Geoscience Reference
In-Depth Information
(
)
(
)
(
)
TT PP
Γ
R
g
al l
=
(3.25)
21
2
1
Potential temperature
: the temperature that a parcel of air in the atmosphere
would have if it were to be brought adiabatically to a pressure of 100 kPa,
q
, is:
●
)
(
)
(
Rc
θ
=
T
100
P
ap
(3.26)
The gradient of potential temperature is that for actual temperature minus
Γ
.
Virtual potential temperature
: analogous to potential temperature,
q
v
is:
●
)
(
)
(
Rc
θ
=+
T
(1
0.61 ) 100
q
P
ap
(3.27)
v
The gradient of virtual potential temperature is that for virtual temperature
minus
Γ
.
Atmospheric stability
: the gradient of
q
v
determines atmospheric stability,
thus:
●
Unstable
: (∂
q
v
/∂z)
Neutral
: (∂
q
v
/∂z)
Stable
: (∂
q
v
/∂z)
<
0
=
0
>
0 (3.28)
Some stable conditions are further distinguished:
Isothermal
:
T
v
is constant
with height:
Inversion
:
T
v
increases
with height
(3.29)
