | !< (3) Zero weights for null mode (can be used to apply IAU on user side) |
| | 20 | INTEGER, INTENT(in) :: nsteps_iau !< number of time steps in IAU |
| | 21 | INTEGER, INTENT(out) :: flag !< Status flag |
| | 22 | |
| | 23 | }}} |
| | 24 | |
| | 25 | Hints: |
| | 26 | * It is recommended to only call this routine after or just before a forecast phase. |
| | 27 | * Calling this routine during a forecast aphse will change the IAU weights and might stop the application of IAU if `nsteps_iau` is below the number of time steps performed in the current forecast phase. |
