Population - Natural increase as a component of population change
Population - Demographic Transition
Population - Population-resource relationships
All for this textbook (37)
Written for
CIE
Geography
Unit 1 - Core Geography (9696)
All documents for this subject (66)
Seller
Follow
danielperea-milla
Content preview
Atmospheric moisture processes
atmospheric moisture - solid, liquid and vapour
- energy is used in the change from one phase to another
● evaporation: heat is absorbed
● heat loss during evaporation passes into the water as latent
heat - vaporisation
● condensation: latent heat locked in water vapour is released
= rise in temperature
● deposition (vapour to ice) = heat is released
● sublimation: heat is absorbed - snow patches disappear
without melting.
Factors affecting evaporation
- occurs when vapour pressure of a water surface exceeds that in
the atmosphere
- vapour pressure: pressure exerted by the water vapour in the
atmosphere - maximum vapour pressure at any point occurs when
the air is saturated
● initial humidity of the air:
❏ if the air is very dry = strong evaporation occurs
❏ is the air is saturated = very little occurs
● supply of heat: the hotter the air, the more evaporation takes
place
● wind strength: air becomes saturated quickly under calm
wind conditions
Factors affecting condensation
occurs when:
- enough water vapour is evaporated into an air mass for it to
become saturated - rare
- when the temperature drops so that dew point (temp. at which air
saturates) is reached - common
such cooling occurs in 3 main ways:
- radiation cooling of the air
, - contact cooling of the air when it rests over a cold surface
- expansive cooling of air when it rises.
Condensation requires a some tiny particles or nucleus onto which
water vapour can attach:
- lower atmosphere - sea salt, dust, pollution particles…
- condensation occurs when the relative humidity is as low as 80%
Other processes
Freezing: liquid ---> solid once the temperature is below 0ºC.
Melting: solid ---> liquid when air temperature is above 0ºC.
Sublimation: solid ---> vapour with no intermediate liquid state
Deposition: vapour ---> ice
Precipitation
all of the deposition of moisture from the atmosphere (solid or liquid
state) - including rain, hail, snow and dew.
1) minute droplets of water rise to the atmosphere - forming clouds -
after they have been condensed from water vapour
2) if droplets coalesce (join), they form larger droplets which
eventually fall as rain
Formation
of droplets
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller danielperea-milla. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R58,25. You're not tied to anything after your purchase.