Spatial Patterns of Climate change

Question 1

What is a temperature anomaly?

Answer 1

A temperature anomaly refers to a depature from a reference value/long term baseline (1961-1980)

Question 2

Why can we say the rise in CO₂ in recent years is entierly anthropogenic?

Answer 2

Because if caused by natural forcings, there would have been an increase in solar radiaition
(e.g. positive solar forcing causing more CO₂ to be released from the ocean)
But there hasn’t

Question 3

What is the difference in land vs oceanic regions in terms of warming?

Answer 3

Land (terrestrial) regions have warmed faster than oceans

Question 4

What are the 3 reasons behind why the terrestrial surface is warming more than oceans?

Answer 4

• Heat capacity - land has a lower heat capacity than water
• Suface energy balance - this is the energy exchange between the Earth’s surface and atmosphere, oceans have practically unlimited potential for evaporation driving cooling, continents do not
• Atmospheric dynamics - the lapse rates (rate of temp decrease with height) decreases more strongly over oceans than lands

Question 5

When is the greatest warming in the N.Hemipshere?

Answer 5

Greatest warming in the spring and winter in the N.Hemisphere

Question 6

There has been a larger change in surface temperature near the pole than global average (polar amplification)
Why?

Answer 6

• Melting of ice (13% per decade)
• Ice is more reflective (albedo)
• Less ice = less reflection and increased absorption = associated warming

Question 7

Why is the intensified warming of the poles, not as strong in Antarctica?

Answer 7

• Arctic is an ocean covered by sea ice
• Antarctica is an elevated continent covered in more permanent ice and snow
• (however not the case for the Antarctic peninsula)

Question 8

Define Permafrost

Answer 8

Soil, rock or sediment that continously remains below 0°C for 2yrs

Question 9

What are the core lays which exist around the permafrost?

Answer 9

• Active layer (living biomass + carbon exchange)
• Permafrost with low ice content (more affected by changes in temperature
• Ice rich (ground ice) permafrost (thicker layer trapping GHGs)
• Mud despoits from thawing
• Permafrost

Question 10

What are some issues associated with the thawing of permafrost?

Answer 10

• Harder than concrete - thawing can destroy infrastructure which is built upon it
• Microbes begin to decompose trapped organic carbon, releasing GHGs (started to decreas however due to stored carbon being used up)
• Bacteria + viruses in ice and soil could be released, which have been trapped for >400K

Question 11

How can the warming of the poles affect atmospheric circulation?

Answer 11

• Warming of the poles results in weaker atmospheric pressure gradient (warm air rises = low pressure)
• Results in lower wind speeds
• In the north, leads to weakening of the west-to-east jet streams in the northern hemisphere - climate instability
• Could lead to wavey polar vortex (cotroversial)

Question 12

Are CO₂ concentrations the same globally?

Answer 12

More or less

Question 13

What is the link between surface temperature and precipitation?

Answer 13

Areas that have become wetter have not warmed as much as other land areas

Question 14

What is Latent heat?

Answer 14

Latent heat is energy released/absorbed, by a thermodynamic system, during a constant-temperature process
E.g. condensatio or evaporation (phase change)

Question 15

What is sensible heat?

Answer 15

Release/absorption of heat by a thermodynamic system without a change in phase

Question 16

There is enhanced …….. from wetter surfaces

Answer 16

There is enhanced latent vs sensible heat fluxes from wetter surfaces (evaporation)

Question 17

What is the issues with predicting future precipitation?

Answer 17

There is lots of uncertainity within the models
(however generally good enough to try to understand what is happening)

Question 18

Where are we likely to see an increase in precipitation trends?

Answer 18

North of 30°N

Question 19

Where are we likely to see a decrease in precipitation trends?

Answer 19

South and Sub-Saharan Africa
e.g. decrease in the South Asian monsoon due to decrease pressure gradient between warming see and land)

Question 20

If there is predicted tropospheric water vapour increases due to rising temperature, what affect will this have?

Answer 20

Cloud cover changes

Question 21

How does solar radiation change from different latitudes?
How does this affect circulation?

Answer 21

• The angle of incoming solar raidation depends on latitudes (less curve = higher concentration of light
• Will also influence seasonal temperature of locations
• Results in average surface temperatures being warmer at lower latitudes
• Atmospheric and oceanic circulation allow the distribution of this heat

Question 22

Between 40°N and 40°S, how is incoming heat radiation relative to outgoing heat radiation

Answer 22

Incoming heat radiation from the sun exceeds the outgoing heat radiation from the Earth

Question 23

North and South of 40°, how is outgoing heat radiation relative to incoming heat radiation?

Answer 23

Outgoing heat radiation from Earth exceeds the incoming heat radiation from the sun

Question 24

What are the 3 atmospheric circulation cells called?

Answer 24

• Hadley
• Ferrel
• Polar

Question 25

The Hadely cell in the largest cell, cloest to the equator
How does it operate?

Answer 25

• Warmer less dense air rises and moves out towards the poles
• It then cools and sinks towards the surface, where it moves back towards the equator

Question 26

The polar cell is the smallest cell
Describe how it operates

Answer 26

• Cool dense air descends on the polar regions between 60-70° N/S
• The air moves towards the warmer equators, where it starts to warm and rise, returning to the poles at high levels

Question 27

Describe some key features of the ferrel cell

Answer 27

• Not driven by temperature
• Cells flow in the opposite direction to other cells
• Transport heat from equator to poles, resulting in semi-permanenet areas of high + low pressures

Question 28

The atmospheric cells create distinct climate zones, what climate do they produce in these areas of low pressure

Answer 28

• The rising air creates low pressures, resulting in increased rainfall
• Rainforests or UK wet climate

Question 29

The atmospheric cells create distinct climate zones, what climate do they produce in these areas of high pressure

Answer 29

• Air decends and creates high pressure
• Produces little rainfall and clear skies
• Relatively dry areas and deserts

Question 30

How does climate change affect the atmospheric cells?

Answer 30

Climates changes: changes in temperature and precipitation causes the cells to change
Causes the cells to move towards the poles

Question 31

If climate change affects the atmospheric cells, how does this affect the Atlantic and southern polar jet winds?

Answer 31

Intensification and a polewards shift of Atlantic and S.Polar jet

Question 32

If climate change affects the atmospheric cells, how does this affect the NH winter storm-track and extra-tropical storm activity?

Answer 32

• Increased intensity and poleward shift in N.Hemisphere storm-track activity
• Increased storm activity in the extra-tropical Hadely cells

Question 33

Apart from winds, what else can changes in global circulation affect

Answer 33

Changes in global circulation also affect wave height (happened since the 1950s)

Question 34

If climate change is affecting atmospheric circulation, how has this affected the Hadley cell and the S.Asian Monsoon?

Answer 34

• Indication of stronger Hadley Circulation (equatorial cell)
• Intensification of the Monsoon

Question 35

Due to global warming there has been an increase in the global mean temperature, where is this seen most?

Answer 35

In the N.Hemisphere

Question 36

Due to global warming, there is a prediction of a global increase in mean precipitation, where will this be highest?

Answer 36

Increased precipitation at higher latitudes - less in the tropics