Weather hazards and climate change Flashcards
(48 cards)
What is the atmosphere?
The atmosphere is the layer of air surrounding the Earth’s surface which extends hundreds of kilometres high
What is weather and what is climate?
Weather is the short term day to day conditions of the atmosphere
while Climate is the long term average temperature and rainfall.
Which part of the atmosphere does weather take place in?
Troposphere
What is the Coriolis effect and its impacts on the weather of the uk?
Apparent force, due to the spinning of the Earth, which deflects movement of particles and wind.
In the UK, which winds are blown from the south due to the Ferrell cell but the earth spins to the right causing the prevailing wind to hit the UK in a south-westerly direction.
What is a glacial and an interglacial?
A glacial is a period of cold while an interglacial is a period of warm?
What are the patterns of climate across the UK
The general pattern of the climate across the UK has four distinct regions:
south-east – cold winters, warm and dry summers
south-west – mild and very wet winters, warm and wet summers
north-west – mild winter, cool summers and heavy rain all year
north-east – cold winter, cool summers and steady rain all year
What was the last major cold period?
The last major cold period was known as the Pleistocene. It started 2.6 million years ago and ended just 10,000 years ago. Since then, conditions have been warmer. This current warm phase is known as the Holocene. The Holocene and Pleistocene are part of the Quaternary Period of Earth’s history.
What human factors increase global warming?
Burning fossil fuels, eg coal, gas and oil - these release carbon dioxide into the atmosphere.
Deforestation - trees absorb carbon dioxide during photosynthesis. If they are cut down, there will be higher amounts of carbon dioxide in the atmosphere.
Dumping waste in landfill - when the waste decomposes it produces methane.
Agriculture - agricultural practices lead to the release of nitrogen oxides into the atmosphere.
What are droughts? Why are deserts not considered in drought?
when there is abnormally low rainfall for an extended period of time. Droughts can last from weeks to months and even years. A desert would not be considered in drought unless it had less rainfall than normal, for a long period of time.
What is subsidence?
Subsidence is when the ground beneath a building sinks, pulling the property’s foundations down with it. Subsistence usually occurs when the ground loses moisture and shrinks.
Explain one meteorological cause of drought.
A reduction in rainfall can cause drought because of changes in the
global atmospheric circulation where areas come under the influence
of high pressure
What is the hadley cell?
A large-scale atmospheric circulation pattern where:
Warm air rises near the equator, creating low pressure and heavy rainfall.
Air moves poleward at high altitudes, cools, and sinks near 30° N/S (subtropics), forming deserts.
Surface trade winds flow back toward the equator.
What is the ferrel cell?
A mid-latitude atmospheric circulation cell (between 30°–60° N/S) where:
Cold air sinks near 30° N/S (subtropical high-pressure zones).
Surface winds (Westerlies) blow toward the poles.
Warm air rises near 60° N/S (subpolar low pressure), creating stormy weather (UK WEATHER)
What is the Polar Cell?
The smallest and weakest atmospheric circulation cell, located between 60°–90° N/S, where:
Cold, dense air sinks at the poles (high pressure).
Surface polar easterlies blow toward mid-latitudes.
Air rises near 60° N/S (polar front), fueling storm systems.
What are trade winds
Steady, warm winds that blow from the subtropical high-pressure zones (30° N/S) toward the equator (0°) due to the Hadley Cell circulation.
What are ocean currents?
Large-scale, continuous movements of seawater driven by:
Wind (e.g., trade winds, westerlies).
Earth’s rotation (Coriolis effect).
Density differences (temperature & salinity).
How do ocean currents affect climate?
By transferring heat globally:
Warm currents (e.g., Gulf Stream) heat coastal regions (e.g., UK is warmer than Canada at same latitude).
Cold currents (e.g., California Current) cool coasts (e.g., San Francisco’s fog).
What is the jet stream?
A fast-flowing, narrow air current in the upper atmosphere (~9-16 km high), driven by:
Temperature contrasts (polar vs. tropical air).
Earth’s rotation (Coriolis effect).
Flows west-to-east in mid-latitudes at 200–300 km/h.
What is the gulf stream
A warm, powerful ocean current in the Atlantic:
Starts in the Gulf of Mexico → crosses Atlantic → warms NW Europe.
How does the gulf stream affect UK climate?
It delivers heat and moisture:
Winter: Keeps UK 5–8°C warmer than same-latitude areas (e.g., Canada’s Newfoundland).
Summer: Mild temperatures (less extreme heat).
Rainfall: Moist air from the Atlantic brings frequent rain (“UK drizzle”).
What are some natural causes of climate change?
Solar Variability
Volcanic Eruptions
Orbital Changes (Milankovitch Cycles)
How do volcanoes cause short-term cooling?
Sulfur dioxide (SO₂) erupts into the stratosphere forms aerosols that reflect sunlight.
How does the Sun influence climate naturally?
Variations in the intensity of solar radiation hitting the Earth may produce changes in global and regional climate.
What is eccentricity in Milankovitch cycles?
Changes in Earth’s orbit from circular to elliptical over ~100,000 years.
High eccentricity = more extreme seasonal differences.
Currently: Earth’s orbit is weakly elliptical (minimal impact).
