Changes between Version 53 and Version 54 of InitPdaf


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Timestamp:
Feb 22, 2023, 3:56:28 PM (21 months ago)
Author:
lnerger
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  • InitPdaf

    v53 v54  
    9494The routine `init_pdaf` in the example also initializes several variables that are not used to call `PDAF_init`. These variables control some functionality of the user-supplied routines for the data assimilation system and are shared with these routines through the Fortran module `mod_assimilation`. These variables are for example:
    9595 * `delt_obs`: An integer specifying the number of time steps between two analysis steps
    96  * `rms_obs`: Assumed observation error
     96 * `rms_obs`: Assumed observation error (when PDAF-OMI is used the observation error is usually defined separately for each observation, see the [wiki:PDAF_OMI_Overview description of OMI])
    9797 * `cradius`: Localization cut-off radius in grid points for the observation domain
    9898 * `sradius`: support radius, if observation errors are weighted (i.e. `locweight>0`)
     
    100100It is useful to define variables like these at this central position. Of course, their definition has to be adapted to the particular model used. The example codes describe the options for `locweight`.
    101101
    102 The setting of `locweight` influence the weight function for the localization. If PDAF-OMI is used, the choices are standardized as follows
     102The setting of `locweight` influences the weight function for the localization. If PDAF-OMI is used, the choices are standardized as follows
    103103
    104104||= '''locweight''' =||= '''0''' =||= '''1''' =||= '''2''' =||= '''3''' =||= '''4''' =||
    105 ||= '''function''' =|| unit weight || exponential |||||||| 5-th order polynomial ||
    106 ||= '''regulation''' =||= - =||= - =||= - =||= regulation using[[BR]]mean variance =||= regulation using variance[[BR]]of single observation point =||
    107 ||= '''cradius''' =||||||||||||= weight=0 if distance > cradius =||
    108 ||= '''sradius''' =||= no impact =||= weight = exp(-d / sradius) =||||||||= weight = 0 if d >= sradius[[BR]] else[[BR]] weight = f(sradius, distance) =||
     105||= '''function''' =|| unit weight ||  exponential  ||||||||  5-th order polynomial  ||
     106||= '''regulation''' =||  -  ||  -  ||  -  ||  regulation using[[BR]]mean variance  ||  regulation using variance[[BR]]of single observation point  ||
     107||= '''cradius''' =||||||||||||  weight=0 if distance > cradius  ||
     108||= '''sradius''' =||  no impact  ||  weight = exp(-d / sradius)  ||||||||  weight = 0 if d >= sradius[[BR]] else[[BR]] weight = f(sradius, distance)  ||
     109
     110Here, 'regulation' refers to the regulated localization introduced in Nerger, L., Janjić, T., Schröter, J., Hiller, W. (2012). A regulated localization scheme for ensemble-based Kalman filters. Quarterly Journal of the Royal Meteorological Society, 138, 802-812. ​[https://doi.org/10.1002/qj.945 doi:10.1002/qj.945].
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