Atmosphere, Climate, Weather Flashcards
Define weather
the hourly/ daily conditions in our surroundings – include wind, temperature and rainfall
Define climate
the average weather pattern in a particular terrestrial region over a long period of time (typically more than 30 years)
What are 3 variations in climate?
Seasonal cycles El ninos (yearly cycles) long term cycles (i.e: ice age)
Name 5 factors that affect climate
- Atmospheric composition
- Sunlight
- Ice sheets
- Oceans
- Altitude
- Latitude
- Distance from the sea
- Prevailing winds
- Aspect
- Cloud cover
- Human activities
How does the atmosphere affect climate?
Stops heat escaping
Allows sunlight through
What are the 4 main greenhouse gases
CO2
Nitrous Oxides
Methane
CFCs
How much of the atmosphere is composed of nitrogen
78%
How much of the atmosphere is composed of O2
21%
How much of the atmosphere is composed of Argon
0.9%
What are the 6 things that comprise the atmosphere?
Nitrogen O2 Argon Trace gases Water vapour Solid particles
How much of the atmosphere is water vapour?
0-4%
How much of the atmosphere is trace gases
0.037%
Why does pressure decrease with height?
Because gravity pulls atmospheric molecules closer together (denser, more concentrated)
So the higher an object, the less close particles are together
How does air pressure at the top and bottom of mount everest differ?
70% less pressure at top (particles more spaced out)
What are the 4 main layers of the atmosphere
Troposphere
Stratosphere
Mesophere
Thermosphere
What is a pause?
- Top boundary of each layer
where the temperature profile abruptly changes
Which sphere does weather happen
Troposphere
which sphere do we live in
troposphere
where is 80% of the atmospheric mass
troposphere
What mainly heats the troposhere?
Earth’s surface - not the sun
How do we know the earth heats the troposphere and not the sun?
Because heat decreases with height in troposphere
Where are jet streams found
troposphere
What is a jet stream
ribbon of air/ very strong winds (5-7 miles up, 100s miles across, 200 mph) – marks the highest point that weather can occur
What causes a jet stream
temperature differences between tropical air masses and polar air masses
What is the boundary between the troposphere and stratosphere called?
Tropopause
Which sphere contains the ozone layer?
Stratosphere
How does the ozone layer protect earth
Absorbs harmful UV rays
Keeps earth warm
what is the uppermost layer of the atmosphere
thermosphere
how high up is the stratopause?
~31 miles
How high up is the mesopause?
~ 52 miles up
how high up does the thermosphere go to?
~75 miles up (but no clear separation between thermosphere and space)
what is space also known as?
exosphere
what heats the thermosphere?
the sun
what happens to the temperature in thermosphere?
It INCREASES with height
- because it is directly heated by the sun
des the mesosphere increase or decrease with height?
decreases - still only heated by earth’s surface NOT direct from the sun
which layer has the highest temperature
thermosphere
- due to high energy radiation being absorbed by gases
what % of solar radiation passes through the Earth’s surface?
~74%
how much solar radiation do clouds absorb?
~19%
how much visible solar radiation is reflected back into space by atmosphere and clouds?
26%
what do O2 and nitrogen do to solar radiation
selectively absorb is and turn it into heat energy
where is most solar energy absorbed
Ozone layer (by O3 gas in stratosphere)
which areas on earth receive most solar input and why?
areas near equator because earth is spherical therefore they are closer to the sun
What are the 3 hemispheres of the earth?
Northern
Equator (tropical)
Southern
How much is the Earth’s axis tilted?
23.4 degrees
What drives wind patterns
sunlight
what happens to warm air at the equator
it rises
where does cool air move towards
the poles (because it is cooler)
What happens to cool air on the way to the poles?
It drops as rain
How are deserts created?
Cool, dry air absorbs heat and moisture from the land at around 30 degrees in the southern and northern hemisphere
Where do surface currents go?
Warm tropical currents move polewards along East Coasts - (this brings heat from the tropics forming temperate climates nearer the poles)
Cool water from high latitudes is forced towards equator along West Coasts
Where do deep currents occur
Through Earth’s rotation and temperature differences, forming upwellings
What is the gulf stream
A stream carrying warm water from tropical regions of Atlantic
How often do El ninos occur
every 3-7 years - unpredictable
What is an el nino
A climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean, dramatically affecting distribution and abundance of marine and terrestrial life
Name a positive effect El ninos can have on terrestrial plants
Abnormal amounts of precipitation in the Americas (increases populations of plants and therefore animals)
What is a negative effect El ninos can have on marine life
Disrupt phytoplankton upwellings - causes food chain to collapse
Fish stocks reduce
How does solar energy drive hydrological cycles
Solar energy causes condensation and precipitation - affects evapouration and transpiration
What is the Collision-Coalescence Process
merging of water droplets to form rain
How do water droplets form rain?
Collision-Coalescence Process
What is the Bergeron Process
Formation of ice crystals that attract more water vapour
What is the formation of ice crystals known as?
Bergeron Process
What are the 3 types of rainfall
Relief
Convectional
Frontal
What are the 5 types of clouds
Stratus / strato Cumulus/ cumulo Cirrus/ cirro Alto Nimbus/ Nimbo
What are rain shadows
When mountains act as a physical barrier forcing warm air to rise - as air temp cools, rain falls on windward side
What is an air mass
a large body of air moving in a particular direction, with the same temperature, pressure and humidity throughout
What brings warm, dry weather to the UK
Tropical continental air mass
What brings cold, heavy snow showers to the UK
Polar continental air mass
What brings a mixture of sunshine, rain, hail and sleet (mixed weather) to UK
Polar maritime air mass
What does tropical continental air mass bring to the UK
Warm dry weather
What does polar maritime air mass bring to UK
Mixed weather
What does polar continental air mass bring to UK
Cold, heavy snow showers