Darrell E. Burch, "Absorption of Infrared Radiant Energy by CO2 and H2O. III. Absorption by H2O between 0.5 and 36 cm−1 (278 μ−2 cm)*," J. Opt. Soc. Am. 58, 1383-1394 (1968)
Interferometric techniques have been employed to measure the H2O absorption between approximately 12.6 cm−1 and 36.0 cm−1. The experimental results, along with results obtained between 0.5 cm−1 and 10 cm−1 by other workers, have been compared with calculated values of transmittance based on theoretically determined positions, strengths, widths, and shapes of the absorption lines. From these comparisons it has become apparent that none of the well-known theoretical line shapes are correct for the extreme wings of the H2O lines below approximately 40 cm−1. The amount of continuum absorption which must be added to the theoretical absorption coefficient to provide agreement with the experimental results has been determined for N2- and self-broadened lines. A table of the line parameters has been included, along with a discussion of the procedure to be followed in calculating the transmittance of homogeneous and inhomogeneous paths.
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Screens, filters, and beam splitters. Additional filtering included: 5 mm of cold crystalline quartz, 2 mm of cold, black polyethylene, 2 mm black polyethylene at room temperature, crystalline-quartz windows on the absorption cell, and the NaCl chopper. The cold filters were in the vacuum compartment of the detector dewar and in thermal contact with the liquid helium.
Region in (cm−1)
Nominal thickness of Mylar beam splitter
Screen mesh and spacing in microns
Thickness of cold KBr
18.6–36.0
3 mil (75 μ)
Two 200 mesh (127 μ)
2 mm
12.7–18.6
5 mil (125 μ)
Two 100 mesh (254 μ)
5 mm
Table II
Parameters for H2O lines below 38.8 cm−1.
ν0 cm−1
J′ J″
τ′ τ″
Isotope
Temperature
320°K
300°K
280°K
260°K
240°K
220°K
0.74
6
−5
S=1.35−2
1.39−2
1.42−2
1.43−2
1.42−2
1.38−2
5
−1
α°=0.087
0.090
0.094
0.099
0.104
0.110
2.27
4
−3
6.95−4
4.73−4
3.01−4
1.77−4
9.30−5
4.28−5
3
1
0.091
0.095
0.099
0.10
0.11
0.12
2.69
1
1
D
6.47−4
7.53−4
8.85−4
1.05−3
1.26−3
1.54−3
1
0
0.098
0.102
0.106
0.111
0.117
0.123
4.03
5
−4
D
6.75−4
7.42−4
8.16−4
8.98−4
9.89−4
1.09−3
4
0
0.089
0.093
0.097
0.10
0.11
0.11
4.62
6
−5
D
5.15−4
5.52−4
5.91−4
6.30−4
6.67−4
7.01−4
5
−1
0.086
0.090
0.094
0.098
0.10
0.11
4.80
4
0
D
9.86−4
1.09−3
1.20−3
1.32−3
1.45−3
1.60−3
4
−1
0.088
0.091
0.095
0.099
0.10
0.11
6.11
3
−2
2.26
2.55
2.88
3.28
3.76
4.32
2
2
0.092
0.096
0.100
0.105
0.111
0.117
6.79
3
−2
18
5.75−3
6.48−3
7.34−3
8.36−3
9.58−3
1.10−2
2
2
0.092
0.096
0.10
