3.b. The pathways and processes which control the cycling of water and carbon vary over time.

Question 1

Why is it important for changes to be monitored?

(Monitoring changes to the global water and carbon cycles)

Answer 1

To assess the potentially damaging impact of climate change, as this is essential.

Question 2

State 3 ways in which accurate monitoring of changes can be done.

(Monitoring changes to the global water and carbon cycles)

Answer 2

Global air temperatures.

Sea surface temperatures (SST).

Sea ice thickness.

Rates of deforestation.

Question 3

Why does monitoring rely heavily on satellite technology and remote sensing?

(Monitoring changes to the global water and carbon cycles)

Answer 3

As ground-based measurements of environmental change at a global scale are impractical.

Question 4

How can monitoring allow for observations on various time scales?

(Monitoring changes to the global water and carbon cycles)

Answer 4

Continuous monitoring by satellite on a day-to-day, month-to-month or year-to-year basis.

Question 5

How can GIS techniques be used in relation to satellite data?

(Monitoring changes to the global water and carbon cycles)

Answer 5

Data can be mapped and analysed to show areas of anomalies and trends, and regions of greatest change.

Question 6

What is GIS?

(Monitoring changes to the global water and carbon cycles)

Answer 6

Geographical Information Systems.

Question 7

What is the NOAA?

(Remote sensing: satellite technology to monitor changes to the water and carbon cycles)

Answer 7

National Oceanic and Atmospheric Administration.

Question 8

How is artic sea ice monitored?

(Remote sensing: satellite technology to monitor changes to the water and carbon cycles)

Answer 8

By NASA’s Earth Observing System, they have done this since 1978.

Measures microwave energy radiated from Earth’s surface.

Comparison of time series images are used to show changes.

Question 9

How is sea surface temperature monitored?

(Remote sensing: satellite technology to monitor changes to the water and carbon cycles)

Answer 9

By NOAA satellites.

Radiometers measure the wave band of radiation emitted from the ocean surface.

Changes in global SSTs and areas of upwelling and downwelling.

Question 10

How is deforestation monitored?

(Remote sensing: satellite technology to monitor changes to the water and carbon cycles)

Answer 10

By ESA albedo (reflectivity) images various satellites.

Measurements of reflectivity of Earth’s surface and land use changes.

Question 11

When is rainfall the most common? Why?

(Diurnal (daily) changes)
(Short-term changes in the water cycle)

Answer 11

The afternoon.

As temps rise through the middle of the day and evaporation rates are highest. Convectional rainfall occurs once moisture has risen in atmosphere, and been cooled through lapse rates - produced as precipitation.

Question 12

How is the water cycle impacted during the night?

(Diurnal (daily) changes)
(Short-term changes in the water cycle)

Answer 12

Temperatures drop.

This reduces evaporation and respiration.

Question 13

Seasonal changes are influenced by what?

(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 13

Solar radiation.

Question 14

How is the carbon cycle impacted on a daily basis?

(Diurnal (daily) changes)
(Short-term changes in the carbon cycle)

Answer 14

Phytoplankton and terrestrial plants.

Photosynthesis occurs in the daytime, especially during midday.
At night this reverses.

Question 15

Solar radiation inputs in December (Southern England) can reach how high?

(Seasonal changes)
(Short-term changes in the water cycle)

Answer 15

150W/m2.

Question 16

Solar radiation inputs in June (Southern England) can reach how high?

(Seasonal changes)
(Short-term changes in the water cycle)

Answer 16

800W/m2.

Question 17

When does solar radiation peak? How does this impact the water cycle?

(Seasonal changes)
(Short-term changes in the water cycle)

Answer 17

June.

This means 80% of precipitation is lost, normally through evapotranspiration.

This can result in low river flows.

Question 18

In the carbon cycle, there are considerable seasonal variation where? What is this?

(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 18

In the Tropics.

This is the difference between rainy and dry seasons and associated water availability.

Question 19

When is vegetation at full foliage? What does this result in?

(Daylength in the UK)
(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 19

In the summer

This leads to a drop in atmospheric CO2.

Question 20

By the end of the Summer, what rises? What rises back up?

(Daylength in the UK)
(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 20

By the end of Summer, decomposition rates rise and the drop in atmospheric CO2 is reversed (increasing).

Question 21

Global CO2 changes are dominated by what? Why?

(Daylength in the UK)
(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 21

The Northern hemisphere.

This is because they have a much greater land mass.

Question 22

In growing season, what leads to a huge drop in atmospheric CO2 levels? Where else does this happen?

(Daylength in the UK)
(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 22

In growing season, ecosystems such as the boreal forests extract huge amounts of CO2 from the atmosphere, having a global impact.

This also happens in the oceans, with phytoplankton blooms occurring when water temperatures rise, and there is more intense sunlight.

