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c $Header: /u/gcmpack/MITgcm/pkg/exf/README,v 1.1.4.3 2003/02/12 07:55:53 dimitri Exp $ |
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c |
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c |
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c ========================================= |
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c External Forcing Package for the MITgcmUV |
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c ========================================= |
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c |
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c Current Version: 0.2.2 (11-Jan-2003) |
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c |
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c |
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c General Outline: |
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c ---------------- |
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c |
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c This package contains routines to handle external forcing of the |
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c MITgcmUV general circulation model. The following features are |
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c available: |
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c |
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c (a) Reading-in atmospheric state and/or surface fluxes from files |
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c and bi-linear interpolation in time. |
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c |
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c (b) Surface flux forcing by: |
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c |
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c surface heat flux --> qnet |
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c short wave radiation --> qsw (optional) |
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c fresh water flux --> empmr |
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c zonal wind stress --> fu |
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c meridional wind stress --> fv |
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c |
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c In order to get the appropriate fluxes users can either use |
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c flux data directly or they can provide atmospheric state |
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c (atmospheric temperature, atmospheric specific humidity, etc.) |
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c which is subsequently used to estimate the fluxes by using |
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c bulk parameterizations. |
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c |
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c (c) Relaxation to monthly climatologies of: |
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c |
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c sea surface temperature --> theta( k = 1 ) |
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c sea surface salinity --> salt ( k = 1 ) |
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c potential temperature --> theta( k = 1,nr ) |
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c salinity --> salt ( k = 1,nr ) |
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c |
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c As of version 0.2.1, pkg/exf only supports the reading-in |
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c of the relaxation fields. See TODO.txt for suggestions on |
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c completing the relaxation package. |
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c |
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c |
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c Interface to MITgcm release1: |
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c ----------------------------- |
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c |
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c The following MITgcm files are affected by pkg/exf: |
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c |
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c CPPOPTIONS.h - Define INCLUDE_EXTERNAL_FORCING_PACKAGE |
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c and append desired pkg/exf CPP options. |
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c |
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c packages_readparms.F - EXF_READPARMS |
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c |
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c packages_init_variables.F - EXF_INIT |
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c |
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c the_main_loop.F - Adjoint compiler directives. |
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c |
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c forward_step.F - EXF_GETFORCING |
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c |
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c |
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c CPP options: |
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c ------------ |
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c |
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c See EXF_CPPOPTIONS.h for definition of pkg/exf CPP options. |
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c |
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c |
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c Data files: |
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c ----------- |
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c |
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c data.exf :: variables related to surface fluxes |
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c data.exf_clim :: variables for relaxation to climatological fields |
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c |
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c |
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c Routines: |
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c ---------- |
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c |
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c The package consists of two sets of routines. The first set is |
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c related to surface fluxes, the second set allows one to include |
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c relaxation to climatological fields. |
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c |
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c |
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c Call trees: |
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c ----------- |
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c |
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c exf_readparms |
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c | |
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c |---- exf_summary |
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c |---- exf_clim_readparms |
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c |---- exf_clim_summary |
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c |
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c |
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c exf_Init |
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c | |
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c |---- exf_init_hflux |
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c |---- exf_init_sflux |
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c |---- exf_init_ustress |
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c |---- exf_init_vstress |
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c |---- exf_init_evap |
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c |---- exf_init_runoff |
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c |---- exf_init_atemp |
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c |---- exf_init_aqh |
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c |---- exf_init_lwflux |
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c |---- exf_init_swflux |
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c |---- exf_init_precip |
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c |---- exf_init_uwind |
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c |---- exf_init_vwind |
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c |---- exf_clim_init |
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c |
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c |
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c exf_GetForcing |
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c | |
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c |---- exf_getclim |
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c |---- exf_getffields |
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c |---- exf_GetSurfaceFluxes |
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c |---- exf_MapFields |
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c |
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c |
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c =============== |
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c Surface fluxes: |
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c =============== |
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c |
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c Getting the forcing fields: |
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c |
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c o exf_init_??? - Initialise external forcing fields ???. |
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c |
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c o exf_GetsurfaceFluxes - Mid-level routine for adding fluxes as |
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c control variables. |
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c |
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c o exf_GetFFields - Get the current field values. |
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c |
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c o exf_SwapFFields - Swap data fields. |
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c |
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c Routines specific to bulk formulae: |
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c |
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c o exf_bulkqsat - Compute the saturation specific humidity. |
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c |
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c o exf_bulkcdn - Evaluate the neutral drag coefficient as a |
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c function of the mean wind speed at a given |
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c height. |
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c |
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c o exf_bulkrhn - Evaluate the Stanton number. |
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c |
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c Getting the time data (calendar): |
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c |
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c o exf_GetFFieldsRec - Get the record number for the current |
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c timestep of a given field, some flags, |
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c and the linear interpolation factor. |
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c |
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c Reading the forcing data: |
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c |
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c o exf_set_atemp - Read an atmospheric temperature record. |
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c |
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c o exf_set_aqh - Read an atmospheric humidity record. |
