weather and climate Flashcards
weather
the day to day conditions of the atmosphere
climate
the average weather conditions of an area occurring over many years
global atmosphere
the worldwide movement of air which transports heat from tropical to polar latitudes
hemisphere
a half of the earth
troposphere
lowest layer of the atmosphere
trade wind
wind that blows from tropics towards the equator
northern hemisphere
the half of the earth above the equator
southern hemisphere
the half of the earth below the equator
what does warm air do ?
rises and condenses into clouds and creates low pressure
what does cold air do ?
sinks and creates high pressure
difference in temperature causes …
differences in air pressure
how is heat energy transferred away from equator?
wind blows from areas of high pressure to areas of low pressure
what weather does high pressure cause
dry and sunny
what weather does low pressure cause
cloudy
how does the earth heat
sun releases light energy
equator
hottest line of latitude
where sun rays are most concentrated
north and south pole
coldest lines of latitude
where sun rays are least concentrated as there is a low angle of sunlight
what are the 3 cells
hadley
polar
ferrel
ocean currents
large scale movements of water that transfer heat energy from warmer to cooler regions
surface currents
currents causes by winds to transfer heat away from equator
ITCZ stands for …
inter-tropical coverage zone
why does position of ITCZ change
to create seasons
what creates wind
air moves from areas of thigh pressure to low pressure
where are subtropical jets
i between Hadley and ferrel cell
where are polar jets
in between ferrel and polar cell
where is ITCZ
in between 2 hadley cells
jet stream
fast moving air current that travels west to east in upper atmosphere
what causes unsettled weather
warm moist air of ferrel cell meets dry air of polar cell
anti-clockwise
ocean currents in southern hemisphere
clockwise
ocean currents in northern hemisphere
climate change
large scale,long term shift in the planets weather patterns or average temp
evidence for natural climate change (4)
ice cores
tree rings
historical sources
pollen records
ice cores
ice sheets(layers of ice)formed each year
scientists drill to get long cores of ice
bubbles in layers show amount of co2
more co2 = warmer period
tree rings
tree grows new ring each year
rings are thicker in warm,wet conditions
scientists count rings to find age of tree
pollen records
pollen gets preserved in sediment
in lakes or peat bogs
scientists date pollen which shows species living at that time
species show conditions of the time
historical sources
daily weather reports since 1973
diaries,paintings,books
paintings of fairs and markets on frozen rivers
natural causes of climate change (3)
Milankovitch cycles
solar variation and sunspots
volcanic activity
milankovitch cycles
precession
eccentricity
axial tilt
precession
earth wobbling on its axis
eccentricity
the orbit of the earth changes over time
axial tilt
earth is tilted to create seasons
solar variation and sunspots
amount of radiation the sun provides varies over time
volcanism
larger volacnic eruptions eject a lot of ash and dust into atmosphere
can partially block out solar radiation
reduces temp
human causes of climate change
industry
farming
energy
transport
industry
industrial waste ends up in landfill and decays releasing methane
cement production releases co2
population growth =more
farming
rice paddies and cows release methane
clearing land of trees for agriculture (trees absorb co2)
population growth = bigger demand
transport
most vehicles run on fossil fuels which release greenhouse gases when burnt
car ownership rapidly increasing in emerging countries
energy
co2 released when fossil fuels like coal and oil are burned
3 greenhouse gases
water vapour
carbon dioxide
methane
green house gas
gas that traps heat in the atmosphere
green house effect
important for humans beacuse it traps suns heat in our atmosphere to keep us warm
enhanced greenhouse effect
human activity increases greenhouse gases released into atmosphere
traps too much heat causing global warming
global warming
warming of earth responsible for climate change
effects of climate change
retreating glaciers
rising sea levels
changing patters of crop yeild
rising sea levels
rising temps melt ice + thermal expansion rises sea levels
increases rate of coastal erosion+floods
retreating glaciers
glacier=slow moving rivers of ice
rising temperatures melt them
used in places in nepal for watering crops with underground sources
changing patterns of crop yields
warmer temps=more frequent droughts
lower crop yields=food shortages/malnutrition + starvation
