3.4. Case Settings, Model Namelist, and CPPs

There are two important files that define the case, cice.settings and ice_in. cice.settings is a list of env variables that define many values used to setup, build and run the case. ice_in is the input namelist file for CICE. Variables in both files are described below. In addition, the first table lists available preprocessor macros to activate or deactivate various features when compiling.

3.4.1. Table of C Preprocessor (CPP) Macros

The CICE model supports a number of C Preprocessor (CPP) Macros. These can be turned on during compilation to activate different pieces of source code. The main purpose is to introduce build-time code modifications to include or exclude certain libraries or Fortran language features. More information can be found in C Preprocessor (CPP) Macros. The following CPPs are available.

CPP Macros

CPP name

description

General Macros

CESM1_PIO

Provide backwards compatible support for PIO interfaces/version released with CESM1 in about 2010

ESMF_INTERFACE

Turns on ESMF support in a subset of driver code. Also USE_ESMF_LIB and USE_ESMF_METADATA

FORTRANUNDERSCORE

Used in ice_shr_reprosum86.c to support Fortran-C interfaces. This should generally be turned on at all times. There are other CPPs (FORTRANDOUBULEUNDERSCORE, FORTRANCAPS, etc) in ice_shr_reprosum.c that are generally not used in CICE but could be useful if problems arise in the Fortran-C interfaces

GPTL

Turns on GPTL initialization if needed for PIO

NO_F2003

Turns off some Fortran 2003 features

NO_I8

Converts integer*8 to integer*4. This could have adverse affects for certain algorithms including the ddpdd implementation associated with the bfbflag

NO_R16

Converts real*16 to real*8. This could have adverse affects for certain algorithms including the lsum16 implementation associated with the bfbflag

NO_SNICARHC

Does not compile hardcoded (HC) 5 band snicar tables tables needed by shortwave=dEdd_snicar_ad. May reduce compile time.

USE_NETCDF

Turns on netCDF code. This is normally on and is needed for released configurations. An older value, ncdf, is still supported.

USE_PIO1

Modifies CICE PIO implementation to be compatible with PIO1. By default, code is compatible with PIO2

Application Macros

CESMCOUPLED

Turns on code changes for the CESM coupled application

CICE_IN_NEMO

Turns on code changes for coupling in the NEMO ocean model

CICE_DMI

Turns on code changes for the DMI coupled model application

ICE_DA

Turns on code changes in the hadgem driver

RASM_MODS

Turns on code changes for the RASM coupled application

Library Macros

_OPENMP

Automatically defined when compiling with OpenMP

_OPENACC

Automatically defined when compiling with OpenACC

3.4.2. Table of CICE Settings

The cice.settings file contains a number of environment variables that define configuration, file system, run, and build settings. Several variables are set by the cice.setup script. This file is created on a case by case basis and can be modified as needed.

CICE settings

variable

options/format

description

default value

ICE_CASENAME

string

case name

set by cice.setup

ICE_SANDBOX

string

sandbox directory

set by cice.setup

ICE_MACHINE

string

machine name

set by cice.setup

ICE_ENVNAME

string

environment name

set by cice.setup

ICE_MACHCOMP

string

machine_environment name

set by cice.setup

ICE_SCRIPTS

string

scripts directory

set by cice.setup

ICE_CASEDIR

string

case directory

set by cice.setup

ICE_RUNDIR

string

run directory

set by cice.setup

ICE_OBJDIR

string

compile directory

${ICE_RUNDIR}/compile

ICE_RSTDIR

string

unused

${ICE_RUNDIR}/restart

ICE_HSTDIR

string

unused

${ICE_RUNDIR}/history

ICE_LOGDIR

string

log directory

${ICE_CASEDIR}/logs

ICE_DRVOPT

string

unused

standalone/cice

ICE_TARGET

string

build target

set by cice.setup

ICE_IOTYPE

string

I/O source code

set by cice.setup

binary

uses io_binary directory, no support for netCDF files

netcdf

uses io_netCDF directory, supports netCDF files

pio1

uses io_pio directory with PIO1 library, supports netCDF and parallel netCDF thru PIO interfaces

pio2

uses io_pio directory with PIO2 library, supports netCDF and parallel netCDF thru PIO interfaces

ICE_CLEANBUILD

true, false

automatically clean before building

true

ICE_CPPDEFS

user defined preprocessor macros for build

null

ICE_QUIETMODE

true, false

reduce build output to the screen

false

ICE_GRID

string (see below)

grid

set by cice.setup

gbox12

12x12 box

gbox80

80x80 box

gbox128

128x128 box

gbox180

180x180 box

gx1

1-deg displace-pole (Greenland) global grid

gx3

3-deg displace-pole (Greenland) global grid

tx1

1-deg tripole global grid

ICE_NTASKS

integer

number of MPI tasks

set by cice.setup

ICE_NTHRDS

integer

number of threads per task

set by cice.setup

ICE_OMPSCHED

string

OpenMP SCHEDULE env setting

static,1

ICE_TEST

string

test setting if using a test

set by cice.setup

ICE_TESTNAME

string

test name if using a test

set by cice.setup

ICE_TESTID

string

test name testid

set by cice.setup

ICE_BASELINE

string

baseline directory name, associated with cice.setup –bdir

set by cice.setup

ICE_BASEGEN

string

baseline directory name for regression generation, associated with cice.setup -bgen

set by cice.setup

ICE_BASECOM

string

baseline directory name for regression comparison, associated with cice.setup -bcmp

set by cice.setup

ICE_BFBCOMP

string

location of case for comparison, associated with cice.setup –bcmp

set by cice.setup

ICE_BFBTYPE

string

type and files used in BFBCOMP

restart

log

log file comparison for bit for bit

logrest

log and restart files for bit for bit

qcchk

QC test for same climate

qcchkf

QC test for different climate

restart

restart files for bit for bit

ICE_SPVAL

string

special value for cice.settings strings

set by cice.setup

ICE_RUNLENGTH

integer (see below)

batch run length default

set by cice.setup

-1

15 minutes (default)

0

30 minutes

1

59 minutes

2

2 hours

other \(2 < N < 8\)

N hours

8 or larger

8 hours

ICE_ACCOUNT

string

batch account number

set by cice.setup, .cice_proj or by default

ICE_QUEUE

string

batch queue name

set by cice.setup or by default

ICE_THREADED

true, false

force threading in compile, will always compile threaded if ICE_NTHRDS \(> 1\)

false

ICE_COMMDIR

mpi, serial

specify infrastructure comm version

set by ICE_NTASKS

ICE_SNICARHC

true, false

turn on hardcoded (HC) SNICAR tables in Icepack

false

ICE_BLDDEBUG

true, false

turn on compile debug flags

false

ICE_COVERAGE

true, false

turn on code coverage flags

false

3.4.3. Tables of Namelist Options

CICE reads a namelist input file, ice_in, consisting of several namelist groups. The tables below summarize the different groups and the variables in each group. The variables are organized alphabetically and the default values listed are the values defined in the source code. Those values will be used unless overridden by the CICE namelist file, ice_in. The source code default values as listed in the table are not necessarily the recommended production values.

