OCR GCSE Geography B Key Terms

The process by which rising air cools and expands due to a decrease in atmospheric pressure with altitude.

The process by which sinking air warms and compresses as atmospheric pressure increases closer to the Earth's surface, preventing cloud formation.

Occurs when there is insufficient soil moisture to meet the needs of crops, leading to failing harvests.

An area of high atmospheric pressure where air sinks, warms, and prevents cloud formation, leading to clear skies and intense summer heat.

A climate characterized by a severe lack of available water, typically receiving less than 250mm of rain per year.

The process where water vapour turns into liquid water, forming clouds and releasing latent heat.

The point where two or more rivers or streams meet.

The process by which warm, moist, less dense air rises in the atmosphere.

The deflection of moving air caused by the Earth's rotation, deflecting winds to the right in the Northern Hemisphere and causing weather systems to spin.

An extended period of deficient rainfall relative to the statistical average for a region.

Prolonged periods of abnormally low rainfall, often caused by sinking air in high-pressure anticyclones that blocks cloud formation.

Countries with medium or rapidly growing levels of economic development, heavily influencing their capacity for hazard resilience.

A climate event occurring every 2–7 years where reversed trade winds lead to intense high-pressure systems and severe droughts near Australia.

A natural cycle of warming and cooling in the central and eastern Pacific Ocean that significantly affects global weather patterns.

The strengthening of the natural greenhouse effect through human activities, trapping more heat in the atmosphere and driving climate change.

The periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean.

A low-pressure belt at 0° latitude created by rapidly rising warm air, resulting in heavy rainfall.

Weather that is significantly different from the average or usual weather pattern for a particular location.

The calm, central part of a tropical storm where air descends, creating high pressure and clear skies.

The ring of intense thunderstorms surrounding the eye, containing the strongest winds and heaviest rain.

Friction-driven atmospheric circulation cells located between 30° and 60° latitude that sit mechanically between the Hadley and Polar cells.

Rapid flooding of low-lying areas caused by intense rainfall associated with severe thunderstorms, hurricanes, or tropical storms.

The worldwide large-scale movement of air (winds) that transports heat from the tropical Equator to the Poles via three atmospheric cells.

A global scale atmospheric circulation feature in which warm air rises at the equator and sinks at around 30° North and South.

Atmospheric circulation cells located between 0° and 30° latitude, driven by intense insolation at the equator.

A period of at least three consecutive days where daily maximum temperatures meet or exceed a specific threshold.

A weather system caused by descending (sinking) air that warms and prevents condensation, leading to clear, dry, and calm weather.

A prolonged water deficit that leads to a significant reduction in surface and subsurface water stores, such as rivers, lakes, and aquifers.

A surface or rock type (e.g., slate, granite) that prevents water infiltration, increasing surface runoff.

The amount of incoming solar radiation reaching a given area, which is highest at the Equator.