Key Terms: Weather Hazards (AQA GCSE Geography): Revision Note

Global atmospheric circulation – key term glossary

Air mass – A large body of air with similar temperature and moisture characteristics.

Atmospheric circulation – The large-scale movement of air that helps to distribute thermal energy across the Earth.

Coriolis effect – The deflection of winds due to the Earth's rotation, causing them to curve right in the Northern Hemisphere and left in the Southern Hemisphere.

Ferrel cell – The middle circulation cell found between 30° and 60° latitude, responsible for the UK's changeable weather.

Global wind belts – The global zones where wind travels consistently in a particular direction due to pressure differences and the Coriolis effect. Includes the trade winds, the westerlies and the easterlies.

Hadley cell – The largest atmospheric cell stretching from the equator to about 30°, where warm air rises and cools to form clouds and rain.

High pressure – A weather system where air sinks, leading to dry, settled conditions.

Insolation – The amount of solar radiation reaching the Earth's surface.

ITCZ (Intertropical Convergence Zone) – A low-pressure zone near the equator where trade winds converge and cause thunderstorms.

Low pressure – A weather system where air rises, often resulting in clouds, wind and rain.

Polar cell – The smallest and coldest atmospheric cell, extending from 60° latitude to the poles.

Trade winds – Winds that blow from the subtropical high-pressure belts to the equator, deflected by the Coriolis effect.

Tropical storms - key terms glossary

Cyclone – The name for a tropical storm in the Indian Ocean and southern Pacific.

Eye (of the storm) – The calm, clear centre of a tropical storm with low pressure and light winds.

Eyewall – The area surrounding the eye where the most severe weather occurs, including the strongest winds and heaviest rain.

Hurricane – The name for a tropical storm in the Atlantic Ocean and Caribbean Sea.

Low vertical wind shear – A situation where wind speed and direction change little with height, allowing storms to strengthen.

Saffir-Simpson Scale – A classification system for tropical storms based on wind speed, ranging from 1 (weakest) to 5 (strongest).

Typhoon – The name for a tropical storm in the western Pacific and South China Sea.

Tropical storm – A powerful, rotating low-pressure system with heavy rain and strong winds that forms over warm ocean waters.

Tropopause – The boundary between the troposphere and stratosphere, above which storm clouds do not extend.

Warm ocean temperatures – Sea surface temperatures of at least 27°C, required for the formation and intensification of tropical storms.

Effects of tropical storms - key terms glossary

Primary effects – Immediate impacts of a storm, such as flooding, building collapse, and injuries.

Secondary effects – Impacts that occur after the storm, like homelessness, disease outbreaks, and food shortages.

Economic impacts – Damage to infrastructure, disruption to businesses, and loss of income due to the storm.

Environmental impacts – Damage to ecosystems, pollution, and destruction of crops and wildlife habitats.

Homelessness – A common secondary effect when homes are destroyed or severely damaged.

Storm surge – A rise in sea level caused by a tropical storm, leading to coastal flooding.

Waterborne disease – Illnesses like cholera or typhoid that spread when clean water supplies are contaminated.

Management of tropical storms - key terms glossary

Cone of uncertainty - Also known as the Tropical Cyclone Track Forecast Cone and is a graphic used to show the most likely path of a tropical cyclone centre over five days.

Evacuation – Moving people from areas expected to be affected by storms to safer locations.

Forecasting – The use of weather data and computer models to predict the path and strength of tropical storms.

Hurricane watch – An official alert issued when a storm is expected to reach a region, giving people time to prepare.

LIC (Low-Income Country) – Countries with limited resources and infrastructure, making storm management more difficult.

Monitoring – Tracking the development of storms using satellites, radar, and computer models.

Planning – Strategies such as education, drills, and evacuation routes used to reduce storm damage.

Protection – Measures like sea walls, reinforced buildings, and storm shelters that reduce storm impact.

UK weather hazards - key terms glossary

Anticyclone – A high-pressure weather system bringing dry, stable weather – hot in summer and cold in winter.

Continentality – The effect of land masses on climate, where inland areas are hotter in summer and colder in winter than coastal areas.

Depression – A low-pressure system bringing cloudy, wet, and windy weather, common in the UK.

Drought – A prolonged period of below-average rainfall that leads to water shortages.

Extreme weather – Unusual or severe weather that poses risks to life or property.

Flooding – When water overflows onto normally dry land, often caused by heavy rainfall or river overflow.

Hailstorm – A storm that produces balls or lumps of ice that can damage property and crops.

Heatwave – An extended period of hot weather that can cause health risks and disrupt infrastructure.

North Atlantic Drift – A warm ocean current that keeps the UK's climate milder than other places at similar latitudes.

Polar continental – A dry and cold air mass affecting the UK in winter.