:tocdepth: 3

.. _index:

Index of primary variables and parameters 
==========================================

This index defines many of the symbols used frequently in the CICE model
code. Values appearing in this list are fixed or recommended; most
namelist parameters are indicated ( :math:`E_\circ`) with their default
values. For other namelist options, see Section :ref:`tabnamelist`. All
quantities in the code are expressed in MKS units (temperatures may take
either Celsius or Kelvin units).  

.. csv-table:: *Alphabetical Index*
   :header: " ", " ", " "
   :widths: 15, 30, 15, 1   

   "**A**", "", ""
   "a11,a12", "structure tensor components", ""
   "a2D", "history field accumulations, 2d", "" 
   "a3Dz", "history field accumulations, 3D vertical", ""
   "a3Db", "history field accumulations, 3D bio grid", ""
   "a3Dc", "history field accumulations, 3D categories", ""
   "a4Di", "history field accumulations, 4D categories, vertical ice", ""
   "a4Db", "history field accumulations, 4D categories, vertical bio grid", ""
   "a4Ds", "history field accumulations, 4D categories, vertical snow", ""
   "a_min", "minimum area concentration for computing velocity", "0.001"
   "a_rapid_mode", ":math:`{\bullet}` brine channel diameter", ""
   "advection", ":math:`\bullet` type of advection algorithm used (‘remap’ or ‘upwind’)", "remap"
   "afsd(n)", "floe size distribution (in category n)", ""
   "ahmax", ":math:`\bullet` thickness above which ice albedo is constant", "0.3m"
   "aice_extmin", "minimum value for ice extent diagnostic", "0.15"
   "aice_init", "concentration of ice at beginning of timestep", ""
   "aice0", "fractional open water area", ""
   "aice(n)", "total concentration of ice in grid cell (in category n)", ""
   "albedo_type", ":math:`\bullet` type of albedo parameterization (‘ccsm3’ or ‘constant’)", ""
   "albcnt", "counter for averaging albedo", ""
   "albice", "bare ice albedo", ""
   "albicei", ":math:`\bullet` near infrared ice albedo for thicker ice", ""
   "albicev", ":math:`\bullet` visible ice albedo for thicker ice", ""
   "albocn", "ocean albedo", "0.06"
   "albpnd", "melt pond albedo", ""
   "albsno", "snow albedo", ""
   "albsnowi", ":math:`\bullet` near infrared, cold snow albedo", ""
   "albsnowv", ":math:`\bullet` visible, cold snow albedo", ""
   "algalN", "algal nitrogen concentration", mmol/m\ :math:`^3`
   "alv(n)dr(f)", "albedo: visible (near IR), direct (diffuse)", ""
   "alv(n)dr(f)_ai", "grid-box-mean value of alv(n)dr(f)", ""
   "amm", "ammonia/um concentration", "mmol/m\ :math:`^3`"
   "ANGLE", "for conversions between the POP grid and latitude-longitude grids", "radians"
   "ANGLET", "ANGLE converted to T-cells", "radians"
   "aparticn", "participation function", ""
   "apeff_ai", "grid-cell-mean effective pond fraction", ""
   "apondn", "area concentration of melt ponds", ""
   "arlx1i", "relaxation constant for dynamics (stress)", ""
   "araftn", "area fraction of rafted ice", ""
   "aredistrn", "redistribution function: fraction of new ridge area", ""
   "ardgn", "fractional area of ridged ice", ""
   "aspect_rapid_mode", ":math:`\bullet` brine convection aspect ratio", "1"
   "astar", "e-folding scale for participation function", "0.05"
   "atm_data_dir", ":math:`\bullet` directory for atmospheric forcing data", ""
   "atm_data_format", ":math:`\bullet` format of atmospheric forcing files", ""
   "atm_data_type", ":math:`\bullet` type of atmospheric forcing", ""
   "atmbndy", ":math:`\bullet` atmo boundary layer parameterization (‘default’ or ‘constant’)", ""
   "avail_hist_fields", "type for history field data", ""
   "awtidf", "weighting factor for near-ir, diffuse albedo", "0.36218"
   "awtidr", "weighting factor for near-ir, direct albedo", "0.00182"
   "awtvdf", "weighting factor for visible, diffuse albedo", "0.63282"
   "awtvdr", "weighting factor for visible, direct albedo", "0.00318"
   "**B**", "", ""
   "bfb_flag", ":math:`\bullet` for bit-for-bit reproducible diagnostics", ""
   "bgc_data_dir", ":math:`\bullet` data directory for bgc", ""
   "bgc_data_type", ":math:`\bullet` source of silicate, nitrate data", ""
   "bgc_flux_type", ":math:`\bullet` ice–ocean flux velocity", ""
   "bgc_tracer_type", "tracer_type for bgc tracers", ""
   "bgrid", "nondimensional vertical grid points for bio grid", ""
   "bignum", "a large number", ":math:`10^{30}`"
   "block", "data type for blocks", ""
   "block_id", "global block number", ""
   "block_size_x(y)", "number of cells along x(y) direction of block", ""
   "blockGlobalID", "global block IDs", ""
   "blockLocalID", "local block IDs", ""
   "blockLocation", "processor location of block", ""
   "blocks_ice", "local block IDs", ""
   "bphi", "porosity of ice layers on bio grid", ""
   "brlx", "relaxation constant for dynamics (momentum)", ""
   "bTiz", "temperature of ice layers on bio grid", ""
   "**C**", "", ""
   "c<n>", "real(\ :math:`n`)", ""
   "calc_strair", ":math:`\bullet` if true, calculate wind stress", "T"
   "calc_Tsfc", ":math:`\bullet` if true, calculate surface temperature", "T"
   "Cdn_atm", "atmospheric drag coefficient", ""
   "Cdn_ocn", "ocean drag coefficient", "" 
   "Cf", ":math:`\bullet` ratio of ridging work to PE change in ridging", "17."