0.11
0.11
0.12
8.06
2
0
D
2.79−3
3.22−3
3.75−3
4.40−3
5.21−3
6.26−3
2
−1
0.096
0.10
0.10
0.11
0.12
0.12
8.50
5
−1
D
3.05−3
3.28−3
3.51−3
3.75−3
3.99−3
4.20−3
4
1
0.085
0.089
0.093
0.098
0.10
0.11
8.90
2
2
D
3.11−3
3.54−3
4.06−3
4.68−3
5.44−3
6.38−3
3
−2
0.092
0.096
0.10
0.11
0.11
0.12
10.74
10
−7
9.57−2
7.64−2
5.84−2
4.22−2
2.84−2
1.75−2
9
−3
0.074
0.077
0.079
0.081
0.084
0.087
10.85
5
−4
2.77
2.95
3.14
3.33
3.51
3.65
4
0
0.089
0.093
0.097
0.102
0.107
0.113
11.89
10
−7
18
2.44−4
1.95−4
1.49−4
1.08−4
7.28−5
4.48−5
9
−3
0.075
0.077
0.079
0.082
0.085
0.088
12.68
4
−3
2.47+1
2.72+1
2.99+1
3.30+1
3.64+1
4.02+1
3
1
0.091
0.095
0.099
0.104
0.109
0.115
13.05
4
−3
18
5.38−2
5.93−2
6.54−2
7.21−2
7.96−2
8.78−2
3
1
0.091
0.095
0.099
0.10
0.11
0.12
13.10
10
−4
1.14−2
8.43−3
5.92−3
3.89−3
2.34−3
1.26−3
11
−8
0.069
0.070
0.072
0.074
0.076
0.078
14.58
7
2
1.77−1
1.52−1
1.25−1
9.96−2
7.48−2
5.23−2
6
6
0.049
0.050
0.051
0.052
0.053
0.055
14.65
6
1
2.43
2.28
2.10
1.88
1.62
1.34
5
5
0.064
0.065
0.067
0.068
0.070
0.073
14.78
7
3
5.45−1
4.67−1
3.87−1
3.07−1
2.31−1
1.61−1
6
5
0.049
0.050
0.051
0.053
0.054
0.056
14.92
4
−1
2.62+1
2.82+1
3.03+1
3.25+1
3.46+1
3.66+1
3
3
0.080
0.082
0.085
0.089
0.092
0.097
15.68
6
2
9.29−1
8.72−1
8.01−1
7.16−1
6.18−1
5.10−1
5
4
0.061
0.063
0.065
0.066
0.069
0.071
15.87
5
0
3.51
3.55
3.56
3.52
3.42
3.24
4
4
0.067
0.069
0.071
0.073
0.075
0.078
16.29
6
−2
7.05−1
6.93−1
6.72−1
6.39−1
5.93−1
5.32−1
7
−6
0.083
0.086
0.090
0.093
0.098
0.103
16.30
4
−1
18
6.49−2
6.99−2
7.51−2
8.06−2
8.60−2
9.12−2
3
3
0.079
0.082
0.085
0.088
0.089
0.096
16.79
8
3
1.27−1
9.82−2
7.21−2
4.98−2
3.18−2
1.84−2
7
7
0.042
0.042
0.043
0.044
0.046
0.047
16.82
8
4
4.26−2
3.28−2
2.41−2
1.67−2
1.06−2
6.15−3
7
6
0.042
0.042
0.043
0.045
0.046
0.047
16.96
1
1
D
1.85−1
2.16−1
2.54−1
3.03−1
3.66−1
4.48−1
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
18.26
1
1
18
2.95
3.43
4.03
4.78
5.75
7.01
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
18.58
1
1
1.49+3
1.73+3
2.04+3
2.42+3
2.91+3
3.54+3
1
−1
0.107
0.111
0.116
0.122
0.128
0.136
19.99
2
0
D
3.38−1
3.90−1
4.55−1
5.35−1
6.36−1
7.66−1
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
20.71
5
1
1.82+1
1.84+1
1.84+1
1.82+1
1.76+1
1.67+1
4
3
0.073
0.076
0.079
0.083
0.087
0.092
21.96
1
1
1.59
1.15
7.78−1
4.92−1
2.83−1
1.45−1
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
24.84
2
0
18
2.02
2.31
2.67
3.11
3.66
4.34
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
25.09
2
0
1.00+3
1.15+3
1.33+3
1.55+3
1.82+3
2.16+3
2
−2
0.100
0.104
0.109
0.115
0.122
0.129
28.07
10
−1
9.15−2
6.45−2
4.27−2
2.62−2
1.46−2
7.14−3
