The data request

The criteria the checker applies are not written into its code. They live in two CSV files bundled with the package:

ISMIP7_variable_request.csv

one row per variable: its dimensions, type, units, standard_name, whether it is mandatory, and the value range allowed in each region.

experiments_ismip7.csv

one row per experiment: the nominal start years it may begin at, the year it ends, and how long it runs.

The tables on this page are generated from those files when the pages are built, so they say what the checker enforces. If the docs and a run disagree, compare ismip7-compliance-checker --version against the version in the sidebar.

Both files are ordinary CSV and open in a spreadsheet: variable request, experiments.

Variables

Variables are grouped by their dimensions, since that decides which checks apply: the gridded variables are checked against the grid extents and resolutions, the scalars are not, and x,y,z,t variables carry snapshots rather than an annual series.

Type is ST for a state variable, a snapshot, or FL for a flux, an annual average; the two are timestamped differently, as described in Time encoding. Mandatory says whether a submission must include the variable: a missing mandatory variable is an error, and a missing optional one is a warning you can quiet by declaring it, as described in Variables your model does not represent.

Gridded variables (x,y,t)

Variable	Long name	Type	Units	Mandatory	standard_name
lithk	Ice thickness	ST	m	yes	land_ice_thickness
orog	Surface elevation	ST	m	yes	surface_altitude
topg	Bedrock elevation	ST	m	yes	bedrock_altitude
base	Ice base elevation	ST	m	yes	—
hfgeoubed	Geothermal heat flux	FL	W m-2	no	upward_geothermal_heat_flux_in_land_ice
acabf	Surface mass balance flux	FL	kg m-2 s-1	yes	land_ice_surface_specific_mass_balance_flux
libmassbfgr	Basal mass balance flux beneath grounded ice	FL	kg m-2 s-1	yes	land_ice_basal_specific_mass_balance_flux
libmassbffl	Basal mass balance flux beneath floating ice	FL	kg m-2 s-1	yes	land_ice_basal_specific_mass_balance_flux
dlithkdt	Ice thickness imbalance	FL	m s-1	yes	tendency_of_land_ice_thickness
xvelsurf	Surface velocity in x	ST	m s-1	no	land_ice_surface_x_velocity
yvelsurf	Surface velocity in y	ST	m s-1	no	land_ice_surface_y_velocity
zvelsurf	Surface velocity in z	ST	m s-1	no	land_ice_surface_upward_velocity
xvelbase	Basal velocity in x	ST	m s-1	no	land_ice_basal_x_velocity
yvelbase	Basal velocity in y	ST	m s-1	no	land_ice_basal_y_velocity
zvelbase	Basal velocity in z	ST	m s-1	no	land_ice_basal_upward_velocity
xvelmean	Mean velocity in x	ST	m s-1	yes	land_ice_vertical_mean_x_velocity
yvelmean	Mean velocity in y	ST	m s-1	yes	land_ice_vertical_mean_y_velocity
litemptop	Surface temperature	ST	K	no	temperature_at_top_of_ice_sheet_model
litempavg	Depth average temperature	ST	K	no	—
litempbotgr	Basal temperature beneath grounded ice sheet	ST	K	no	temperature_at_base_of_ice_sheet_model
litempbotfl	Basal temperature beneath floating ice shelf	ST	K	no	temperature_at_base_of_ice_sheet_model
strbasemag	Basal drag	ST	Pa	yes	land_ice_basal_drag
licalvf	Calving flux	FL	kg m-2 s-1	yes	land_ice_specific_mass_flux_due_to_calving
ligroundf	Grounding line flux	FL	kg m-2 s-1	yes	—
lifmassbf	Ice front melt flux	FL	kg m-2 s-1	yes	—
sftgif	Land ice area fraction	ST	1	yes	land_ice_area_fraction
sftgrf	Grounded ice sheet area fraction	ST	1	yes	grounded_ice_sheet_area_fraction
sftflf	Floating ice sheet area fraction	ST	1	yes	floating_ice_shelf_area_fraction
thdrflf	Thermal forcing at the ice base under floating ice shelves	ST	K	no	—
deltag	Anomaly in geopotential height from reference geoid	ST	m	no	geopotential_height_anomaly