Question 23

Phytoplankton blooms occur when water temperatures rise, and there is more intense sunlight. What time of the year is this? Where?

(Daylength in the UK)
(Seasonal changes)
(Short-term changes in the carbon cycle)

Answer 23

This occurs between March to June/ July in the North Atlantic ocean.

The resulting algal blooms are so extensive, they are visible from space .

Question 24

Is the Earth’s climate stable? Why?

(Long-term changes in the water and carbon cycles)

Answer 24

The Earth’s climate is unstable.

This is because temperatures constantly fluctuate at regular intervals.

Question 25

In the last 400,000 years, there have been how many glacial and interglacial period cycles? (Long-term changes in the water and carbon cycles)

Answer 25

4 cycles of glacial and interglacial periods.

Question 26

How long does each glacial and interglacial period cycle last? (Long-term changes in the water and carbon cycles)

Answer 26

Around 100,000 years. (glacial-interglacial-glacial).

Question 27

When was the height of the last glacial period? (Glacial periods) (Long-term changes in the water and carbon cycles)

Answer 27

20,000 years ago.

Question 28

20,000 years ago during the height of the last glacial period, global average temperatures were how much lower? (Glacial periods) (Long-term changes in the water and carbon cycles)

Answer 28

5°C lower.

Question 29

20,000 years ago during the height of the last glacial period what covered Scotland, Northern Ireland, Northern England, and Northern Wales? What would this have caused? (Glacial periods) (Long-term changes in the water and carbon cycles)

Answer 29

An ice sheet averaging 1km thick. This would have created isostatic change (Scotland rising back up, Southern England rising back down).

Question 30

What are the temperatures of most interglacials like? What about 250 million years ago? (Inter-glacial periods) (Long-term changes in the water and carbon cycles)

Answer 30

A similar average temperature as today. However, 250 million years ago global temperatures were even more extreme, with average temperatures being 22°C, (7-8°C warmer than today). These climatic shifts had a major impact on the water and carbon cycles.

Question 31

What happens to water during glacial periods? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 31

there is a net transfer of water from the ocean reservoir to storage in ice sheets, glaciers, and permafrost:

Question 32

During recent glacial periods what have sea levels been seen to fall to? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 32

Global sea level fell by 100-130 m.

Question 33

During recent glacial periods, ice sheets and glaciers have been seen to expand to cover what? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 33

Ice sheets and glaciers expand to cover 1/3 of continental land mass.

Question 34

During glacial periods ice sheets have previously moved where? What has this done? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 34

Ice sheets move equator-wards, destroying masses of forest and grassland. The area covered by vegetation, and water stored in the biosphere shrinks.

Question 35

During glacial periods, how may climates change in the tropics? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 35

In the tropics, the climate becomes drier and deserts/grasslands displace masses of rainforests.

Question 36

During glacial periods there are lower rates of what? What impacts does this have? (Water cycle) (Long-term changes in the water and carbon cycles)

Answer 36

Lower rates of evapotranspiration during glacial phases: This reduce exchanges of water between the atmosphere, biosphere, oceans, and soils. This (together with freshwater stored as snow and ice), slows the water cycle greatly.

Question 37

There are dramatic increases and decreases in CO2 in the atmosphere. What happens to CO2 concentrations during peak glacial periods? What about interglacials? (Carbon cycle) (Long-term changes in the water and carbon cycles)

Answer 37

CO2 concentrations fell to 180ppm. In warmer inter-glacial periods this increased to 280ppm.

Question 38

Why may it be that CO2 concentration in the atmosphere be higher in interglacials, but lower in glacials?

Answer 38

This is possibly explained through the excess CO2 finding its way from the atmosphere into the deep ocean. Changes in ocean circulation during glacial periods bring nutrients to the surface and stimulate phytoplankton growth. Phytoplankton fix large amounts of CO2 by photosynthesis before dying, sinking to the deep ocean, storing the carbon.

Question 39

The carbon pool in vegetation shrinks during glacial periods. Why?

Answer 39

This is because ice sheets advance and occupy large areas of the continent.

Question 40

The carbon pool in vegetation shrinks during glacial periods, as ice sheets advance and occupy large areas of the continent. What does this cause?

Answer 40

This causes deserts to expand, tundra to replace temperate forests, and grasslands to encroach on tropical rainforests. As much of the land is buried by ice, carbon stored in soils will no longer be exchanged with the atmosphere.

Question 41

Expanses of tundra beyond the ice-limit, are able to do what?

Answer 41

Expanses of tundra beyond the ice-limit sequester huge amounts of carbon in the permafrost.

Question 42

During glacial periods there is less vegetation cover, fewer forests, lower temperatures, and lower precipitation meaning what? What are the implications of this?

Answer 42

The total volume of carbon fixed in photosynthesis declines. The implications are an overall slowing of the carbon flux - smaller amounts of CO2 returned to the atmosphere through decomposition.