11
−7
0.052
0.053
0.053
0.054
0.055
0.056
28.31
2
−1
D
6.84−2
7.93−2
9.28−2
1.10−1
1.31−1
1.59−1
1
0
0.095
0.099
0.10
0.11
0.12
0.12
28.68
2
0
1.03
7.29−1
4.87−1
3.02−1
1.70−1
8.44−2
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
29.77
1
0
D
3.99−1
4.67−1
5.52−1
6.60−1
8.00−1
9.85−1
0
0
0.096
0.100
0.105
0.110
0.117
0.124
30.00
2
−2
4.34−1
3.11−1
2.10−1
1.32−1
7.50−2
3.79−2
1
0
0.099
0.103
0.108
0.113
0.119
0.126
30.13
3
−1
3.13−1
2.17−1
1.41−1
8.49−2
4.61−2
2.20−2
2
1
0.092
0.095
0.098
0.10
0.11
0.11
30.23
9
−6
1.03
8.79−1
7.25−1
5.72−1
4.28−1
2.97−1
8
−2
0.077
0.080
0.083
0.086
0.089
0.094
30.56
4
0
4.34+1
4.66+1
4.99+1
5.33+1
5.67+1
5.97+1
3
2
0.083
0.086
0.091
0.095
0.100
0.107
32.37
5
−2
5.07+1
5.28+1
5.47+1
5.62+1
5.70+1
5.70+1
4
2
0.080
0.083
0.086
0.090
0.094
0.098
32.94
2
−2
7.17+2
8.29+2
9.67+2
1.14+3
1.36+3
1.64+3
1
0
0.099
0.103
0.108
0.113
0.120
0.127
33.21
3
−3
D
5.39−1
6.20−1
7.17−1
8.38−1
9.88−1
1.18
2
−1
0.095
0.099
0.10
0.11
0.11
0.12
33.47
5
−2
18
6.88−2
7.18−2
7.44−2
7.65−2
7.77−2
7.78−2
4
2
0.080
0.083
0.086
0.090
0.094
0.099
33.68
2
0
D
9.45−2
1.09−1
1.28−1
1.51−1
1.80−1
2.17−1
1
1
0.100
0.104
0.108
0.113
0.119
0.125
36.59
3
−1
4.87+3
5.46+3
6.15+3
6.96+3
7.91+3
9.02+3
3
−3
0.095
0.099
0.104
0.110
0.116
0.124
36.74
1
0
18
2.83
3.31
3.91
4.67
5.65
6.95
0
0
0.096
0.100
0.105
0.110
0.117
0.124
37.14
1
0
1.41+3
1.65+3
1.95+3
2.33+3
2.82+3
3.47+3
0
0
0.096
0.100
0.105
0.111
0.117
0.124
37.90
3
1
18
1.05+1
1.17+1
1.30+1
1.45+1
1.62+1
1.81+1
3
−1
0.091
0.095
0.100
0.10
0.11
0.12
38.24
7
−3
3.74
3.49
3.19
2.84
2.44
2.00
8
−7
0.078
0.080
0.083
0.086
0.089
0.093
38.45
3
−1
7.41+2
8.32+2
9.37+2
1.06+3
1.21+3
1.38+3
2
1
0.091
0.095
0.099
0.104
0.109
0.115
38.62
6
−1
8.18+1
7.96+1
7.62+1
7.15+1
6.53+1
5.75+1
5
3
0.070
0.071
0.073
0.076
0.078
0.081
38.79
3
1
5.37+3
5.96+3
6.63+3
7.39+3
8.25+3
9.23+3
3
−1
0.091
0.095
0.099
0.105
0.111
0.117
The table is to be read as indicated by the following example for the 0.74 cm−1 line. J′=6, J″=5, τ′=−5, τ″=−1, S=1.35 × 10−2 g−1 cm2, α°=0.087 cm−1. The isotope is H2O16 unless indicated otherwise; D corresponds to HDO, 18 to H2O18.
Table III
Comparison of experimental results with calculated KL0(ν) due to N2-broadened lines below 38.8 cm−1.
Values given for present work have been modified to apply to air broadening, rather than N2 broadening, in order to compare them with atmospheric measurements. They also apply to relatively dry samples for which self broadening is negligible. The other workers did not account for self broadening. Differences of temperature have not been taken into account.
