Theme B - Weather And Climate

Question 1

State each element of the weather, give the recording instrument and units of measurement for each

Answer 1

1. Temperature - max/min thermometer (*C)
2. Cloud type
3. Precipitation - rain gauge (mm)
4. Wind speed - anemometer (knots)
5. Wind direction - wind vane (compass points)
6. Cloud cover (oktas)
7. Air pressure - barometer (mb)

Question 2

Give a description of how each element of the weather is measured

Answer 2

1. precipitation - read the level of water in the measuring cylinder of the rain gauge at the same time each day. Then empty it and reposition the rain gauge for the next 24 hours.
2. Temperature - a max/min thermometer has two sides, one for the hotter and one for the colder temps. The Mercury pushes metal markers up the tubes. The markers stay at their highest point even when temp changes. To find the temp read the bottom of each marker then use the magnet to reset markers to the top of the Mercury.
3. Wind speed - an anemometer usually has small cups which spin round as they catch the wind. Most anemometers have digital readouts which tell you the wind speed.
4. Wind direction - on a wind vane the arrows point to where the wind is coming from
5. Cloud cover - look at the sky and estimate how many eighths (oktas) of the sky are covered by cloud
6. Air pressure - read needle on barometer. There may be second needle that can be set to show what air pressure was at any one time and main needle shows how pressure has changed.

Question 3

Describe where each weather instrument should be placed.

Answer 3

1. Rain gauge - must be in the open where nothing will stop rain falling into it. Often sunk partway into ground so it’s less likely not be knocked over
2. Thermometer - we measure temp in the shade. Always done so everyone understand what a temp reading means. Usually kept in a white wooden box with vents in the sides that allow air to pass through. Called a Stevenson screen.
3. Wind vane - must be high enough for nothing to shelter it from the wind so that true wind direction can be seen. High roof or church spire are good places.
4. Anemometer - must be high up so nothing can shelter from wind.

Question 4

Name and describe each source of information for weather forecasting

Answer 4

1. Land-based weather stations - every 3 hours these record all the elements of the weather discussed in the last section. There are over 10,000 of these around the world.
2. Ships - these have digital weather stations and record and transmit weather data
3. Satellites - these monitor the earth from space and record data such as pictures of the clouds, and wind speed and direction.
   - Geostationary satellites- stay above one place over earth all the time
   - Polar satellites - travel around the earth 14 times a day
4. Weather balloons - sent up through the atmosphere with digital instruments attached to measure temp, pressure and wind speed. They transmit the info to a computer
5. Weather buoys - fixed or drifting in the sea, use digital instruments to record weather and transmit the info to a computer

Question 5

What is an air mass?

Answer 5

An air mass is a large body of air which takes on the temp and moisture characteristics of the area where it is situated. E.g if the air mass is stationary over the Sahara desert it will become hot and dry. It then moves as an airstream and brings those characteristics with it.

Question 6

Name each airmass, it’s temperature and its moisture characteristics

Answer 6

1. Polar maritime -
   summer - warm/cool
   Winter - warm/cold
   Moisure - wet/dry
2. Polar continental
   summer - hot/cool
   Winter - warm/cold
   Moisure - wet/dry
3. Tropical continental
   summer - hot/cold
   Winter - mild/cold
   Moisure - wet/dry
4. Tropical maritime
   summer - warm/cold
   Winter - mild/cold
   Moisure - wet/dry

Question 7

Define anticyclone then give its;

• Air movement
• cloud cover
• wind speed
• wind direction
• duration

Answer 7

Definition - an area of high pressure

Air movement - air is sinking

cloud cover - clouds cannot form

wind speed - gentle, blowing out from centre of high pressure, isobars far apart

wind direction - generally clockwise

duration - slow-moving, days or even more than a week

Question 8

Define depressions and explain its;

• Air movement
• cloud cover
• wind speed
• wind direction
• duration

Answer 8

Definition - an area of low pressure

Air movement - air is rising

Cloud cover - as it rises air cools and condenses to form clouds

wind speed - strong blowing into centre of low pressure, isobars close together

wind direction - anti-clockwise

duration - moves quickly, 24 hours

Question 9

Explain the weather during an anticyclone

Answer 9

• always dry
• little or no cloud
• calm or gentle wind
• in summer day temperatures are high because of cloudless skies and night temperatures can be cool as the earths heat radiates into the atmosphere
• in winter day temps are low because days are short and sun is not powerful. At night cloudless skies allow the temperature to fall below 0*C and frost forms. Air near the ground is chilled and any moisture in it condenses to form fog

Question 10

Explain the weather during a depression

Answer 10

A predictable sequence of weather occurs as the depression moved over any location.

1. First the warm front approaches. At the warm front air rises over cold air so clouds form and rain falls.
2. Between the fronts is the warm sector so temperature rise a little, heavy rain stops and there may be some drizzle.
3. The cold front arrives. Again the warm moist air is lifted over the cold air so clouds and heavy rain occur.
4. Following the fronts there is the cold sector with lower temperatures. Clouds break up and showers become fewer.

