1 - Atmosphere Flashcards
WHAT % INSOLATION REFLECTED BY CLOUDS?
17%
WHAT % INSOLATION REFLECTED BY ATMOSPHERIC GASES AND DUST?
8%
WHAT % INSOLATION REFLECTED BY EARTH’S SURFACE?
6%
WHAT % INSOLATION ABSORBED BY EARTH’S SURFACE?
46%
WHAT % INSOLATION ABSORBED BY ATMOSPHERE?
19%
HOW DOES LATITUDE AFFECT THE GLOBAL HEAT BUDGET?
Curvature of the earth’s surface means that solar energy is muchmore concentrated at the tropics giving higher insolation.
HOW DOES THE EARTH’S TILT AFFECT GLOBAL HEAT BUDGET?
This means the polar regionshave months over winterwhere they receive noinsolation at all whereas thetropics receive high insolationall year round.
HOW DOES THE ALBEDO AFFECT GLOBAL HEAT BUDGET?
The polar regions have an overall higher albedo, due to polar icecaps and snow. This increases reflection and reduces insolation.
HOW DOES THE ATMOSPHERE AFFECT GLOBAL HEAT BUDGET?
At the poles, energy travels throughthe atmosphere at an angle,increasing the chance of it beingabsorbed or reflected.
EXPLAIN THE HADLEY CELL
Warm air rises at the equator forming an area of low pressure.
As it enters the upper atmosphere it spreads out to 30 N and S.
It cools, sinks and returns as sub-tropical high pressure.
It then returns to the equator in the lower atmosphere as the easterly trade winds.
Hadley cell is thermally direct because it is driven by rising/falling air.
EXPLAIN THE POLAR CELL
Cold air sinks at the poles forming an area of high pressure.
Air moves along the Earth’s surface towards the equator as polar easterlies.
When it reaches 60 N or S it has warmed enough to rise forming temperate low pressure.
It then returns to the poles in the upper atmosphere
Polar cell is thermally direct because it is driven by rising/falling air.
EXPLAIN THE FERREL CELL
Located between the polar and Hadley cells.
Ferrel cell is thermally indirect because it is driven by friction.
Air sinks at 30 N and S and rises at 60 N and S.
DESCRIBE THE OCEAN CURRENT IN THE NORTH ATLANTIC
- North Atlantic Ocean currents form a clockwise gyres (loop) due to the Coriolis effect.
2. Warm currents travel from the equator towards the poles EG North Atlantic Drift
3. Cold currents return cool water from the poles EG Canary current.
WHAT IS THERMOHALINE CIRCULATION?
Thermohaline circulation is driven by differences in temperature and salinity.
This results in cold, saline water sinking eg Norwegian Current.
This travels through the deep ocean back to the equator, eventually displacing warm water pole wards eg Canary Current.
HOW ARE OCEAN CURRENTS AFFECTED BY PREVAILING WINDS?
Ocean currents are also influenced by prevailing winds with energy being transferred by friction to ocean currents.
HOW DO LAND MASSES AFFECT OCEAN CURRENTS?
Land masses like North America also divert ocean currents.
WHAT IS THE CORIOLIS EFFECT?
Coriolis effect deflects currents to the right in the Northern Hemisphere.
WHAT IS THE ITCZ?
Area of low pressure where the trade winds from Hadley cells north and south of the (thermal) equator meet.
DESCRIBE THE TROPICAL CONTINENTAL AIR MASS
Warm/hot
High humidity
High precipitation
Unstable air mass
Gulf of Guinea
DESCRIBE THE TROPICAL MARITIME AIR MASS
Hotter/ very hot
Low humidity
Low precipitation
Stable air mass
Sahara Desert
WHEN DOES THE ITCZ REACH ITS FARTHEST POINT SOUTH?
January
WHEN DOES THE ITCZ REACH ITS FARTHEST POINT NORTH?
July
WHAT IS CREATED TO THE SOUTH OF THE ITCZ?
A band of rainfall is created to the south where maritime air is pushed up, cooling and condensing to form clouds.
WHY DO SOME PLACES HAVE TWIN PEAKS OF RAINFALL AND OTHERS ONE?
The twin peaks are caused by the ITCZ moving northwards in the early part of the year and then southwards later in the year in line with the thermal equator.
WHY DOES IT GET DRIER AS YOU MOVE INLAND ACROSS WESTERN AFRICA?
Places by the coast are influenced by the wet tropical maritime air for most of the year whereas places inland are influenced by the tropical continental.
