3.B.2 - Weather and Climate Flashcards
What is the atmosphere?
The layer of gases surrounding the Earth.
What keeps the atmosphere in place?
Gravity.
Describe the physical appearance of gases in the atmosphere.
Odourless and transparent.
By international convention, what is the furthest extent of the atmosphere?
1000km above sea level.
What is weather?
The condition of the atmosphere at a local level.
What is climate?
The average weather conditions of a location based on the weather experienced over the past 30 years.
Within what depth of the atmosphere is most of our weather and climate concentrated?
16km above sea level at the Equator and 8km above sea level at the poles.
What is paleoclimatology?
The study of changes in climate throughout history.
According to scientists, how old is the Earth?
4.5 billion years old
True or False?: When the Earth first formed 4.5 billion years ago, there was an atmosphere.
False - There was no atmosphere.
What was the surface of the Earth like when it first formed 4.5 billion years ago?
Molten
What kick-started the formation of the atmosphere?
Volcanoes releasing gases from the Earth’s interior.
What happened when the planet cooled during the formation of the atmosphere?
Water vapour that had been emitted by volcanoes condensed to form the oceans.
What happened to the carbon dioxide in the atmosphere once water vapour condensed to create the oceans during its formation?
It dissolved into the oceans and began to make sedimentary rocks.
When did life appear on Earth?
2 billion years ago.
How did the appearance of life in the oceans affect the formation of the atmosphere?
Organisms began to photosynthesis, releasing oxygen into the atmosphere.
What happened once there was sufficient oxygen in the atmosphere that had been photosynthesised by early life?
It formed the ozone layer, blocking out harmful UV radiation.
How did the ozone layer affect the formation of the atmosphere?
Life was able to move to shallower depths of the ocean without being harmed by UV radiation, and photosynthesise more.
True or False: The gases of the atmosphere are chemically combined.
False - the atmosphere is a mixture. None of the chemicals that compose it are chemically combined.
What are the 5 categories of atmospheric components?
- Major components
- Variable components
- Inert gases
- Pollutants
- Non-gaseous substances
What are the 2 variable components of the atmosphere?
- Nitrogen
2. Oxygen
What percentage of the atmosphere is nitrogen?
78.1%
What percentage of the atmosphere is oxygen?
20.9%
True or False? : The major components of the atmosphere are passive gases which have little effect on our weather and climate.
True - Our weather and climate is mainly effected by smaller, more variable components.
What are the 3 variable components of the atmosphere?
- Carbon dioxide
- Water vapour
- Ozone
What percentage of the atmosphere is carbon dioxide?
0.04%
What percentage of the atmosphere is water vapour?
5%
What percentage of the atmosphere is ozone?
Trace
What is responsible for the 0.01% rise in atmospheric carbon dioxide concentrations in recent years?
Human activities such as the combustion of fossil fuels and deforestation.
By scientific consensus, what is the affect of increasing carbon dioxide concentrations in the atmosphere?
Anthropogenic climate change
How does carbon dioxide cause climate change?
Ut contributes to the greenhouse effect by absorbing terrestrial long-wave radiation emitted by the Earth.
Why is the percentage of water vapour in the atmosphere variable?
Because it varies from place to place depending on temperature.
Which gas provides the majority of the Earth’s greenhouse effect?
Water vapour
What does ozone do in the atmosphere?
Absorbs/filters incoming ultraviolet radiation.
What is the name of the chemical which depletes ozone in the atmosphere?
CFCs - chlorofluorocarbons.
What are the 4 inert gases in the atmosphere (in order of abundance)?
- Argon
- Neon
- Helium
- Krypton
What is the 3rd largest component of the atmosphere?
Argon
What percentage of the atmosphere is argon?
0.9%
What percentage of the atmosphere is neon, helium and krypton?
Trace
What are the 3 pollutants which make up the atmosphere?
- Sulphur dioxide
- Nitrogen oxides
- Methane
What are the 3 types of nitrogen oxides in the atmosphere?
- Nitrogen monoxide
- Nitrogen dioxide
- Nitrous oxide
What role do pollutants play in the atmosphere?
They assist with the greenhouse effect by absorbing outgoing terrestrial long-wave radiation.
What is the name given to the non-gaseous component of the atmosphere?
Particulates
Give 4 examples of particulates.
- Dust
- Volcanic ash
- Rain
- Snow
What percentage of the atmosphere is particulates?