Question 11

What are synoptic charts?

Answer 11

Synoptics charts are weather maps that summarise weather at a particular time. They show isobar spacing and weather systems.

Question 12

Explain isobars for depressions and anticyclones

Answer 12

Depressions - will have fronts and isobars are close together with the lowest value in the centre.

Anticyclones - isobars are further apart and the highest value is in the centre.

Question 13

What is a satellite image and how do weather systems appear on them?

Answer 13

Photographs taken from space and sent back to earth.
A depression will show up as swirls of white cloud along the fronts, on a dark background.
An anticyclone will be shown as clear skies allowing the land and coastline to be visible.

Question 14

What is a weather forecast?

Answer 14

A prediction of the weather expected in an area.
A short range broadcast is for the next 24 hours.
Medium range - five days
Long range - 3 months.
Long range is less precise and dependable then for short range

Question 15

What is the greenhouse gas effect

Answer 15

Needed for us to survive on the planet. Greenhouse gases like carbon dioxide lets the Suns heat into the atmosphere around the earth and stops some of it escaping. Without it we would freeze. However human activities accelerate the process.

Question 16

What is global warming?

Answer 16

Global warming or climate change is the rise in global temperature. There is evidence that world temperatures went up by 0.5*C in the last century. Even a small rise in overall temp could have huge impacts.

Question 17

State and explain the reasons for global warming.

Answer 17

1. Changes in the earths orbit - earth changes its orbit every 100,000 years sometimes it goes round the sun in a circle and sometimes it’s more like an oval taking earth further from the sun so earth cools down.
2. Sunspots - tiny patches on the sun. Lots of sunspots means more energy from the sun so earth could get warmer. Fewer sunspots means earth is a little cooler.
3. Volcanic activity - when volcanoes erupt they can send large amounts of ash, dust and gases into the atmosphere. This can cool earth by shutting out some of the Suns energy.
4. Human activity - burning fossil fuels (coal, oil and gas found underground made from dead plants and animals over many years) releases Carbon dioxide and other gases into the atmosphere accelerating the greenhouse gas effect and warming earth.

Question 18

State and explain effects of global warming

Answer 18

1. Global temp rise leads to ice caps melting meaning sea levels rising which could flood low-lying coasts
2. More severe storms and wetter conditions in some areas due to more energy in earths atmosphere
3. Increased temperature in areas means drier land which is bad for crop growth in agriculture, could lead to famine
4. Sea level rise due to sea being warmer causing water expansion.

Question 19

Give a definition of weather and climate

Answer 19

Weather - the day to day conditions of the atmosphere

Climate - average weather taken over about 35 years, the sort of weather we usually expect to get

Question 20

State and explain international agreements to deal with climate change

Answer 20

1. International agreements
   Kyoto protocol 1997 - signed by over 180 countries. MEDCs agreed to cut greenhouse gas emissions by 5.2% below 1990 levels to slow global warming.

UN CC Conference in Copenhagen 2009 - China, India and the USA made some commitment to reduce emissions

2. Wind turbines e.g top of Antrim plateau
   - fossil fuels produce CO2 and pollutants when burned
   - by using nuclear or renewable energy (wind, tidal, solar) greenhouse gas emissions are reduced
   - there are problems because wind, tides and sun are not constantly available
   - another alternative is to use biofuels like landfill gas
3. Reducing use of private cars
   Central London congestion charge (£8) per visit reduced traffic by 15%
   Belfast park and ride and bus lanes encourage commuters to reach work quicker by bus rather than car.
   - transport 35% energy used in UK
   - public transport carries many people and takes only slightly more fuel than a car that carries possibly only one person.
   - reducing private transport and increasing public reduces emissions
4. Reducing deforestation
   President of Guyana wants rich countries to invest in sustainable development of rainforest resources (nuts, fruits and oils) rather than timber - trees absorb CO2, deforestation stops this and releases CO2 when trees are burned. Preserving rain forests would slow global warming.

Question 21

Explain alternative sources of energy to deal with climate change

Answer 21

Wind turbines e.g top of Antrim plateau

• fossil fuels produce CO2 and pollutants when burned
• by using nuclear or renewable energy (wind, tidal, solar) greenhouse gas emissions are reduced
• there are problems because wind, tides and sun are not constantly available
• another alternative is to use biofuels like landfill gas

Question 22

Problems with securing international co-operation

Answer 22

Climate change is a global issue it cannot be solved by individuals or nations acting alone international agreements are needed to make significant progress.

• individuals and nations reluctant to make major lifestyle changes to cut c02 emissions. People will change to energy saving light bulbs bar don’t want to give up their car
• MEDCs factories produced lots of co2 in the past when they were developing. Now LEDCs want to be allowed to produce co2 to catch up while they are developing.
• MEDCs have expensive technology to help them reduce emissions whereas LEDCs can’t afford this without help.