Climate and weather

Question 1

Air pressure

Answer 1

Air pressure is the pressure at any given point, created by the weight of air Colum above that point

Question 2

Gravity

Answer 2

The force that causes two bodies to be pulled towards each other

Question 3

Atmospheric pressure

Answer 3

Atmospheric pressure is the result of the force of gravity acting on air. Decreases as altitude increases, measured in milibars

Question 4

Convection

Answer 4

Circulatory movement of liquids and gases resulting from regional differences in temperature and pressure rising and falling in response to gravity

Question 5

Dew point

Answer 5

The point at which water vapour in the air is saturated and begins to condense into droplets

Question 6

Density

Answer 6

Thickness of material relative to size (tightly packed materials with little space between them)

Question 7

Pressure Gradient Force

Answer 7

Force which moves matter from region of higher pressure to to region of lower pressure

Question 9

Climate vs weather

Answer 9

Climate refers to an area’s long-term conditions for periods of 30 years or more.

weather measured over a shorter period e.g 24 hour. Refers to how hot or dry cold or wind,cloudy or clear a specific place at a specific point in time

Question 10

Main forces which drive world wide climate patterns?

Answer 10

The major factors which influence the climate in any area worldwide include:

The Earth spins west to east on it own axis, which drives all major wind systems and ocean currents (corollas force)

Proximity or distance from the coastline and whether the coastline has warm or cold ocean currents

latitude (Distance from tropics and equator)

Altitude (m above sea level

Question 11

General climate of South Africa

Answer 11

Subtropical with dry stable conditions, large amounts of sunshine, falling within a belt of subtropical high-pressure systems

Question 12

3 main factors which influence SA’s climate

Answer 12

1. The oceans

• Cold Benguela current on the west coast and warm Agulhas current east coast.
• Benguela current moves S to N, determining the arid climate on the west coast.
• Augulus’ current move N to S in the Indian Ocean determines the higher rainfall temperate climate on the east coast.

**2. The altitude **

• Increase in altitude from the coast to the inland of South Africa due to the Drakensberg escarpment.
• lead to a climate zone known as the temperate eastern plateau, which has a moderate climate (influence from altitude and ocean current is moderate due to being a moderate distance from both).

**3. the latitude **

SA sits at littude between 20 to 33S. Speicifc wind associted with each lattiude which alter regions climate

Question 13

The oceans

How do oceans around South Africa effect its climate?

Answer 13

The benguela current run along SA west carrying cold water which is cooled .Cold water does not hold much water inside it so the west coast a fairly dry climate.Along it path effects cliamte additionely due to cool wind which blow form ocean onto land
Augulus current
The current runs alongs SA east coast.Carries warm water.Warm air holds moisture well so that East coast has a much wetter climate (and greener and vegtation).The winds that blow landward are warm and moisture liaden

Question 14

Seasonal Infleuces of oceans

Answer 14

ocean currents beyong just infleucing climate additionely infleuce seasons.This due to oceans storing absorbed heat during the summer which is realsed during the winter.Coversely cold water take time to be warmed up by incoming solar radiation and thus moderates how fast air tempreture rise over the sea.Consquentely regions genraaly experience warmer winters and cooler summer than inland areas of similar latitude.

Question 15

season tempretures of SA

Answer 15

OCT-MAR (Summer)
average 15-36C
lowveld ocasionley above 30

APR-SEPT(WINTER)

mild with snow on hihest peaks and frost aboove 1000masl.Sometimes black frost can occur .Black frost is very low air temp and very liitle mositure caused by wind chill).Black frost devistate subtropical svannah tree areas. In same way very heav frost in low lying area can devistae vegeatation growing.

Question 16

Seasonal rainfall

Answer 16

General Climate: SA is mostly dry, with an average annual rainfall of 502 mm.

Rainfall Zones: Divided into summer and winter rainfall areas.

Eastern Rainfall: Most rain falls in the eastern half, influenced by the Indian Ocean.

Winter Rainfall: Found in the Southern & Southwestern Cape (Mediterranean climate), with wet winters and dry summers, due to cold fronts from the south/southwest.

