Radiation
How long is the solar cycle?
11 years
What are GCMs and NWPs? Name the main differences
General Circulation Model GCMs:
* project the average behavior of the atmosphere as a result of slow changes in boundary conditions or physical parameters.
Numerical Weather Prediction NWPs:
* initial value problem
* Shorter Time scales
What are ocean currents driven by? (3 things)
Salinity gradient, temperature gradients, wind stress
Why do we need parametrization and cannot resolve everything?
Subgrid processes influence mean of grid box strongly
What do we need parametrization in models for?
To handle subgrid-scale processes.
What are the three main atmospheric windows?
Visible, infrared, radio
What are the three forces, determining the horizontal velocity vector?
Frictional force, pressure gradient force, coriolis force
What are components of the cryosphere? Give at least 4
Snow, River and lake ice, sea ice, glaciers, ice shelves/sheets, frozen ground (permafrost)
Comparing uplift by convection and by fronts, which phenomena is easier to resolve with increasing model resolution?
frontal (larger spatial scale)
Why are oceans often simulated on different grids than the atmosphere?
To avoid the singularity at the poles.
Which approximation of Planck's law is used for low frequencies?
Rayleigh-Jeans Approximation
Explain the Continuity Equation of the Mass Conservation in your own words.
the change in density of a fluid parcel is proportional to the velocity divergence
* the overall mass balance: Input = Output
* The equation relates convergence of horizontal winds with vertical motion
What is the main cause for anthropogenic ocean acidification?
Increasing CO2 concentrations in the atmosphere
What happens for positive and negative CAPE (convective available potential energy)?
positive -> rise
negative -> sink
What are sigma coordinates?
Pressure coordinates normalized by surface pressure.
What is the assumption on the radiative transfer equation made by Schwardschild's equation?
No scattering
What are diagnostic and prognostic equations? Name all 6 primitive equations which are defined in this lecture. Why do we need 6?
Prognostic equations are time-dependent while diagnostic equations are no time-dependent. The primitive equations describe large-scale atmospheric motions. These laws are expressed by the equations which describe the change of momentum, temperature, and moisture. The 6 Laws which are specified in this lecture are:
Momentum Equation, (Prognostic)
Thermodynamic Equation, (Prognostic)
Moisture conservation (Prognostic)
Mass conservation, (Prognostic)
Hydrostatic approximation, (Diagnostic)
Equation of state (Diagnostic)
We need six, because we have six prognostic variables that weh ave to determine so we need six equations for a complete system of equations.
What does the thermodynamic and the dynamic part of a sea ice model determine and what fundamental laws of physics are they based on?
Thermodynamic: ice formation (melt + growth), based on conservation of energy
Dynamic: ice motion, based on conserveration of momentum
What are the key differences between parameterization of convection and land-surface processes?
convection: changes drastically in time and space --> need for superparameterization
land-surface: relatively stable in time, Averaging surface usage, describes grid-cell relatively wel
Name the three effects that lead to spectral line broadening.
Pressure broadening (Lorentz), Doppler broadening, natural broadening.