   "cgrid", "vertical grid points for ice grid (compare bgrid)", ""
   "char_len", "length of character variable strings", "80"
   "char_len_long", "length of longer character variable strings", "256"
   "check_step", "time step on which to begin writing debugging data", ""
   "check_umax", "if true, check for ice speed :math:`>` umax_stab", ""
   "cldf", "cloud fraction", ""
   "cm_to_m", "cm to meters conversion", "0.01"
   "coldice", "value for constant albedo parameterization", "0.70"
   "coldsnow", "value for constant albedo parameterization", "0.81"
   "conduct", ":math:`\bullet` conductivity parameterization", ""
   "congel", "basal ice growth", "m"
   "cosw", "cosine of the turning angle in water", "1."
   "coszen", "cosine of the zenith angle", ""
   "Cp", "proportionality constant for potential energy", "kg/m\ :math:`^2`/s\ :math:`^2`"
   "cp_air", "specific heat of air", "1005.0 J/kg/K"
   "cp_ice", "specific heat of fresh ice", "2106. J/kg/K"
   "cp_ocn", "specific heat of sea water", "4218. J/kg/K"
   "cp_wv", "specific heat of water vapor", "1.81x\ :math:`10^3` J/kg/K"
   "cp063", "diffuse fresnel reflectivity (above)", "0.063"
   "cp455", "diffuse fresnel reflectivity (below)", "0.455"
   "Cs", "fraction of shear energy contributing to ridging", "0.25"
   "Cstar", "constant in Hibler ice strength formula", "20."
   "cxm", "combination of HTN values", ""
   "cxp", "combination of HTN values", ""
   "cym", "combination of HTE values", ""
   "cyp", "combination of HTE values", ""        
   "**D**", "", ""
   "d_afsd_[proc]", "change in FSD due to processes", ""
   "daice_da", "data assimilation concentration increment rate", ""
   "daidtd", "ice area tendency due to dynamics/transport", "1/s"
   "daidtt", "ice area tendency due to thermodynamics", "1/s"
   "dalb_mlt", "[see **icepack_shortwave.F90**]", "-0.075"
   "dalb_mlti", "[see **icepack_shortwave.F90**]", "-0.100"
   "dalb_mltv", "[see **icepack_shortwave.F90**]", "-0.150"
   "darcy_V", "Darcy velocity used for brine height tracer", ""
   "dardg1(n)dt", "rate of fractional area loss by ridging ice (category n)", "1/s"
   "dardg2(n)dt", "rate of fractional area gain by new ridges (category n)", "1/s"
   "daymo", "number of days in one month", ""
   "daycal", "day number at end of month", ""
   "days_per_year", ":math:`\bullet` number of days in one year", "365"
   "dbl_kind", "definition of double precision", "selected_real_kind(13)"
   "dbug", ":math:`\bullet` write extra diagnostics", ".false."
   "Delta", "function of strain rates (see Section :ref:`dynam`)", "1/s"
   "default_season", "Season from which initial values of forcing are set.", "winter"
   "denom1", "combination of constants for stress equation", ""
   "depressT", "ratio of freezing temperature to salinity of brine", "0.054 deg/ppt"
   "dhbr_bt", "change in brine height at the bottom of the column", ""
   "dhbr_top", "change in brine height at the top of the column", ""
   "dhsn", "depth difference for snow on sea ice and pond ice", ""
   "diag_file", ":math:`\bullet` diagnostic output file (alternative to standard out)", ""
   "diag_type", ":math:`\bullet` where diagnostic output is written", "stdout"
   "diagfreq", ":math:`\bullet` how often diagnostic output is written (10 = once per 10 dt)", ""
   "distrb", "distribution data type", ""
   "distrb_info", "block distribution information", ""
   "distribution_type", ":math:`\bullet` method used to distribute blocks on processors", ""
   "distribution_weight", ":math:`\bullet` weighting method used to compute work per block", ""
   "divu", "strain rate I component, velocity divergence", "1/s"
   "divu_adv", "divergence associated with advection", "1/s"
   "dms", "dimethyl sulfide concentration", "mmol/m\ :math:`^3`"
   "dmsp", "dimethyl sulfoniopropionate concentration", "mmol/m\ :math:`^3`"
   "dpscale", ":math:`\bullet` time scale for flushing in permeable ice", ":math:`1\times 10^{-3}`"
   "dragio", "drag coefficient for water on ice", "0.00536"
   "dSdt_slow_mode", ":math:`\bullet` drainage strength parameter", ""
   "dsnow", "change in snow thickness", "m"
   "dt", ":math:`\bullet` thermodynamics time step", "3600. s"
   "dt_dyn", "dynamics/ridging/transport time step", ""
   "dT_mlt", ":math:`\bullet` :math:`\Delta` temperature per :math:`\Delta` snow grain radius", "1. deg"
   "dte", "subcycling time step for EVP dynamics (:math:`\Delta t_e`)", "s"
   "dte2T", "dte / 2(damping time scale)", ""
   "dtei", "1/dte, where dte is the EVP subcycling time step", "1/s"
   "dump_file", ":math:`\bullet` output file for restart dump", ""
   "dumpfreq", ":math:`\bullet` dump frequency for restarts, y, m, d, h or 1", ""
   "dumpfreq_n", ":math:`\bullet` restart output frequency", ""
   "dump_last", ":math:`\bullet` if true, write restart on last time step of simulation", ""
   "dwavefreq", "widths of wave frequency bins", "1/s"
   "dxhy", "combination of HTE values", ""
   "dxt", "width of T cell (:math:`\Delta x`) through the middle", "m"
