weather and climate Flashcards
What is the amount of heat energy that reaches the equator and poles described as?
equator-surplus
poles-deficit
What happens with solar radiation at the equator?
warmed air rises to 15km, causing low pressure. Air current dives, cools and moves north and south to form Hadley cells. The cooled air sinks to 30 degrees north and south of the equator, leading to high pressure.
What happens with cool air when it moves back towards the equator as trade winds?
The rest travels to Poles forming the lower part of Ferrel cells.
What happens at 60 degrees north and south?
warmer air of Ferrel cells meets colder polar air. Warmer air rises to form Polar cells. Air travels to Poles, where it cools and sinks, forming areas of high pressure.
What is ocean circulation?
Ocean currents also transfer heat energy from areas of surplus (Equator) to ares of deficit (Poles). Wind-driven surface currents and deeper ocean currents move warm water toward Poles and colder water towards Equator.
What happens in the Arctic and Antarctic?
Water gets very cold and dense, so it sinks. Warmer water from Equator replaces this surface water, creating ocean currents, e.g. the Gulf Stream. Cooled water flows back towards the Equator, forming cold currents, e.g. Humboldt Current.
What is the Quaternary period?
Covers last 2.6 million years. More than 60 cold periods with ice advances, lasting about 100,000 years, warmer interglacial periods lasting about 15,000 years.
What have been recent temperature changes?
In last 250 years Earth’s temperature has risen significantly compared to before. Average temperatures in middle of last Ice age was about 5 degrees Celsius below today’s average temperature.
What is the Eccentricity cycle:
Earth’s orbit changes approximately every 100,000 years. More circular orbit-coller periods; more elliptical orbit-warmer periods.
What is axial tilt cycle?
Roughly every 40,000 years tilt of Earth’s axis varies. Greater angle of tilt-hotter summer and colder winter.
What is the precession cycle?
Earth ‘wobbles’ on its axis roughly every 24,000 years, changing direction axis is facing. Can effect differences between seasons.
What are other natural causes of climate change?
Solar radiation levels vary. Lower solar radiation makes glacial periods more likely; higher solar radiation leads to interglacial periods. Large scale volcanic eruption can eject ash and dust into atmosphere. Acts as blanket over Earth, blocking out solar radiation causing temperatures to fall for a time.
What is evidence for climate change?
Historical sources: such as diaries.
Ice cores: trap volcanic ash, microbes, air bubbles. These reveal information on climate when ice formed.
Preserved pollen: provides evidence on warm and cold growing conditions.
What are greenhouse gases relased by?
human activities including industry, tansport, energy production and farming.
What is the enhanced greenhoue effect?
Human activity releases increasing levels of co2 and other greenshouse gases into atmosphere, increasing greenhouse effect-more warming.
What is the proccess of solar radiation entering and leaving Earth?
Heat energy from sun passes through atmosphere and heats up Earth. Much ofheat energy is radiated back into space. Greenhouse gases in atmosphere, e.g. co2, trap some of heat.
How does industry help the human cause of climate change?
Rising demand for consumer good increases production, burning more fossil fuels, which release greenhouse gases.
How does energy help the human cause of climate change?
New technologies and population increase demand for electricity production from coal, oil and natural gas, which all produce greenhousse gases,
How does farming help the human cause of climate change?
Global population growth increases demand for food. Mechanisation burns more fuel, and demand for meat for western-style diets increae methane levels.
How does transport help the human cause of climate change?
Rising affluence increases car ownership and air travel, releasing more greenhouse gases into atmosphere.
What are negitive impacts of climate change on enviroment?
Melting ice sheets and retreating glaciers add water to oceans, making sea levels rise. Arctic melting could cause Gulf stream to move south leading to colder temperatures in Western Europe. Rising sea levels will cause coastal flooding. Soils will become contaminated with salt, causing plants to die. In Maldives sea levels rise between 20cm and 1m before 2100. High sea levels = flooding 2007 more than 1,600 evacuated-unemployment-loss of tourism-airport near coast-cost of evacuating increasing-groundwater supplies contaminated with seawater flowing onto islands-contaminates soil-higher temperatures=death of coral reef-mass emigration from country-rainwater harvesting-raise level of infrastructure.
What are negitive impacts of climate change on people?
Changes in climates near Equator, e.g. African’s Sahel, could mean longer periods of less rainfall, so lower crop yields. Many low-lying islands e.g. Maldives face greater flood risk from rising sea levels. There will be more costal reefs. Some islands will have to be evacuated.
What was the Medievel Warm Period?
(950-1100) higher temperatures meant greater crop yields and growing population. Due to incease in solar radiation.
What was the Little Ice Age?
(1600-1685) temperatures were enough to freeze the Thames, due to increased volcanic activity and decreased solar radiation.
What is the UK’s climate today?
Temperate, wet climate. Extreme weather is rare, but meeting major air masses makes frontal rainfall common.
Where the UK located from the equator?
between 50 degrees North and 60 degrees North.
How does maritime influence impact on the UK’s climate?
Most of air reaching UK contains lots of moisture as we are surrounded by sea, leading to rainfall all year.
How does prevailing winds impact on the UK’s climate?
Main or prevailing wind for UK comes from South West. Air travels long distances over Athlantic Ocean, bringing moisture, leading to more rainfall.
How does the Norht Athlantic drift influence the UK’s climate?
Ocean current brings warm water north to UK. In winter makes UK climate milder than would be expected for its latitude.
How does Atmospheric circulation impact on the UK’s climate?
UK is near ‘boundary’ between northern Ferrel and Polar circulation cells. Where warmer air from south and cooler air from north meet, causing unsettled weather.
Hiow does altitude impact on the UK’s climate?
Higher an area is, cooler and wetter it is, so areas in UK vary.
How does climate vary in the UK?
North-west: mild winters and cool summers.
south-west: mild winters and warm summers.
Norht-east: cold winters and cool summers.
South-east: cold winters and warm summers
How do tropical cyclones form?
Need source of warm ocean temperatures (27 plus). Rising warm air causes thunderstorms which group together, making a strong flow. An area of very low pressure forms at and up, forming a tropical cyclone.
