Chapter 2 part 1

Question 1

Horizontal divergence is expressed mathematically as

Answer 1

Question 2

When thedivergence is positive, the air parcel

Answer 2

grows (i.e., its area increases)

Question 3

If the divergence is negative, it is called

Answer 3

convergence, then the air parcel shrinks (i.e., area decreases).

Question 4

The relationship between horizontal divergence and the change in a parcel’s area
(A) can be expressed as:

Answer 4

The above equation states that the fractional change in the area is equal to the
horizontal divergence.

Question 5

The relationship between horizontal divergence and the vertical velocity can be
obtained from

Answer 5

the continuity equation as:

Question 6

In the troposphere, the vertical velocity is

Answer 6

close to zero (w~0) at two altitudes

Question 7

In the troposphere, the vertical velocity is close to zero (ݓ~0) at two altitudes.

Answer 7

The first is Earth’s surface, which forms a solid boundary.
• The second is the tropopause, above which the rapid increase in stratospheric potential temperature strongly inhibits vertical motion.

Question 8

Divergence aloft is associated with

Answer 8

air throughout the troposphere

Question 9

Divergence aloft is associated with air throughout the troposphere, which
is associated with

Answer 9

pressure and at the surface

Question 10

Convergence aloft is associated with

Answer 10

sinking air throughout the troposphere

Question 11

Convergence aloft is associated with sinking air throughout the troposphere,
which is associated with

Answer 11

high pressure and divergence at the surface

Question 12

So, starting at the surface, the vertical velocity becomes

Answer 12

more with height when there is surface convergence, reaches some maximum vertical velocity, and then becomes positive with height becoming divergence aloft

Question 13

Similarly, starting again at the surface, the vertical velocity becomes more negative
with height when there is

Answer 13

surface divergence, reaches some maximum negative velocity, and then becomes less negative with height again near convergence aloft.

Question 14

When the surface divergence (or convergence) with height changes into

Answer 14

upper air convergence (or divergence)

Question 15

When the surface divergence (or convergence) with height changes into upper air
convergence (or divergence), at some level in the troposphere (called

Answer 15

the level of non-divergence, LND), the divergence becomes zero.