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.)