Revised 17/11/11
PHYSICAL DATA
Quantity
Astronomical constants
Mean radius of Earth
Radius of sun
Mean earth-sun distance
Obliquity of the ecliptic
Eccentricity of Earth s orbit
Earth s angular velocity
Solar constant
Gravitational constant
Atmospheric gases
Gas constant universal
Specific gas constant dry air
Specific gas constant water vapour
Mean acceleration due to gravity (at Earth s surface)
Mean atmospheric pressure at Earth surface
(standard pressure)
Dry adiabatic lapse rate dry air (g/cp)
Magnitude
Units
Symbol
6.37 x 103
0.70 x 106
150 x 106
23° 27´
0.0167
7.29 x 10-5
1.37
6.67 x 10-11
km
km
km
rz
(rad) s-1
kW m-2
N m2 kg-2
So
G
8.314
287
461
9.81
J mol-1K-1
J kg-1K-1
J kg-1K-1
m s-2
R*
R
Rv
g
1013.25
hPa
ps
9.8
K km
-1
d
-1
Molecular weights dry air
water
carbon dioxide
28.97
18.02
44.01
g mol
g mol-1
g mol-1
Specific heat capacities
At constant pressure
dry air
water vapour 20°C
carbon dioxide
At constant volume
dry air
1004
1.88 x 103
0.85 x 103
717
J kg-1
J kg-1
J kg-1
J kg-1
4.22 x 103
4.18 x 103
2.50 x 106
3.35 x 105
1.00 x 103
0.917 x 103
1.01 x 10-6
73 x 10-3
J kg-1 K-1
J kg-1 K-1
J kg-1
J kg-1
kg m-3
kg m-3
m2 s-1
N m-1
6.022 x 1023
1.602 x 10-19
6.626 x 10-34
1.381 x 10-23
8.854 x 10-12
2.998 x 108
1 + 279.10-6 (@0.5 m)
5.670 x 10-8
1.805 x 10-8
2.898 x10-3
mol-1
C
Js
J K-1
F m-1
m s-1
Water
Specific heat capacity of water
0°C
20°C, 40°C
Latent heat of evaporation, 0°C
Latent heat of fusion of ice, 0°C
Density of water, 0°C
Density of ice, 0°C
Kinematic viscosity, 20°C
Surface tension, 20°C
General
Avogadro number (molecules/mol)
Electronic charge
Planck constant
Boltzmann constant
Permittivity of free space
Velocity of light in vacuum
Refractive index of air at standard pressure
Stefan Boltzmann constant
or
Wien s displacement constant
Revised 17/11/11
K-1
K-1
K-1
K-1
W m-2 K-4
W m-2 K-4 sr-1
mK
cp
cv
v
NA
e
h
kB
0
c
n
b
ICAO standard atmosphere:
Temperature, pressure and density as function of geopotential altitude
(From International Meteorological Tables, 1966, WMO)
H:
T :
p:
:
geopotential altitude in m or geopotential in standard gpm
temperature, °C
pressure in hPa
density in kg m-3
H
-1000
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
10500
11000
11500
12000
12500
13000
13500
14000
14500
15000
15500
T
21.500
18.250
15.000
11.750
8.500
5.250
2.000
-1.250
-4.500
-7.750
-11.000
-14.250
-17.500
-20.750
-24.000
-27.250
-30.500
-33.750
-37.000
-40.250
-43.500
-46.750
-50.000
-53.250
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
p
1139.29
1074.77
1013.25
954.608
898.745
845.560
794.952
746.825
701.085
657.640
646.402
577.283
540.199
505.068
471.810
440.348
410.607
382.514
355.998
330.990
307.424
285.236
264.362
244.743
226.320
209.161
193.304
178.648
165.104
152.586
141.018
130.326
120.445
111.314
1.3470
1.2849
1.2250
1.1673
1.1116
1.0581
1.0065
0.95686
0.90912
0.86923
0.81913
0.77677
0.73612
0.69711
0.65970
0.62384
0.58950
0.55662
0.52517
0.49509
0.46635
0.43890
0.41271
0.38772
0.36392
0.33633
0.31083
0.28726
0.26548
0.24535
0.22675
0.20956
0.19367
0.17899
H
16000
16500
17000
17500
18000
18500
19000
19500
20000
20500
21000
21500
22000
22500
