Changes to the water cycle over time - natural variation

Question 1

How do storm events change water cycle processes and stores on a local scale? (short term effects)

Answer 1

1. High surface runoff
2. High surface water storage
3. High river channel flow

Question 2

Describe the seasonal changes to the water cycle in the Amazon Rainforest. (short term)

Answer 2

• Amazon Rainforest was in drought from 2023-2024 since during the dry season, precipitation levels are lower than evapotranspiration.

Question 3

Describe long term change in the cryosphere.

Answer 3

1. On average it takes 20,000 years to warm up to an interglacial period
2. On average it takes 100,000 years to cool down to a glacial period

Question 4

How many glacial cycles have there been since the beginning of the world?

Answer 4

8 glacial cycles

Question 5

Describe the seasonal changes to the water cycle in California. (short term)

Answer 5

• California drought was severe in 2015
• California has been in drought for 20 years until 2023/2024 but heavy snowfall (snowpack 54%) over winter recharged stores through the dry summer.

Question 6

Describe long term change in orbital theory (eccentricity)

Answer 6

100,000 year cycle - the earth moves from a circular orbit to an elliptical orbit.

Question 7

Describe long term change in orbital theory (obiquity)

Answer 7

41,000 year cycle - As the tilt decreases, seasons are milder, this causes slightly warmer winters and cooler summers.

Question 8

Describe long term change in orbital theory (precession)

Answer 8

20,000 year cycle - The earth wobbles slightly on its rotational axis, this causes seasonal contrasts to be more extreme in one hemisphere and milder in the other.

Question 9

Give 2 examples of famous storms which impacted the water cycle.

Answer 9

1. The Beast from the East
2. Storm Desmond in the River Eden

Question 10

What is ENSO circulation?

Question 11

How does normal ENSO circulation affect the water cycle?

Question 12

How does La Nina affect the water cycle?

Answer 12

The La Nina effect occurs every 2-7 years and causes cooler temperatures in a predictable way

Question 13

How does El Nino affect the water cycle?

Answer 13

The El Nino effect occurs every 2-7 years and causes warm temperatures in a predictable way.

Question 14

How do volcanic eruptions affect the water cycle?

Answer 14

• Ash provides a condensation nuclei, increasing cloud cover
• Tonnes of water vapour being sent into the stratosphere, increases the cincentration of greenhouse gases to increase the natural greenhouse effect

Question 15

How much water vapour was released by the Hunga Tonga eruption?

Answer 15

150 million tonnes of water vapour sent into the stratosphere, enhancing the natural greenhouse effect.

Question 16

How does anthropogenic climate change impact the water cycle?

Answer 16

• Reduced albedo effect
• Negative feedback - increased evapotranspiration, increases cloud cover, more sun rays reflected
• Increased drought
• El Nino’s occur more frequently