Comments from the data request

lithk

Ice thickness of the ice sheet

orog

Surface elevation of the ice sheet

topg

The bedrock topography (may change during the projections)

base

Should get standard name land_ice_temperature

hfgeoubed

Geothermal Heat flux at the ice interface

acabf

Surface Mass Balance flux

libmassbfgr

Basal mass balance flux (only beneath grounded ice)

libmassbffl

Basal mass balance flux (only beneath floating ice)

dlithkdt

dHdt

xvelsurf

u-velocity at land ice surface

yvelsurf

v-velocity at land ice surface

zvelsurf

w-velocity at land ice surface

xvelbase

u-velocity at land ice base

yvelbase

v-velocity at land ice base

zvelbase

w-velocity at land ice base

xvelmean

Vertical mean land ice velocity

yvelmean

The vertical mean land ice velocity is the average from the bedrock to the surface of the ice

litemptop

Ice temperature at surface

litempavg

Should get standard name land_ice_temperature

litempbotgr

Ice temperature at base of grounded ice sheet

litempbotfl

Ice temperature at base of floating ice shelf

strbasemag

Basal drag

licalvf

Ice mass change resulting from iceberg calving. Only for grid cells in contact with ocean

ligroundf

Flux of ice mass across the grounding line. Only for grounding line grid cells. Should get standard name: land_ice_specific_grounding_line_flux

lifmassbf

Ice mass change resulting from ice front melting. Only for grid cells in contact with ocean. Should get standard name: land_ice_specific_mass_flux_due_to_ice_front_melting

sftgif

Fraction of grid cell covered by land ice (ice sheet, ice shelf, ice cap, glacier)

sftgrf

Fraction of grid cell covered by grounded ice sheet, where grounded indicates that the quantity correspond to the ice sheet that flows over bedrock

sftflf

Fraction of grid cell covered by ice sheet flowing over seawater

thdrflf

Thermal forcing (thermal driving) interpolated to the ice draft under floating ice shelves (fill value for purely grounded ice or not ice)

deltag

The change in geoid height should be relative to the reference geoid

Three-dimensional variables (x,y,z,t)

Variable	Long name	Type	Units	Mandatory	standard_name
litemp	Ice temperature	ST	K	no	land_ice_temperature

Comments from the data request

litemp

3D temperature snapshots at (1900 if in historical), initial state, 2014, 2100, 2200, and 2300. Output on the model native vertical coordinate. Only for models that have 3D temperature calculation

Time-independent gridded variables (x,y)

Variable	Long name	Type	Units	Mandatory	standard_name
refgeoid	Reference geoid	ST	m	no	geoid_height_above_reference_ellipsoid

Comments from the data request

refgeoid

This field is calculated with respect to the WGS84 reference ellipsoid

Scalar variables (t)

Variable	Long name	Type	Units	Mandatory	standard_name
lim	Total ice mass	ST	kg	yes	land_ice_mass
limnsw	Mass above floatation	ST	kg	yes	land_ice_mass_not_displacing_sea_water
iareagr	Grounded ice area	ST	m^2	yes	grounded_ice_sheet_area
iareafl	Floating ice area	ST	m^2	yes	floating_ice_shelf_area
tendacabf	Total SMB flux	FL	kg s-1	yes	tendency_of_land_ice_mass_due_to_surface_mass_balance
tendlibmassbfgr	Total BMB flux beneath grounded ice	FL	kg s-1	yes	tendency_of_land_ice_mass_due_to_basal_mass_balance
tendlibmassbffl	Total BMB flux beneath floating ice	FL	kg s-1	yes	tendency_of_land_ice_mass_due_to_basal_mass_balance
tendlicalvf	Total calving flux	FL	kg s-1	yes	tendency_of_land_ice_mass_due_to_calving
tendlifmassbf	Total ice front melting flux	FL	kg s-1	yes	—
tendligroundf	Total grounding line flux	FL	kg s-1	yes	—

Comments from the data request

lim

spatial integration, volume times density

limnsw

spatial integration, volume times density

iareagr

spatial integration

iareafl

spatial integration

tendacabf

spatial integration

tendlibmassbfgr

spatial integration

tendlibmassbffl

spatial integration (computed beneath floating ice only)

tendlicalvf

spatial integration

tendlifmassbf

spatial integration, should get standard name: tendency_of_land_ice_mass_due_to_ice_front_melting

tendligroundf

spatial integration, should get a standard name

Value ranges

Every value in a file should lie within the range its variable and region allow. The bounds differ between Antarctica and Greenland where the ice sheets differ. A few values outside them are a warning and a large share of the field is an error, unless the severity column says the bound is soft everywhere; see Value ranges.

