Syllabus concepts to know

• 2.4.1 Climate describes atmospheric conditions over relatively long periods of time, whereas weather describes the conditions in the atmosphere over a short period of time.
• 2.4.2 A biome is a group of comparable ecosystems that have developed in similar climatic conditions, wherever they occur.
• 2.4.3 Abiotic factors are the determinants of terrestrial biome distribution.
• 2.4.4 Biomes can be categorized into groups that include freshwater, marine, forest, grassland, desert and tundra.
• 2.4.5 The tricellular model of atmospheric circulation explains the behaviour of atmospheric systems and the distribution of precipitation and temperature at different latitudes.
• 2.4.6 The oceans absorb solar radiation and ocean currents distribute the resulting heat around the world.
• 2.4.7 Global warming is leading to changing climates and shifts in biomes.
• 2.4.8 There are three general patterns of climate types that are connected to biome types.
• 2.4.9 The biome predicted by any given temperature and rainfall pattern may not develop in an area because of secondary influences or human interventions.
• 2.4.10 The El Niño Southern Oscillation (ENSO) cycle is the fluctuation in wind and sea surface temperatures that characterizes conditions in the tropical Pacific Ocean.
• 2.4.11 El Niño is due to a weakening or reversal of the normal east–west (Walker) circulation, which increases surface stratification and decreases upwelling of cold, nutrient-rich water near the coast of north-western South America.
• 2.4.12 Tropical cyclones are rapidly circulating storm systems with a low-pressure centre that originate in the tropics and are characterized by strong winds.
• 2.4.13 Rises in ocean temperatures resulting from global warming are increasing the intensity and frequency of hurricanes and typhoons because warmer water and air have more energy.