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c |
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c o exf_set_hflux - Read an atmospheric heat flux record. |
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c |
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c o exf_set_ustress - Read an atmospheric zonal wind stress record. |
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c |
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c o exf_set_vstress - Read an atmospheric meridional wind stress |
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c record. |
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c |
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c o exf_set_uwind - Read an atmospheric zonal wind record. |
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c |
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c o exf_set_vwind - Read an atmospheric meridional wind record. |
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c |
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c o exf_set_precip - Read a precipitation record. |
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c |
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c o exf_set_sflux - Read a salt flux record. |
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c |
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c o exf_set_lwflux - Read a long wave radiative flux record. |
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c |
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c o exf_set_swflux - Read a short wave radiative flux record. |
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c |
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c |
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c At the moment, a basic premise of this package is that the external |
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c forcing fields are available as data sets that are regularly spaced |
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c in time and space. In later versions this assumption will be relaxed |
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c for time as well as for space. |
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c |
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c |
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c ============ |
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c Climatology: |
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c ============ |
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c |
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c o exf_clim_init - Initialise the climatology code. |
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c |
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c o exf_set_climtemp - Get the temperature climatology's |
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c value for a given model timestep. |
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c |
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c o exf_set_climsalt - Get the salinity climatology's |
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c value for a given model timestep. |
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c |
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c o exf_set_climsst - Get the sea surface temp. climatology's |
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c value for a given model timestep. |
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c |
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c o exf_set_climsss - Get the sea surface salin. climatology's |
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c value for a given model timestep. |
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c |
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c |
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c HOW TO GET STARTED? |
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c |
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c There are two verification experiments, global_with_exf and |
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c lab_sea that use pkg/exf. Experiment verification/global_with_exf |
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c is a repeat of verification/global_ocean.90x40x15, except that it |
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c uses the pkg/exf and pkg/cal instead of the external_fields_load |
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c routine. Experiment verification/lab_sea gives exaples of using |
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c pkg/exf in conjunction with pkg/seaice. |
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c |
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c |
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c ATTENTION: |
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c ========== |
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c |
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c Users of this package are urged to CHECK THE SIGNS AND UNITS of |
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c their data sets, especially in relation to the sign conventions |
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c of the MITgcmUV! |
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c |
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c Relevant MITgcmUV routines are: |
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c |
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c calc_gt.F |
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c calc_gs.F |
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c calc_mom_rhs.F |
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c external_forcing.F |
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c |
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c Relevant external forcing package routines are: |
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c |
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c exf_set_hflux |
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c . |
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c . |
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c exf_set_vwind |
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c exf_MapFields |
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c |
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c All adaptations of signs and units to specific data sets should be |
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c done in the routines that read the respective data. Users should |
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c neither modify "external_forcing" nor "exf_MapFields" for this |
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c purpose.Each data set has its own read routine. This eases customi- |
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c zation (signs and units etc.). |
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c |
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c Some routines have to be customized for the current specific |
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c application: |
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c |
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c e.g. exf_set_climtemp |
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c exf_set_climsalt |
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c exf_set_climsst |
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c exf_set_climsss |
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c |
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c |
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c ======== |
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c HISTORY: |
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c ======== |
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c |
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c started: Christian Eckert eckert@mit.edu 30-Jun-1999 |
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c |
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c changed: Christian Eckert eckert@mit.edu 11-Jan-2000 |
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c - Restructured the code in order to create a package |
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c for the MITgcmUV. |
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c |
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c Christian Eckert eckert@mit.edu 12-Feb-2000 |
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c - Changed Routine names (package prefix: exf_) |
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c |
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c Christian Eckert eckert@mit.edu 02-May-2000 |
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c - CVS version of the package. |
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c |
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c Patrick Heimbach, heimbach@mit.edu 04-May-2000 |
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c - Added computation of evaporation rate for |
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c ALLOW_ATM_TEMP case |
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c - changed the handling of precip and sflux with respect |
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c to CPP options ALLOW_BULKFORMULAE and ALLOW_ATM_TEMP |
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c - included some CPP flags ALLOW_BULKFORMULAE to make |
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c sure ALLOW_ATM_TEMP, ALLOW_ATM_WIND are used only in |
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c conjunction with defined ALLOW_BULKFORMULAE |
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c - statement functions discarded and external functions |
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c initialised. |
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c - file precision and field type are now prescribed in |
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c data.exf; |
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c separately possible for exf_sflx.h and exf_clim.h |
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c related fields. |
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c - created exf_constants.h that contains |
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c 1. numbers |
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c 2. physical constants |
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c 3. empirical parameters |
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c 4. control parameters |
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c |
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c Ralf Giering ralf.giering@fastopt.de 18-Jun-2000 |
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c - exf_getffields.F: |
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c Swapping of forcing fields has to be switched off |
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c if TAMC is used, because of generation of spurious |
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c dependencies. (P.H.) |
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c |
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c Patrick Heimbach heimbach@mit.edu 20-Jun-2000 |
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c - sign change of ustress/vstress incorporated into |
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c scaling factors scal_ust, scal_vst in exf_mapfields.F |
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c - Corrected description on how to implement exf package |
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c for c27 onwards. |
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c - Included unit and sign conventions valid for c28 |
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c in README. |
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c |
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c mods for pkg/seaice: menemenlis@jpl.nasa.gov 20-Dec-2002 |
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c |
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c ================================================================== |
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