Weather and Climate Flashcards
What are the factors that determine climate and weather?
Heat energy from the sun and how that energy is circulated around the earth through the movement of air and ocean currents.
What causes wind to circulate?
The energy difference of the surplus of heat at the equator and the deficit of heat energy at the poles.
What is the troposphere?
The lowest layer of the earth’s atmosphere.
Where does most of the earth’s weather form?
In the troposphere.
Where does global atmospheric circulation take place?
In the polar, ferrel and hadley cells.
Where are hadley cells located?
Closest to the equator.
Where are polar cells located?
Closest to the poles.
Where are ferrel cells located?
In-between hadley and polar cells.
What is the coriolis effect?
The spinning of the earth.
Which direction does the earth spin in?
From west to east.
Which way is the wind/air always deflected in the northern hemisphere?
To the right.
Which way is the wind/air always deflected in the southern hemisphere?
To the left.
Describe how air moves in hadley cells.
Latitudes 30N and 30S
Rising moist air at the equator creates low pressure. The moist air then cools, condenses and falls as rain. (This is where you find tropical rainforests).
At 30N and 30S the cooler air sinks back to Earth’s surface and creates high pressure areas, with cloudy skies. (Where hot deserts are found).
Describe how air moves in polar cells.
Latitudes 60N and 60S
Air sinks over the poles producing high pressure, then flows towards the low pressure in the mid-latitudes where it meets the warm air of the ferrel cell.
Describe how air moves in ferrel cells.
30N and 30S to latitudes 60N and 60S
Air moves from the high pressure at 30N/S to the low pressure at 60N/S. These winds collect moisture as they blow over oceans and at 60N/S they meet cold air from the poles.The warm air rises over the cold air as it’s less dense.
This causes unsettled weather in the UK.
What are jet streams?
Very fast ribbons of wind high up in the atmosphere that push cold and warm air masses around.
What do ocean currents do?
Transfer and redistribute heat across the Earth.
What is the Gulf stream?
The main ocean current in the Northen hemisphere.
What is the North Atlantic Drift?
A surface current that is carried by the South Westerlies.
What is climate change?
A large-scale, long-term shift in the planet’s weather patterns or average temperatures.
What are interglacial periods?
The times in the past when the temperature of the Earth has become warmer, melting the large ice sheets.
What are glacial periods (ice ages)?
The times in the past when the temperature of the Earth had dropped and ice sheets have covered the lands.
What period are we currently in?
The Quaternary period which began 2.6 million years ago.
What are Milankovitch cycles?
(Eccentricity, Axal tilt and Precession)
Changes in the earth’s orbit around the sun or changes in its axis, leading to changes in the earth’s climate and seasonal variations.
Describe volcanism (eruption theory).
Big volcanic eruptions produce ash and sulphur dioxide gas, which will stop some sunlight reaching the earth’s surface. The sunlight is reflected off the ash and gas, back into space. This cools the planet and lowers the average temperature.
Describe solar variation (solar output theory).
Sunspots are black areas on the surface of the sun. Sometimes the sun has lots of these spots. At other times they disappear. Temperatures are greatest when there are plenty of sunspots because it means other areas of the sun are working even harder.
Describe ice cores as evidence for climate change.
Compressed layers of ice containing gases - long term evidence.
Describe tree rings as evidence for climate change.
Wider in warm weather, thinner in cold weather - short/medium term evidence.
Describe pollen analysis as evidence for climate change.
Trapped in ice and rocks, not well preserved - short term evidence.
Describe historical records as evidence for climate change.
Reports, photos, paintings, diaries - short/medium term evidence.
What is anthropogenic climate change?
Climate change caused by humans.
What key human activities have led to climate change?
Food production, more energy production to meet the needs of industry and person use, production of more consumer goods in factories and the growth of transport.
Human activities burn fossil fuels, releasing greenhouse gases such as CO2, nitrous oxide and methane.
How do human activities lead to climate change?
Human activities burn fossil fuels, releasing greenhouse gases such as CO2, nitrous oxide and methane.
What are some key impacts of climate change?
Sea level rise, lower crop yields and glacial retreat.
What are air masses?
Bodies of air that share the same characteristics.
How are air masses moved around?
By prevailing winds.
What are the 5 UK air masses?
Polar maritime
Arctic maritime
Tropical maritime
Polar continental
Tropical continental