3.4.3.1. setup_nml

setup_nml namelist options

variable

options/format

description

default value

bfbflag

off

local reduction then global scalar sum

off

lsum4

local reduction with real*4 then global scalar sum

lsum8

local reduction with real*8 then global scalar sum

lsum16

local reduction with real*16 then global scalar sum

ddpdd

parallel double double algorithm

reprosum

fixed point double integer sum

conserv_check

logical

check conservation

.false.

cpl_bgc

logical

couple bgc thru driver

.false.

days_per_year

integer

number of days in a model year

365

day_init

integer

the initial day of the month if not using restart

1

debug_forcing

logical

write extra forcing diagnostics

.false.

debug_model

logical

write extended model point diagnostics

.false.

debug_model_i

integer

local i index of debug_model point

-1

debug_model_iblk

integer

iblk value for debug_model point

-1

debug_model_j

integer

local j index of debug_model point

-1

debug_model_task

integer

mpi task value for debug_model point

-1

debug_model_step

logical

initial timestep to write debug_model output

0

diagfreq

integer

frequency of diagnostic output in timesteps

24

diag_type

stdout

write diagnostic output to stdout

stdout

file

write diagnostic output to file

diag_file

string

diagnostic output file

‘ice_diag.d’

dt

real

thermodynamics time step length in seconds

dumpfreq

d

write restart every dumpfreq_n days

‘y’,’x’,’x’,’x’,’x’

d1

write restart once after dumpfreq_n days

h

write restart every dumpfreq_n hours

h1

write restart once after dumpfreq_n hours

m

write restart every dumpfreq_n months

m1

write restart once after dumpfreq_n months

y

write restart every dumpfreq_n years

y1

write restart once after dumpfreq_n years

1

write restart every dumpfreq_n time steps

11

write restart once after dumpfreq_n time steps

dumpfreq_base

init

restart output frequency relative to year_init, month_init, day_init

‘init’,’init’,’init’,’init’,’init’

zero

restart output frequency relative to year-month-day of 0000-01-01

dumpfreq_n

integer array

write restart frequency with dumpfreq

1,1,1,1,1

dump_last

logical

write restart on last time step of simulation

.false.

histfreq

d

write history every histfreq_n days

‘1’,’h’,’d’,’m’,’y’

h

write history every histfreq_n hours

m

write history every histfreq_n months

x

unused frequency stream (not written)

y

write history every histfreq_n years

1

write history every histfreq_n time step

histfreq_base

init

history output frequency relative to year_init, month_init, day_init

‘zero’,’zero’,’zero’,’zero’,’zero’

zero

history output frequency relative to year-month-day of 0000-01-01

histfreq_n

integer array

frequency history output is written with histfreq

1,1,1,1,1

history_chunksize

integer array

chunksizes (x,y) for history output (hdf5 only)

0,0

history_deflate

integer

compression level (0 to 9) for history output (hdf5 only)

0

history_dir

string

path to history output directory

‘./’

history_file

string

output file for history

‘iceh’

history_format

binary

write history files with binary format

cdf1

cdf1

write history files with netcdf cdf1 (netcdf3-classic) format

cdf2

write history files with netcdf cdf2 (netcdf3-64bit-offset) format

cdf5

write history files with netcdf cdf5 (netcdf3-64bit-data) format

default

write history files in default format

hdf5

write history files with netcdf hdf5 (netcdf4) format

pio_pnetcdf

write history files with pnetcdf in PIO, deprecated

pio_netcdf

write history files with netcdf in PIO, deprecated

pnetcdf1

write history files with pnetcdf cdf1 (netcdf3-classic) format

pnetcdf2

write history files with pnetcdf cdf2 (netcdf3-64bit-offset) format

pnetcdf5

write history files with pnetcdf cdf5 (netcdf3-64bit-data) format

history_iotasks

integer

pe io tasks for history output with history_root and history_stride (PIO only), -99=internal default

-99

history_precision

integer

history file precision: 4 or 8 byte

4

history_rearranger

box

box io rearranger option for history output (PIO only)

default

default

internal default io rearranger option for history output

subset

subset io rearranger option for history output

history_root

integer

pe root task for history output with history_iotasks and history_stride (PIO only), -99=internal default

-99

history_stride

integer

pe stride for history output with history_iotasks and history_root (PIO only), -99=internal default

-99

hist_avg

logical

write time-averaged data

.true.,.true.,.true.,.true.,.true.

hist_suffix

character array

appended to history_file when not x

x,x,x,x,x

hist_time_axis

character

history file time axis interval location: begin, middle, end

end

ice_ic

default

equal to internal

default

internal

initial conditions set based on ice_data_type,conc,dist inputs

none

no ice

‘path/file’

restart file name

incond_dir

string

path to initial condition directory

‘./’

incond_file

string

output file prefix for initial condition

‘iceh_ic’

istep0

integer

initial time step number

0

latpnt

real

latitude of (2) diagnostic points

90.0,-65.0

lcdf64

logical

use 64-bit netCDF format, deprecated, see history_format, restart_format

.false.

lonpnt

real

longitude of (2) diagnostic points

0.0,-45.0

memory_stats

logical

turns on memory use diagnostics

.false.

