The Atmosphere

Question 1

What is an isotherm?

Answer 1

lines joining places of equal temperature?

Question 2

Briefly explain what a heat equator is?

Answer 2

An isotherm joining places that have the highest temperature at a particular time

Question 3

What do patterns of isotherms show?

Answer 3

In Jan ,Southern Hemisphere has Summer while Northern Hemisphere has winter
in July ,Southern Hemisphere has Winter while Northern hemisphere has summer
20^ north and south of the equator have high temperatures all year
The Heat Equator is North of the equator in July
The Heat equator is south of the equator in January

Question 4

What is radiation?

Answer 4

The transfer of heat by means of waves

Question 5

What is terrestrial radiation

Answer 5

Radiation from the Earth

Long wavelength

Question 6

Factors that affect Solar Radiation?

Answer 6

Length of the day & night(longer day, longer radiation)
The angle the suns rays hit the Earth(more direct rays means less rays Absorption, Reflection and Scattering)
Parallelism of Earths axis

Question 7

Define parallelism

Answer 7

The constant alignment of the Earths axis as Earth revolves

Question 8

When are the solstices?

Answer 8

21 June and 21 December (Longer Day/Shorter Night)
One hemisphere is tilted towards the sun and has summer and the other other hemisphere titled away from the sun experiencing Winter

Question 9

When are the equinoxes?

Answer 9

20 March and 22 September(Day=Night)
The hemispheres are tilted neither away or towards the sun
Balanced

Question 10

What is the circle of illumination?

Answer 10

line between light and dark halves of Earth

Question 11

What is the apparent Migration Of the sun?

Answer 11

Movement the sun makes during the year
Above the Tropic of Cancer in June
Above the Tropic of Capricorn in December

Question 12

What is radiation surplus and radiation deficit?

Answer 12

Surplus
-More radiation comes in then leaves

Deficit
-More radiation goes out than is received

Question 13

What is the tri-cellular model of global air circulation?

Answer 13

Model of global air circulation featuring three cells of circulation in each hemisphere?
See exercise book and Pg99

Question 14

What is the ITCZ?

Answer 14

Inter-tropical convergence zone

Area where winds from twoc cells converge between the two Hadley cells

Question 15

What are the characteristics of a HADLEY cell?

Answer 15

Warm Air At The Surface Rises Causing Cumulonimbus Clouds
Risen Air Diverges And Moves Poleward
30Degrees North & South cool air subsides
Subsiding air diverges at the surface and air returns to the equator completing the Hadley Cell

Question 16

What are the characteristics of a Ferrel cell?

Answer 16

Air Subsides at 30^
Warmed Air Moves Poleward
60^ Warm Air Meets Cold Air and converges causing air to rise
Rising air diverges. Some moves equatorward and subsides at 30^ completing the FERREL cell

Question 17

What are the characteristics of a Polar cell?

Answer 17

Cold air subsides over the pole
Air moves to the equator at the surface and meets warm air from Ferrel cell at 60^
Converging air rises at 60
Air moves poleward completing Polar cell

Question 18

What is a berg wind and name the conditions necessary for berg winds to occur?

Answer 18

Hot dry wind blowing from to the coast

Conditions

1. HP over the interior
2. LP over the coastal region
3. Air needs to be heated adiabatically(1 Degree per 100m)

Resulting In
1.Very hot dry air
2.Veld fires
3.Dehydration
See Exercise Book

Question 19

What is drought?

Answer 19

When the rainfall received is so low or unreliable that natural vegetation and farming activities suffer

Question 20

What are the types of droughts?

Answer 20

seasonal/periodic-unpredictable
Disastrous-persistent
Invisible-only seen when there’s a reduction in production over many years

Question 21

What are the results of drought?

Answer 21

Short term

1. Lower agricultural outputs-leads to increased imports and decreased exports
2. Water restrictions, jobs lost, high food prices

Long Term

1. Desertification
2. Increased run-off-increase in soil erosion

Question 22

What ways can drought be combated?

Answer 22

1. Better farming methods

2. Advanced warning systems

Question 23

What is desertification?

Answer 23

The process in which quality of soil and vegetation cover decreases and land changes to a desert
Land becomes degraded

Question 24

What are the causes of desertification?

Answer 24

1. Increase animals-overgrazing-vegetation cant re-establish-soil exposed to wind and rain
2. Population growth-increase demand for wood for cooking-deforestation-vegetation removed-soil exposed