   "dxu", "width of U cell (:math:`\Delta x`) through the middle", "m"
   "dyhx", "combination of HTN values", ""
   "dyn_dt", "dynamics and transport time step (:math:`\Delta t_{dyn}`)", "s"
   "dyt", "height of T cell (:math:`\Delta y`) through the middle", "m"
   "dyu", "height of U cell (:math:`\Delta y`) through the middle", "m"
   "dvidtd", "ice volume tendency due to dynamics/transport", "m/s"
   "dvidtt", "ice volume tendency due to thermodynamics", "m/s"
   "dvirdg(n)dt", "ice volume ridging rate (category n)", "m/s"
   "**E**", "", ""                       
   "e11, e12, e22", "strain rate tensor components", ""
   "ecci", "yield curve minor/major axis ratio, squared", "1/4"
   "eice(n)", "energy of melting of ice per unit area (in category n)", "J/m\ :math:`^2`"
   "emissivity", "emissivity of snow and ice", "0.95"
   "eps13", "a small number", "10\ :math:`^{-13}`"
   "eps16", "a small number", "10\ :math:`^{-16}`"
   "esno(n)", "energy of melting of snow per unit area (in category n)", "J/m\ :math:`^2`"
   "evap", "evaporative water flux", "kg/m\ :math:`^2`/s"
   "ew_boundary_type", ":math:`\bullet` type of east-west boundary condition", ""
   "eyc", "coefficient for calculating the parameter E, 0\ :math:`<` eyc :math:`<`\ 1", "0.36"                      
   "**F**", "", ""
   "faero_atm", "aerosol deposition rate", "kg/m\ :math:`^2`/s"
   "faero_ocn", "aerosol flux to the ocean", "kg/m\ :math:`^2`/s"
   "fbot_xfer_type", ":math:`\bullet` type of heat transfer coefficient under ice", ""
   "fcondtop(n)(_f)", "conductive heat flux", "W/m\ :math:`^2`"
   "fcor_blk", "Coriolis parameter", "1/s"
   "ferrmax", "max allowed energy flux error (thermodynamics)", "1x :math:`10^{-3}` W/m\ :math:`^2`"
   "ffracn", "fraction of fsurfn used to melt pond ice", ""
   "fhocn", "net heat flux to ocean", "W/m\ :math:`^2`"
   "fhocn_ai", "grid-box-mean net heat flux to ocean (fhocn)", "W/m\ :math:`^2`"
   "field_loc_center", "field centered on grid cell", "1"
   "field_loc_Eface", "field centered on east face", "4"
   "field_loc_NEcorner", "field on northeast corner", "2"
   "field_loc_Nface", "field centered on north face", "3"
   "field_loc_noupdate", "ignore location of field", "-1"
   "field_loc_unknown", "unknown location of field", "0"
   "field_loc_Wface", "field centered on west face", "5"
   "field_type_angle", "angle field type", "3"
   "field_type_noupdate", "ignore field type", "-1"
   "field_type_scalar", "scalar field type", "1"
   "field_type_unknown", "unknown field type", "0"
   "field_type_vector", "vector field type", "2"
   "first_ice", "flag for initial ice formation", ""
   "flat", "latent heat flux", "W/m\ :math:`^2`"
   "floediam", "effective floe diameter for lateral melt", "300. m"
   "floeshape", "floe shape constant for lateral melt", "0.66"
   "floe_rad_l", "lower bounds for FSD size bins (radius)", "m"
   "floe_rad_c", "centers of FSD size bins (radius)", "m"
   "floe_binwidth", "width of FSD size bins (radius)", "m"
   "flux_bio", "all biogeochemistry fluxes passed to ocean", ""
   "flux_bio_ai", "all biogeochemistry fluxes passed to ocean, grid cell mean", ""
   "flw", "incoming longwave radiation", "W/m\ :math:`^2`"
   "flwout", "outgoing longwave radiation", "W/m\ :math:`^2`"
   "fm", "Coriolis parameter * mass in U cell", "kg/s"
   "formdrag", ":math:`\bullet` calculate form drag", ""
   "fpond", "fresh water flux to ponds", "kg/m\ :math:`^2`/s"
   "fr_resp", "bgc respiration fraction", "0.05"
   "frain", "rainfall rate", "kg/m\ :math:`^2`/s"
   "frazil", "frazil ice growth", "m"
   "fresh", "fresh water flux to ocean", "kg/m\ :math:`^2`/s"
   "fresh_ai","grid-box-mean fresh water flux (fresh)", "kg/m\ :math:`^2`/s"
   "frz_onset", "day of year that freezing begins", ""
   "frzmlt", "freezing/melting potential", "W/m\ :math:`^2`"
   "frzmlt_init", "freezing/melting potential at beginning of time step", "W/m\ :math:`^2`"
   "frzmlt_max", "maximum magnitude of freezing/melting potential", "1000. W/m\ :math:`^2`"
   "frzpnd", ":math:`\bullet` Stefan refreezing of melt ponds", "‘hlid’"
   "fsalt", "net salt flux to ocean", "kg/m\ :math:`^2`/s"
   "fsalt_ai", "grid-box-mean salt flux to ocean (fsalt)", "kg/m\ :math:`^2`/s"
   "fsens", "sensible heat flux", "W/m\ :math:`^2`"
   "fsnow", "snowfall rate", "kg/m\ :math:`^2`/s"
   "fsnowrdg", "snow fraction that survives in ridging", "0.5"
   "fsurf(n)(_f)", "net surface heat flux excluding fcondtop", "W/m\ :math:`^2`"
   "fsw", "incoming shortwave radiation", "W/m\ :math:`^2`"
   "fswabs", "total absorbed shortwave radiation", "W/m\ :math:`^2`"
   "fswfac", "scaling factor to adjust ice quantities for updated data", ""
   "fswint", "shortwave absorbed in ice interior", "W/m\ :math:`^2`"
   "fswpenl", "shortwave penetrating through ice layers", "W/m\ :math:`^2`"
   "fswthru", "shortwave penetrating to ocean", "W/m\ :math:`^2`"
   "fswthru_ai", "grid-box-mean shortwave penetrating to ocean (fswthru)", "W/m\ :math:`^2`"
