Weather, climate and ecosystems

A2: Unit 4 - Global Challenge

Weather and climate -a course outline:

1. Weather forecasting2. Global atmospheric circulation system3. Depressions 4. Anticyclones5. Extreme weather events6. Seasonal variations in climate7. El Niño and La Nina8. Climate change

Weather and climate

TRUE or FALSE

1. Winds blow from areas of low to high pressure.2. Isobars are lines joining equal wind speeds.3. Winds in the northern hemisphere are deflected to the right by the Coriolis force.4. The Inter-tropical Convergence Zone is the area of low pressure at the equator, causing warm and dry conditions.5. At the polar front, warm air from the tropics rises over cooler air from the Arctic causing low pressure and rainfall.

The global atmospheric circulation system

TRUE or FALSE

6. A jet stream is a fast wind moving from the poles to the equator.7. The boundary between two air masses is called a front.8. High pressure is associated with overcast skies and prolonged rainfall.9. A cold front is where cold, dense, polar air moves towards warm air forcing the warm air to rise.

Las Vegas, Nevada, USA

Sudan, Africa

Technical fix: human ingenuity allows us to work round nature’slimitations.

Determinism: nature controlssocieties and ecosystems.

Graphing the sensitivity of society to weather

The global atmospheric circulation system

Air masses affecting British weather

ANTICYCLONES• An anticyclone is an area of high pressure. The sinking air (causing high pressure) has the effect of suppressing any rising air which might otherwise form clouds. • Anticyclones are therefore associated with fine and dry weather.• Anticyclone systems are large scale and stable.