Campbell Scientific IRGASON Integrated CO2/H2O Open-Path Gas Analyzer and 3D Sonic Anemometer User Manual
Page 60
Appendix B. Equations
(
)
+
−
+
=
v
v
d
d
X
X
T
R
PM
1000
1
15
.
273
ρ
(B-5)
Dew Point from Molar Mixing Ratio
tmp
d
tmp
d
d
T
T
T
_
_
502
.
17
97
.
240
−
=
(B-6
2
)
(
)
+
⋅
=
v
v
tmp
d
X
f
P
X
ln
T
1000
61121
.
0
_
(B-7
2
)
(
) (
)
2
9
5
10
9
.
5
10
2
.
3
00072
.
1
PT
P
f
−
−
Ч
+
Ч
+
=
(B-8
2
)
Water Vapor Molar Mixing Ratio from Dew Point
1000
e
P
e
X
v
−
=
(B-9)
+
⋅
⋅
=
d
d
T
T
EXP
f
e
97
.
240
502
.
17
61121
.
0
(B-10
2
)
Water Vapor Mass Density from Dew Point
(
)(
)
(
)
+
+
=
d
d
v
T
T
EXP
T
R
f
97
.
240
502
.
17
15
.
273
61121
.
0
018
.
0
ρ
(B-11
2
)
Vapor Pressure from Molar Mixing Ratio and Water Vapor Density
v
v
X
P
X
e
+
=
1000
(B-12)
(
)
v
v
M
T
R
e
15
.
273
+
=
ρ
(B-13)
1
Leuning, R (2004) Measurements of Trace Gas Fluxes in the Atmosphere
Using Eddy Covariance: WPL Revisited. The Handbook of Micrometeorology,
29, 119-132. New York: Kluwer Academic Publishers. Eq. 6.23
2
Buck, A L (1981) New Equations for Computing Vapor Pressure and
Enhancement Factor. Journal of Applied Meteorology 20, 1527-1532. Eqs.
2a, 3a, and 6
B-2