   "fyear", "current data year", ""
   "fyear_final", "last data year", ""
   "fyear_init", ":math:`\bullet` initial data year", ""
   "**G**", "", ""
   "gravit", "gravitational acceleration", "9.80616 m/s\ :math:`^2`"
   "grid_file", ":math:`\bullet` input file for grid info", ""
   "grid_format", ":math:`\bullet` format of grid files", ""
   "grid_type", ":math:`\bullet` ‘rectangular’, ‘displaced_pole’, ‘column’ or ‘regional’", ""
   "gridcpl_file", ":math:`\bullet` input file for coupling grid info", ""
   "grow_net", "specific biogeochemistry growth rate per grid cell", "s :math:`^{-1}`"
   "Gstar", "piecewise-linear ridging participation function parameter", "0.15"
   "**H**", "", ""
   "halo_info", "information for updating ghost cells", ""
   "heat_capacity", ":math:`\bullet` if true, use salinity-dependent thermodynamics", "T"
   "hfrazilmin", "minimum thickness of new frazil ice", "0.05 m"
   "hi_min", "minimum ice thickness for thinnest ice category", "0.01 m"
   "hi_ssl", "ice surface scattering layer thickness", "0.05 m"
   "hicen", "ice thickness in category n", "m"
   "highfreq", ":math:`\bullet` high-frequency atmo coupling", "F"
   "hin_old", "ice thickness prior to growth/melt", "m"
   "hin_max", "category thickness limits", "m"
   "hist_avg", ":math:`\bullet` if true, write averaged data instead of snapshots", "T"
   "histfreq", ":math:`\bullet` units of history output frequency: y, m, w, d or 1", ""
   "histfreq_n", ":math:`\bullet` integer output frequency in histfreq units", ""
   "history_dir", ":math:`\bullet` path to history output files", ""
   "history_file", ":math:`\bullet` history output file prefix", ""
   "hm", "land/boundary mask, thickness (T-cell)", ""
   "hmix", "ocean mixed layer depth", "20. m"
   "hour", "hour of the year", ""
   "hp0", "pond depth at which shortwave transition to bare ice occurs", "0.2 m"
   "hp1", ":math:`\bullet` critical ice lid thickness for topo ponds (dEdd)", "0.01 m"
   "hpmin", "minimum melt pond depth (shortwave)", "0.005 m"
   "hpondn", "melt pond depth", "m"
   "hs_min", "minimum thickness for which :math:`T_s` is computed", "1.\ :math:`\times`\ 10\ :math:`^{-4}` m"
   "hs0", ":math:`\bullet` snow depth at which transition to ice occurs (dEdd)", "0.03 m"
   "hs1", ":math:`\bullet` snow depth of transition to pond ice", "0.03 m"
   "hs_ssl", "snow surface scattering layer thickness", "0.04 m"
   "Hstar", "determines mean thickness of ridged ice", "25. m"
   "HTE", "length of eastern edge (:math:`\Delta y`) of T-cell", "m"
   "HTN", "length of northern edge (:math:`\Delta x`) of T-cell", "m"
   "HTS", "length of southern edge (:math:`\Delta x`) of T-cell", "m"
   "HTW", "length of western edge of (:math:`\Delta y`) T-cell", "m"    
   "**I**", "", ""
   "i(j)_glob", "global domain location for each grid cell",""
   "i0vis","fraction of penetrating visible solar radiation", "0.70"
   "iblkp","block on which to write debugging data", ""
   "i(j)block", "Cartesian i,j position of block", ""
   "ice_hist_field", "type for history variables", ""
   "ice_ic", ":math:`\bullet` choice of initial conditions (see :ref:`tab-ic`)", ""
   "ice_stdout", "unit number for standard output", ""
   "ice_stderr", "unit number for standard error output", ""
   "ice_ref_salinity", "reference salinity for ice–ocean exchanges", "4. ppt"
   "icells", "number of grid cells with specified property (for vectorization)", ""
   "iceruf", "ice surface roughness", "5.\ :math:`\times`\ 10\ :math:`^{-4}` m"
   "icetmask", "ice extent mask (T-cell)", "" 
   "iceumask", "ice extent mask (U-cell)", ""
   "idate", "the date at the end of the current time step (yyyymmdd)", ""
   "idate0", "initial date", ""
   "ierr", "general-use error flag", ""
   "igrid", "interface points for vertical bio grid", ""
   "i(j)hi", "last i(j) index of physical domain (local)", ""
   "i(j)lo", "first i(j) index of physical domain (local)", ""
   "incond_dir", ":math:`\bullet` directory to write snapshot of initial condition", ""
   "incond_file", ":math:`\bullet` prefix for initial condition file name", ""
   "int_kind", "definition of an integer", "selected_real_kind(6)"
   "integral_order", "polynomial order of quadrature integrals in remapping", "3"
   "ip, jp", "local processor coordinates on which to write debugging data", ""
   "istep", "local step counter for time loop", ""
   "istep0", ":math:`\bullet` number of steps taken in previous run", "0"
   "istep1", "total number of steps at current time step", ""
   "Iswabs", "shortwave radiation absorbed in ice layers", "W/m\ :math:`^2`"
   "**J**", "", ""
   "**K**", "", ""
   "kalg", ":math:`\bullet` absorption coefficient for algae", ""
   "kappav", "visible extinction coefficient in ice, wavelength\ :math:`<`\ 700nm", "1.4 m\ :math:`^{-1}`"
   "kcatbound", ":math:`\bullet` category boundary formula", ""
   "kdyn", ":math:`\bullet` type of dynamics (1 = EVP, 0 = off)", "1"
   "kg_to_g", "kg to g conversion factor", "1000."
