Balanced Flow
•
The pressure and velocity distributions in atmospheric
systems are related by relatively simple, approximate
force balances.
•
We can gain a qualitative understanding by considering
steady-state conditions
, in which the fluid flow does not
vary with time, and by assuming there are no vertical
motions.
•
To explore these balanced flow conditions, it is useful to
define a new coordinate system, known as
natural
coordinates.
Natural Coordinates
•
Natural coordinates
are defined by a set of mutually
orthogonal unit vectors whose orientation depends on
the direction of the flow.
t
ˆ
n
ˆ
k
ˆ
t
ˆ
n
ˆ
k
ˆ
t
ˆ
n
ˆ
k
ˆ
t
ˆ
n
ˆ
k
ˆ
Unit vector
points along the
direction of the flow.
Unit vector
is perpendicular to
the flow, with positive to the left.
Unit vector
points upward.
t
ˆ
n
ˆ
k
ˆ

This
** preview**
has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*