W1: Introduction to the Earth System Flashcards
What makes up the Earth Sytem?
- Gases
- Aerosol
- Clouds
- Troposphere
- Stratosphere
List the Atmosphere complex levels (5)
- Gases
- Aerosol
- Clouds
- Troposphere
- Stratosphere
List the Cryosphere complex levels (2)
- Both poles
- High alpine environments
List the Lithosphere complex levels (4)
- Mantle
- Upper mantle
- Core
- Asthenosphere
List the Land Surface complex levels (6)
- People
- Animals
- Plants
- River systems
- Agricultural lands
- Urban areas
List the Ocean complex levels (2)
- Shallow ocean
- Deep ocean
What is a cycle in terms of the Earth System? Name some cycles (3)
Movement of matter and energy often cyclical: often regenerating
- Hydrological
- Carbon cycle
- Nitrogen cycle
What was the initial approach to understanding the earth system?
Remote observation satellites
- Observing a quantity of something
What is the alternative approach to understanding the earth system?
Fluxes on forest scale ecosystems
What is a flux network
A big international network of towers monitoring the exchange of greenhouse gasses, energy and water above an ecosystem using sensors
What does an Open Path Analyser measure?
Measures the concentration between ball and sensor using lasers or alternative methods at high temporal resolution
Describe some features of the Open Path Analyser (3 large)
- Like satellite measurements you’re only getting a concentration
- If coupled with flux towers (sonic anemometer) you get an understanding of very small air movement over time at extremely high temporal resolution (milliseconds)
- Coupling sonic anemometers with satellite concentration data above an ecosystem such as a forest we can understand how atmospheric concentrations change with time.
- Sonic anemometer will allow you to calculate the actual net air movement.
What is the advantage of an Open Path Analyser?
Clear picture of what’s happening immediately beneath the tower and the ecosystem within its footprint
What are the disadvantages of an Open Path Analyser? (4)
- Expensive
- Requires a lot of maintenance
- Don’t get global coverage: good coverage in NA, EU, EAS
- Little coverage in important ecosystems e.g. Amazon and Congo
What is another name for Flux Towers?
Eddy covariance towers
List some characteristics of a Climate Model (4)
- Very physically based
- Relies generally on physical processes: drives weather forecasts
- Relies on atmospheric circulation and radiation and understanding of how wind moves around the earth
- Other physical components: sea ice, ocean circulation, land physics and hydrology
List some characteristics of an Earth System Model (2)
- Far better representation of the chemistry of the atmosphere
- Key difference is that life is incorporated; ocean ecology; living things process components within system, plant ecology and land use on surface
Why cant we always use Climate Models to project more global data?
E.g. weather forecasts
- Demands a huge amount of processing power:
- Takes a few hours to run just for the UK.
- Scaling that up to the whole earth and including ocean ecology, plant ecology and chemistry goes past the reaches of computing power
What is a GCM?
General circulation model
What is an ESM?
Earth system model
How do GCMs and ESMs break things down?
- Grid system
- Quantifies the exchanges and movement of material
- Operate from ~0.5 to ~2.5 degrees (1 degree about 100km in latitude)
- -Computer programmes can represent the movement of substances and energies vertically and horizontally
What is the metric size of a 1 degree grid?
100km in latitude
List some GCM and ESM variables at the surface (6)
- Temperature
- Humidity
- Pressure
- Moisture fluxes
- Heat fluxes
- Radiation fluxes
List some GCM and ESM variables in the atmospheric column (6)
- Wind vectors
- Humidity
- Clouds
- Temperature
- Height
- Precipitation
- Aerosols
How do GCMs and ESMs work?
- Breaks the system as a whole into elements that equations within a computer model can now solve
- Consistent fields of data across the earth
What does RCPs stand for?
Representative Concentration Pathways
What are RCPs?
- Scenarios of radiative forcing, not emissions
- Effect on number of watts per m2 that we are retaining in the atmosphere as heat
Which RCP is optimistic in line with what? And pessimistic in line with what?
RCP 2.8
RCP 8.5
RCP 2.8: Optimistic keeping to IPCC target
RCP 8.5: Pessimistic continue with all fossil combustion
ESMs are complex but what can’t they represent?
- Dynamic vegetation models
- Pest & disease models
- Crop models: depends on management
- Hydrological models