   "kice", "thermal conductivity of fresh ice (:cite:`Bitz99`)", "2.03 W/m/deg"
   "kitd", ":math:`\bullet` type of itd conversions (0 = delta function, 1 = linear remap)", "1"
   "kmt_file", ":math:`\bullet` input file for land mask info", ""
   "krdg_partic", ":math:`\bullet` ridging participation function", "1"
   "krdg_redist", ":math:`\bullet` ridging redistribution function", "1"
   "krgdn", "mean ridge thickness per thickness of ridging ice", ""
   "kseaice", "thermal conductivity of ice for zero-layer thermodynamics", "2.0 W/m/deg"
   "ksno", "thermal conductivity of snow", "0.30 W/m/deg"
   "kstrength", ":math:`\bullet` ice stength formulation (1= :cite:`Rothrock75`, 0 = :cite:`Hibler79`)", "1"
   "ktherm", ":math:`\bullet` thermodynamic formulation (0 = zero-layer, 1 = :cite:`Bitz99`, 2 = mushy)", ""        
   "**L**", "", ""
   "l_brine", "flag for brine pocket effects", ""
   "l_conservation_check", "if true, check conservation when ridging", ""
   "l_fixed_area", "flag for prescribing remapping fluxes", ""
   "l_mpond_fresh", ":math:`\bullet` if true, retain (topo) pond water until ponds drain", ""
   "latpnt", ":math:`\bullet` desired latitude of diagnostic points", "degrees N"
   "latt(u)_bounds", "latitude of T(U) grid cell corners", "degrees N"
   "lcdf64", ":math:`\bullet` if true, use 64-bit  format", ""
   "Lfresh", "latent heat of melting of fresh ice = Lsub - Lvap", "J/kg"
   "lhcoef", "transfer coefficient for latent heat", ""
   "lmask_n(s)", "northern (southern) hemisphere mask", ""
   "local_id", "local address of block in current distribution", ""
   "log_kind", "definition of a logical variable", "kind(.true.)"
   "lonpnt", ":math:`\bullet` desired longitude of diagnostic points", "degrees E"
   "lont(u)_bounds", "longitude of T(U) grid cell corners", "degrees E"
   "Lsub", "latent heat of sublimation for fresh water", "2.835\ :math:`\times` 10\ :math:`^6` J/kg"
   "ltripole_grid", "flag to signal use of tripole grid", ""
   "Lvap", "latent heat of vaporization for fresh water", "2.501\ :math:`\times` 10\ :math:`^6` J/kg"
   "**M**", "", ""
   "m_min", "minimum mass for computing velocity", "0.01 kg/m\ :math:`^2`"
   "m_to_cm", "meters to cm conversion", "100."
   "m1", "constant for lateral melt rate", "1.6\ :math:`\times`\ 10\ :math:`^{-6}` m/s deg\ :math:`^{-m2}`"
   "m2", "constant for lateral melt rate", "1.36"
   "m2_to_km2", "m\ :math:`^2` to km\ :math:`^2` conversion", "1\ :math:`\times`\ 10\ :math:`^{-6}`"
   "maskhalo_bound", ":math:`\bullet` turns on *bound_state* halo masking", ""
   "maskhalo_dyn", ":math:`\bullet` turns on dynamics halo masking", ""
   "maskhalo_remap", ":math:`\bullet` turns on transport halo masking", ""
   "master_task", "task ID for the controlling processor", ""
   "max_blocks", "maximum number of blocks per processor", ""
   "max_ntrcr", "maximum number of tracers available", "5"
   "maxraft", "maximum thickness of ice that rafts", "1. m"
   "mday", "day of the month", ""
   "meltb", "basal ice melt", "m"
   "meltl", "lateral ice melt", "m"
   "melts", "snow melt", "m"
   "meltt", "top ice melt", "m"
   "min_salin", "threshold for brine pockets", "0.1 ppt"
   "mlt_onset", "day of year that surface melt begins", ""
   "month", "the month number", ""
   "monthp", "previous month number", ""
   "mps_to_cmpdy", "m per s to cm per day conversion", "8.64\ :math:`\times`\ 10\ :math:`^6`"
   "mtask", "local processor number that writes debugging data", ""
   "mu_rdg", ":math:`\bullet` e-folding scale of ridged ice", ""
   "my_task", "task ID for the current processor", ""
   "**N**", "", ""
   "n_aero", "number of aerosol species", ""
   "natmiter", ":math:`\bullet` number of atmo boundary layer iterations", "5"
   "nblocks", "number of blocks on current processor", ""
   "nblocks_tot", "total number of blocks in decomposition", ""
   "nblocks_x(y)", "total number of blocks in x(y) direction", ""
   "nbtrcr", "number of biology tracers", ""
   "ncat", "number of ice categories", "5"
   "ncat_hist", "number of categories written to history", ""
   "ndte", ":math:`\bullet` number of subcycles", "120"
   "ndtd", ":math:`\bullet` number of dynamics/advection steps under thermo", "1"
   "new_day", "flag for beginning new day", ""
   "new_hour", "flag for beginning new hour", ""
   "new_month", "flag for beginning new month", ""
   "new_year", "flag for beginning new year", ""
   "nfreq", "number of wave frequency bins", "25"
   "nfsd", "number of floe size categories","12"
   "nghost", "number of rows of ghost cells surrounding each subdomain", "1"
   "ngroups", "number of groups of flux triangles in remapping", "5"
   "nhlat", "northern latitude of artificial mask edge", "30\ :math:`^\circ`\ S"
   "nilyr", "number of ice layers in each category", "7"
   "nit", "nitrate concentration", "mmol/m\ :math:`^3`"
   "nlt_bgc_[chem]", "ocean sources and sinks for biogeochemistry", ""
   "nml_filename", "namelist file name", ""
   "nprocs", ":math:`\bullet` total number of processors", ""
   "npt", ":math:`\bullet` total number of time steps (dt)", ""
   "ns_boundary_type", ":math:`\bullet` type of north-south boundary condition", ""
   "nslyr", "number of snow layers in each category", ""
   "nspint", "number of solar spectral intervals", ""