Western Aridity: Areas like Nama Karoo and Succulent Karoo are dry because of the cold Benguela Current, which reduces moisture in the air.

Mountains & Rainfall: Moist air from the south/southeast rises over mountains, causing rain on the seaside.warms ait decneds over mountains increasing in temp cousing low rainfall rainfall shadows on inlandside of mountains

West Coast: Very dry due to:

Cold Atlantic air (holds little moisture),

No mountain ranges to cause rain,

Lack of air inversion at ~600m above sea level.

Question 17

Altitude

Answer 17

Air temp in Sa decreases at rate of 6c per 1000m increase in altitude

Higer altitude ar cooler affecting want plant and animlas live Monatne forest at higher altitude are cooler thus may have more decidous trees,sea level forests are warmer and have evrgreen or mangroove despite being at the same latitude.

Question 18

latitude

Answer 18

distance from equator and location between tropic of capricorn and cancer.Areas between these belts recive more sunlight throughout the year than area north or south of belt

Additionely areas within this region do not experience clealry defined winter and summer climatic conditions rather having wetter
and drier seasons

Question 19

High pressure Cells (anticyclones)

Answer 19

Influecned by the rotation of eath and pressure gradient
rotate anticlockwise

Rotating downward sprialing mass of air

asscoited with clear skies and settled weather

Question 20

Low pressure Cell (Cyclones)

Answer 20

clockwise direction
rotating upward moving air mass
At earth surface air move inwards toward centre.
Associted with the upliftment of air,condensation,cloud fromation and rainfall

Question 21

Tropical cyclones

Answer 21

small intense cell of less than 100km which occur occasinley along coast of maozmabique.
Bring stromy conditions strongwinds and heavy rainfall.
Lp cell which occur frequentely on thus known as tropical cyclone

Question 22

coastal lows

Answer 22

small weakly dveloped cell occuring over south coast of SA
Associted with cold fronts
Travels east the North along SA coast
Dissipates somehwere over the coast of kwazulu natal
bring overcast conditions with osccational mist or drizzle

Question 23

Mid latitude cyclones

Answer 23

Large cyclone which move between the 30* and 60* latitudes of eath North and South
Lp systems which also known as tempate cyclone or mid lattiude depressions
contain clod and warm fronts
bring overcast conditions frequentely with drizzle or snow

Question 24

What is wind?

Answer 24

wind created by movement of air from area of high pressure to area of ow pressure

Question 25

What froms the trade wind on either side of equator

Answer 25

Air masses which are deflected into ribbons that spiral in an easterly direction around the earth.

Question 26

what cause wind in coatal areas

Answer 26

land and water has diffrent cooling rates which lead to air moveents and a general increase in wind

Question 27

wind and alitude

Answer 27

Wind generally increases with altitude e.g upper peaks of drakensburg

Question 28

Types of winds

Answer 28

**berg winds ** asscoited with coastal and lowveld areas hot dry wind which blow from land to seaward direction (can raise temp) by 10* Caused by low pressure cell over South africa which causes wind to blow in an outward direction towards sea .Blow over escarpment of SA heat up 1*DALR (dry adabatic laspse rate) per 100m till reaching lowveld and coastal areas *draw diagram* **Mountain winds ** *draw diagram* pg 27 Anabatic winds Ealrly in morning air in contact will mountainside heat up qucker than air in low lying pans.The resulting warmer is less dnese than and thus will begin to rsie up slopes.rsising air known as anabatic wind fog is often evident rsing out of slope Sun rays strike west slopes at higher angle of incende so the infleuce in greater on west slopes katabatic winds Result from air on high grounds cooling quicker due to radiation.Cooler air then move down slope increasing in speed as it does so.Result in wind couuring at night as temp drops

Question 29

Sea and land breezes

Answer 29

Onshore and offshore breezes water and land cool down at diffrecnes rate resulting in firrecnes in air pressure. *draw diagram* pg 28 | Day wind air over land heats up quicker than water.Warm air sies over l

Question 30

Cold front

Answer 30

Draw diagram A cold front is the boundary where cold air pushes into warm air. Cold air moves forward and wedges warm air upwards Rising warm air cools, forming clouds. Cumulonimbus clouds can form, causing thunderstorms. Temperature drops quickly. Weather clears quickly after the front passes.

