Parameters 2: Indicator of parameter

Code tables

Id Name Units
0 Reserved
1 Pressure Pa
2 Pressure reduced to MSL Pa
3 Pressure tendency Pa s1
4 Potential vorticity K m2 kg1 s1
5 ICAO Standard Atmosphere reference height m
6 Geopotential m2 s2
7 Geopotential height gpm
8 Geometrical height m
9 Standard deviation of height m
10 Total ozone Dobson
11 Temperature K
12 Virtual temperature K
13 Potential temperature K
14 Pseudo-adiabatic potential temperature K
15 Maximum temperature K
16 Minimum temperature K
17 Dew-point temperature K
18 Dew-point depression (or deficit) K
19 Lapse rate K m1
20 Visibility m
21 Radar spectra (1)
22 Radar spectra (2)
23 Radar spectra (3)
24 Parcel lifted index (to 500 hPa) K
25 Temperature anomaly K
26 Pressure anomaly Pa
27 Geopotential height anomaly gpm
28 Wave spectra (1)
29 Wave spectra (2)
30 Wave spectra (3)
31 Wind direction Degree true
32 Wind speed m s1
33 u-component of wind m s1
34 v-component of wind m s1
35 Stream function m2 s1
36 Velocity potential m2 s1
37 Montgomery stream function m2 s2
38 Sigma coordinate vertical velocity s1
39 Vertical velocity Pa s1
40 Vertical velocity m s1
41 Absolute vorticity s1
42 Absolute divergence s1
43 Relative vorticity s1
44 Relative divergence s1
45 Vertical u-component shear s1
46 Vertical v-component shear s1
47 Direction of current Degree true
48 Speed of current m s1
49 u-component of current m s1
50 v-component of current m s1
51 Specific humidity kg kg1
52 Relative humidity %
53 Humidity mixing ratio kg kg1
54 Precipitable water kg m2
55 Vapour pressure Pa
56 Saturation deficit Pa
57 Evaporation kg m2
58 Cloud ice kg m2
59 Precipitation rate kg m2 s1
60 Thunderstorm probability %
61 Total precipitation kg m2
62 Large scale precipitation kg m2
63 Convective precipitation kg m2
64 Snowfall rate water equivalent kg m2 s1
65 Water equivalent of accumulated snow depth kg m2
66 Snow depth m
67 Mixed layer depth m
68 Transient thermocline depth m
69 Main thermocline depth m
70 Main thermocline anomaly m
71 Total cloud cover %
72 Convective cloud cover %
73 Low cloud cover %
74 Medium cloud cover %
75 High cloud cover %
76 Cloud water kg m2
77 Best lifted index (to 500 hPa) K
78 Convective snow kg m2
79 Large scale snow kg m2
80 Water temperature K
81 Land cover (1 = land, 0 = sea) Proportion
82 Deviation of sea level from mean m
83 Surface roughness m
84 Albedo %
85 Soil temperature K
86 Soil moisture content kg m2
87 Vegetation %
88 Salinity kg kg1
89 Density kg m3
90 Water run-off kg m2
91 Ice cover (1 = ice, 0 = no ice) Proportion
92 Ice thickness m
93 Direction of ice drift Degree true
94 Speed of ice drift m s1
95 u-component of ice drift m s1
96 v-component of ice drift m s1
97 Ice growth rate m s1
98 Ice divergence s1
99 Snow melt kg m2
100 Significant height of combined wind waves and swell m
101 Direction of wind waves Degree true
102 Significant height of wind waves m
103 Mean period of wind waves s
104 Direction of swell waves Degree true
105 Significant height of swell waves m
106 Mean period of swell waves s
107 Primary wave direction Degree true
108 Primary wave mean period s
109 Secondary wave direction Degree true
110 Secondary wave mean period s
111 Net short-wave radiation flux (surface) W m2
112 Net long-wave radiation flux (surface) W m2
113 Net short-wave radiation flux (top of atmosphere) W m2
114 Net long-wave radiation flux (top of atmosphere) W m2
115 Long-wave radiation flux W m2
116 Short-wave radiation flux W m2
117 Global radiation flux W m2
118 Brightness temperature K
119 Radiance (with respect to wave number) W m1 sr1
120 Radiance (with respect to wave length) W m3 sr1
121 Latent heat flux W m2
122 Sensible heat flux W m2
123 Boundary layer dissipation W m2
124 Momentum flux, u-component N m2
125 Momentum flux, v-component N m2
126 Wind mixing energy J
127 Image data
128 Reserved for originating centre use
255 Missing value
Notes:

( 1) SI units only are used for GRIB; the accuracy or precision with which the data are represented is a function of the range of the values, the decimal and/or binary scaling, and the number of bits used; GRIB enables suitable scaling factors to be selected to obviate the need to define parameters in non-SI units.

( 2) The code figures 0 to 127 are used to represent parameters which are exchanged between a number of centres; since the products generated by centres can be extremely diverse, code figures 128 to 254 are reserved for definition by the originating centre and may differ from centre to centre.

( 3) By convention, downward fluxes of radiation or other quantities shall be assigned negative values; upward fluxes of radiation or other quantities shall be assigned positive values.

( 4) Latitude and longitude are in millidegrees (thousandths of a degree).

( 5) Provision is made for three types of spectra:
-1- direction and frequency
-2- direction and radial number;
-3- radial number and radial number.

( 6) The “parcel lifted index” (as defined in the International Meteorological Vocabulary (WMO–No. 182) under Latitude and longitude are in millidegrees (thousandths of a degree). temperature (T500) and that of a parcel of air lifted from the surface (Tparcel) following the dry and moist adiabatic process. Negative values of (T500 – Tparcel) suggest instability. The “best lifted index” is defined as the most unstable of a collection of parcel lifted indices, with parcel initial condition defined for a collection of 30 hPa thick layers stacked one upon the other with the lowest resting on the ground. Commonly four to six such layers are used in the calculation.