   "nstreams", "number of history output streams (frequencies)", ""
   "nt_<trcr>", "tracer index", ""
   "ntrace", "number of fields being transported", ""
   "ntrcr", "number of tracers", ""
   "nu_diag", "unit number for diagnostics output file", ""
   "nu_dump", "unit number for dump file for restarting", ""
   "nu_dump_eap", "unit number for EAP dynamics dump file for restarting", ""
   "nu_dump_[tracer]", "unit number for tracer dump file for restarting", ""
   "nu_forcing", "unit number for forcing data file", ""
   "nu_grid", "unit number for grid file", ""
   "nu_hdr", "unit number for binary history header file", ""
   "nu_history", "unit number for history file", ""
   "nu_kmt", "unit number for land mask file", ""
   "nu_nml", "unit number for namelist input file", ""
   "nu_restart", "unit number for restart input file", ""
   "nu_restart_eap", "unit number for EAP dynamics restart input file", ""
   "nu_restart_[tracer]", "unit number for tracer restart input file", ""
   "nu_rst_pointer", "unit number for pointer to latest restart file", ""
   "num_avail_hist_fields_[shape]", "number of history fields of each array shape", ""
   "nvar", "number of horizontal grid fields written to history", ""
   "nvarz", "number of category, vertical grid fields written to history", ""
   "nx(y)_block", "total number of gridpoints on block in x(y) direction", ""
   "nx(y)_global", "number of physical gridpoints in x(y) direction, global domain", ""
   "nyr", "year number", ""
   "**O**", "", ""
   "ocean_bio", "concentrations of bgc constituents in the ocean", ""
   "oceanmixed_file", ":math:`\bullet` data file containing ocean forcing data", ""
   "oceanmixed_ice", ":math:`\bullet` if true, use internal ocean mixed layer", ""
   "ocn_data_dir", ":math:`\bullet` directory for ocean forcing data", ""
   "ocn_data_format", ":math:`\bullet` format of ocean forcing files", ""
   "ocn_data_type", ":math:`\bullet` source of surface temperature, salinity data", ""
   "omega", "angular velocity of Earth", "7.292\ :math:`\times`\ 10\ :math:`^{-5}` rad/s"
   "opening", "rate of ice opening due to divergence and shear", "1/s"
   "**P**", "", ""
   "p001", "1/1000", ""
   "p01", "1/100", ""
   "p025", "1/40", ""
   "p027", "1/36", ""
   "p05", "1/20", ""
   "p055", "1/18", ""
   "p1", "1/10", ""
   "p111", "1/9", ""
   "p15", "15/100", ""
   "p166", "1/6", ""
   "p2", "1/5", ""
   "p222", "2/9", ""
   "p25", "1/4", ""
   "p333", "1/3", ""
   "p4", "2/5", ""
   "p5", "1/2", ""
   "p52083", "25/48", ""
   "p5625m", "-9/16", ""
   "p6", "3/5", ""
   "p666", "2/3", ""
   "p75", "3/4", ""
   "phi_c_slow_mode", ":math:`\bullet` critical liquid fraction", ""
   "phi_i_mushy", ":math:`\bullet` solid fraction at lower boundary", ""
   "phi_sk", "skeletal layer porosity", ""
   "phi_snow", ":math:`\bullet` snow porosity for brine height tracer", ""
   "pi", ":math:`\pi`", ""
   "pi2", ":math:`2\pi`", ""
   "pih", ":math:`\pi /2`", ""
   "piq", ":math:`\pi /4`", ""
   "pi(j,b,m)loc", "x (y, block, task) location of diagnostic points", ""
   "plat", "grid latitude of diagnostic points", ""
   "plon", "grid longitude of diagnostic points", ""
   "pndaspect", ":math:`\bullet` aspect ratio of pond changes (depth:area)", "0.8"
   "pointer_file", ":math:`\bullet` input file for restarting", ""
   "potT", "atmospheric potential temperature", "K"
   "PP_net", "total primary productivity per grid cell", "mg C/m\ :math:`^2`/s"
   "precip_units", ":math:`\bullet` liquid precipitation data units", ""
   "print_global", ":math:`\bullet` if true, print global data", "F"
   "print_points", ":math:`\bullet` if true, print point data", "F"
   "processor_shape", ":math:`\bullet` descriptor for processor aspect ratio", ""
   "prs_sig", "replacement pressure", "N/m"
   "Pstar", "ice strength parameter", "2.75\ :math:`\times`\ 10\ :math:`^4`\ N/m"
   "puny", "a small positive number", "1\ :math:`\times`\ 10\ :math:`^{-11}`" 
   "**Q**", "", ""
   "Qa", "specific humidity at 10 m", "kg/kg"
   "qdp", "deep ocean heat flux", "W/m\ :math:`^2`"
   "qqqice", "for saturated specific humidity over ice", "1.16378\ :math:`\times`\ 10\ :math:`^7`\ kg/m\ :math:`^3`"
   "qqqocn", "for saturated specific humidity over ocean", "6.275724\ :math:`\times`\ 10\ :math:`^6`\ kg/m\ :math:`^3`"
   "Qref", "2m atmospheric reference specific humidity", "kg/kg"
   "**R**", "", ""
   "R_C2N", "algal carbon to nitrate factor", "7. mole/mole"
   "R_gC2molC", "mg/mmol carbon", "12.01 mg/mole"
   "R_chl2N", "algal chlorophyll to nitrate factor", "3. mg/mmol"
   "R_ice", ":math:`\bullet` parameter for Delta-Eddington ice albedo", ""
   "R_pnd", ":math:`\bullet` parameter for Delta-Eddington pond albedo", ""
   "R_S2N", "algal silicate to nitrate factor", "0.03 mole/mole"
   "R_snw", ":math:`\bullet` parameter for Delta-Eddington snow albedo", ""
   "r16_kind", "definition of quad precision", "selected_real_kind(26)", ""
   "Rac_rapid_mode", ":math:`\bullet` critical Rayleigh number", "10"
   "rad_to_deg", "degree-radian conversion", ":math:`180/\pi`"
   "radius", "earth radius", "6.37\ :math:`\times`\ 10\ :math:`^6` m"
   "rdg_conv", "convergence for ridging", "1/s"
   "rdg_shear", "shear for ridging", "1/s"
