IB ESS HL 6.1.2 Atmospheric circulation Question Bank

atmospheric/tri-cellular circulation (including Hadley, Ferrel \& polar cells) creates patterns of climate that determine dominant vegetation types; low pressure due to intense heating/high insolation at the equator causes / rising moist air in the tropics creates high precipitation giving rise to rainforests; moving polewards (at high altitude), air cools, becomes denser and sinks forming a high-pressure zone / descending/dry air ( $20-30^{\circ}$ latitude/tropics) creates water

limiting/arid conditions giving rise to deserts; some of the air continues towards the poles to equalize temperature difference / atmosphere transfers heat from (sub-)tropics to mid-latitudes giving rise to temperate biomes; descending/dry air (high latitude/polar regions) creates water-limiting conditions in tundra; water vapour (from mid-latitudes/temperate regions) is transferred to high latitudes giving rise to heavy precipitation/snow in boreal forest; water vapour is transferred from ocean surfaces overland generating freshwater aquatic systems; prevailing winds/jet streams (blowing from high to low pressure) bring precipitation to a region, eg temperate rainforest in mountainous region/riverine/water-margin systems; rain shadow effect of high mountains causes dry winds in the leeward side, resulting in arid or semi-arid biomes (eg Tibetan Plateau, Mongolian Gobi desert and steppes); atmosphere may be responsible for shifting biomes due to global warming/climate change;