Download Climatic Controls: Water Bodies and Continents How are water

Climatic Controls: Water
Bodies and Continents
How are water bodies and land
masses connected?
Water bodies provide sources of
moisture for the land masses of the
world
 In general, locations near water bodies
experience wetter climates than
locations found far from water bodies
(Continentality)

Even at high latitudes?

At high latitudes however, the air is
very cold and unable to evaporate and
hold much water vapour

This results in cold weather deserts
Are there any other exceptions?
Areas that experience offshore winds
for much of the year get dry winds that
blow from the land to the water
 Even in coastline locations, these
winds can cause desert conditions
 Another exception is areas that receive
a lot of cold air due to cold ocean
currents - this air does not evaporate,
nor hold much water vapour

How do water bodies affect
temperature?

Land masses that receive solar
radiation convert the energy into heat
that tends to be concentrated on the
first few centimeters of the earth making the surface much warmer than
even a few inches deep
How do water bodies affect
temperature?

In contrast, solar radiation falling on a
water body is able to penetrate to
significant depths

In addition, convection currents
distribute the energy received from the
sun downwards
How do water bodies affect
temperature?

As a result, water bodies do not heat
up as much during the summer as land
masses

The temperatures that occur in the
areas that are close to water bodies
are lower in the summer
How do water bodies affect
temperature?

In the winter, water bodies maintain
their hear longer and do not cool off as
much as land masses

Therefore, large water bodies act as
“heaters” to the land that is adjacent to
them
What is the result of this
differential heating?

Differences in air pressure result in the
development of regional wind systems
that can alter the global wind systems
(hot air is less dense than cold air and
has a tendency to rise, creating a low
pressure area)
What is the result of this
differential heating?

Surface winds blow towards a low
pressure area to replace the rising air
Summer

Over land masses, low pressure areas
develop and winds blow inland towards
to low pressure system
Winter
In the winter, the land masses cool off
to a much greater degree than
surrounding bodies of water
 High pressure areas develop over the
land mass as cold, dense air sinks to
the earth’s surface
 Winds blow offshore out of the high
pressure system

Monsoons

The largest land mass in the world is Asia
and therefore, this effect is most noticeable
there and results in the distinctive wind
system known as the monsoons

Monsoon - a regional circulation pattern
in which there is a seasonal reversal of
wind and pressure
Monsoons

What are 3 ways that animals deal with the
drought before the monsoons?

What are 3 positives about the monsoons?
See “Australia: Eye of the storm - monsoons
(start video at 18 min.)