   "real_kind", "definition of single precision real", "selected_real_kind(6)"
   "refindx", "refractive index of sea ice", "1.310"
   "revp", "real(revised_evp)", ""
   "restart", ":math:`\bullet` if true, initialize using restart file instead of defaults", "T"
   "restart_age", ":math:`\bullet` if true, read age restart file", ""
   "restart_bgc", ":math:`\bullet` if true, read bgc restart file", ""
   "restart_dir", ":math:`\bullet` path to restart/dump files", ""
   "restart_file", ":math:`\bullet` restart file prefix", ""
   "restart_format", ":math:`\bullet` restart file format", ""
   "restart_[tracer]", ":math:`\bullet` if true, read tracer restart file", ""
   "restart_ext", ":math:`\bullet` if true, read/write halo cells in restart file", ""
   "restore_bgc", ":math:`\bullet` if true, restore nitrate/silicate to data", ""
   "restore_ice", ":math:`\bullet` if true, restore ice state along lateral boundaries", ""
   "restore_ocn", ":math:`\bullet` restore sst to data", ""
   "revised_evp", ":math:`\bullet` if true, use revised EVP parameters and approach", ""
   "rfracmin", ":math:`\bullet` minimum melt water fraction added to ponds", "0.15"
   "rfracmax", ":math:`\bullet` maximum melt water fraction added to ponds", "1.0"
   "rhoa", "air density", "kg/m\ :math:`^3`"
   "rhofresh", "density of fresh water", "1000.0 kg/m\ :math:`^3`"
   "rhoi", "density of ice", "917. kg/m\ :math:`^3`"
   "rhos", "density of snow", "330. kg/m\ :math:`^3`"
   "rhosi", "average sea ice density (for hbrine tracer)", "940. kg/m\ :math:`^3`"
   "rhow", "density of seawater", "1026. kg/m\ :math:`^3`"
   "rnilyr", "real(nlyr)", ""
   "rside", "fraction of ice that melts laterally", ""
   "rsnw_fresh", "freshly fallen snow grain radius", "100. :math:`\times` 10\ :math:`^{-6}` m"
   "rsnw_melt", ":math:`\bullet` melting snow grain radius", "1000. :math:`\times` 10\ :math:`^{-6}` m"
   "rsnw_nonmelt", "nonmelting snow grain radius", "500. :math:`\times` 10\ :math:`^{-6}` m"
   "rsnw_sig", "standard deviation of snow grain radius", "250. :math:`\times` 10\ :math:`^{-6}` m"
   "runid", ":math:`\bullet` identifier for run", ""
   "runtype", ":math:`\bullet` type of initialization used", ""
   "**S**", "", ""
   "s11, s12, s22", "stress tensor components", ""
   "saltmax", "max salinity, at ice base (:cite:`Bitz99`)", "3.2 ppt"
   "scale_factor", "scaling factor for shortwave radiation components", ""
   "sec", "seconds elasped into idate", ""
   "secday", "number of seconds in a day", "86400."
   "shcoef", "transfer coefficient for sensible heat", ""
   "shear", "strain rate II component", "1/s"
   "shlat", "southern latitude of artificial mask edge", "30\ :math:`^\circ`\ N"
   "shortwave", ":math:`\bullet` flag for shortwave parameterization (‘ccsm3’ or ‘dEdd’)", ""
   "sig1(2)", "principal stress components (diagnostic)", ""
   "sil", "silicate concentration", "mmol/m\ :math:`^3`"
   "sinw", "sine of the turning angle in water", "0."
   "Sinz", "ice salinity profile", "ppt"
   "sk_l", "skeletal layer thickness", "0.03 m"
   "snoice", "snow–ice formation", "m"
   "snowpatch", "length scale for parameterizing nonuniform snow coverage", "0.02 m"
   "skl_bgc", ":math:`\bullet` biogeochemistry on/off", ""
   "spval", "special value (single precision)", ":math:`10^{30}`", ""
   "spval_dbl", "special value (double precision)", ":math:`10^{30}`", ""
   "ss_tltx(y)", "sea surface in the x(y) direction", "m/m"
   "sss", "sea surface salinity", "ppt"
   "sst", "sea surface temperature", "C"
   "Sswabs", "shortwave radiation absorbed in snow layers", "W/m\ :math:`^2`"
   "stefan-boltzmann", "Stefan-Boltzmann constant", "5.67\ :math:`\times`\ 10\ :math:`^{-8}` W/m\ :math:`^2`\ K\ :math:`^4`"
   "stop_now", "if 1, end program execution", ""
   "strairx(y)", "stress on ice by air in the x(y)-direction (centered in U cell)", "N/m\ :math:`^2`"
   "strairx(y)T", "stress on ice by air, x(y)-direction (centered in T cell)", "N/m\ :math:`^2`"
   "strax(y)", "wind stress components from data", "N/m\ :math:`^2`"
   "strength", "ice strength (pressure)", "N/m"
   "stress12", "internal ice stress, :math:`\sigma_{12}`", "N/m"
   "stressm", "internal ice stress, :math:`\sigma_{11}-\sigma_{22}`", "N/m"
   "stressp", "internal ice stress, :math:`\sigma_{11}+\sigma_{22}`", "N/m"
   "strintx(y)", "divergence of internal ice stress, x(y)", "N/m\ :math:`^2`"
   "strocnx(y)", "ice–ocean stress in the x(y)-direction (U-cell)", "N/m\ :math:`^2`"
   "strocnx(y)T", "ice–ocean stress, x(y)-dir. (T-cell)", "N/m\ :math:`^2`"
   "strtltx(y)", "surface stress due to sea surface slope", "N/m\ :math:`^2`"
   "swv(n)dr(f)", "incoming shortwave radiation, visible (near IR), direct (diffuse)", "W/m\ :math:`^2`"
   "**T**", "", ""
   "Tair", "air temperature at 10 m", "K"
   "tarea", "area of T-cell", "m\ :math:`^2`"
   "tarean", "area of northern hemisphere T-cells", "m\ :math:`^2`"
   "tarear", "1/tarea", "1/m\ :math:`^2`"
   "tareas", "area of southern hemisphere T-cells", "m\ :math:`^2`"
   "tcstr", "string identifying T grid for history variables", ""
   "tday", "absolute day number", ""
   "Tf", "freezing temperature", "C"
   "Tffresh", "freezing temp of fresh ice", "273.15 K"
   "tfrz_option", ":math:`\bullet` form of ocean freezing temperature", ""