month_init

integer

the initial month if not using restart

1

ndtd

integer

number of dynamics/advection/ridging/steps per thermo timestep

1

npt

integer

total number of npt_units to run the model

99999

npt_unit

d

run npt days

1

h

run npt hours

m

run npt months

s

run npt seconds

y

run npt years

1

run npt timesteps

numin

integer

minimum internal IO unit number

11

numax

integer

maximum internal IO unit number

99

pointer_file

string

restart pointer filename

‘ice.restart_file’

print_global

logical

print global sums diagnostic data

.true.

print_points

logical

print diagnostic data for two grid points

.false.

restart

logical

exists but deprecated, now set internally based on other inputs

restart_chunksize

integer array

chunksizes (x,y) for restart output (hdf5 only)

0,0

restart_deflate

integer

compression level (0 to 9) for restart output (hdf5 only)

0

restart_dir

string

path to restart directory

‘./’

restart_ext

logical

read/write halo cells in restart files

.false.

restart_file

string

output file prefix for restart dump

‘iced’

restart_format

binary

write restart files with binary format

cdf1

cdf1

write restart files with netcdf cdf1 (netcdf3-classic) format

cdf2

write restart files with netcdf cdf2 (netcdf3-64bit-offset) format

cdf5

write restart files with netcdf cdf5 (netcdf3-64bit-data) format

default

write restart files in default format

hdf5

write restart files with netcdf hdf5 (netcdf4) format

pio_pnetcdf

write restart files with pnetcdf in PIO, deprecated

pio_netcdf

write restart files with netcdf in PIO, deprecated

pnetcdf1

write restart files with pnetcdf cdf1 (netcdf3-classic) format

pnetcdf2

write restart files with pnetcdf cdf2 (netcdf3-64bit-offset) format

pnetcdf5

write restart files with pnetcdf cdf5 (netcdf3-64bit-data) format

restart_iotasks

integer

pe io tasks for restart output with restart_root and restart_stride (PIO only), -99=internal default

-99

restart_rearranger

box

box io rearranger option for restart output (PIO only)

default

default

internal default io rearranger option for restart output

subset

subset io rearranger option for restart output

restart_root

integer

pe root task for restart output with restart_iotasks and restart_stride (PIO only), -99=internal default

-99

restart_stride

integer

pe stride for restart output with restart_iotasks and restart_root (PIO only), -99=internal default

-99

runid

string

label for run (currently CESM only)

‘unknown’

runtype

continue

restart using pointer_file

initial

initial

start from ice_ic

sec_init

integer

the initial second if not using restart

0

timer_stats

logical

controls extra timer output

.false.

use_leap_years

logical

include leap days

.false.

use_restart_time

logical

set initial date using restart file on initial runtype only

.false.

version_name

string

model version

‘unknown_version_name’

write_ic

logical

write initial condition

.false.

year_init

integer

the initial year if not using restart

0

3.4.3.2. grid_nml

grid_nml namelist options

variable

options/format

description

default value

bathymetry_file

string

name of bathymetry file to be read

‘unknown_bathymetry_file’

bathymetry_format

default

NetCDF depth field

‘default’

pop

pop thickness file in cm in ascii format

close_boundaries

logical

force two gridcell wide land mask on boundaries for rectangular grids

.false.

dxrect

real

x-direction grid spacing for rectangular grid in cm

0.0

dxscale

real

user defined rectgrid x-grid scale factor

1.0

dyrect

real

y-direction grid spacing for rectangular grid in cm

0.0

dyscale

real

user defined rectgrid y-grid scale factor

1.0

gridcpl_file

string

input file for coupling grid info

‘unknown_gridcpl_file’

grid_atm

A

atm forcing/coupling grid, all fields on T grid

A

B

atm forcing/coupling grid, thermo fields on T grid, dyn fields on U grid

C

atm forcing/coupling grid, thermo fields on T grid, dynu fields on E grid, dynv fields on N grid

CD

atm forcing/coupling grid, thermo fields on T grid, dyn fields on N and E grid

grid_file

string

name of grid file to be read

‘unknown_grid_file’

grid_format

bin

read direct access grid and kmt files

bin

nc

read grid and kmt files

grid_ice

B

use B grid structure with T at center and U at NE corner

B

C

use C grid structure with T at center, U at E edge, V at N edge

grid_ocn

A

ocn forcing/coupling grid, all fields on T grid

A

B

ocn forcing/coupling grid, thermo fields on T grid, dyn fields on U grid

C

ocn forcing/coupling grid, thermo fields on T grid, dynu fields on E grid, dynv fields on N grid

CD

ocn forcing/coupling grid, thermo fields on T grid, dyn fields on N and E grid

grid_type

displaced_pole

read from file in popgrid

rectangular

rectangular

defined in rectgrid

regional

read from file in popgrid

tripole

read from file in popgrid

kcatbound

-1

single category formulation

1

0

old formulation

1

new formulation with round numbers

2

WMO standard categories

3

asymptotic scheme

kmt_file

string

name of land mask file to be read

unknown_kmt_file

kmt_type

boxislands

ocean/land mask set internally, complex test geometory

file

channel

ocean/land mask set internally as zonal channel

channel_oneeast

ocean/land mask set internally as single gridcell east-west zonal channel

channel_onenorth

ocean/land mask set internally as single gridcell north-south zonal channel

default

ocean/land mask set internally, land in upper left and lower right of domain,

file

ocean/land mask setup read from file, see kmt_file

wall

ocean/land mask set at right edge of domain

latrefrect

real

lower left corner lat for rectgrid in deg

71.35

lonrefrect

real

lower left corner lon for rectgrid in deg

-156.5

nblyr

integer

number of zbgc layers

0

ncat

integer

number of ice thickness categories

0

nfsd

integer

number of floe size categories

1

nilyr

integer

number of vertical layers in ice

0

nslyr

integer

number of vertical layers in snow

0

orca_halogrid

logical

use orca haloed grid for data/grid read

.false.

scale_dxdy

logical

apply dxscale, dyscale to rectgrid

false

use_bathymetry

logical

use read in bathymetry file for seabedstress option

.false.

