What do we mean by the tropics? The weather and the climates it produces across the tropical zone are significantly different from those experienced by the people living in higher latitudes, so forecasters across Europe and much of North America are unfamiliar with its effects. In this book, Jim Galvin demystifies the topic in this zone that is increasingly of interest to those studying weather and climate. This book was written for weather forecasters, meteorology, environmental science and geography students as an introductory guide. It builds on the experience of the author, his professional experience in the World Area Forecast Centre at the Met Office, Exeter, using studies into the weather and climate seen within the tropical air mass conducted over many years. Its unique approach presents a practical approach to tropical weather studies, drawing on both academic and practical knowledge, covering air mass dynamics, seasonal changes, moist and dry weather, climate variability and human health in chapters and appendices that build up the overall picture, summarising our current state of knowledge. As an overview, it covers the broad range of effects connected with climate and weather in a straightforward way and is clearly illustrated throughout.

About the Author xiPreface xiiAcknowledgements xiii1 Setting the Scene 11.1 Introduction 11.2 What do we mean by 'the tropics'? 21.3 The geography of the tropics 51.4 The tropical troposphere 51.5 Climate and population in the tropics 71.6 Question 82 The Energy Balance and the Dynamics of Weather in the Tropics 92.1 The tropical 'heat engine' 9 2.2 Absorption, reflection and apparent solar elevation 92.3 Emission from the surface 112.4 The radiation balance and the tropical zone 122.5 The dynamics of weather systems in the tropics 142.6 Questions 153 Winds, Temperature and Weather in the Tropical Zone 163.1 Winds 163.2 Temperature 203.3 The weather patterns and climates of the tropics 213.4 Clouds and fog in the tropics 233.5 Questions 284 The Subtropical Jet Streams 294.1 The formation of jet streams at the margins of the tropics 294.2 Weather associated with the subtropical jet stream 314.3 Folds and bifurcations in the flow 334.4 Clear?]air turbulence 344.5 Questions 365 Synoptic?]scale Weather Systems 385.1 Introduction 385.2 Convection in the tropics 385.3 The inter?]tropical convergence zone 425.4 The depth of convective clouds 475.5 Layer clouds and shallow convection 485.6 The effects of heavy rainfall in the tropics 485.7 Atmospheric teleconnections 495.8 Questions 496 Climate, Flora and Fauna 516.1 The relationship of climate to plants and animals 516.2 Tropical rainforest 516.3 Seasonal tropical forest 576.4 The savannas 586.5 Tropical deserts and scrublands 606.6 Mountain climates 616.7 Tropical oceans and coasts 656.8 Climatic variability 676.9 Questions 687 Dry Environments 697.1 Background 697.2 Wind and weather in the deserts 707.3 Fog and low cloud 787.4 Severe weather in the dry tropics 797.5 The effects of desert weather 827.6 Settlement and the over?]use of scarce water supplies 847.7 Questions 858 Monsoons 868.1 Introduction 868.2 The summer monsoon over southern Asia 868.3 The summer monsoon over East Asia 898.4 Variations of rainfall in the Asian summer monsoon 938.5 The Asian winter monsoon 948.6 The West African summer monsoon 968.7 The West African winter monsoon 1038.8 Rainfall and the monsoons in East Africa 1048.9 The South American-Caribbean 'monsoons' 1068.10 The Australian summer monsoon 1078.11 Variable broad?]scale factors affecting the monsoons 1118.12 Questions 1129 Tropical Revolving Storms 1149.1 Broad?]scale convection and the development of tropical storms 1149.2 Tropical storm development and decline 1149.3 The effects of tropical revolving storms 1209.4 Storm tracks in the Pacific Ocean 1249.5 The formation and tracks of hurricanes in the North Atlantic-Caribbean 1259.6 Tropical