n
Stability factor
q
Air density
q′
Apparent soil density
q(k)
Reflectivity
q hum
Moist air density
q i
Gas i concentration
q V
Air absolute humidity
r
Stefan–Boltzman constant
C
Dry adiabatic gradient
s
Momentum vertical flux; instantaneous transmittance to direct radiation;
time constant; relaxation time
s ij
Shear stress matrix
s di
Diffuse radiation transmissivity
s k
Kolmogorov time scale
s t
Total transmissivity
#
Angle concerning second rotation of coordinates
u
Latitude
/ H , w H Stability function for sensible heat
/ M
Stability function for momentum
/ V
Stability function for water vapour
/ e
Dimensionless dissipation factor
; xx m
ð Þ
Autocorrelation function
; xy m
ð Þ
Cross-correlation function
U(x)
Radiation flux attenuated by absorption
v
Absolute air humidity; gas concentration in a surface
w
Scalar vectorial quantity, zenith angle
w M
Similarity function for momentum
X
Decoupling factor
x
Solid angle
x 0
Fundamental angular frequency
xxiv
Greek Symbols