Symbol
Meaning
Typical unit
Introducing
equation
H D
Surface heat content
[J]
2.106
I
Radiance (intensity) from reflection, scattering, or emission
[W m
À2 sr
À1
]
2.3
I
Emission intensity from a vibrational band
[W m
À2 sr
À1
]
3.38
I, Q, U, V
Stokes parameters
4.6
I ⊥, I k
Intensity of electromagnetic field perpendicular (parallel) to scattering plane as
scattered by a particle
4.122
I a,b,c , I N
Moment of inertia (axes) and total for the
nucleus
[kg m
2
]
2.33
I i
Incident irradiance
4.20
I L
Radiance from a perfectly diffusing
Lambertian surface
[W m
À2 sr
À1
]
2.80
I M
Moment of inertia of a molecule
3.34
I ref
Reflected spectral intensity from a particle
[W m
À2 sr
À1
nm
À1
]
4.119
I s , I l
Moment of inertia about the short (long) axis
of an irregular object
[kg m
2
]
2.38
I th
Thermal spectral intensity
4.121
Iv, Fu, Ro
Coefficients for the efficiency of the
entrainment of a particle within the gas flow,
the gravitational interaction, and radiation
pressure effects in the Zakharov formulation
4.99
i x
Orbital inclination
[rad]
1.17
I ϑ
Radiance in a frequency interval
[W m
À2 sr
À1
Hz
À1
]
3.10
J
Total angular momentum quantum number Unitless
3.33
J’, J i
Energy levels in a resonance scattering
process
3.119
j flu
Flux from a reservoir into vacuum
[molecule m
À2
s
À1
]
3.101
j x
Gas flux
[m
À2 s
À1
]
2.136
j υ
Emission coefficient
[W m
À3 sr
À1
Hz
À1
]
3.15
J υ
Source function
[W m
À2 sr
À1
Hz
À1
]
3.17
k
Boltzmann’s constant
[J K
À1
]
2.8
K
Shape factor
Unitless
2.54
k E
Parameter of the Lunar-Lambert function
Unitless
2.79
k in
Ion-neutral momentum transfer collision
rate
[cm
3 s
À1
]
5.33
k M
Parameter of Minnaert function
Unitless
2.76
k N
Normalization constant for B λ
2.10
k N
Wavenumber of incident radiation
[m
À1
]
4.17
Kn, Kn 0
Knudsen number and Knudsen number of
the source
Unitless
3.47, 3.49
(continued)
Symbols Used
xxvii
Meaning
Typical unit
Introducing
equation
H D
Surface heat content
[J]
2.106
I
Radiance (intensity) from reflection, scattering, or emission
[W m
À2 sr
À1
]
2.3
I
Emission intensity from a vibrational band
[W m
À2 sr
À1
]
3.38
I, Q, U, V
Stokes parameters
4.6
I ⊥, I k
Intensity of electromagnetic field perpendicular (parallel) to scattering plane as
scattered by a particle
4.122
I a,b,c , I N
Moment of inertia (axes) and total for the
nucleus
[kg m
2
]
2.33
I i
Incident irradiance
4.20
I L
Radiance from a perfectly diffusing
Lambertian surface
[W m
À2 sr
À1
]
2.80
I M
Moment of inertia of a molecule
3.34
I ref
Reflected spectral intensity from a particle
[W m
À2 sr
À1
nm
À1
]
4.119
I s , I l
Moment of inertia about the short (long) axis
of an irregular object
[kg m
2
]
2.38
I th
Thermal spectral intensity
4.121
Iv, Fu, Ro
Coefficients for the efficiency of the
entrainment of a particle within the gas flow,
the gravitational interaction, and radiation
pressure effects in the Zakharov formulation
4.99
i x
Orbital inclination
[rad]
1.17
I ϑ
Radiance in a frequency interval
[W m
À2 sr
À1
Hz
À1
]
3.10
J
Total angular momentum quantum number Unitless
3.33
J’, J i
Energy levels in a resonance scattering
process
3.119
j flu
Flux from a reservoir into vacuum
[molecule m
À2
s
À1
]
3.101
j x
Gas flux
[m
À2 s
À1
]
2.136
j υ
Emission coefficient
[W m
À3 sr
À1
Hz
À1
]
3.15
J υ
Source function
[W m
À2 sr
À1
Hz
À1
]
3.17
k
Boltzmann’s constant
[J K
À1
]
2.8
K
Shape factor
Unitless
2.54
k E
Parameter of the Lunar-Lambert function
Unitless
2.79
k in
Ion-neutral momentum transfer collision
rate
[cm
3 s
À1
]
5.33
k M
Parameter of Minnaert function
Unitless
2.76
k N
Normalization constant for B λ
2.10
k N
Wavenumber of incident radiation
[m
À1
]
4.17
Kn, Kn 0
Knudsen number and Knudsen number of
the source
Unitless
3.47, 3.49
(continued)
Symbols Used
xxvii