3.4.3.3. domain_nml

domain_nml namelist options

variable

options/format

description

default value

add_mpi_barriers

logical

throttle communication

.false.

block_size_x

integer

block size in x direction

-1

block_size_y

integer

block size in y direction

-1

debug_blocks

logical

add additional print statements to debug the block decomposition

.false.

distribution_type

cartesian

2D cartesian block distribution method

cartesian

rake

redistribute blocks among neighbors

roundrobin

1 block per proc until blocks are used

sectcart

blocks distributed to domain quadrants

sectrobin

several blocks per proc until used

spacecurve

distribute blocks via space-filling curves

spiralcenter

distribute blocks via roundrobin from center of grid outward in a spiral

wghtfile

distribute blocks based on weights specified in distribution_wght_file

distribution_wght

block

full block weight method with land block elimination

latitude

blockall

full block weight method without land block elimination

latitude

latitude/ocean sets work_per_block

distribution_wght_file

string

distribution weight file when distribution_type is wghtfile

‘unknown’

ew_boundary_type

cyclic

periodic boundary conditions in x-direction

cyclic

open

Dirichlet boundary conditions in x

maskhalo_dyn

logical

mask unused halo cells for dynamics

.false.

maskhalo_remap

logical

mask unused halo cells for transport

.false.

maskhalo_bound

logical

mask unused halo cells for boundary updates

.false.

max_blocks

integer

maximum number of blocks per MPI task for memory allocation

-1

nprocs

integer

number of MPI tasks to use

-1

-1

find number of MPI tasks automatically

ns_boundary_type

cyclic

periodic boundary conditions in y-direction

open

open

Dirichlet boundary conditions in y

tripole

U-fold tripole boundary conditions in y

tripoleT

T-fold tripole boundary conditions in y

nx_global

integer

global grid size in x direction

-1

ny_global

integer

global grid size in y direction

-1

processor_shape

slenderX1

1 processor in the y direction used with distribution_type=cartesian

slenderX2

slenderX1

1 processor in the y direction (tall, thin)

slenderX2

2 processors in the y direction (thin)

square-ice

more processors in x than y, \(\sim\) square

square-pop

more processors in y than x, \(\sim\) square

3.4.3.4. tracer_nml

tracer_nml namelist options

variable

options/format

description

default value

n_aero

integer

number of aerosol tracers

0

n_algae

0,1,2,3

number of algal tracers

0

n_dic

0,1

number of dissolved inorganic carbon

0

n_doc

0,1,2,3

number of dissolved organic carbon

0

n_don

0,1

number of dissolved organize nitrogen

0

n_fed

0,1,2

number of dissolved iron tracers

0

n_fep

0,1,2

number of particulate iron tracers

0

n_iso

integer

number of isotope tracers

0

n_zaero

0,1,2,3,4,5,6

number of z aerosol tracers in use

0

tr_aero

logical

aerosols

.false.

tr_fsd

logical

floe size distribution

.false.

tr_FY

logical

first-year ice area

.false.

tr_iage

logical

ice age

.false.

tr_iso

logical

isotopes

.false.

tr_lvl

logical

level ice area and volume

.false.

tr_pond_lvl

logical

level-ice melt ponds

.false.

tr_pond_cesm

DEPRECATED

tr_pond_topo

logical

topo melt ponds

.false.

tr_snow

logical

advanced snow physics

.false.

restart_aero

logical

restart tracer values from file

.false.

restart_age

logical

restart tracer values from file

.false.

restart_fsd

logical

restart floe size distribution values from file

.false.

restart_FY

logical

restart tracer values from file

.false.

restart_iso

logical

restart tracer values from file

.false.

restart_lvl

logical

restart tracer values from file

.false.

restart_pond_lvl

logical

restart tracer values from file

.false.

restart_pond_topo

logical

restart tracer values from file

.false.

restart_snow

logical

restart snow tracer values from file

.false.

3.4.3.5. thermo_nml

thermo_nml namelist options

variable

options/format

description

default value

a_rapid_mode

real

brine channel diameter in m

0.5e-3

aspect_rapid_mode

real

brine convection aspect ratio

1.0

conduct

bubbly

conductivity scheme [45]

bubbly

MU71

conductivity [40]

dSdt_slow_mode

real

slow drainage strength parameter m/s/K

-1.5e-7

floediam

real

effective floe diameter for lateral melt in m

300.0

hfrazilmin

real

min thickness of new frazil ice in m

0.05

hi_min

real

minimum ice thickness in m

0.01

kitd

0

delta function ITD approximation

1

1

linear remapping ITD approximation

ksno

real

snow thermal conductivity

0.3

ktherm

-1

thermodynamic model disabled

1

1

Bitz and Lipscomb thermodynamic model

2

mushy-layer thermodynamic model

phi_c_slow_mode

\(0<\phi_c < 1\)

critical liquid fraction

0.05

phi_i_mushy

\(0<\phi_i < 1\)

solid fraction at lower boundary

0.85

Rac_rapid_mode

real

critical Rayleigh number

10.0

Tliquidus_max

real

maximum liquidus temperature of mush (C)

0.0

3.4.3.6. dynamics_nml

dynamics_nml namelist options

variable

options/format

description

default value

advection

remap

linear remapping advection scheme

remap

upwind

donor cell advection

algo_nonlin

anderson

use nonlinear anderson algorithm for implicit solver

picard

picard

use picard algorithm

alphab

real

\(\alpha_{b}\) factor in [34]

20.0

arlx

real

revised_evp value

300.0

brlx

real

revised_evp value

300.0

capping_method

max

max capping in [15]

max

sum

sum capping in [31]

Cf

real

ratio of ridging work to PE change in ridging

17.0

coriolis

constant

constant coriolis value = 1.46e-4 s\(^{-1}\)

latitude

latitude

coriolis variable by latitude

zero

zero coriolis

Cstar

real

constant in Hibler strength formula

20

deltaminEVP

real

minimum delta for viscosities

1e-11

deltaminVP

real

minimum delta for viscosities

2e-9

dim_fgmres

integer

maximum number of Arnoldi iterations for FGMRES solver

50

dim_pgmres

integer

maximum number of Arnoldi iterations for PGMRES preconditioner

5

e_plasticpot

real

aspect ratio of elliptical plastic potential

2.0

e_yieldcurve

real

aspect ratio of elliptical yield curve

2.0

elasticDamp

real

elastic damping parameter

0.36

evp_algorithm

standard_2d

standard 2d EVP memory parallel solver

standard_2d

shared_mem_1d

1d shared memory solver

kdyn

-1

dynamics algorithm OFF

1

0

dynamics OFF

1

EVP dynamics

2

EAP dynamics

3

VP dynamics

kstrength

0

ice strength formulation [15]