Furashov’s30 work was done with 5.5-m path in spectrometer.
Worker’s names appear in footnotes.
Ryadov et al.31 made field measurements over a 150-m path.
Burroughs et al.32 employed an HCN laser as a source and a 15-m absorption cell to contain air samples.
Chang and Lester6 used a superheterodyne radiometer with harmonic mixing.
Tables (5)
Table I
Screens, filters, and beam splitters. Additional filtering included: 5 mm of cold crystalline quartz, 2 mm of cold, black polyethylene, 2 mm black polyethylene at room temperature, crystalline-quartz windows on the absorption cell, and the NaCl chopper. The cold filters were in the vacuum compartment of the detector dewar and in thermal contact with the liquid helium.
Region in (cm−1)
Nominal thickness of Mylar beam splitter
Screen mesh and spacing in microns
Thickness of cold KBr
18.6–36.0
3 mil (75 μ)
Two 200 mesh (127 μ)
2 mm
12.7–18.6
5 mil (125 μ)
Two 100 mesh (254 μ)
5 mm
Table II
Parameters for H2O lines below 38.8 cm−1.
ν0 cm−1
J′ J″
τ′ τ″
Isotope
Temperature
320°K
300°K
280°K
260°K
240°K
220°K
0.74
6
−5
S=1.35−2
1.39−2
1.42−2
1.43−2
1.42−2
1.38−2
5
−1
α°=0.087
0.090
0.094
0.099
0.104
0.110
2.27
4
−3
6.95−4
4.73−4
3.01−4
1.77−4
9.30−5
4.28−5
3
1
0.091
0.095
0.099
0.10
0.11
0.12
2.69
1
1
D
6.47−4
7.53−4
8.85−4
1.05−3
1.26−3
1.54−3
1
0
0.098
0.102
0.106
0.111
0.117
0.123
4.03
5
−4
D
6.75−4
7.42−4
8.16−4
8.98−4
9.89−4
1.09−3
4
0
0.089
0.093
0.097
0.10
0.11
0.11
4.62
6
−5
D
5.15−4
5.52−4
5.91−4
6.30−4
6.67−4
7.01−4
5
−1
0.086
0.090
0.094
0.098
0.10
0.11
4.80
4
0
D
9.86−4
1.09−3
1.20−3
1.32−3
1.45−3
1.60−3
4
−1
0.088
0.091
0.095
0.099
0.10
0.11
6.11
3
−2
2.26
2.55
2.88
3.28
3.76
4.32
2
2
0.092
0.096
0.100
0.105
0.111
0.117
6.79
3
−2
18
5.75−3
6.48−3
7.34−3
8.36−3
9.58−3
1.10−2
2
2
0.092
0.096
0.10
0.11
0.11
0.12
8.06
2
0
D
2.79−3
3.22−3
3.75−3
4.40−3
5.21−3
6.26−3
2
−1
0.096
0.10
0.10
0.11
0.12
0.12
8.50
5
−1
D
3.05−3
3.28−3
3.51−3
3.75−3
3.99−3
4.20−3
4
1
0.085
0.089
0.093
0.098
0.10
0.11
8.90
2
2
D
3.11−3
3.54−3
4.06−3
4.68−3
5.44−3
6.38−3
3
−2
0.092
0.096
0.10
0.11
0.11
0.12
10.74
10
−7
9.57−2
7.64−2
5.84−2
4.22−2
2.84−2
1.75−2
9
−3
0.074
0.077
0.079
0.081
0.084
0.087
10.85
5
−4
2.77
2.95
3.14
3.33
3.51
3.65
4
0
0.089
0.093
0.097
0.102
0.107
0.113
11.89
10
−7
18
2.44−4
1.95−4
1.49−4
1.08−4
7.28−5
4.48−5
9
−3
0.075
0.077
0.079
0.082
0.085
0.088
12.68
4
−3
2.47+1
2.72+1
2.99+1
3.30+1
3.64+1
4.02+1
3
1
0.091
0.095
0.099
0.104
0.109
