Internal Controls

Question 1

what are 4 IPCC predictions for end of 2100

Answer 1

warmer and wetter +3

> 400 ppm atm co2 conc

reduced icesheets

higher sea level

Question 2

what other era closely represents our current era?

Answer 2

Pliocene 3 mill yrs ago

similar fauna and flora eg africa

same co2 conc 390ppmv

Question 3

how was the pliocene different to us today?

Answer 3

temps were 3 degrees warmer

sea level 25m higher

Question 4

name 3 external climate controls

Answer 4

solar variability eg intensity

orbital forcing / gravitational forces eg tides

cosmic material eg meteroties

Question 5

name 4 internal controls

Answer 5

green house gases - natural or human

global ocean circ - salinity

orography - veg/albedo

tectonic uplift

Question 6

name a natural greenhouse gas contrubuter

Answer 6

volcanic eruptions

pump out co2 and methane

ash/mud reduces solar radiation

Question 7

describe the global carbon cycle in terrestrial area

Answer 7

plants respire and photosynthesise.

take in co2 and water (light) and create glucose and o2.

co2 stores in soil

microbian respiration which releases co2

fossil carbon locked underground for many years

Question 8

describe global carbon cycle in ocean

Answer 8

photosynethesis in upper part of ocean

huge store of carbon

organisms die and sink to bottom locking up carbon

respiration and decompositoon

Question 9

define biological pump

Answer 9

marine carbon pump

sequestration of carbon from atmosphere and land runoff to ocean interior and seafloor sediments

Question 10

define vertical deep mixing

Answer 10

warm water on oceans surface currents are carried from low latitudes to high latitudes.

water cools and becomes more dense so they sink

Question 11

describe the fast carbon cycle

Answer 11

photosynthesis - take in co2
higher photosynethesis in summer months so less co2 present on earth this time

winter when few plants are growing and many are decaying then co2 conc increase

seasonational variations
lowest co2 in august and highest in december

Question 12

describe the slow carbon cycle

Answer 12

transfer to oceans

deposition of carbon compounds to ocean floor

ocean sediments to carbon rich rock

carbon rock to tectonic margins

carbon compounds released back to atmopshere from volcanic eruptions and uplift of land

Question 13

how slow is slow carbon cycle

Answer 13

tens and hundreds of millions of years

Question 14

how much do oceans cover earth

Answer 14

71%

Question 15

How much more co2 does ocean store than biosphere

Answer 15

20%

Question 16

why is there highs and lows of methae and co2 in ocean

Answer 16

hypothesis -
interglacial and glacial periods

biological pump - more algae in colder waters so higher intake of co2

Question 17

describe process of chemical weathering

Answer 17

water and carbon from a weak carbonic acid

acid dissolved rocks and releases calcium/ potassium/ sodium ions and magnesium

they enter ocean where calcium ions combibe with bicarbonate ions to form calcium carbonate

this is controlled by tectonic uplift of mountains

Question 18

how many big gyres are there

Answer 18

4

Question 19

what controls the gyres

Answer 19

global wind patterns

earths rotation

earths landmasses

the coriolus force changes or deflects direction of wind driven currents

Question 20

what is the ocean deepwater and thermohaline circulation driven by

Answer 20

water density

which is contolled by temp and salinity

Question 21

what is the thermohaline circulation

Answer 21

driven by global density gradients created by surface heat and freshwater fluxes

travels polewards from equatorial Atlantic region and cools sinking

Question 22

what is the Atlantic meridional overturning circulation

Answer 22

current in atlantic ocean

characterised by northward flows of warm salty water to upper layers and southward flow of colder deep waters that part of thermohaline circulation

cools to 2-4 degrees / high salinity which sinks down

Question 23

what is the global conveyor belt

Answer 23

circulation system in ocean

forms thermohaline currents that are driven by density

flows from warm surface currents to cold deep currents

warm waters cools and sinks and cold water warms and rises

takes 1,000 years to complete full cycle

Question 24

give an example of the global conveyor belt

Answer 24

north atlantic deep water

warm gulf stream moves to norweigian sea and cools to 2-4 degrees, high salinity - it sinks and

Question 25

what is the modern circumpoalr current in antarctica?

Answer 25

antarctica is isolated due to this current making the island very cold

the current flows throguh 2 gateways at S america and Australia

in the past these gateways were closed - but opened during eocene-oligocene transition 34 mill yrs ago

Question 26

when did s america gateway open

Answer 26

drake passage

35 mill yrs ago

Question 27

when did australia gate way open

Answer 27

austrlia tasman antarctica passage

50 mill yrs ago