1

1

ice strength formulation [52]

krdg_partic

0

old ridging participation function

1

1

new ridging participation function

krdg_redist

0

old ridging redistribution function

1

1

new ridging redistribution function

kridge

-1

ridging disabled

1

1

ridging enabled

ktransport

-1

transport disabled

1

1

transport enabled

Ktens

real

Tensile strength factor (see [3])

0.0

k1

real

1st free parameter for landfast parameterization

7.5

k2

real

2nd free parameter (N/m\(^3\)) for landfast parameterization

15.0

maxits_fgmres

integer

maximum number of restarts for FGMRES solver

1

maxits_nonlin

integer

maximum number of nonlinear iterations for VP solver

10

maxits_pgmres

integer

maximum number of restarts for PGMRES preconditioner

1

monitor_fgmres

logical

write velocity norm at each FGMRES iteration

.false.

monitor_nonlin

logical

write velocity norm at each nonlinear iteration

.false.

monitor_pgmres

logical

write velocity norm at each PGMRES iteration

.false.

mu_rdg

real

e-folding scale of ridged ice for krdg_partic = 1 in m^0.5

3.0

ndte

integer

number of EVP subcycles

120

ortho_type

cgs

Use classical Gram-Shchmidt in FGMRES solver

mgs

mgs

Use modified Gram-Shchmidt in FGMRES solver

precond

diag

Use Jacobi preconditioner for the FGMRES solver

pgmres

ident

Don’t use a preconditioner for the FGMRES solver

pgmres

Use GMRES as preconditioner for FGMRES solver

Pstar

real

constant in Hibler strength formula (N/m\(^2\))

2.75e4

reltol_fgmres

real

relative tolerance for FGMRES solver

1e-1

reltol_nonlin

real

relative tolerance for nonlinear solver

1e-8

reltol_pgmres

real

relative tolerance for PGMRES preconditioner

1e-6

revised_evp

logical

use revised EVP formulation

.false.

seabed_stress

logical

use seabed stress parameterization for landfast ice

.false.

seabed_stress_method

LKD

linear keel draft method [34]

LKD

probabilistic

probability of contact method [11]

ssh_stress

coupled

computed from coupled sea surface height gradient

geostrophic

geostropic

computed from ocean velocity

threshold_hw

real

Max water depth for grounding (see [1])

use_mean_vrel

logical

Use mean of two previous iterations for vrel in VP

.true.

visc_method

avg_strength

average strength for viscosities on U grid

avg_zeta

avg_zeta

average zeta for viscosities on U grid

yield_curve

ellipse

elliptical yield curve

ellipse

3.4.3.7. shortwave_nml

shortwave_nml namelist options

variable

options/format

description

default value

ahmax

real

albedo is constant above this thickness in meters

0.3

albedo_type

ccsm3`

NCAR CCSM3 albedo implementation

ccsm3

constant

four constant albedos

albicei

\(0<\alpha <1\)

near infrared ice albedo for thicker ice

0.36

albicev

\(0<\alpha <1\)

visible ice albedo for thicker ice

0.78

albsnowi

\(0<\alpha <1\)

near infrared, cold snow albedo

0.70

albsnowv

\(0<\alpha <1\)

visible, cold snow albedo

0.98

dT_mlt

real

\(\Delta\) temperature per \(\Delta\) snow grain radius

1.5

kalg

real

absorption coefficient for algae

0.6

rsnw_mlt

real

maximum melting snow grain radius

R_ice

real

tuning parameter for sea ice albedo from Delta-Eddington shortwave

0.0

R_pnd

real

tuning parameter for ponded sea ice albedo from Delta-Eddington shortwave

0.0

R_snw

real

tuning parameter for snow (broadband albedo) from Delta-Eddington shortwave

1.5

shortwave

ccsm3

NCAR CCSM3 shortwave distribution method

ccsm3

dEdd

Delta-Eddington method (3-band)

dEdd_snicar_ad

Delta-Eddington method with 5 band snow

snw_ssp_table

snicar

lookup table for dEdd_snicar_ad

test

test

reduced lookup table for dEdd_snicar_ad testing

sw_dtemp

real

temperature difference from melt to start redistributing

0.02

sw_frac

real

fraction redistributed

0.9

sw_redist

logical

redistribute internal shortwave to surface

.false.

3.4.3.8. ponds_nml

ponds_nml namelist options

variable

options/format

description

default value

dpscale

real

time scale for flushing in permeable ice

1.0

frzpnd

cesm

CESM pond refreezing forumulation

cesm

hlid

Stefan refreezing with pond ice thickness

hp1

real

critical ice lid thickness for topo ponds in m

0.01

hs0

real

snow depth of transition to bare sea ice in m

hs1

real

snow depth of transition to pond ice in m

0.03

pndaspect

real

aspect ratio of pond changes (depth:area)

0.8

rfracmax

\(0 \le r_{max} \le 1\)

maximum melt water added to ponds

0.85

rfracmin

\(0 \le r_{min} \le 1\)

minimum melt water added to ponds

0.15

3.4.3.9. snow_nml

snow_nml namelist options

variable

options/format

description

default value

drhosdwind

real

wind compactions factor for now in kg-s/m^4

27.3

rhosmax

real

maximum snow density in kg/m^3

rhosmin

real

minimum snow density in kg/m^3

rhosnew

real

new snow density in kg/m^3

rsnw_fall

real

radius of new snow in 1.0e-6 m

rsnw_tmax

real

maximum snow radius in 1.0e-6 m

snwgrain

logical

snow metamorophsis flag

.false.

snwlvlfac

real

fractional increase in snow

0.3

snwredist

bulk

bulk snow redistribution scheme

none

ITD

ITD snow redistribution scheme

ITDrdg

ITDrdg snow redistribution scheme

none

snow redistribution scheme off

snw_aging_table

file

read 1D and 3D fields for dry metamorophsis lookup table

test

snicar

read 3D fields for dry metamorophsis lookup table

test

internally generated dry metamorophsis lookup table for testing

snw_drdt0_fname

string

snow aging file drdt0 fieldname

unknown

snw_filename

string

snow aging table data filename

unknown

snw_kappa_fname

string

snow aging file kappa fieldname

unknown

snw_rhos_fname

string

snow aging file rhos fieldname

unknown

snw_T_fname

string

snow aging file T fieldname

unknown

snw_tau_fname

string

snow aging file tau fieldname

unknown

snw_Tgrd_fname

string

snow aging file Tgrd fieldname

unknown

use_smliq_pnd

logical

use liquid in snow for ponds

.false.

