2.2: The Global Energy Budget

Question 1

explain latitudinal radiation

Answer 1

area around equator receives most direct and concentrated sunlight (0) , near the poles is dispersed and pass through thicker atmosphere (more reflection)

Question 2

why is energy transferred?

Answer 2

latitudinal radiation causes a surplus at Tropics and deficit at poles: energy is transferred by winds and ocean currents. The horizontal transfer from low to high latitudes is an important secondary energy budget

Question 3

what is the effect of climate change?

Answer 3

Climate Change induced a positive feedback offsetting balance between insolation and reradiation

Question 4

describe annual temperature patterns

Answer 4

seasonal variation in insolation: equatorial areas receive similar amt through a year while higher latitudes have higher variation

Question 5

give examples of annual T patterns

Answer 5

January: highest in Africa, lowest in Siberia
July: highest in North Africa and near east, Mexico, S US, lowest in Southern Hemisphere
anomalies: effects of Andes on warm ocean currents

Question 6

describe pressure variation

Answer 6

Near Earth’s surface the pressure decreases with height at a rate of about 3.5 millibars for every 30 metres (100 feet). However, over cold air the decrease in pressure can be much steeper because its density is greater than warmer air.

Question 7

describe surface pressure belts

Answer 7

On the earth’s surface, there are seven pressure belts. They are the Equatorial Low (0) , the two Subtropical highs (30), the two Subpolar lows (60) , and the two Polar highs. Except for the Equatorial low, the others form matching pairs in the Northern and Southern Hemispheres.

Question 8

how do pressure belts variate?

Answer 8

They oscillate with the apparent movement of the sun. In the northern hemisphere in winter they move southwards and in the summer northwards.

Question 9

what is the equatorial low pressure belt (doldrums) ?

Answer 9

area of low pressure on ITCZ,Lies between 10°N and 10°S latitudes, extremely low pressure with calm conditions, absence of Surface winds

Question 10

What is the Inter-tropical Convergence zone?

Answer 10

northeast and the southeast trade winds converge. It encircles Earth near the thermal equator though its specific position varies seasonally (June: further N)

Question 11

how do winds work?

Answer 11

Winds blow from an area of low pressure, whereas rising air releases large amt of latent heat stimulating convection

Question 12

describe low-latitude winds (10-30)

Answer 12

mostly easterly, form reliable trade winds, weather is predictable and warm, dry mornings and showery afternoons due to evaporation from tropical areas

Question 13

describe higher-latitude winds (35-60)

Answer 13

westerly dominate, volatile, contain rapidly decaying depression bringing unsettled weather, strongest higher in atm, important for formation of tropical cyclones

Question 14

explain ocean currents

Answer 14

surface ocean currents caused by influence of prevailing winds, rotation of Earth causes water in gyres (circular patterns) to pile up at western edges of basins (clockwise in N, anti in S)

Question 15

describe ocean currents

Answer 15

currents that start in equatorial regions will be warmer and carry their T polewards (helped by westerly winds) e.g. The North Atlantic Drift. Others like the Labrador current may decrease temperature is wind blows over the sea onto land

Question 16

explain the ocean conveyor belt

Answer 16

deep-sea transfer of E by thermohaline circulation: Oceanic convection from colder polar regions where water is cold and salty sinks to bottom of connected Pacific, Atlantic, Indian ocean basins, while freshwater freezes to surface ice. salt

Question 17

describe the ocean conveyor belt

Answer 17

warm water arrives from Pacific and Indian ocean to North, where it loses heat due to surface winds and sinks, moving its way back towards southern pole as deep ocean current.