0.115
13.05
4
−3
18
5.38−2
5.93−2
6.54−2
7.21−2
7.96−2
8.78−2
3
1
0.091
0.095
0.099
0.10
0.11
0.12
13.10
10
−4
1.14−2
8.43−3
5.92−3
3.89−3
2.34−3
1.26−3
11
−8
0.069
0.070
0.072
0.074
0.076
0.078
14.58
7
2
1.77−1
1.52−1
1.25−1
9.96−2
7.48−2
5.23−2
6
6
0.049
0.050
0.051
0.052
0.053
0.055
14.65
6
1
2.43
2.28
2.10
1.88
1.62
1.34
5
5
0.064
0.065
0.067
0.068
0.070
0.073
14.78
7
3
5.45−1
4.67−1
3.87−1
3.07−1
2.31−1
1.61−1
6
5
0.049
0.050
0.051
0.053
0.054
0.056
14.92
4
−1
2.62+1
2.82+1
3.03+1
3.25+1
3.46+1
3.66+1
3
3
0.080
0.082
0.085
0.089
0.092
0.097
15.68
6
2
9.29−1
8.72−1
8.01−1
7.16−1
6.18−1
5.10−1
5
4
0.061
0.063
0.065
0.066
0.069
0.071
15.87
5
0
3.51
3.55
3.56
3.52
3.42
3.24
4
4
0.067
0.069
0.071
0.073
0.075
0.078
16.29
6
−2
7.05−1
6.93−1
6.72−1
6.39−1
5.93−1
5.32−1
7
−6
0.083
0.086
0.090
0.093
0.098
0.103
16.30
4
−1
18
6.49−2
6.99−2
7.51−2
8.06−2
8.60−2
9.12−2
3
3
0.079
0.082
0.085
0.088
0.089
0.096
16.79
8
3
1.27−1
9.82−2
7.21−2
4.98−2
3.18−2
1.84−2
7
7
0.042
0.042
0.043
0.044
0.046
0.047
16.82
8
4
4.26−2
3.28−2
2.41−2
1.67−2
1.06−2
6.15−3
7
6
0.042
0.042
0.043
0.045
0.046
0.047
16.96
1
1
D
1.85−1
2.16−1
2.54−1
3.03−1
3.66−1
4.48−1
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
18.26
1
1
18
2.95
3.43
4.03
4.78
5.75
7.01
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
18.58
1
1
1.49+3
1.73+3
2.04+3
2.42+3
2.91+3
3.54+3
1
−1
0.107
0.111
0.116
0.122
0.128
0.136
19.99
2
0
D
3.38−1
3.90−1
4.55−1
5.35−1
6.36−1
7.66−1
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
20.71
5
1
1.82+1
1.84+1
1.84+1
1.82+1
1.76+1
1.67+1
4
3
0.073
0.076
0.079
0.083
0.087
0.092
21.96
1
1
1.59
1.15
7.78−1
4.92−1
2.83−1
1.45−1
1
−1
0.107
0.111
0.116
0.122
0.128
0.135
24.84
2
0
18
2.02
2.31
2.67
3.11
3.66
4.34
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
25.09
2
0
1.00+3
1.15+3
1.33+3
1.55+3
1.82+3
2.16+3
2
−2
0.100
0.104
0.109
0.115
0.122
0.129
28.07
10
−1
9.15−2
6.45−2
4.27−2
2.62−2
1.46−2
7.14−3
11
−7
0.052
0.053
0.053
0.054
0.055
0.056
28.31
2
−1
D
6.84−2
7.93−2
9.28−2
1.10−1
1.31−1
1.59−1
1
0
0.095
0.099
0.10
0.11
0.12
0.12
28.68
2
0
1.03
7.29−1
4.87−1
3.02−1
1.70−1
8.44−2
2
−2
0.100
0.104
0.109
0.115
0.121
0.129
29.77
1
0
D
3.99−1
4.67−1
5.52−1
6.60−1
8.00−1
9.85−1
0
0
0.096
0.100
0.105
0.110
0.117
0.124
30.00
2
−2
4.34−1
3.11−1
2.10−1
1.32−1
7.50−2
3.79−2
1
0
0.099
0.103
0.108
0.113
0.119
0.126
30.13
3
−1
3.13−1
2.17−1
1.41−1
8.49−2
4.61−2
2.20−2
2
1
0.092
0.095
0.098
0.10
