Solar radiation is absorbed by the Earth's land surface, oceans – which cover about 71% of the globe – and atmosphere. Warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the Earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones. Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C. By photosynthesis green plants convert solar energy into chemically stored energy, which produces food, wood and the biomass from which fossil fuels are derived. COUNT 8
QSN1 The Earth's oceans cover what percentage of the globe? ANS1 71 QSN2 What is the average temperature of the Earth's surface in Celsius? ANS2 14 QSN3 What is the process by which green plants convert solar energy to stored energy? ANS3 photosynthesis QSN4 How much of the earth is covered by oceans? ANS4 about 71% QSN5 What is the cause of atmospheric circulation? ANS5 Warm air containing evaporated water from the oceans rises QSN6 How does the water vapor that rises in warm air turn into clouds? ANS6 When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds QSN7 What creates wind, cyclones and anti-cyclones? ANS7 The latent heat of water condensation amplifies convection QSN8 What is the process in which plants convert solar energy into stored energy called? ANS8 photosynthesis