Variable	Units	AIS min	AIS max	GrIS min	GrIS max	Severity
lithk	m	0	5500	0	5000	graded
orog	m	0	5500	0	4500	graded
topg	m	-7000	5500	-4000	4000	graded
base	m	-4000	4000	-4000	4000	graded
hfgeoubed	W m-2	0	0.3	0	0.3	always a warning
acabf	kg m-2 s-1	-0.0006	0.001	-0.0006	0.001	graded
libmassbfgr	kg m-2 s-1	-0.0003	0.0001	-0.0003	0.0001	graded
libmassbffl	kg m-2 s-1	-0.008	0.001	-0.008	0.001	graded
dlithkdt	m s-1	-0.0001	0.0001	-0.0001	0.0001	graded
xvelsurf	m s-1	-0.0004	0.0004	-0.0008	0.0008	graded
yvelsurf	m s-1	-0.0004	0.0004	-0.0008	0.0008	graded
zvelsurf	m s-1	-4.00E-06	4.00E-06	-8.00E-06	8.00E-06	graded
xvelbase	m s-1	-0.0004	0.0004	-0.0008	0.0008	graded
yvelbase	m s-1	-0.0004	0.0004	-0.0008	0.0008	graded
zvelbase	m s-1	-5.00E-06	5.00E-06	-8.00E-06	8.00E-06	graded
xvelmean	m s-1	-0.0008	0.0008	-0.0008	0.0008	graded
yvelmean	m s-1	-0.0008	0.0008	-0.0008	0.0008	graded
litemptop	K	183	290	183	290	graded
litempavg	K	183	290	183	290	graded
litempbotgr	K	183	290	183	290	graded
litempbotfl	K	183	290	183	290	graded
strbasemag	Pa	0	1.00E+06	0	1.00E+06	graded
licalvf	kg m-2 s-1	-10	0	-10	0	graded
ligroundf	kg m-2 s-1	-10	10	-10	10	graded
lifmassbf	kg m-2 s-1	-10	0	-10	0	graded
sftgif	1	0	1	0	1	graded
sftgrf	1	0	1	0	1	graded
sftflf	1	0	1	0	1	graded
thdrflf	K	-1	30	-1	30	graded
deltag	m	-4000	4000	-4000	4000	graded
refgeoid	m	-500	500	-500	500	graded
litemp	K	183	274	183	274	graded
lim	kg	0	1.00E+25	0	1.00E+25	graded
limnsw	kg	0	1.00E+25	0	1.00E+25	graded
iareagr	m^2	0	1.00E+25	0	1.00E+25	graded
iareafl	m^2	0	1.00E+25	0	1.00E+25	graded
tendacabf	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded
tendlibmassbfgr	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded
tendlibmassbffl	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded
tendlicalvf	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded
tendlifmassbf	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded
tendligroundf	kg s-1	-1.00E+09	1.00E+09	-1.00E+09	1.00E+09	graded

Missing values

Where each variable is defined, and so where a fill value is the right thing to find, is given by the fill_policy column of the data request; what the checker does about it is described in Errors and warnings.

fill_policy	The variable is	Variables
forbidden	defined everywhere; no missing values anywhere	lithk, acabf, libmassbfgr, libmassbffl, dlithkdt, licalvf, ligroundf, lifmassbf, sftgif, sftgrf, sftflf, lim, limnsw, iareagr, iareafl, tendacabf, tendlibmassbfgr, tendlibmassbffl, tendlicalvf, tendlifmassbf, tendligroundf
outside_domain	defined throughout the computational domain, including where there is no ice; missing outside it	orog, topg, base, hfgeoubed, thdrflf, deltag, refgeoid
no_ice	defined only where there is ice (sftgif > 0)	xvelsurf, yvelsurf, zvelsurf, xvelbase, yvelbase, zvelbase, xvelmean, yvelmean, litemptop, litempavg, strbasemag, litemp
no_grounded_ice	defined only where there is grounded ice (sftgrf > 0)	litempbotgr
no_floating_ice	defined only where there is floating ice (sftflf > 0)	litempbotfl

Experiments

An experiment’s row fixes the nominal years its files may cover, and with them the time axis every annual file must carry. The modeler chooses the start year of historical and ocx, within the range given; every projection runs from 2015 to a fixed end year.

Experiment	Earliest start year	Latest start year	End year	Duration (years)
historical	1850	2014	2014	set by the start year
ssp370	2015	2015	2100	86
ssp245	2015	2015	2100	86
ssp126	2015	2015	2300	286
ssp585	2015	2015	2300	286
ssp534-over	2015	2015	2300	286
ctrl	2015	2015	2300	286
ocx	1950	2015	2025	set by the start year

The nominal years here are what a file name’s year range refers to. The timestamps inside the file are derived from them and are not the same thing; Time encoding explains the difference.