   "thinS", "minimum ice thickness for brine tracer", ""
   "time", "total elapsed time", "s"
   "time_beg", "beginning time for history averages", ""
   "time_bounds", "beginning and ending time for history averages", ""
   "time_end", "ending time for history averages", ""
   "time_forc", "time of last forcing update", "s"
   "Timelt", "melting temperature of ice top surface", "0. C"
   "tinyarea", "puny \* tarea", "m\ :math:`^2`"
   "Tinz", "Internal ice temperature", "C"
   "TLAT", "latitude of cell center", "radians"
   "TLON", "longitude of cell center", "radians"
   "tmask", "land/boundary mask, thickness (T-cell)", ""
   "tmass", "total mass of ice and snow", "kg/m\ :math:`^2`"
   "Tmin", "minimum allowed internal temperature", "-100. C"
   "Tmltz", "melting temperature profile of ice", ""
   "Tocnfrz", "temperature of constant freezing point parameterization", "-1.8 C"
   "tr_aero", ":math:`\bullet` if true, use aerosol tracers", ""
   "tr_bgc_[tracer]", ":math:`\bullet` if true, use biogeochemistry tracers", ""
   "tr_brine", ":math:`\bullet` if true, use brine height tracer", ""
   "tr_FY", ":math:`\bullet` if true, use first-year area tracer", ""
   "tr_iage", ":math:`\bullet` if true, use ice age tracer", ""
   "tr_lvl", ":math:`\bullet` if true, use level ice area and volume tracers", ""
   "tr_pond_cesm", ":math:`\bullet` if true, use CESM melt pond scheme", ""
   "tr_pond_lvl", ":math:`\bullet` if true, use level-ice melt pond scheme", ""
   "tr_pond_topo", ":math:`\bullet` if true, use topo melt pond scheme", ""
   "trcr", "ice tracers", ""
   "trcr_depend", "tracer dependency on basic state variables", ""
   "Tref", "2m atmospheric reference temperature", "K"
   "trestore", ":math:`\bullet` restoring time scale", "days"
   "tripole", "if true, block lies along tripole boundary", ""
   "tripoleT", "if true, tripole boundary is T-fold; if false, U-fold", ""
   "Tsf_errmax", "max allowed :math:`T_{\mathit sf}` error (thermodynamics)", "5.\ :math:`\times`\ 10\ :math:`^{-4}`\ deg"
   "Tsfc(n)", "temperature of ice/snow top surface (in category n)", "C"
   "Tsnz", "Internal snow temperature", "C"
   "Tsmelt", "melting temperature of snow top surface", "0. C"
   "TTTice", "for saturated specific humidity over ice", "5897.8 K"
   "TTTocn", "for saturated specific humidity over ocean", "5107.4 K"
   "**U**", "", ""
   "uarea", "area of U-cell", "m :math:`^2`" 
   "uarear", "1/uarea", "m :math:`^{-2}`"
   "uatm", "wind velocity in the x direction", "m/s"
   "ULAT", "latitude of U-cell centers", "radians"
   "ULON", "longitude of U-cell centers", "radians"
   "umask", "land/boundary mask, velocity (U-cell)", ""
   "umax_stab", "ice speed threshold (diagnostics)", "1. m/s"
   "umin", "min wind speed for turbulent fluxes", "1. m/s"
   "uocn", "ocean current in the x-direction", "m/s"
   "update_ocn_f", ":math:`\bullet` if true, include frazil ice fluxes in ocean flux fields", ""
   "use_leap_years", ":math:`\bullet` if true, include leap days", ""
   "use_restart_time", ":math:`\bullet` if true, use date from restart file", ""
   "ustar_min", ":math:`\bullet` minimum friction velocity under ice", ""
   "ucstr", "string identifying U grid for history variables", ""
   "uvel", "x-component of ice velocity", "m/s"
   "uvel_init", "x-component of ice velocity at beginning of time step", "m/s"
   "uvm", "land/boundary mask, velocity (U-cell)", ""
   "**V**", "", ""
   "vatm", "wind velocity in the y direction", "m/s"
   "vice(n)", "volume per unit area of ice (in category n)", "m"
   "vicen_init", "ice volume at beginning of timestep", "m"
   "viscosity_dyn", "dynamic viscosity of brine", ":math:`1.79\times 10^{-3}` kg/m/s"
   "vocn", "ocean current in the y-direction", "m/s"
   "vonkar", "von Karman constant", "0.4"
   "vraftn", "volume of rafted ice", "m"
   "vrdgn", "volume of ridged ice", "m"
   "vredistrn", "redistribution function: fraction of new ridge volume", ""
   "vsno(n)", "volume per unit area of snow (in category n)", "m"
   "vvel", "y-component of ice velocity", "m/s"
   "vvel_init", "y-component of ice velocity at beginning of time step", "m/s"
   "**W**", "", ""
   "warmice", "value for constant albedo parameterization", "0.68"
   "warmsno", "value for constant albedo parameterization", "0.77"
   "wave_sig_ht", "significant height of waves", "m"
   "wave_spectrum", "wave spectrum", "m\ :math:`^2`/s"
   "wavefreq", "wave frequencies", "1/s"
   "wind", "wind speed", "m/s"
   "write_history", "if true, write history now", "" 
   "write_ic", ":math:`\bullet` if true, write initial conditions", ""
   "write_restart", "if 1, write restart now", ""
   "**X**", "", ""
   "**Y**", "", ""
   "ycycle", ":math:`\bullet` number of years in forcing data cycle", ""
   "yday", "day of the year", ""
   "yield_curve", "type of yield curve", "ellipse"   
   "yieldstress11(12, 22)", "yield stress tensor components", ""
   "year_init", ":math:`\bullet` the initial year", ""
   "**Z**", "", ""
   "zlvl", "atmospheric level height", "m"
   "zref", "reference height for stability", "10. m"
   "zTrf", "reference height for :math:`T_{ref}`, :math:`Q_{ref}`, :math:`U_{ref}`", "2. m"
   "zvir", "gas constant (water vapor)/gas constant (air) - 1", "0.606"