Trace
True or False? : Particulate concentration does not vary spatially.
False - Particulate concentration does vary spatially.
What happens to atmospheric pressure as you increase altitude?
It decreases.
True or False? : Changes in atmospheric pressure with altitude depend on the layer of the atmosphere you are in.
False - Atmospheric pressure always decreases with altitude, regardless of your layer.
How can the atmosphere be divided up into 4 different layers?
By changes in temperature with altitude.
What is the term given to the act of dividing up the atmosphere into layers depending on changes in temperature with altitude?
Atmospheric stratification.
What are the 4 stratified layers of the atmosphere, from lowest to highest?
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
What are the 4 isothermal boundaries between the layers of the atmosphere (from lowest to highest)?
- Tropopause
- Stratopause
- Mesopause
- Thermopause
What happens in the isothermal boundary layers between the layers of the atmosphere?
Temperature remains constant with changes in altitude.
What is the troposphere?
The layer of the atmosphere closest to the Earth.
What is the planetary boundary layer?
The lowest part of the atmosphere where friction between the air and the Earth exists.
In which layer of the atmosphere does nearly all weather and climate occur?
The troposphere.
True or False? : 50% of the mass of the atmosphere is found in the troposphere.
False - 75% of the mass of the atmosphere is found in the troposphere.
What percentage of water vapour and clouds can be found in the troposhere?
99%
What is the height of the tropopause at the Equator?
20km above sea level
What happens to temperature as you increase your altitude in the troposphere?
It decreases with altitude.
What lapse rate does temperature decrease by with altitude in the troposphere?
The ELR - environmental lapse rate, which is a decrease of 6.49 degrees C for every 1km rise in altitude.
Why does temperature decrease with altitude in the troposphere?
Because the air is warmed by the adjacent ground as it emits outgoing terrestrial long-wave radiation.
What happens to temperature as you increase your altitude at the poles?
There is a temperature inversion and temperature actually increases with altitude at the poles!
Why is the troposphere sometimes called the convective region of the atmosphere?
As it contains all of the convective activity of the atmosphere.
What is the name of the boundary between the troposphere and the stratosphere?
The tropopause.
What is an isothermal layer?
A layer of the atmosphere where there is no change in temperature with changes in altitude.
True or False? : The height of the tropopause is constant with spatial and temporal variation.
False - There are latitudinal and seasonal variations in its height.
What is the role of the tropopause?
It acts as a lid for convection in the atmosphere, and as an upper ceiling for weather.
What is the stratosphere?
The 2nd layer of the atmosphere.
What is the height of the stratopause at the Equator.
50km above sea level.
What percentage of atmospheric mass is found in the stratosphere?
20%
What happens to temperature as you increase your altitude in the stratosphere?
It also increases.
Why is there an increase in temperature with altitude in the stratosphere?
The ozone layer is located here, where the UV rays of the Sun are absorbed by ozone.
Why is the stratosphere stable?
Layers of warmer air sit above layers of cooler air.
True or False? : The stratosphere is very dry.
True - There is no clouds or weather.
In which layer of the atmosphere do planes fly, and why?
The stratosphere - because it is dry so there are no clouds.
How does the stratosphere protect the Earth from meteorites?
It is the layer in which they burn themselves out.
What is the name of the isothermal layer between the stratosphere and the mesosphere?
The stratopause.
What is the former name of the stratopause?
The mesopeak.
What is the mesosphere?
The 3rd layer of the atmosphere.
What happens to temperature as you increase altitude in the mesosphere?
Temperature decreases.
Why does temperature decrease with altitude in the mesosphere?
Because there is no ozone to absorb incoming radiation.
Which 3 layers compose the middle atmosphere?
The stratosphere, the mesosphere and the thermosphere.
What is the name of the isothermal layer between the mesosphere and the thermosphere?
The mesopause.
What is the height of the mesopause at the Equator?
100km above sea level.
What is temperature like at the mesopause?
The coldest naturally occurring place on Earth.
What is the thermosphere?
The top layer of the atmosphere.
What happens to temperature with altitude in the thermosphere as you increase your altitude?
It increases with altitude.
Why does temperature increase with altitude in the thermosphere?
Unfiltered radiation from the Sun causes molecules of oxygen to break apart into ions, releasing energy.
Why would a person not feel warm in the thermosphere?
The layer is so close to the vacuum of space that few gas atoms would come into contact with them.