Urban Climates

Question 1

Describe the temperature of Urban areas in comparison to other areas?

Answer 1

Warmer

Question 2

What is the name given to urban areas as a result of their temperature characteristics?

Answer 2

Urban Heat Island

Question 3

How do Windows help to increase temperature?

Answer 3

Enhance and reflect heat from the sun towards the ground. (E.g Walkie Talkie building in London was burning through cars)

Question 4

How do air conditioning units make urban areas warmer?

Answer 4

They release the warm air into the atmosphere

Question 5

How do factories and cars increase the temperature of urban areas?

Answer 5

They produce a lot of greenhouse gases which constantly thicken the greenhouse gas layer which make it difficultly for heat to escape. Therefore they act as a pollution dome

Question 6

How do tall buildings help to heat up an area?

Answer 6

Because they are tall they cause conditional instability forcing clouds to form which similar to the greenhouse gas layer traps, like a blanket, the heat in the urban areas

Question 7

How do building materials such as concrete and brick lead to an urban heat island?

Answer 7

They retain heat better than most materials so therefore surrounding them is a hotter area

Question 8

How do drainage systems lead to an urban heat island?

Answer 8

Because they transport water away from the surface underground, this means the heat used to evaporate them normally is used to heat up the urban area

Question 9

How do people lead to an urban heat island?

Answer 9

We produce terrestrial heat and so in urban areas there are lots therefore lots of heat

Question 10

How does a lack of greenery in urban areas lead to a heat island?

Answer 10

Because plants retain heat through photosynthesis and don’t release to atmosphere so is stored where it can’t warm up area

Question 11

What is the rate at which temperature increases the closer you get to the city from the edges?

Answer 11

2-4Celsius

Question 12

Describe the amount of rainfall in urban areas?

Answer 12

There is likely to be more

Question 13

How do high rise buildings lead to more rain?

Answer 13

They cause conditional instability which forces cloud to form

Question 14

How does the urban heat island effect lead to more rain?

Answer 14

Increased heat also encourages cloud formation

Question 15

How do factories help to increase rainfall?

Answer 15

They release water vapour and hygroscopic nuclei that attract water towards them and so assist with droplet formation

Question 16

How does the undercutting of air at ground level altitudes lead to increased precipitation?

Answer 16

The undercutting at grounds level altitudes forces air to rise faster and thus produce precipitation

Question 17

Why does fog occur in urban areas?

Answer 17

The urban area is significantly warmed during the day, in winter especially, at night the increase amount of darker hours and less incoming heat radiation means there is a temperature inversion and the urban area cools. The cooler area means that the water vapour released by factories, and hygroscopic nuclei that assist with droplet formation, can reach their dew point and so low altitude clouds/fog forms.

Question 18

When does fog mostly occur in urban areas?

Answer 18

Autumn and Winter seasons

Question 19

What are winds like in urban areas?

Answer 19

They can be very powerful

Question 20

What are 3 ways buildings cause increased wind speeds and turbulence?

Answer 20

• Uneven heights and surfaces of them means there isn’t a smooth flow for air therefore there is increased turbulence of air
• They can force air downwards if high enough into canyons of air which increases their speed and power
• Tall buildings may force air around them and in grid like cities e.g New York this may produce channels or tunnels of air in the streets

Question 21

What is the Venturi effect?

Answer 21

The forcing of air downwards by buildings into canyons where their speed increases with change of directions and can knock people over

Question 22

How can urban areas counteract increased wind speeds?

Answer 22

Buildings on stilts

Question 23

What is the difference between primary and secondary pollutants?

Answer 23

Primary pollutants are those that are produced directly from one process, however secondary are usually primary pollutants that have reacted with another or gone thorough a second process such as reacting with the sunlight

Question 23

Describe the quality of urban area’s atmosphere in comparison to rural areas

Answer 23

Bad quality

Question 24

What are 3 primary pollutants?

Answer 24

Sulphur oxides
Nitrogen Oxides
Carbon Monoxide and Dioxide
Volatile Organic Compounds such as Hydrocarbons

Question 25

What is an example of a secondary pollutant?

Answer 25

Ozone (Usually produced when a primary pollutant reacts with sunlight)

Question 26

What leads to the formation of photochemical smogs?

Answer 26

When primary pollutants react with sunlight to turn into Ozone. This smoke them reacts with existing fog or clouds in a hydroscopic manner to assist with more smog that now has dangerous Ozone in it

Question 28

Where is photochemical smog a massive problems?

Answer 28

Los Angeles> lots of cars, lots of sunshine, and topography traps the chemicals.

Question 29

Why is ozone and photochemical smog a massive problem?

Answer 29

Because Ozone is bad for respiratory system

Question 30

What are some examples of particulate matter?

Answer 30

Tobacco, Cement, Ash, Coal, Pollen, dust and sea salt

Question 30

When is the air quality in urban areas likely to be worse?

Answer 30

Winter, because the temperature inversions trap the chemicals in Smog and photosmog over the city

Question 30

When was Smog a real problems for London?

Answer 30

In 1952 when they lead to 4000 deaths

Question 30

What are some of the sources in urban areas that produce the pollutants that produce photochemical smog?

Answer 30

Things that burn fossil fuels such as factories and cars

Question 31

How is a temperature inversion created and how does it lead to worse air conditions?

Answer 31

During an anticyclone air is forced downwards and trapped at the surface with all the moisture. At night, odd even day, the temperature suddenly drops and so does the atmosphere. Due to the cold air it is unable to support the moisture at the low levels and so condenses to form a low layer of cloud or fog. The chemicals and particulate matter in urban areas then produces smog that mixes with the clouds. Due to the continued presence of the anticyclone these can be trapped close to the surface and therefore worsen air quality.

Question 32

What is particulate matter?

Answer 32

An incredibly small solid in the atmosphere that are around 10 micrometers in diameter

Question 33

Give some examples of the action being taken to reduce the effects of the urban areas climates

Answer 33

Oyster Cards, Boris Bikes, Congestion charges, pedestrianising, expensive parking, DLR, Low emission zones, park and ride, 1952 clean air acts, catalytic converters, lead free petrol

Question 34

What are 5 the sources in urban areas that produce particulate matter?

Answer 34

Cars and vehicle exhausts, smoking, building sites, mines, sea and plants

Question 35

Give 5 examples of particulate matter

Answer 35

Cement, sea salt, pollen, brick, ash, nitrates, sulphates, tobacco

Question 36

Why are particulate matter bad for air quality?

Answer 36

They can be so small that it is difficult for our respiratory systems to flush out. This can therefore lead to respiratory and cardiovascular problems. They can also react with fog to produce smog that creates thick air that is bad for respiratory system