23000
23500
24000
24500
25000
25500
26000
26500
27000
27500
28000
28500
29000
29500
30000
30500
31000
31500
32000
T
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.500
-56.000
-55.500
-55.000
-54.500
-54.000
-53.500
-53.000
-52.500
-52.000
-51.500
-51.000
-50.500
-50.000
-49.500
-49.000
-48.500
-48.000
-47.500
-47.000
-46.500
-46.000
-45.500
-45.000
-44.500
p
102.874
95.0748
87.8666
81.2049
75.0482
69.3583
64.0999
59.2401
54.7487
50.6.25
46.7787
43.2517
39.9978
36.9953
34.2242
31.6663
29.3048
27.1241
25.1101
23.2497
21.5308
19.9425
18.4745
17.1175
15.8628
14.7026
13.6296
12.6370
11.7186
10.8688
10.0823
9.35421
8.68014
Properties of air, water vapour and CO2 (changing by less than 1% per K)
Latent
Virtual
heat of
temperature vaporizatio
Temperature
Densities of air
of air
n of water
Symbol
T
Tv
z
zs(T)
Unit
°C
K
kg m-3
°C
J g-1
Pa K-1
mW m-1 K-1
-5
0
5
10
15
20
25
30
35
40
45
64.3
64.6
64.9
65.2
65.5
65.8
66.2
66.5
66.8
67.1
67.5
24.0
24.3
24.6
25.0
25.3
25.7
26.0
26.4
26.7
27.0
27.4
268.2
273.2
278.2
283.2
288.2
293.2
298.2
303.2
308.2
313.2
318.2
z
zs
Tv
(T)
1.316
1.292
1.269
1.246
1.225
1.204
1.183
1.164
1.146
1.128
1.110
1.314
1.286
1.265
1.240
1.217
1.194
1.169
1.145
1.121
1.096
1.068
-4.57
0.64
5.92
11.32
16.87
22.62
28.62
34.97
41.73
49.03
57.02
density of dry air at standard pressure
density of air saturated with water vapour at temperature
virtual temperature of saturated air
latent heat of vaporization of water
cp /
psychrometer constant
Revised 17/11/11
2513
2501
2489
2477
2465
2454
2442
2430
2418
2406
2394
Thermal
conductivity
of air
k
k
v
Dv
De
0.16542
0.15288
0.14129
0.13058
0.12068
0.11153
0.1.307
0.095257
0.088035
0.081180
0.074873
0.069069
0.063727
0.058809
0.054280
0.050109
0.046267
0.042727
0.039466
0.036459
0.033688
0.031133
0.028777
0.026604
0.024599
0.022749
0.021042
0.019466
0.018012
0.016669
0.015429
0.014283
0.013225
Molecular diffusion coefficients of air
v
Dv
De
10-6 m2 s-1
18.3
18.9
19.5
20.2
20.8
21.5
22.2
22.8
23.5
24.2
24.9
12.9
13.3
13.7
14.2
14.6
15.1
15.5
16.0
16.4
16.9
17.4
thermal conductivity of dry air
thermal diffusivity of dry air
kinematic viscosity of dry air
diffusion coefficient of water vapour in air
diffusion coefficient of CO2 in air
20.5
21.3
22.0
22.7
23.4
24.2
24.9
25.7
26.4
27.2
28.0
12.4
12.9
13.9
13.8
14.2
14.7
15.1
15.6
16.0
16.5
17.0
Saturated vapour pressure for water
T
(°C)
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Revised 17/11/11
(K)
268.2
269.2
270.2
271.2
272.2
273.2
274.2
275.2
276.2
277.2
278.2
279.2
280.2
281.2
282.2
283.2
284.2
285.2
286.2
287.2
288.2
289.2
290.2
291.2
292.2
293.2
es
(hPa)
4.21
4.55
4.90
5.28
5.68
6.11
6.57
7.05
7.58
8.13
8.72
9.35
10.01
10.72
11.47
12.27
13.12
14.02
14.97
15.98
17.04
18.17
19.37
20.63
21.96
23.37
T
(°C)
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
(K)
294.2
295.2
296.2
297.2
298.2
299.2
300.2
301.2
302.2
303.2
304.2
305.2
306.2
307.2
308.2
309.2
310.2
311.2
312.2
313.2
314.2
315.2
316.2
317.2
318.2
es
(hPa)
24.86
26.43
28.09
29.83
31.67
33.61
35.65
37.80
40.06
42.43
44.93
47.55
50.31
53.20
56.24
5.942
62.76
62.62
69.93
73.78
77.80
82.02
86.42
91.03
95.86