Topic 1- Atmosphere As Global Shstem Flashcards
(22 cards)
Where is most solar energy revieved and why
At the equator as suns rays are more conecntrated over a smaller surface area and strike at right angle.
Where is least solar energy recieved and why?
At poles as revieve at lower angle and take longer to heat up a larger surface area
Describe high pressure
Cold air is more dense which brings heat creating low rainfall and no clouds
Describe low pressure
Heated air is more dense so rises above cold air creating low pressure so lots of rainfall and clouds
Describe Low pressure belt
Warm air rises causing lots of rainfall and lots of clouds
Describe high pressure belt
Cold air sinks creating high pressure belt with no rainfall and no clouds
3 types of atmospheric circulation cells and what angle
Hadley-30
Ferrel-60
Polar-at top and bottom
Where do trade winds blow in southern hemisphere
South-east to north-west until they reach equator
Where do trade winds blow in northern hemisphere
North-east to south-west until they reach equator
Westerlies in southern hemisphere
Blow north-west to south-east
Westerlies in northern hemisphere
South-west to north-east until they reach pole
What happens at 30 degrees north and south
Hadley cell is the largest cell and extends from the equator to between 30° and 40° north and south
Trade winds blow from the tropical regions to the equator and travel in an easterly direction
Near the equator, the trade winds meet, and the hot air rises and forms thunderstorms (tropical rainstorms)
From the top of these storms, air flows towards higher latitudes, where it becomes cooler and sinks over subtropical regions
This brings dry, cloudless air, which is warmed by the Sun as it descends: the climate is warm and dry (hot deserts are usually found here)
What happens at 60 degrees north and south
Ferrel cell is the middle cell, and generally occurs from the edge of the Hadley cell to between 60° and 70° north and south of the equator
This is the most complicated cell as it moves in the opposite direction from the Hadley and Polar cells; similar to a cog in a machine
Air in this cell joins the sinking air of the Hadley cell and travels at low heights to mid-latitudes where it rises along the border with the cold air of the Polar cell
This occurs around the mid-latitudes and accounts for frequent unsettled weather (particularly in the UK)
What occurs at poles
Polar cell is the smallest and weakest of the atmospheric cells. It extends from the edge of the Ferrel cell to the poles at 90° north and south
Air in these cells is cold and sinks creating high pressure over the highest latitudes
The cold air flows out towards the lower latitudes at the surface, where it is slightly warmed and rises to return at altitude to the poles
Describe deep ocean currents
Ocean currents are large scales movements of water thst transfer heat energy from warmer to cooler regions.
Surface currents are caused by winds and help transfer heat away from equator
1)There are also deep ocean currents driven by differences in water density so when water freezes at poles,the surrounding water gets saltier which increases the density
2)as it gets denser it sinks causing warmer water to flow in at surface which creates a current
3) this warmer eater is cooled and sinks continouing the cycle which is called thermohaline circulation
Differences between tindouf-high pressure and singapore low-pressure
Tindouf-temperatures up to 36 degrees and low up to 14 degrees
-caused by high pressure systems as cool air is more dense
-warm air trapped at ground causing small amount of rain
-sit in high pressure belt
Singapore-high levels of rain and temperature (26 dgerees)
-on equot,low pressure system causing humid,wet weather
-heated air rises as less dense sinks causing clouds and rain
What happens at equator
At equator the suns warms the earth,which transfers heat to air sbove causing it to rise. This created a low pressure belt. As air rises,it cools and condenses forming clouds and rain
What occurs after 30 degrees north and south between 60 degrees north and south
What are trade winds and westerlies?
The cool air reaches the ground surface and moves as suface winds either back to equator or toeards poles:
-surface winds blowing towards equot are called trade winds
-trade winds blow from from SE the southern hemisphere and from NE in northern hemisphere. As the equot winds meet and heated by sun. This causes them to rise and form clouds
- surface winds blowing towards poles are called westerlies. They blow from NW in southern hemisphere and from SW in northern hemisphere
What occurs 60 degrees north and south of equator
Warmer surface winds meet cold air from poles. Warmer air is more dense so rise above the cold air creating low pressure and rain
What occurs at the poles
At the poles cool air sinks creating high pressure. High pressure drawn back to equator by surface winds
Coriolis effect
Each cell has prevailing winds associated with it
These winds are influenced by the Coriolis effect
The Coriolis effect is the appearance that global winds, and ocean currents curve as they move
The curve is due to the Earth’s rotation on its axis, and this forces the winds to actually blow diagonally
The Coriolis effect influences wind direction around the world in this way:
In the northern hemisphere it curves winds to the right
In the southern hemisphere it curves them left
Global wind belts
The trade winds: Blow from the subtropical high-pressure belts (30 degrees N and S) towards the Equator’s low-pressure zones and are deflected by the Coriolis force
The westerlies: Blow from the sub-tropical high-pressure belts to the mid-latitude low areas, but again, are deflected by the Coriolis force
The easterlies: Polar easterlies meet the westerlies at 60 degrees S