windmin

real

minimum wind speed to compact snow in m/s

3.4.3.10. forcing_nml

forcing_nml namelist options

variable

options/format

description

default value

atmbndy

string

bulk transfer coefficients

similarity

similarity

stability-based boundary layer

constant

constant-based boundary layer

mixed

stability-based boundary layer for wind stress, constant-based for sensible+latent heat fluxes

atmiter_conv

real

convergence criteria for ustar

0.0

atm_data_dir

string

path or partial path to atmospheric forcing data directory

atm_data_format

bin

read direct access binary atmo forcing file format

bin

nc

read netcdf atmo forcing files

atm_data_type

box2001

forcing data for [20] box problem

default

default

constant values defined in the code

hycom

HYCOM atm forcing data in netCDF format

JRA55

JRA55 forcing data [61]

JRA55do

JRA55do forcing data [61]

monthly

monthly forcing data

ncar

NCAR bulk forcing data

oned

column forcing data

atm_data_version

string

date of atm data forcing file creation

_undef

bgc_data_dir

string

path to oceanic forcing data directory

‘unknown_bgc_data_dir’

bgc_data_type

clim

bgc climatological data

default

default

constant values defined in the code

hycom

HYCOM ocean forcing data in netCDF format

ncar

POP ocean forcing data

calc_strair

.false.

read wind stress and speed from files

.true.

.true.

calculate wind stress and speed

calc_Tsfc

logical

calculate surface temperature

.true.

cpl_frazil

external

frazil water/salt fluxes are handled outside of Icepack

fresh_ice_correction

fresh_ice_correction

correct fresh-ice frazil water/salt fluxes for mushy physics

internal

send full frazil water/salt fluxes for mushy physics

default_season

summer

forcing initial summer values

winter

winter

forcing initial winter values

emissivity

real

emissivity of snow and ice

0.985

fbot_xfer_type

Cdn_ocn

variable ocean heat transfer coefficient scheme

constant

constant

constant ocean heat transfer coefficient

fe_data_type

clim

ocean climatology forcing value for iron

default

default

default forcing value for iron

formdrag

logical

calculate form drag

.false.

fyear_init

integer

first year of atmospheric forcing data

1900

highfreq

logical

high-frequency atmo coupling

.false.

ice_data_conc

box2001

ice distribution ramped from 0 to 1 west to east consistent with box2001 test ([20])

default

c1

initial ice concentation of 1.0

default

same as parabolic

p5

initial concentration of 0.5

p8

initial concentration of 0.8

p9

initial concentration of 0.9

parabolic

parabolic in ice thickness space with sum of aicen=1.0

ice_data_dist

box2001

ice distribution ramped from 0 to 1 west to east consistent with box2001 test ([20])

default

default

uniform distribution, equivalent to uniform

gauss

gauss distbution of ice with a peak in the center of the domain

uniform

uniform distribution, equivalent to default

ice_data_type

block

ice block covering about 25 percent of the area in center of domain

default

boxslotcyl

slot cylinder ice mask associated with boxslotcyl test ([67])

box2001

box2001 ice mask associate with box2001 test ([20])

channel

ice defined on entire grid in i-direction and 50% in j-direction in center of domain

default

same as latsst

eastblock

ice block covering about 25 percent of domain at the east edge of the domain

latsst

ice dependent on latitude and ocean temperature

uniform

ice defined at all grid points

ice_ref_salinity

real

sea ice salinity for coupling fluxes (ppt)

4.0

iceruf

real

ice surface roughness at atmosphere interface in meters

0.0005

l_mpond_fresh

.false.

release pond water immediately to ocean

.false.

true

retain (topo) pond water until ponds drain

natmiter

integer

number of atmo boundary layer iterations

5

nfreq

integer

number of frequencies in ocean surface wave spectral forcing

25

oceanmixed_file

string

data file containing ocean forcing data

‘unknown_oceanmixed_file’

oceanmixed_ice

logical

active ocean mixed layer calculation

.false.

ocn_data_dir

string

path to oceanic forcing data directory

‘unknown_ocn_data_dir’

ocn_data_format

bin

read direct access binary ocean forcing files

bin

nc

read netCDF ocean forcing files

ocn_data_type

clim

ocean climatological data formulation

default

default

constant values defined in the code

hycom

HYCOM ocean forcing data in netCDF format

ncar

POP ocean forcing data

precip_units

mks

liquid precipitation data units

mks

mm_per_month

mm_per_sec

(same as MKS units)

m_per_sec

restart_coszen

logical

read/write coszen in restart files

.false.

restore_ocn

logical

restore sst to data

.false.

restore_ice

logical

restore ice state along lateral boundaries

.false.

rotate_wind

logical

rotate wind from east/north to computation grid

.true.

saltflux_option

constant

computed using ice_ref_salinity

constant

prognostic

computed using prognostic salinity

tfrz_option

constant

constant ocean freezing temperature (Tocnfrz)

mushy

linear_salt

linear function of salinity (ktherm=1)

minus1p8

constant ocean freezing temperature (\(-1.8^{\circ} C\))

mushy

matches mushy-layer thermo (ktherm=2)

trestore

integer

sst restoring time scale (days)

90

ustar_min

real

minimum value of ocean friction velocity in m/s

0.0005

update_ocn_f

.false.

do not include frazil water/salt fluxes in ocn fluxes

.false.

true

include frazil water/salt fluxes in ocn fluxes

wave_spec_file

string

data file containing wave spectrum forcing data

wave_spec_type

constant

wave data file is provided, constant wave spectrum, for testing

none

none

no wave data provided, no wave-ice interactions

profile

no wave data file is provided, use fixed dummy wave spectrum, for testing

random

wave data file is provided, wave spectrum generated using random number

ycycle

integer

number of years in forcing data cycle

1

3.4.3.11. zbgc_nml

zbgc_nml namelist options

variable

options/format

description

default value

algaltype_diatoms

real

mobility type between stationary and mobile algal diatoms

0.0

algaltype_phaeo

real

mobility type between stationary and mobile algal phaeocystis

0.5

algaltype_sp

real

mobility type between stationary and mobile small plankton

0.5

algal_vel

real

[32]

