This note pack is a complete summary with diagrams. It summarises all the content for Topic 2 : Climate and Weather Introduction. Chapter 5 : Urban Climates in the Focus Geography Grade 12 Learner's Book.
Subtropical anticyclones and associated weather conditions Geography 12 IEB
All for this textbook (22)
Written for
12th Grade
Geography
200
All documents for this subject (230)
1
review
By: cindykr • 1 year ago
Seller
Follow
Temone
Reviews received
Content preview
Urban Climates
Differences between Rural & Urban Climates
● Temperature, humidity & rainfall in city different from rural area
● City different microclimate to rural
● City warmer than rural
Reasons for temperature variations
● Cities - many artificial sources of heat
○ Eg. air conditioning, power stations, car engines, domestic & industrial heating
● Cities built artificial substances - absorb more heat than soil & grass
○ Eg. concrete, glass, bricks & tar
● Urban areas, water taken away in drains & not many plants
● Rural areas large amount heat used in evaporation from water sources & transpiration from
plants
● High-rise buildings large surface areas
○ Sun strikes side buildings in morning, heat absorbed
● Cities polluted air
○ Causes city cool down more slowly at night
○ Polluted area acts like blanket, trapping warm air close to city in evening
Humidity & Precipitation in Cities
Humidity of air describes how much water vapour there is in the air
Usually, the air is less humid in cities than air in rural areas
● Water in cities carried away by stormwater drains
● Fewer plants in urban areas - less water vapour being added to air through transpiration
● Water vapour in air condenses only if there are hygroscopic nuclei
○ Particles in air such as dust, salt & smoke
○ Attracts water vapour & provide surface for water vapour to condense
○ Pollutions consists of smoke & dust
○ Pollution provides hygroscopic nuclei = increase amount of condensation
● Thunderstorms more frequent over cities - hotter air results stronger upward convection
currents
, Climate factor Rural Area Urban Area
Temperature Cooler - fewer artificial Warmer - lack vegetation cover &
surfaces & more more artificial levels
vegetation cover
More artificial heating
More dust - prevents heat from
escaping
Pollution Less pollution & dust More pollution & dust - industrial
particles activities, combustion processes &
traffic
Cloud Coverage Fewer clouds More clouds - more dust & pollutant
particles in atmosphere
Particles = hygroscopic nuclei /
condensation nuclei
Precipitation Less rain & hail, may get More rain & hail - more hygroscopic
more snow nuclei
Relative humidity Higher relative humidity Lower relative humidity - lack
due to water retention in vegetation & natural levels
soil & vegetation
Warmer air hold more moisture, lack
of evaporation due to little
vegetation & many artificial surfaces
Wind Speed Higher Less - buildings serve as
windbreaks
Fog Visibility Less fog = better visibility More fog & poorer visibility due to
more condensation nuclei in
atmosphere
Fog problem in winter when
inversion causes pollutants to form
near the surface of the earth
Thunderstorms Less often More frequently across urban areas
Warmer air causes stronger,
upward convection & therefore
more
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Temone. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.15. You're not tied to anything after your purchase.
