Atmosphere Flashcards
Global head budget
all energy that leaves the sun doesnt reach the earth some is ABSORBED BY SHORT WAVE RADIATION
46%of it is absorbed by the surface of the earthen the form of short wave radiation
it is ABSORBED by the land and water
ATMOSPHERE
100% leaves and passes through the atmosphere where 23% is absorbed 4% by the CLOUDS and 19% by water vapour and dust particles
REFLECTED
100% leaves, 25% is reflected back
17% by clouds and 8% by the atmospheric gas and dust. this is called LONG WAVE RADIATION
ALBEDO EFFECT
6% of the 52% of the suns energy that reaches the earth is reflected
white= reflected dark= absorbed
which ice and snow vs dark trees in rainforest
reasons for a surplus at the equator
= curvature of the earth - equation= suns rays are more concentrated as it hits a smaller area
= due to the curvature of the earth the suns rays have to travel through a longer distance of atmosphere so are are more likely to be absorbed and reflected
= albedo effect- explains why the equator receives a surplus
=tilt of the earth on its axis-3/4 months of the year the poles tilt away from the earth and are in 24 hour darkness where as there is constant sunlight for 12 hours a day at the equator
Atmospheric circulation
HADLEY CELL
at the equator warm air rises and travels to the poles
the air cools and being to fall 30N and 30S of the equator
the cooled air then returns to the equator. this is the hadley cell
POLAR CELL
cold dense air sinks at the poles and moves toward the equator
at about 60N and and 60S the cold air being to warm. this warm air rises and returns to the pole carrying heat energy.
FERELL CELL
the feral cell is caused by friction between the other 2 cells
the hadley cell draws cool air down at 30N and 30S and the polar cell sends warm air up at 60N and 60S
ocean currents
CORIOLIS FORCE
- this deflects the currents RIGHT in the NORTHERN HEMISPHERE and LEFT in the SOUTHERN HEMISPHERE
- this is caused by the equator travelling faster than the poles. the north atlantic gyre originates in the gulf of mexico then travels up the east coast of north america
PREVAILING WINDS
- surface ocean currents directly respond to prevailing winds= follows the north atlantic drift along the N.Atlantic ocean where it splits 3 ways-
LAND MASSES
currents are blocked and deflected by continental land masses
the water hits the coast to the UK and is deflected back
TEMPERATURE DIFFERENCES
cold water is denser and therefore sinks and travels towards the equator whereas warm water is less dense so rises to the surface and flows away from the equator. the water then reaches the N. Equitorial and goes back to the gulf of mexico. the cycle then repeats itself.
ITCZ
- tropical continental air mass, from sahara desert, dry hot stable harmattan winds
- tropical maritime from the gulf of guinea, wet hot unstable storms
- where the 2 meet, brings rain
- sun directly overhead in july
- not as far overhead in july
- ICTZ moves with the sun
- Thermal equator
Variation of rainfall within West Africa
TRADE WINDS
the meeting point of the hadley cell in the atmosphere
At the equator, WARM AIR RISES and travels towards the poles. The air cools and begins to fall back towards the equator as trade winds.
when the earth moves, the meeting point of the hadley cell moves up and down
AIR MASSES
both of the air masses, although warm are different. the ICTZ is the meeting point of the hot and wet unstable tropical maritime(mT) from the Gulf of guinea (south east trade winds) and a hot dry stable tropical continental (cT) air mass from the SAHARA DESERT (north east trade winds) also known as Harmattan winds
EARTHS TILT
the earth tilts on its axis and gives the northern hemisphere its seasons. as it does this, it pulls the hottest point with it, and so the thermal equator moves. it reaches its most northern point on the 21st JUNE and reaches its most southern point on 21st DECEMBER
RAIN
where these winds meet, the air cools and condenses to form could, which therefore causes heavy rain
