Chapter 7 - The atmosphere and human activites Flashcards
Where is the troposphere?
The troposphere is the layer closest to the surface of the earth, temperature decreases with altitude, the strength of earths gravitational pull decreases with altitude, air pressure decreases with altitude and wind speeds increase with altitude.
Height ranges from 8-17 kilometers from the surface
Where is the stratosphere?
The stratosphere extends to nearly 50 kilometres above the earth’s surface. Pressure falls with altitude whereas temperature inversion occurs, and temperatures increase steadily with altitude. This layer acts as shield against meteorites which burn out when they enter earths gravitational field. It is where ‘good ozone’ is found.
Where is the mesosphere?
The mesosphere is around 50-80 kilometres in height. Pressure continues to decrease, and temperatures rapidly fall because there is no water vapour, dust or ozone to absorb the incoming short-wave radiation. Winds can reach speeds up to 3000 kilometres per hour.
Where is the thermosphere?
The thermosphere is around 80-1000 kilometres in height. Temperatures rise rapidly to as high as 1500 degrees celsius because of the absorption of ultraviolet radiation by atomic oxygen.
What is temperature inversion?
Temperature inversion is a weather condition when the air temperature increases with altitude rather than decreasing. This is caused by the concentration of ozone, which absorbs the incoming ultraviolet radiation coming from the sun.
What gases make up the composition of earths atmosphere?
nitrogen, oxygen, water vapour, carbon dioxide, ozone and argon
What percent is nitrogen of earths atmosphere?
Nitrogen is 78.09% of earth’s atmosphere and is needed for the growth of plants.
What percentage is oxygen of earths atmosphere?
Oxygen is 20.95% of earth’s atmosphere and is produced by photosynthesis to be used in respiration.
What percentage is water vapour of earths atmosphere?
Water vapour is 0.2-4% of earth’s atmosphere and is the source for all types of precipitation, provides most of the natural greenhouse gases and is vital to existence of life.
What percentage is carbon dioxide of earths atmosphere?
Carbon dioxide is 0.03% of earth’s atmosphere and is used by plants in photosynthesis to produce oxygen and glucose (to support other life) and is a greenhouse gas.
What percentage is ozone of earths atmosphere?
Ozone (O3) is 0.00006% of earth’s atmosphere and absorbs ultraviolet radiation.
What percentage is argon of earths atmosphere?
Argon is 0.93% of earth’s atmosphere and can create an inert atmosphere that protects materials from reacting with oxygen or other gases.
What is the ozone layer?
The ozone layer sits in the stratosphere and shields living organisms and plants from harmful ultraviolent radiation.
What is the natural greenhouse effect?
The natural greenhouse effect is the process that helps keep the earth’s surface and atmosphere warm. 1. Radiation is emitted by the sun. 2. Some radiation passes through the layer of greenhouse gases. 3. Earth absorbs radiation and heats up. 4. Earth emits radiation. 5. Greenhouse gases absorb outgoing radiation and the atmosphere heats up.
What is smog?
Smog (smoke and fog) occurs where the burning of fossil fuels in industry, homes and vehicles provides additional particles that act as condensation nuclei for fog to form around.
What is photochemical smog?
Photochemical smog involves chemical reactions included by sunlight on certain pollutants that converts them into harmful substances such as ground-level or tropospheric ozone (bad ozone).
What are volatile organic compounds?
Volatile organic compounds (VOCs) are chemicals that easily enter the atmosphere as gases, mainly from evaporation. They cause smog. Volatile organic compounds are produced from industrial processes and vehicle emissions.
What physical conditions can increase the concentration of smog?
Certain physical conditions can create temperature inversion that then traps and increases the concentration of smog. High air pressure which causes the upper air to sink, calm conditions resulting from high pressure (winds will disperse smog) and valleys surrounded by steep-sided hills, which trap the smog.
What is acid rain?
Acid rain is precipitation with a pH value less that 6. The acidity results from the burning of fossil fuels in factories which release sulphur dioxide and nitrogen oxides. If these gases mix with water vapour, they form sulphuric and nitric acids which can be moved by winds and fall to earth as acid rain. Vehicle emissions can add further nitrogen oxides.
How does ozone form?
The ozone layer protects the earth from the sun’s harmful radiation. Ozone is formed when oxygen (o2) filters from the top of the stratosphere and reacts under the influence of ultraviolet radiation to form ozone (o3). It is continually formed, destroyed and replaced naturally, creating a dynamic balance which is then disturbed by human activities.
How does ozone depletion occur?
When chlorofluorocarbons (CFCs) reach the stratosphere, the ultraviolet radiation breaks them down which releases chlorine. Chlorine reacts with oxygen in a destructive process which breaks down the ozone molecules to form chlorine monoxide and oxygen, therefore depleting the layer and forming a hole. This is known as ozone depletion. This hole allows harmful radiation to enter earth’s atmosphere.
What is the enhanced greenhouse effect?
The enhanced greenhouse effect is created by the addition of greenhouse gases to the atmosphere through human activities. This results in more heat being retained in the atmosphere and increases the earth’s temperature. This leads to global warming and climate change.
Where do greenhouse gases come from?
Greenhouse gases come from human activities that increase their abundance.
Where does carbon dioxide come from?
Carbon dioxide comes from the burning of fossil fuels and deforestation.
Where does methane come from?
Methane comes from cattle and rice production, coal mine ventilation, deforestation and decomposition of waste (landfill sites).
Where do CFCs come from?
CFCs come from aerosol sprays, fire extinguishers, refrigeration and air conditioning.
Where do nitrogen oxides come from?
Nitrogen oxides come from vehicle exhausts and chemical fertilizers.
Where does tropospheric ozone (bad ozone) come from?
Tropospheric ozone (bad ozone) comes from chemical reactions involving nitrogen dioxides and unburnt fuel vapours.
What pollutants cause smog?
VOCs and nitrogen oxides
What pollutants cause acid rain?
Sulphur oxides and nitrogen oxides
What pollutants cause ozone depletion?
CFCs
What pollutants cause climate change?
Various greenhouse gases
How does smog impact people?
Irritation of eyes and throat, increasing respiratory diseases such as asthma.
Fine particles carried into the lungs leading to lung cancer, strokes and heart attacks. Breathing difficulties.
How does acid rain impact people?
Acidification of groundwater makes water undrinkable and can cause diarrhoea and upset stomachs.
Aluminium leached from the soil into the groundwater has been linked with pre-senile dementia.
Limestone buildings are chemically weathered.
Crop yields decline.
How does ozone depletion impact people?
Higher levels of ultraviolet radiation causes sun burn, skin cancers and retina damage.
Immune system can be suppressed.
Complete the diagram B showing temperature inversion (3)
from top to bottom:
cold air
warm air
cool air
Match the following statements to the numbered processes shown in the diagram (3)
5, 3, 2, 4, 1
Use the diagram to describe how the features shown may lead to the formation of smog (3)
houses / factories / vehicles, emit pollutants / gases;
winter / low sun provides less warmth to Earth’s surface;
(temperature) inversion / warm air layer, holds cold air near ground;
cold air is denser and unable to rise;
pollutants trapped (by the inversion);
mountains and valleys increase strength of inversion;
