Atmosphere Flashcards
1
Q
explain the surplus/deficit of energy at equator/poles
A
- high albedo at poles/low albedo at equator
- more atmsphr to pass thru at poles bc curve = more likely to be reflected by clouds
- no winter solistice so sun always at equator, 24hr darkness at poles
- sun more conc at equator bc insolation is greatest where rays vertically hit
- suns angle in sky decreases towards pole bc curve = heat energy spread over larger surface
- tilt of axis means sun higher in tropics thru year, focusing energy
2
Q
account for insolation reaching earths surface
A
- 46% absorbed by earth’s surface
- 17% reflected by clouds, 88% by gas particles
- 6% reflected by light surfaces (eg ice) on earth
- 23% absorbed by clouds, dust, water vapour etc
3
Q
describe atmospheric circulation cells & trade winds in the northern hemisphere
A
- hadley formed 0 - 30N & thermally direct
- trade winds move SW towards equator
- ferrel formed 30N - 60N & thermally indirect
- westerly winds complete cell and take air NE
- polar cell - air sinks at poles & movess from 60N to 90N
- polar easterlies take cold air south
- warm air from equator moved to higher latitudes
- cold air from poles move to lower latitudes
4
Q
explain energy redistribution
A
- winds deflected right bc coriolis effect
- winds move from high to low pressure
- air forced to rie at equator bc heat & convection currents
- air sinks at poles bc cool
- cells and winds transfer surplus energy to deficit
5
Q
oceanic circulation in N hemisphere: atlantic
A
- in n hemisphere, a CW loop/gyre is formed
- C effect deflects ocean current to right in n hemisphere
- land mass of americas deflects ocean currents towards the caribbean sea
- north equatorial current pushes surface water westwards, until obstruction via land masses pushes water north]
- SW winds push gulf stream NE towards europe as north atlantic drift
- currents like north atlantic drift carry warm waters to cooler latitudes
- cold waters move south from poles via Labrador Current
- this is a deepwater current bc water is denser at poles bc salinity and temp
6
Q
explain pattern of rainfall in W africa
A
- dependent on movement of ITCZ, meeting point of cT & mT air masses
- ITCZ = zpne of convergence btw warm, wet, low p, unstable mT & hot, dry, high p, stable cT
- warm, moist air forces to rise, colling & condensing into clouds = low pressure
- ITCZ migrates N to S throughout yr w/ passage of overhead sun, thermal equator
- as it moves N to position overhead the tropic of cancer, it brings associated band of rainfall w/it = rainy season Apr-Oct