TOPAZ EnKF with BGC assimilation

main update

Following updates are for making TOPAZ EnKF flexible for hycom configuration options:

• hycom configuration files, regional.grid.(a,b) and regional.depth.(a,b), are read through new modules:

m_get_mod_cnfg.F90
m_io_hycom.F90

• depth read from regional.depth.(a,b) is used for making land mask in Prep_Routines/m_get_def_wet_point.F90 without using meanssh.uf

notes:

• This change removes requirement of depth*.uf file to provide depth information both to EnKF and prepobs.
• configuration-specific meanssh.uf and re_sla.nc are still required for SLA data prepobs.
• BGC observations: SCHL, CHL, POC, NIT, SIL, PHO, OXY are NOT ready to be assimilated.

TODO:

• read meanssh.nc only for SLA assimilation.
• register SCHL, CHL, POC, NIT, SIL, PHO, OXY.
• add m_global_analysis.F90 for ecoregion-dependent parameter estimation.
• add analysis masks based on mixder layer depth, sea ice concentration and surface nitrate concentration.