cyclones in the Indian Ocean 1269.7 Tropical revolving storms in the south?]west Pacific 1279.8 Variability in the development of tropical storms 1289.9 Extra?]tropical transition 1329.10 Conclusion 1329.11 Questions 13210 Mesoscale Weather Systems 13410.1 Introduction 13410.2 Mesoscale convective complexes 13410.3 Sea?] and land?]breeze convergence zones 13510.4 Easterly waves and squall lines 13910.5 Mesoscale convective systems in northern India 14310.6 Depressions in north?]west India, north Pakistan and Afghanistan 14410.7 Cross?]equatorial flows 14410.8 Mesoscale convective systems in the Gulf of Guinea 14510.9 Local convection 14510.10 Extra?]tropical interaction with moist tropical air masses 14810.11 Conclusion 14810.12 Questions 14911 Forecasting Clouds and Weather 15011.1 Background 15011.2 Distribution of significant cloud 15011.3 The effect of high ground as an elevated heat source 15511.4 Tropical upper?]tropospheric troughs 15711.5 Effects of severe convection on aviation 15911.6 Questions 16212 The Variability of Weather and Climate Change in the Tropics 16412.1 Introduction 16412.2 El Niño-La Niña 16412.3 The Madden-Julian Oscillation 16612.4 The quasi?]biennial oscillation 16812.5 A discussion of anthropogenic climate change 17112.6 How is climate likely to change in the tropical zone? 17212.7 Modelling climate change 17512.8 Conclusion 17612.9 Questions 17613 Tropical Agriculture 17713.1 Agricultural productivity and tropical environments 17713.2 Agriculture in the humid tropics and the effects of forest clearance 17813.3 Agriculture in the savannas 18013.4 Dry?]land agriculture 18013.5 Weather and locust swarms 18213.6 The effects of agriculture in the tropics 18313.7 Agriculture and climate change 18513.8 Question 18614 The Importance of the Tropical Ozone Layer 18714.1 Background 18714.2 The role of the tropics in replenishing the extra?]tropical stratospheric ozone 19114.3 The effect of 'global warming' on stratospheric ozone destruction in the tropics 19314.4 The effects of exposure to short?]wave radiation 19414.5 Current state of the stratospheric ozone layer 19514.6 Question 19515 Remote Sensing of Tropical Weather 19615.1 Background 19615.2 Satellite remote sensing 19615.3 Precipitation 19715.4 Wind profilers 19915.5 Thunderstorm observation 19915.6 Monitoring surface cover, fires and volcanic eruptions 19915.7 Question 20216 Tropical Weather and Health 20316.1 Introduction 20316.2 The effects of tropical sunshine and warmth 20316.3 Lifted dust and its effects on health 20316.4 Industrial and smoke pollution 20416.5 Parasitic and infectious diseases 20416.6 Response of the meteorological community 20616.7 Questions 20617 Conclusions and a Look to the Future 20717.1 A summary 20717.2 Forecasting the weather 20817.3 Questions 208Appendix 1 Observations from the Tropics 209Appendix 2 Named Winds of the Tropics 213Appendix 3 An Introduction to Cloud Types, Cloud Species and Precipitation 234A3.1 Introduction 234A3.2 The high clouds 235A3.3 The medium?]level clouds 235A3.4 The low clouds 236A3.5 Cloud species and varieties 239Appendix 4 An Introduction to Meteorological Diagrams, Stability, Instability and Aviation Weather Charts 246A4.1 Temperature-pressure graphs 246A4.2 Stability and instability 248A4.3 Aviation?]significant weather charts 248Appendix 5 Snow in the Desert: A Case Study 250A5.1 Introduction 250A5.2 Development of a depression over the desert 250A5.3 The weather features associated with the upper low 253A5.4 Summary 256Appendix 6 A Climatic Summary for Tropical Countries and States 257Appendix 7 Two Easterly Waves in West Africa in Summer 2009: A Case Study 265A7.1 Introduction 265A7.2 The wave of 28 August to 5 September 2009 266A7.3 The wave of 2-11 September 2009 and the development of Hurricane Fred 270A7.4 A model for the development of squall lines in the Sahel 272A7.5 Conclusion 277References 280Glossary 293Index 303