Weather And Climate Flashcards
Circulation cells?
Different areas of the earth receives different amounts of solar radiation: there is a surplus of heat energy at the equator and a deficit at the poles. Three circulation cells in each hemisphere redistribute heat
What are the 3 circulation cells that redistribute heat?
At the equator, warmed air rises to 15 KM, causing low pressure. The air current divides, cools and moves north and south to form Hadley cells. The cooled air sinks at 30 degrees north and south of the Equator, leading to high pressure.
Some of the cooled air moved back towards the equator as trade winds. The rest travels towards the poles, forming the lower part of Ferrel cells
At 60 degrees north and south, the warmer air of the Ferrel cells meet colder polar air. The warmer air rises to form polar cells. This air travels to the poles, where it cools and sinks, forming areas of high pressure
Oceanic circulation?
Ocean currents also transfer heat energy from areas of surplus (Equator) to areas of deficit (poles). Wind-driven surface currents move warm water towards the poles and colder water towards the Equator. In the Arctic and Antarctic, water gets very cold and dense so it sinks. Warmer water from the Equator replaces this surface water, creating ocean currents, such as the Gulf Stream. Cooled water flows back towards the equator, forming cold currents, such as the Humboldt current
The average climatic conditions of the earth change naturally over time, what does this create?
Both warmer and colder periods
What is the Quaternary period?
The Quaternary period covers the last 2.6 million years, when there have been: more than 60 cold periods of ice advances lasting about 100 000 years, warmer interglacial periods lasting about 15 000 years
Explain recent temperature changes
In the last 250 years the earths temperature has risen significantly compared to before. Average temperature in the middle of the last ice age was about 5 degrees below today’s average temperature
What are the milankovitch cycles?
These are long term changes to the earths orbit and position, changing how much solar radiation the earth receives - resulting in changes in climate
What is the eccentricity cycle?
The earths orbit changes approximately every 100 000 years. More circular orbit ➡️ cooler periods; more elliptical orbit ➡️ warmer periods
What is the Axial tilt cycle?
Roughly every 40 000 years the tilt of the a Earths axis varies. Greater angle of tilt ➡️ hotter summer and colder winter
What is the presses ion cycle?
The earth ‘wobbles’ on its axis roughly every 24000 years, changing the direction the axis if facing. This can affect the direction the axis is facing. This can affect the differences between seasons
What are other natural causes of climate change?
Solar radiation levels may vary, lower solar radiation makes glacial periods more likely; higher solar radiation leads to interglacial periods.
A large scale volcanic eruption can eject ash and dust into the atmosphere. This acts as a blanket over the earth, blocking out solar radiation, causing temperature changes to fall for a time
What is the evidence if climate change?
Historical sources, such as diaries
Ice cores trap volcanic ash, microbes, air bubbles. These reveal information on climate when ice is formed
Preserved pollen provides evidence on warm and cold growing conditions
What is a key contributer to global warming?
Rising greenhouse gases, which are released by human activities including industry, transport, energy production and farming
What is the enhanced greenhouse affect?
Human activity releases increasing levels of CO2 and other greenhouse gases into the atmosphere, increasing the greenhouse affect - more warming
How is heat trapped in the atmosphere?
Heat energy from the sun passes through the atmosphere and heats up the earth
Much of this heat energy is radiated back into space
Greenhouse gases in the atmosphere, such as CO2, trap some of the heat
How does industry impact climate change?
Rising demand for consumer goods increases production, burning more fossil fuels, which relate greenhouse gases
How does energy impact climate change?
New technologies and population growth increase demand for electricity produced growth increase demand for electricity produced from coal, oil and natural gas, which all produce greenhouse gases
How doe farming impact greenhouse gases?
Global population growth increases demand for food. Mechanisation burns more fuel, and the demand for meat for western-style diets increases methane levels
How does transport impact climate change?
Rising affluence increases car ownership and air travel p, releasing more greenhouse gases into the atmosphere
What a re the negative impacts of climate change in the environment?
Melting ice sheets and retreating glaciers add water to oceans, making sea levels rise. Arctic melting could cause the Gulf Stream to move further south leading to colder temperatures in Western Europe.
Rising sea levels will cause coastal flooding. Soils will become contaminated with salt causing plants to dies
What are the impacts of climate changes in people?
Changes in climates near the equator, such as Africa’s Sahel, could mean longer periods of less rainfall, so lower crop yields
Many low-lying islands like the Maldives face greater flood risk from rising sea levels. There will be more coastal flooding, loss of beaches and loss of coral reefs. Some islands will have to be evacuated
Explain past climate changes
The climate has been very different in the past. During the medieval warm period (950-1100) higher temperatures meant greater crop yields and a growing population. This was due to solar radiation
During the little ice age (1600-1685) temperatures were low enough to freeze the Thames, due to increases volcanic activity and decreased solar radiation.
What is the uk’s climate like today?
Today the uk has a temperate, wet climate. Extreme weather us rare, but the meeting of major masses makes frontal rainfall common
How does the uk’s location impact climate change?
The U.K. Is located between 50-60 degrees north. This and other factors have an impact on climate.
(Impact of the uk’s location) what is the maritime influence?
Most of the air reaching the uk contains losts of moisture as we are surrounded by sea leading to rainfall all year
(Impact of the uk’s location) what are prevailing winds?
The main or prevailing wind for the uk comes from the south west. This air travels long distances over the Atlantic Ocean bringing moisture leading to more rainfall
(Impact of the UKs location? What is the North Atlantic drift?q
This ocean current brings warm water north to the uk. In the winter this makes the uk climate milder than would be expected for its latitude
(Impact of the uk’s location) what is atmospheric circulation?
The U.K. In near the ‘boundary’ between the northern Ferrel and Polar circulation cells. This is where warmer air from the south and cooler air from the north meet, causing unsettled weather
(Impact of the uk’s location) what is altitude?
The higher an area is, the cooler and wetter it is, so areas in the uk vary
What are tropical cyclones also a know as?
Hurricanes and typhoons
What is the earths atmosphere constantly doing?
It’s in constant motion, transferring heat around the earth