1.11e-8

alpha2max_low_diatoms

real

light limitation diatoms 1/(W/m^2)

0.8

alpha2max_low_phaeo

real

light limitation phaeocystis 1/(W/m^2)

0.67

alpha2max_low_sp

real

light limitation small plankton 1/(W/m^2)

0.67

ammoniumtype

real

mobility type between stationary and mobile ammonium

1.0

beta2max_diatoms

real

light inhibition diatoms 1/(W/m^2)

0.18

beta2max_phaeo

real

light inhibition phaeocystis 1/(W/m^2)

0.01

beta2max_sp

real

light inhibition small plankton 1/(W/m^2)

0.0025

bgc_flux_type

constant

constant ice–ocean flux velocity

Jin2006

Jin2006

ice–ocean flux velocity of [26]

chlabs_diatoms

real

chl absorbtion diatoms 1/m/(mg/m^3)

0.03

chlabs_phaeo

real

chl absorbtion phaeocystis 1/m/(mg/m^3)

0.05

chlabs_sp

real

chl absorbtion small plankton 1/m/(mg/m^3)

0.01

dEdd_algae

logical

.false.

dmspdtype

real

mobility type between stationary and mobile dmspd

-1.0

dmspptype

real

mobility type between stationary and mobile dmspp

0.5

doctype_l

real

mobility type between stationary and mobile doc lipids

0.5

doctype_s

real

mobility type between stationary and mobile doc saccharids

0.5

dontype_protein

real

mobility type between stationary and mobile don proteins

0.5

dustFe_sol

real

solubility fraction

0.005

fedtype_1

real

mobility type between stationary and mobile fed lipids

0.5

feptype_1

real

mobility type between stationary and mobile fep lipids

0.5

frazil_scav

real

increase in initial bio bracer from ocean scavenging

1.0

fr_dFe

real

fraction of remineralized nitrogen in units of algal iron

0.3

fr_graze_diatoms

real

fraction grazed diatoms

0.01

fr_graze_e

real

fraction of assimilation excreted

0.5

fr_graze_phaeo

real

fraction grazed phaeocystis

0.1

fr_graze_s

real

fraction of grazing spilled or slopped

0.5

fr_graze_sp

real

fraction grazed small plankton

0.1

fr_mort2min

real

fractionation of mortality to Am

0.5

fr_resp

real

frac of algal growth lost due to respiration

0.05

fr_resp_s

real

DMSPd fraction of respiration loss as DMSPd

0.75

fsal

real

salinity limitation ppt

1.0

F_abs_chl_diatoms

real

scales absorbed radiation for dEdd chl diatoms

2.0

F_abs_chl_phaeo

real

scales absorbed radiation for dEdd chl phaeocystis

5.0

F_abs_chl_sp

real

scales absorbed radiation for dEdd small plankton

4.0

f_doc_l

real

fraction of mortality to DOC lipids

0.4

f_doc_s

real

fraction of mortality to DOC saccharides

0.4

f_don_Am_protein

real

fraction of remineralized DON to ammonium

0.25

f_don_protein

real

fraction of spilled grazing to proteins

0.6

f_exude_l

real

fraction of exudation to DOC lipids

1.0

f_exude_s

real

fraction of exudation to DOC saccharids

1.0

grid_o

real

z biology for bottom flux

5.0

grid_o_t

real

z biology for top flux

5.0

grid_oS

real

zsalinity DEPRECATED

grow_Tdep_diatoms

real

temperature dependence growth diatoms per degC

0.06

grow_Tdep_phaeo

real

temperature dependence growth phaeocystis per degC

0.06

grow_Tdep_sp

real

temperature dependence growth small plankton per degC

0.06

humtype

real

mobility type between stationary and mobile hum

1.0

initbio_frac

real

fraction of ocean trcr concentration in bio tracers

1.0

K_Am_diatoms

real

ammonium half saturation diatoms mmol/m^3

0.3

K_Am_phaeo

real

ammonium half saturation phaeocystis mmol/m^3

0.3

K_Am_sp

real

ammonium half saturation small plankton mmol/m^3

0.3

k_bac_l

real

Bacterial degredation of DOC lipids per day

0.03

k_bac_s

real

Bacterial degredation of DOC saccharids per day

0.03

k_exude_diatoms

real

algal exudation diatoms per day

0.0

k_exude_phaeo

real

algal exudation phaeocystis per day

0.0

k_exude_sp

real

algal exudation small plankton per day

0.0

K_Fe_diatoms

real

iron half saturation diatoms nM

1.0

K_Fe_phaeo

real

iron half saturation phaeocystis nM

0.1

K_Fe_sp

real

iron half saturation small plankton nM

0.2

k_nitrif

real

nitrification rate per day

0.0

K_Nit_diatoms

real

nitrate half saturation diatoms mmol/m^3

1.0

K_Nit_phaeo

real

nitrate half saturation phaeocystis mmol/m^3

1.0

K_Nit_sp

real

nitrate half saturation small plankton mmol/m^3

1.0

K_Sil_diatoms

real

silicate half saturation diatoms mmol/m^3

4.0

K_Sil_phaeo

real

silicate half saturation phaeocystis mmol/m^3

0.0

K_Sil_sp

real

silicate half saturation small plankton mmol/m^3

0.0

kn_bac_protein

real

bacterial degradation of DON per day

0.03

l_sk

real

characteristic diffusive scale in m

7.0

l_skS

real

zsalinity DEPRECATED

max_dfe_doc1

real

max ratio of dFe to saccharides in the ice in nm Fe / muM C

0.2

max_loss

real

restrict uptake to percent of remaining value

0.9

modal_aero

logical

modal aerosols

.false.