Question 31

Cold front weather

Answer 31

table 3.1 pg 29

Question 32

warm front

Answer 32

A warm front is the boundry betwen warm air moving froward where in come into conatct with cold air moving away from it Warm air make contact with cold air and is pushed over the top of the cold air The warm rises and cools forming clouds in front of boundry Thus rain Rain begins before the front arrives. As the front passes, temperatures rise and rain eases. If warm air is unstable, heavy showers and thunderstorms can occur.

Question 33

Draw table 3.2 PG29

Question 34

How are cloud formed leading to rain

Answer 34

Cloud formation leading to rain 1 water evapouartes and become a gas 2.Temp decreases with altitude and thus it ability to hold water vapour is reduced. 3.Once a temp is reached where the air cannot hold the water vapour it condenses back into water 4.This point known as dew point 5.As water condeses molecules attach themslefsmto tiny specks of dust soot etc (partcles known as condensation nuclei with droplest of water forming around each nucleus.) 6.Droplets combine forming visable clouds which have flat bottom known as dew point 7.As water weight become too much it start fall becoming rain

Question 35

Why are clouds NB on safari

Answer 35

1. Often reliable indicator of future weather 2.They eventaully beutiful,aand lovely to observe with guests 3.offer stunning photographic opprtunties

Question 36

types of clouds

Answer 36

Cumlus (wedge shaped) stratus (spread out) cirrus (curly) nimbus (cloud)

Question 37

What type of cloud is this

Answer 37

Cumulus Low level cloud (0-2000) height= width fluffy balls of cotton wool flat bottom indicator of the dew point indictive of fair weather

Question 38

Answer 38

Towering cumlus when umlus in unstable air become towering cumlus look like stalk of cauliflower Build up vertically into massive cloud mases also called cumliocongestus taller than they wide low level cloud (0-2000M

Question 39

Answer 39

stratus cloud low level (0-2000m) dark grey layer blanket like quite thin light mist or rain or even sometime snow can come these clouds

Question 40

Answer 40

stratocumulus low lying (0-2000) distict grey masses with open sky inbetween long rows of cloud oreientated at 908to wind direction associted with fair weather rain may fall from indivudaul cloud masses

Question 41

Answer 41

Alto cumulus mid level cloud (2000-6000m) layer of individual cloud masses fitted together in geometric pattern appera white or sometime grey genrally associted with fair condition but morning altostraus can lead to afternoon thunderstorms

Question 42

Answer 42

Altostratus clouds composed of cie crystals create disct layer over sky mid level cloud(2000-6000m) asscoited with development of bad weather

Question 43

Answer 43

cirrus clouds High cloud 6000-12000m shape indicate direction from weather is changing indictive of warm front aproaching

Question 44

Answer 44

cirrocumulus clouds often called mackeral sky as looks like scale of sih ripple in beteen cloud sun and moon visble through them indicive of cold and fair weather

Question 45

Answer 45

cirrostraus clouds indcitive of aproaching warm front create halo around sun high level cloud 6000m-12000m

Question 46

Answer 46

Nimbostratus multi level cloud associated with rainfall dense layer acorss sky

Question 47

Answer 47

cumulionimbus cloud multi level cloud asscoited with heavy rainfall,thunder lightning and strong winds.

Question 48

thunderstorms

Answer 48

need suffecent supply of mositure to develop second condition high lapse rate of temp strong upward draft of air

Question 49

weather during summer

Answer 49

During summer strong high pressure sytem over the ocean lead to dry cooler condition over cape in summer In the interoir low pressure sytem develops This leads to hot rainy conditions often with thundertsroms often with thundertsorms of over interior

Question 50

weather pattern in the winter

Answer 50

In winter low pressure sytems move from the polar regions towards cape bring cold rainy conditions to the cpae in the winter In the interoir there are high pressure systems usaully cuase sunny condition dry condition with clear nights

Question 51

Go over cloud diagram pg 33