tcf-standard-names.rst - pism - [fork] customized build of PISM, the parallel ice sheet model (tillflux branch)
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---
tcf-standard-names.rst (5468B)
---
1 .. include:: ../global.txt
2
3 .. _sec-cf-standard-names:
4
5 CF standard names used by PISM
6 ==============================
7
8 Existing standard names
9 -----------------------
10
11 We start by listing standard names from the CF Standard Name Table. The subset here is a
12 small subset of the `table <CF-standard-names_>`_; we list only
13
14 - those with "land_ice" in the name and
15 - those currently used by PISM
16
17 The existing names starting with "land_ice" are believed to have all been submitted by
18 Magnus Hagdorn to the CF committee circa 2003. The `SeaRISE assessment process <searise_>`_
19 now has a `wiki on CF standard name use <cf-names-for-glaciology_>`_, which to a
20 significant extent duplicates content regarding proposed names on this page. That wiki is
21 an evolving community standard, and it supercedes this page when it comes to actual
22 evolving standards.
23
24 Go to the `CF Conventions <cf-names-proposed_>`_ page for the list of proposed standard
25 names under consideration.
26
27 Because of the use of UDUNITS_, PISM input files do not have to have fields already in the
28 canonical units. Rather, the units attribute has to be valid for UDUNITS conversion into
29 the canonical units. Generally within PISM, the canonical units are used internally.
30
31 .. list-table:: CF standard names used by PISM
32 :name: tab-standard-names
33 :header-rows: 1
34
35 * - CF standard name
36 - Canonical units (SI)
37
38 * - ``bedrock_altitude``
39 - m
40 * - ``floating_ice_sheet_area_fraction``
41 - 1
42 * - ``grounded_ice_sheet_area_fraction``
43 - 1
44 * - ``land_ice_area_fraction``
45 - 1
46 * - ``land_ice_basal_melt_rate``
47 - m s-1
48 * - ``land_ice_basal_temperature``
49 - K
50 * - ``land_ice_basal_upward_velocity``
51 - m s-1
52 * - ``land_ice_basal_x_velocity``
53 - m s-1
54 * - ``land_ice_basal_y_velocity``
55 - m s-1
56 * - ``land_ice_calving_rate``
57 - m s-1
58 * - ``land_ice_lwe_basal_melt_rate``
59 - m s-1
60 * - ``land_ice_lwe_calving_rate``
61 - m s-1
62 * - ``land_ice_lwe_surface_specific_mass_balance``
63 - m s-1
64 * - ``land_ice_sigma_coordinate``
65 - 1
66 * - ``land_ice_specific_mass_flux_due_to_calving_and_ice_front_melting``
67 - kg m-2 s-1
68 * - ``land_ice_surface_specific_mass_balance_flux``
69 - kg m-2 s-1
70 * - ``land_ice_surface_upward_velocity``
71 - m s-1
72 * - ``land_ice_surface_x_velocity``
73 - m s-1
74 * - ``land_ice_surface_y_velocity``
75 - m s-1
76 * - ``land_ice_temperature``
77 - K
78 * - ``land_ice_thickness``
79 - m
80 * - ``land_ice_vertical_mean_x_velocity``
81 - m s-1
82 * - ``land_ice_vertical_mean_y_velocity``
83 - m s-1
84 * - ``land_ice_x_velocity``
85 - m s-1
86 * - ``land_ice_y_velocity``
87 - m s-1
88 * - ``latitude``
89 - degree_north
90 * - ``longitude``
91 - degree_east
92 * - ``magnitude_of_land_ice_basal_drag``
93 - Pa
94 * - ``projection_x_coordinate``
95 - m
96 * - ``projection_y_coordinate``
97 - m
98 * - ``surface_altitude``
99 - m
100 * - ``temperature_at_ground_level_in_snow_or_firn``
101 - K
102 * - ``tendency_of_bedrock_altitude``
103 - m s-1
104 * - ``tendency_of_land_ice_mass_due_to_basal_mass_balance``
105 - kg s-1
106 * - ``tendency_of_land_ice_thickness``
107 - m s-1
108 * - ``upward_geothermal_heat_flux_at_ground_level``
109 - W m-2
110
111
112 *Proposed* standard names
113 -------------------------
114
115 These are *unofficially* proposed by Bueler and Aschwanden, for now.
116
117 .. list-table:: Desired CF standard names
118 :header-rows: 1
119 :widths: 7,2,6
120
121 * - Proposed name
122 - Canonical units (SI)
123 - Comments
124
125 * - ``ice_shelf_basal_specific_mass_balance``
126 - m s-1
127 - positive is loss of ice shelf mass (i.e. use outward normal from ice shelf)
128 * - ``ice_shelf_basal_temperature``
129 - K
130 - absolute (not pressure-adjusted) temperature
131 * - ``land_ice_age``
132 - s
133 -
134 * - ``land_ice_basal_frictional_heating``
135 - W m-2
136 -
137 * - ``land_ice_basal_material_yield_stress``
138 - Pa
139 -
140 * - ``land_ice_basal_material_friction_angle``
141 - degree
142 - majority of standard names with "angle" use canonical units "degree"
143 * - ``land_ice_surface_temperature_below_firn``
144 - K
145 -
146 * - ``land_ice_upward_velocity``
147 - m s-1
148 - compare to CF names "upward_air_velocity" and "upward_sea_water_velocity"
149 * - ``lithosphere_temperature``
150 - K
151 -
152 * - ``upward_geothermal_flux_in_lithosphere``
153 - W m-2
154 - typically applied at depth in lithosphere; compare to
155 "upward_geothermal_heat_flux_at_ground_level"
156 * - ``land_ice_specific_enthalpy``
157 - J kg-1
158 - enthalpy is defined in PISM to be sensible plus latent heat, plus potential energy
159 of pressure; there is a nontrivial issue of the scaling; the enthalpy value for
160 273.15 K (cold) ice at atmospheric pressure is a possible standard
161 * - ``land_ice_liquid_fraction``
162 - 1
163 - liquid water fraction in ice, a pure number between 0 and 1; a diagnostic function
164 of enthalpy
165
166
167 Final technical notes
168 ---------------------
169
170 - PISM also uses attributes ``grid_mapping = "mapping" ;`` and ``coordinates = "lat lon";``
171 on output variables that depend on ``y,x``.
172 - Because PISM uses UDUNITS, it will write some variables in "glaciological units" instead
173 of the SI units listed above, for instance velocities in m year-1 instead of m s-1. This
174 is allowed under CF. When PISM reads such a field from a NetCDF file, the conversion is
175 handled automatically by UDUNITS_.