Weather and Climate

Question 0

What is climate?

Answer 0

it is the condition of the average weather as observed over a long period of time, eg 30 years , and over a large area.

includes:

• pressure
• temperature
• wind
• humidity
• precipitation.

Question 1

What is weather?

Answer 1

• it is the atmospheric conditions as observed over a short period of time in a local area.
• Includes theres conditions:
• temperature
• humidity
• precipitation
• wind
• sunshine

Question 2

Describe a stevenson screen.

Answer 2

• it is made of wood.
• placed with its door to the south.
• Stands 120 centimeters from the ground.
• double roof for insulation.
• painted white.
• has slats on the side to allow gentle flow of air.
• placed away from building or trees.
• contains:
• barograph
• barometer
• wet and dry bulb thermometer
• maximum and minimum thermometers.

Question 3

Describe the minimum and maximum thermometer.

Answer 3

• shows the highest and lowest temp.
• tube shaped like a U.
• one side has a bulb containing alcohol.
• the other has a vacuum.
• mercury is at the bent of the U.
• the mercury is pushed around by the alcohol during expansion or contraction,
• the mercury indicates the current temperature as observed.
• there are a small metal index in each arm.
• they are pushed by the mercury.
• the metal indixes indicates the maximum and minimum temp for the day.
• they have to be resetted by a magnet.
  NB- indexes should be read from their bottom.

Question 4

Describe a Hygrometer ( W and D thermometer )

Answer 4

• Two identical thermometers.
• one of the bulbs covered in a wick that hangs into a container of distilled water.
• the water rises up the wick and evapourates.
• evapouration causes cooling of the bulb.
• the drier the air, the more evaporation will occur.
• the bigger the difference between wet and dry bulbs, the drier the is shall be.
• the difference and a graph is used to calculate the humidity.

Question 5

What is a barometer?

Answer 5

• it is a device used to measure atmospheric pressure.
• it contains a small drum with a vacuum inside.
• the air pressure exerts a force on this drum
• the changes in atmospheric pressures causes the box to contract or expand.
• they pointers moves as it happens.

Question 6

What is a Barograph?

Answer 6

• it is a barometer that also has a vacuum drum, but it is attched to a pen which draws a line on a piece of paper that slowly rotates.
• thus you can have a continuous record of air pressure.

Question 7

What is a anemometer?

Answer 7

• it measures the wind speed.
• it has cups that are connected to arms.
• as the wind blows it turns these cups and arms.
• a counted desplay the wind speed in knots.
• ## must be erected in a open area.

Question 8

What is a wind vane?

Answer 8

• measures the wind direction.

- wind is always measure in the direction it comes from.

Question 9

What is a rain gauge?

Answer 9

• it measures rainfall in mm
• made from non corrosive material.
• place away from structures.

Question 10

Name and explain the types of isolines.

Answer 10

1. isotherms: connects the places with the same temp.
2. isobars: connects places with the same atmospheric pressure.
3. isoyets: connect places with the same rainfall.

Question 11

How do you record the average temp of the day?

Answer 11

Maximum+ minimum devide by 2

Question 12

Know the Station model on page 10.

Answer 12

What i said above.

Question 13

Name the Precipitation symbols ( in notes pg 11 )

Answer 13

LEES DAAR BO!!!!!

Question 14

Name and identify the frontal symbols ( in notas pg 11 )

Answer 14

Ek raak moeg vir dit. die werk is darem beter as natural vergetations.

Question 15

Name the long term factors that influence temp.

Answer 15

• height above sea level.
• angle of the sun
• presence of water.
• ocean currents
• prevailing winds.

Question 16

Explain how the height above sea level influences the temp.

Answer 16

• atmosphere is heated by:
• short-wave radiation from the sun that heats the earth which then releases long wave radiation.
• thus the further from the source of heating, the cooler.
• temeratures drop 1 degree for every 100m up.
• air pressure also decreases as you move and thus less heat retained.

Question 17

Explain how the angle of the sun infuence the temp on the long term.

Answer 17

• when the sun is vertically overhead, the rays strike earth at a verticlle angle.
• less likely to scatter due to reflection.
• all heat concentraded on small area.
• the greater the angle of the rays, the less concentrated the energy.
• rays also travels longer distances through space before reaching the earth.

Question 18

How is the presence of water a long term influence on temp?

Answer 18

• Water allows rays to penetrate deeper.
• thus more heat is dispersed.
• movement of water also disperses heat.
• water also reflects light.
• water heats up slower that land.
• retains heat longer that land.

Question 19

How do ocean currents influence temp as a long term factor.

Answer 19

• warm ocean current move towards polar regions.
• they raise the temp in the area in which they flow.
• cold currents take cold water to equator.
• they lower the temp where they go.

Question 20

how do prevailing wind play as a long term factor that influences temp?

Answer 20

• wind take the temp of the area over which they blow.
• therefore cold wind can decrease temp and decrease rainfall.
• thus this is why namibia is a desert.

Question 21

Name the Short term factors of temperature.

Answer 21

• influence of the seasons.
• local influences like:
• aspect of slope
• land use
• cloud cover
• urban heat islands
• temperature inversion.

Question 22

How does the seasons contribute to the short term influence on temp?

Answer 22

• during the southern hemisphere’s summer, the earth is tilted away from the sun.
• thus the south is closer to the sun and the tremp increases.
• the days are also longer that the night.
• during winter, the earth is tilted towards the sun
• the south is further from the sun, thus the temperature will be colder.

Question 23

Name two local influences of temp and explain why they are.

Answer 23

1. Aspect of slope.
   - in the SH a north- facing slope recieves the greatest amount of sunlight.
   - they are thus warmer that the south- facing.
2. land use:
   - land, cleared of vegetation, heat up more.
   - building material like cement absorbs more heat.
   - built up areas will heat up more that plants.

Question 24

Why do cloud cover contribute to the short term influences of temp?

Answer 24

• the more clouds, the more heat is reflected.
• the earth will recieve less heat and thus absorb less.
• clouds also acts as a insulation.
• thus raising temp.

Question 25

Why are urban heat islands classified as a short term influence of heat?

Answer 25

• the temp is usually higher because:
• building materials absorb more heat than plants.
• cities produce artificial heat.
• pollution absorbs heat.
• tall buildings recieve sunlight for much longer.

Question 26

study pages 18-21 in packet.

Answer 26

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