levo

Weather and Climate

Urban climates and air quality

  • 2 things to know
  • Component 3 Section B

Overview

Urban heat island, urban canyon and how does it affect temperature and three strategies for improving urban air quality.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What is the urban heat island?

Key term

Give three causes of the urban heat island.

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What is the urban heat island?

    Model answer

    The urban heat island is the tendency for a city to be warmer than the surrounding countryside. The difference is typically 2 to 5 °C and can exceed 10 °C on a calm clear night.

  2. 2

    Give three causes of the urban heat island.

    Model answer

    Concrete, brick and tarmac have a high thermal capacity and release stored heat slowly at night. Waste heat from buildings, industry and vehicles adds directly, and tall buildings trap outgoing radiation between them.

  3. 3

    Why is the urban heat island strongest at night and in calm conditions?

    Model answer

    Rural surfaces cool rapidly after sunset while urban materials keep releasing stored heat. Wind would mix the two air bodies, so calm conditions preserve the contrast.

  4. 4

    What is an urban canyon and how does it affect temperature?

    Model answer

    An urban canyon is a street enclosed by tall buildings on both sides. Outgoing longwave radiation is reflected between the walls rather than escaping, which raises temperature.

  5. 5

    How do urban areas affect wind speed?

    Model answer

    Buildings increase surface roughness and reduce mean wind speed across the city. Gaps between tall buildings produce the venturi effect, where funnelled air accelerates sharply.

  6. 6

    How do urban areas affect precipitation?

    Model answer

    Cities receive somewhat more rainfall than their surroundings, often 5 to 15% more. Extra convection from the heat island and abundant condensation nuclei both contribute.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Coastal Landscapes
Glaciated Landscapes
Changing Places
Water and Carbon Cycles

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

One therefore represents 250 metres.
centimetremetremillimetre

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

ACustomary rights are often unwritten.
BA government can lease the same land to an investor.
COccupants then have no legal defence against eviction.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Due west is a bearing of 270°.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Weather and Climate, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.