Air pressure, wind and fronts – Coriolis effect

GeographyWeather & ClimateAges 15–16

A pressure map with a draggable high-pressure centre (H) and low-pressure centre (L), with isobars drawn automatically. Air parcels move from high to low pressure and are deflected by the Coriolis effect (to the right in the Northern Hemisphere, to the left in the Southern Hemisphere), forming an anticyclone around the high and a cyclone around the low; change the pressure difference, latitude, hemisphere and friction to see how wind speed and direction change. The panel below shows a cross-section of a cold front (cold air undercuts and lifts warm air, bringing thunderstorms) or a warm front (warm air glides up over cold air, bringing steady rain).