0.11
0.11
30.23
9
−6
1.03
8.79−1
7.25−1
5.72−1
4.28−1
2.97−1
8
−2
0.077
0.080
0.083
0.086
0.089
0.094
30.56
4
0
4.34+1
4.66+1
4.99+1
5.33+1
5.67+1
5.97+1
3
2
0.083
0.086
0.091
0.095
0.100
0.107
32.37
5
−2
5.07+1
5.28+1
5.47+1
5.62+1
5.70+1
5.70+1
4
2
0.080
0.083
0.086
0.090
0.094
0.098
32.94
2
−2
7.17+2
8.29+2
9.67+2
1.14+3
1.36+3
1.64+3
1
0
0.099
0.103
0.108
0.113
0.120
0.127
33.21
3
−3
D
5.39−1
6.20−1
7.17−1
8.38−1
9.88−1
1.18
2
−1
0.095
0.099
0.10
0.11
0.11
0.12
33.47
5
−2
18
6.88−2
7.18−2
7.44−2
7.65−2
7.77−2
7.78−2
4
2
0.080
0.083
0.086
0.090
0.094
0.099
33.68
2
0
D
9.45−2
1.09−1
1.28−1
1.51−1
1.80−1
2.17−1
1
1
0.100
0.104
0.108
0.113
0.119
0.125
36.59
3
−1
4.87+3
5.46+3
6.15+3
6.96+3
7.91+3
9.02+3
3
−3
0.095
0.099
0.104
0.110
0.116
0.124
36.74
1
0
18
2.83
3.31
3.91
4.67
5.65
6.95
0
0
0.096
0.100
0.105
0.110
0.117
0.124
37.14
1
0
1.41+3
1.65+3
1.95+3
2.33+3
2.82+3
3.47+3
0
0
0.096
0.100
0.105
0.111
0.117
0.124
37.90
3
1
18
1.05+1
1.17+1
1.30+1
1.45+1
1.62+1
1.81+1
3
−1
0.091
0.095
0.100
0.10
0.11
0.12
38.24
7
−3
3.74
3.49
3.19
2.84
2.44
2.00
8
−7
0.078
0.080
0.083
0.086
0.089
0.093
38.45
3
−1
7.41+2
8.32+2
9.37+2
1.06+3
1.21+3
1.38+3
2
1
0.091
0.095
0.099
0.104
0.109
0.115
38.62
6
−1
8.18+1
7.96+1
7.62+1
7.15+1
6.53+1
5.75+1
5
3
0.070
0.071
0.073
0.076
0.078
0.081
38.79
3
1
5.37+3
5.96+3
6.63+3
7.39+3
8.25+3
9.23+3
3
−1
0.091
0.095
0.099
0.105
0.111
0.117
The table is to be read as indicated by the following example for the 0.74 cm−1 line. J′=6, J″=5, τ′=−5, τ″=−1, S=1.35 × 10−2 g−1 cm2, α°=0.087 cm−1. The isotope is H2O16 unless indicated otherwise; D corresponds to HDO, 18 to H2O18.
Table III
Comparison of experimental results with calculated KL0(ν) due to N2-broadened lines below 38.8 cm−1.
Values given for present work have been modified to apply to air broadening, rather than N2 broadening, in order to compare them with atmospheric measurements. They also apply to relatively dry samples for which self broadening is negligible. The other workers did not account for self broadening. Differences of temperature have not been taken into account.
Furashov’s30 work was done with 5.5-m path in spectrometer.
Worker’s names appear in footnotes.
Ryadov et al.31 made field measurements over a 150-m path.
Burroughs et al.32 employed an HCN laser as a source and a 15-m absorption cell to contain air samples.
Chang and Lester6 used a superheterodyne radiometer with harmonic mixing.