mort_pre_diatoms

real

mortality diatoms

0.007

mort_pre_phaeo

real

mortality phaeocystis

0.007

mort_pre_sp

real

mortality small plankton

0.007

mort_Tdep_diatoms

real

temperature dependence of mortality diatoms per degC

0.03

mort_Tdep_phaeo

real

temperature dependence of mortality phaeocystis per degC

0.03

mort_Tdep_sp

real

temperature dependence of mortality small plankton per degC

0.03

mu_max_diatoms

real

maximum growth rate diatoms per day

1.2

mu_max_phaeo

real

maximum growth rate phaeocystis per day

0.851

mu_max_sp

real

maximum growth rate small plankton per day

0.851

nitratetype

real

mobility type between stationary and mobile nitrate

-1.0

op_dep_min

real

light attenuates for optical depths exceeding min

0.1

phi_snow

real

snow porosity for brine height tracer

0.5

ratio_chl2N_diatoms

real

algal chl to N in mg/mmol diatoms

2.1

ratio_chl2N_phaeo

real

algal chl to N in mg/mmol phaeocystis

0.84

ratio_chl2N_sp

real

algal chl to N in mg/mmol small plankton

1.1

ratio_C2N_diatoms

real

algal C to N in mol/mol diatoms

7.0

ratio_C2N_phaeo

real

algal C to N in mol/mol phaeocystis

7.0

ratio_C2N_proteins

real

algal C to N in mol/mol proteins

7.0

ratio_C2N_sp

real

algal C to N in mol/mol small plankton

7.0

ratio_Fe2C_diatoms

real

algal Fe to C in umol/mol diatoms

0.0033

ratio_Fe2C_phaeo

real

algal Fe to C in umol/mol phaeocystis

1.0

ratio_Fe2C_sp

real

algal Fe to C in umol/mol small plankton

0.0033

ratio_Fe2N_diatoms

real

algal Fe to N in umol/mol diatoms

0.23

ratio_Fe2N_phaeo

real

algal Fe to N in umol/mol phaeocystis

0.7

ratio_Fe2N_sp

real

algal Fe to N in umol/mol small plankton

0.23

ratio_Fe2DOC_s

real

Fe to C of DON saccharids nmol/umol

1.0

ratio_Fe2DOC_l

real

Fe to C of DOC lipids nmol/umol

0.033

ratio_Fe2DON

real

Fe to C of DON nmol/umol

0.023

ratio_Si2N_diatoms

real

algal Si to N in mol/mol diatoms

1.8

ratio_Si2N_phaeo

real

algal Si to N in mol/mol phaeocystis

0.0

ratio_Si2N_sp

real

algal Si to N in mol/mol small plankton

0.0

ratio_S2N_diatoms

real

algal S to N in mol/mol diatoms

0.03

ratio_S2N_phaeo

real

algal S to N in mol/mol phaeocystis

0.03

ratio_S2N_sp

real

algal S to N in mol/mol small plankton

0.03

restart_bgc

logical

restart tracer values from file

.false.

restart_hbrine

logical

.false.

restart_zsal

logical

zsalinity DEPRECATED

.false.

restore_bgc

logical

restore bgc to data

.false.

R_dFe2dust

real

g/g [57]

0.035

scale_bgc

logical

.false.

silicatetype

real

mobility type between stationary and mobile silicate

-1.0

skl_bgc

logical

biogeochemistry

.false.

solve_zbgc

logical

.false.

solve_zsal

logical

zsalinity DEPRECATED, update salinity tracer profile

.false.

tau_max

real

long time mobile to stationary exchanges

1.73e-5

tau_min

real

rapid module to stationary exchanges

tr_bgc_Am

logical

ammonium tracer

.false.

tr_bgc_C

logical

algal carbon tracer

.false.

tr_bgc_chl

logical

algal chlorophyll tracer

.false.

tr_bgc_DMS

logical

DMS tracer

.false.

tr_bgc_DON

logical

DON tracer

.false.

tr_bgc_Fe

logical

iron tracer

.false.

tr_bgc_hum

logical

.false.

tr_bgc_Nit

logical

.false.

tr_bgc_PON

logical

PON tracer

.false.

tr_bgc_Sil

logical

silicate tracer

.false.

tr_brine

logical

brine height tracer

.false.

tr_zaero

logical

vertical aerosol tracers

.false.

t_iron_conv

real

desorption loss pFe to dFe in days

t_sk_conv

real

Stefels conversion time in days

3.0

t_sk_ox

real

DMS oxidation time in days

10.0

T_max

real

maximum temperature degC

0.0

y_sk_DMS

real

fraction conversion given high yield

0.5

zaerotype_bc1

real

mobility type between stationary and mobile zaero bc1

1.0

zaerotype_bc2

real

mobility type between stationary and mobile zaero bc2

1.0

zaerotype_dust1

real

mobility type between stationary and mobile zaero dust1

1.0

zaerotype_dust2

real

mobility type between stationary and mobile zaero dust2

1.0

zaerotype_dust3

real

mobility type between stationary and mobile zaero dust3

1.0

zaerotype_dust4

real

mobility type between stationary and mobile zaero dust4

1.0

z_tracers

logical

.false.

3.4.3.12. icefields_nml

There are several icefield namelist groups to control model history output. See the source code for a full list of supported output fields.

  • icefields_nml is in cicecore/cicedyn/analysis/ice_history_shared.F90

  • icefields_bgc_nml is in cicecore/cicedyn/analysis/ice_history_bgc.F90

  • icefields_drag_nml is in cicecore/cicedyn/analysis/ice_history_drag.F90

  • icefields_fsd_nml is in cicecore/cicedyn/analysis/ice_history_fsd.F90

  • icefields_mechred_nml is in cicecore/cicedyn/analysis/ice_history_mechred.F90

  • icefields_pond_nml is in cicecore/cicedyn/analysis/ice_history_pond.F90

  • icefields_snow_nml is in cicecore/cicedyn/analysis/ice_history_snow.F90

icefields_nml namelist options

variable

options/format

description

default value

f_<var>

d

write field var every histfreq_n days

h

write field var every histfreq_n hours

m

write field var every histfreq_n months

x

do not write var to history

y

write field var every histfreq_n years

1

write field var every time step

md

e.g., write both monthly and daily files

f_<var>_ai

d

write field cell average var every histfreq_n days

h

write field cell average var every histfreq_n hours

m

write field cell average var every histfreq_n months

x

do not write cell average var to history

y

write field cell average var every histfreq_n years

1

write field cell average var every time step

md

e.g., write both monthly and daily files