chapter 4

Question 1

The QG Thermodynamic Equation

This equation can be derived from

Answer 1

the thermodynamic energy equation in pressure coordinates

Question 2

the following is the

Answer 2

the thermodynamic energy equation in pressure coordinates

Question 3

describe each term in the equation

Answer 3

Question 4

c_p and a in the following equation means

Answer 4

Question 5

describe the following terms in the equation

Answer 5

Question 6

this is called

Answer 6

static stability parameter

Question 7

Answer 7

is a positive number for a stable atmosphere, and a negative number for an unstable atmosphere.

Question 8

the following is the

Answer 8

the quasi geostrophic (QG) thermodynamic energy equation in pressure coordinates

Question 9

in this equation the …………………. is simply substituted for ……………………………..

Answer 9

geostrophic wind is simply substituted for the actual wind in the advection term

Question 10

the following terms are

Answer 10

Question 11

the above equation states that

Answer 11

temperature change at a particular location and height is a function of temperature advection by geostrophic wind and vertical motion.

Question 12

Warm temperature advection result in

Answer 12

Question 13

cold temperature advection result in

Answer 13

Question 14

Ascent vertical motion result in

Answer 14

Question 15

Decent vertical motion result in

Answer 15

Question 16

Diabatic effects:

Answer 16

Diurnal (day and night) l heating/cooling plays a major role in temperature changes near the surface

Question 17

(5) is the

Answer 17

hydrostatic equation in height coordinates (x, y, z)

Question 18

(6) is the

Answer 18

the hydrostatic equation in pressure coordinates

Question 19

the geopotential tendency

Answer 19

Question 20

the following is the

Answer 20

QG thermodynamic energy equation

Question 21

Note that equation 5 and 7 are identical, which are written in different forms, because

Answer 21

in a hydrostatic atmosphere, do Φ⁄do p is proportional to the temperature (T) of the layer.

Question 22

the following is the

Answer 22

QG vorticity equation

Question 23

The geopotential tendency equation is derived from

Answer 23

The QG Thermodynamic Energy Eq.

QG Vorticity Eq.

Question 24

For a sinusoidal disturbance having a zero mean value, the

Answer 24

horizontal Laplacian of a field is proportional to the negative of the field

Question 25

……………………………………………………………., the horizontal Laplacian of a field is proportional to the negative of the field

Answer 25

For a sinusoidal disturbance having a zero mean value

Question 26

Answer 26

geopotential tendency is positive

Question 27

the following is the

Answer 27

absolute vorticity advection

Question 28

PVA =

Answer 28

Question 29

NVA

Answer 29

Question 30

when heights are rising T-adv. increases with

Answer 30

pressure

Question 31

when heights are rising T-adv. decreases with

Answer 31

height

Question 32

when heights are falling T-adv. decreases with

Answer 32

pressure

Question 33

when heights are falling T-adv. increases with

Answer 33

height

Question 34

Strong CA over ………………. has the same effect as ……………… over ………………..

Answer 34

weak CA

weak WA

strong WA

Question 35

It is the vertical derivative of the advection that matters. Strong CA over weak CA has the same effect as weak WA over strong WA, because in both cases the

Answer 35

derivative has the same value

Question 36

The differential heating term (third term on RHS) behaves similarly to the

Answer 36

differential thermal advection term.

Question 37

That is, the Term-C is proportional to

Answer 37

he vertical derivative of diabatic heating

Question 38

when heights rise:

heating

cooling

Answer 38

Heating decreases with height

Cooling increases with height

Question 39

when heights fall:

heating

cooling

Answer 39

Heating increases with height

Cooling decreases with height

Question 40

Another useful way of writing the essence of the Q-G tendency equation is in qualitative form, as:

Answer 40

Question 41

Thus, in quasi-geostrophic theory, there are only three ways for heights to

Answer 41

fall

Question 42

Thus, in quasi-geostrophic theory, there are only three ways for heights to fall. These are through:

Answer 42

1. Positive Vorticity Advection
2. WA that increases with height
3. Diabatic heating that increases with height

Question 43

Le Chatelier’s Principle, states that

Answer 43

many natural systems will resist changes, and if forced to change, will react with process that try to restore the original state.

Question 44

We can see Le Chatelier’s principle at work in

Answer 44

the differential thermal advection and diabatic heating terms of the Q-G tendency equation

Question 45

For example, cold advection (or …………………….) over warm advection (or ………………………….) forces

Answer 45

diabatic cooling

diabatic heating

height rises at 500 mb, as well as height falls at 200 and 1000 mb

Question 46

A

Answer 46

200 mb

Question 47

B

Answer 47

500 mb

Question 48

C

Answer 48

1000 mb

Question 49

D

Answer 49

cold advection

Question 50

E

Answer 50

Warm avection

Question 51

A

Answer 51

200 mb

Question 52

B

Answer 52

500 mb

Question 53

C

Answer 53

1000 mb

Question 54

D

Answer 54

Question 55

E

Answer 55

Question 56

these height rises and falls indicate that there must be a change in

Answer 56

the vorticity at these levels

Question 57

However, these height rises and falls indicate that there must be a change in the vorticity at these levels:

Answer 57

• increased vorticity where there are height falls, and
• decreased vorticity where there are height rises

Question 58

To accomplish this vorticity change in a …………………….. framework

Answer 58

quasi-geostrophic

Question 59

To accomplish this vorticity change in a quasi-geostrophic framework, there must be

Answer 59

convergence where there are height falls, and divergence where there are height rises.

Question 60

The convergence/divergence pattern leads to:

Answer 60

• upward motion and adiabatic cooling in the lower levels, and
• subsidence and adiabatic warming in the upper levels.

Question 61

The adiabatic heating/cooling thus, opposes the

Answer 61

original temperature change due to advection.

Question 62

Le Chatelier’s Principle doesn’t mean that

Answer 62

the effects of the differential heating (advection) will be completely cancelled by the adiabatic heating/cooling from the secondary circulation, but does illustrate that the atmosphere will resist the changes imposed by the thermal forcing, and will respond with a secondary circulation.