Droughts and High Pressure Systems

Flashcards covering key vocabulary and concepts related to droughts, heatwaves, and high pressure systems.

Drought

Occurs in areas with little rainfall, a shortage of water stored in rivers, lakes, and aquifers, or due to human impacts like deforestation and intensive agriculture.

Global Atmospheric Circulation Model

Causes a high pressure belt around 30° north and south of the Equator, producing low rainfall and increasing drought risk.

Heatwaves and Droughts

High pressure systems cause extended periods of clear skies which raise temperatures and reduce rainfall. In summer, heatwaves and droughts can lead to wildfires.

Wildfires

A common secondary effect of droughts and heatwaves which often have a greater impact than the drought itself, leading to loss of life, property, and resources and disrupting transportation and services.

Aquifer

An underground layer of permeable rock containing water that can be extracted using a well/ pump.

Indian Ocean Dipole

Effect caused by changing temperatures of the Indian Ocean which affect evaporation rates. A positive dipole ‘turns off’ vital rain systems causing droughts.

Snowpack

Layers of snow that accumulate in high altitudes. Their slow melting feeds streams and rivers.

Jet Stream

Areas of high winds caused by the temperature differences in the atmosphere. Global warming reduces these temperature differences slowing down the jet stream.

Global warming's impact on drought

Changing ocean temperatures affect climate phenomenon increasing drought risks. Rising land temperatures increase evaporation rates. Affects jet stream which stalls pressure systems.

Impacts of Stalled High Pressure Systems

Can turn one or two dry days into weeks, causing a drought due to the slowing or stalling of the jet stream.