Unit 4: Global Challenge Introduction to Atmospheric Processes Aim: What are the fundamental parts of ‘Weather & Climate’? Key points to learn/ revise… 1.The structure of the atmosphere 2.The Earth’s energy budget 3.Factors affecting climate THE NATURAL ENVIRONMENT

The Structure of the Earth’s Atmosphere The atmosphere = mix of solids, liquids & gases held to earth by gravity Up to approx 80km above earth’s surface, composition = 78% nitrogen, 21% oxygen & small amounts of other gases Most weather occurs in the lowest part of atmosphere (troposphere) –Troposphere (16km above surface, temperature falls with height as atmosphere thins, by approx 6 degrees per km) –Stratosphere (16-48km above surface, lacks dust & water vapour, temperature increases with height due to absorption of solar radiation) –Mesosphere (48-80km above surface, temperatures decrease because decreasing density prevents absorption of energy) –Thermosphere (80+km above surface, a virtual vacuum, temperature rise in absorbed energy due to energised short wave radiation.) COPY THIS INFORMATION ON TO YOUR COPY OF THE DIAGRAM

The Earth’s Energy Budget Read through your copy of the notes Answer the question ‘Explain the variation on insolation across the earth’s surface.’

Factors Affecting Climate Latitude Distance from sea Prevailing Wind Ocean currents Altitude Aspect Seasons Using p Nagle answer the following questions… 1.Explain why average temperatures are colder in Aberdeen compared to in London 2.Why in Britain do people desire to buy south-facing properties? 3.If the wind in Britain was easterly what effect would it have on the weather? 4.Describe global temperature patterns (fig 8.6 & 8.7)

We must be aware of the news in geography… Where are these weather/ climate issues taking place? Who are they affecting? At what scale are the impacts felt? Can they be managed? New Orleans, USA, September 2005 Heat wave, UK, July 2006 Aral Sea, Central Asia Hurricane Mitch, 1998 Great storms, UK 1987 Famine in drought gripped Southern Africa Coastal flooding Forest fires Fuel prices rise Increasing number of low-cost airlines Penguin populations decline by 33% in 25 years as Antarctica’s ice shrinks