Processes Of Change - Water

Question 1

What is Evapotranspiration

Answer 1

The total output of water from the drainage basin directly back into the atmosphere

Question 2

What is condensation

Answer 2

As the air cools it holds less water vapour. This means that if it’s cooled significantly it will become saturated. This is known as the dew point temp. Excess water in the air will then be converted to liquid water.

Question 3

What is precipitation

Answer 3

Atmospheric moisture is returned to the terrestrial system through precipitation.

Question 4

When does precipitation occur

Answer 4

When the temp of air is reduced to dew point but the volume remains constant e.g. Warm moist air passes over a cold surface
When volume of air increases but there’s no addition of heat e.g. masses of air of different temps and densities meet

Question 5

What is the global atmospheric circulation model summary

Answer 5

At the equator high temps=high evaporation rates. The warm moist air rises, cools and condenses to form towering banks of cloud and heavy rainfall in a low pressure zone called ITCZ

Question 6

In the mid latitudes what is cloud formation driven by?

Answer 6

The convergence of warm air from the Tropics and cold from the Arctic.

Question 7

What is runoff generation?

Answer 7

Atmospheric moisture that is transferred to the oceans as surface runoff or as groundwater flow.

Question 8

What is a key process in runoff generation and why?

Answer 8

Infiltration as it determines how much water runs off and how much enters the soil as soil water storage/ soil throughflow and then percolates to bedrock to become groundwater flow.

Question 9

How is surface runoff generated?

Answer 9

When rainfall intensity is greater than infiltration capacity or when rain falls on soils that are already saturated

Question 10

Where is the majority of ice locked up?

Answer 10

95% is locked up in the worlds two great ice sheets covering Antarctica and Greenland.

Question 11

How many major glacial periods in history?

Answer 11

5

Question 12

What happens to sea levels during glacial periods

Answer 12

Lower due to volume of ice stored on land

Question 13

What was the sea level of the last glacial period

Answer 13

120 m lower than present

Question 14

What are interglacials

Answer 14

When global ablation exceeds accumulation

Question 15

How is glacial ice formed

Answer 15

Snow falling on glaciers and ice sheets become compressed and enter long term storage forming layers of glacial ice

Question 16

How much of a rise in sea levels could total melting of all polar sheets cause

Answer 16

60m rise in sea level

Question 17

Rising sea levels as positive feedback

Answer 17

It’s positive feedback on the rate of removal of glacial ice since they can destabilise glaciers and ice shelves leading to accelerated rates of iceberg calving

Question 18

What does the rate of evaporation depend on

Answer 18

Amount of solar energy
Availability of water
Humidity of air- closer the air is the saturation point the slower the evap
Temp of air- warmer air holds more water vapour