L10 - Climate Modelling

Question 1

What goal would you use an empirical vs physical model for?

Answer 1

Empirical models use real data and highlight relationships between variables. They are good at predicting (e.g. interpolation)
Physical models are used to study mechanisms, and the impact of a perturbation on a whole system (e.g. STELLA)

Question 2

what processes should be considered for climate modelling?

Answer 2

1. Radiative (e.g. absorption, reflection)
2. Dynamic (e.g. advection, diffusion)
3. Surface processes (e.g. albedo, emissivity, energy exchanges, land/ocean)

Question 3

State variables

Answer 3

Can change in space and time and depend on its own history. Can only be directly influenced by fluxes ( X(t+1)..)

Question 4

Fluxes

Answer 4

Flow of energy/material from or to state variables

Question 5

Parameters

Answer 5

Fixed for one simulation and can only indirectly influence state variables

Question 6

Spatio-temporal models

Answer 6

Different locations can be different variables

Question 7

low to high complexity models

Answer 7

EBM (energy balance model) < EMIC (Earth model of intermediate complexity) < GCM (global circulation model)

Question 8

problems in climate modelling

Answer 8

1. uncertainty in correctness
2. uncertainty in grid size (may miss important variations)
3. non-liner or chaotic dynamics (butterfly effect into future)

Question 9

Can GCM be used for regional modelling?

Answer 9

No because the grid size is not fine enough and does not include small scale variations in topography/cover (which is important). Instead use RAMS or RCM

Question 10

How many ocean vs atmosphere layers in GCMs?

Answer 10

10-30 ocean layers and 10-20 atmosphere layers

Question 11

IAM

Answer 11

Integrated assessment model. Combine physical and social systems