Wednesday

1. In model output RAINNC is:

All precipitation from microphysics

All precipitation from the cumulus parameterization

Just the rain from microphysics

The total rain from microphysics and cumulus scheme

2. At which of these grid sizes would you most likely NOT use cumulus parameterization?

1 km

10 km

100 km

Cumulus parameterization is recommended for domains with a grid size greater than or equal to 10 km. You likely would not need to use cumulus parameterization below 3 km. In between 3 and 10 km, you would need a cumulus scheme that's aware of the smaller grid sizes.

Explanation

Cumulus parameterization is recommended for domains with a grid size greater than or equal to 10 km. You likely would not need to use cumulus parameterization below 3 km. In between 3 and 10 km, you would need a cumulus scheme that's aware of the smaller grid sizes.

3. Which of these statements is FALSE?

You should use a microphysics scheme for any grid size

You should only use a microphysics scheme when you don't use a cumulus scheme

You can use microphysics and cumulus schemes on the same domain

A cumulus scheme considers atmospheric conditions that are conditionally unstable and sub-saturated, while a microphysics scheme is only active in a grid volume that's saturated.

Explanation

A cumulus scheme considers atmospheric conditions that are conditionally unstable and sub-saturated, while a microphysics scheme is only active in a grid volume that's saturated.

4. Which type of physics should you consider changing in multiple nested domains?

Land surface model

Cumulus scheme

Planetary boundary layer physics

Microphysics

Cumulus schemes are designed for grid spacing large enough that cumulus clouds are consistent to occupy only a portion of the grid box, hence when the grid size becomes smaller, the scheme may be replaced by explicit clouds on the grid.

Explanation

Cumulus schemes are designed for grid spacing large enough that cumulus clouds are consistent to occupy only a portion of the grid box, hence when the grid size becomes smaller, the scheme may be replaced by explicit clouds on the grid.

5. Which of the following is/are required to build the WRF model?

A C compiler

A Fortran compiler

The netCDF library

All of the above

6. Which circumstance(s) would require you to issue a 'clean -a' and reconfigure, prior to recompiling the code?

You are compiling with a different compiler

You made some edits to a physics routine

You made some modifications to the registry file

A and b

A and c

All of the above

Any time you make modifications to your configuration - using a different compiler, netcdf, versions, paths, setting new environment variables you would like to incorporate into your compilation, or when you make modifications to the registry files, you must clean and reconfigure before recompiling. If you only make modifications to any other files (e.g., physics routines), you can simply issue the compile command, and it should not take nearly as long as a full compile.

Explanation

Any time you make modifications to your configuration - using a different compiler, netcdf, versions, paths, setting new environment variables you would like to incorporate into your compilation, or when you make modifications to the registry files, you must clean and reconfigure before recompiling. If you only make modifications to any other files (e.g., physics routines), you can simply issue the compile command, and it should not take nearly as long as a full compile.

7. Which of these is a FALSE statement for land points?

The PBL scheme gets its heat flux from the LSM

The PBL scheme gets its moisture flux from the LSM

The PBL scheme gets its surface friction from the LSM

The PBL scheme gets its surface friction from the surface-layer scheme