SE2

Experiment Ideas:

Grace Liu: gap flow

Nick Forcone: initial conditions of vortex streets (e.g. u variation with latitude)

Wandi Yu: GW: tropopause, lapse rate, vertical remapping, vertical hyperviscosity

Jishi Zhang: GW: mountain shape/height

Yuming Jin: Gap flow (ne30), change u0, T0, shape of the topograph, include Coriolis 

Ankur Mahesh: changing number and shape bubbles for squall line (have one big bubble, one small bubble, a different number of bubbles, etc.)

Giacomo Giuliani: GW (88, 120), SL(hres)

GW test case 

• Tests completed

  • NE30L88

  • NE30L120

  • NE30L207

• Sensitivity studies:

  • Wandi:

    • Modify the lapse rates in the troposphere and stratosphere. 

    • Change the height of the tropopause; this is currently 20 km.

    • Modify the stratospheric lapse rate. 

  • (Giacomo) Turn off Rayleigh friction, make sure TOM sponge layer is turned on, and then adjust vertical profile

  • (Ankur) Hyperviscosity:  span range where model crashes, model is noisy, default, model is over diffused?

  • (Jishi) Adjust height of mountain:   as it gets taller, expect flow to become noisier and eventually crash.  

  • Low priority: look at vertical remap - use version without monotonicity at surface

Mountain Flow: Gap Flow

• Tests completed

  • NE30

  • NE60

• Sensitivity studies:  Try to some them at NE30 and NE60

  • Adjust height of mountain 

  • The response through the gap varies on the geometry of the gap; this can be classified as a long gap (x_gap << x_lon) or a short gap (x_gap >= x_lon) (Stull 2015). The default setup has xgap = 50 km, x_lon = 40 km. Try making the gap shorter, with xgap=100km and x_lon = 40 km, or making this a long gap, with xgap=50km and x_lon=100 km.

  • Turn off Rayleigh friction, make sure TOM sponge layer is turned on, and then adjust vertical profile

Mountain Flow: Vortex Street

• Tests completed

• Senstivity studies

  • (Mark Taylor)

    • run1: default case
      run2: turn Rayleigh friction off
      run3: turn on TOM sponge layer (set nu_top=2.5e5) on top 3 levels
      run4: increase number of levels for which TOM sponge layer is appliede

  • (Nick) Change the wind speed, u0.

  • Change to an oval mountain shape

Squall Line

• Tests completed

  • NE60

• Sensitivity studies

  • Hyperviscosity:  span range where model crashes, model is noisy, default, model is over diffused?

  • Turn off Rayleigh friction, make sure TOM sponge layer is turned on, and then adjust vertical profile

    • Note that SE Squall Line is the only model that does not use a Rayleigh friction and uses the default style of TOM sponge in the SE dycore.  (Nicholas) 

  • (Nick) Make the bubbles weaker (e.g. 3K --> 1K)

  • (Ankur) changing number and shape bubbles for squall line (have one big bubble, one small bubble, a different number of bubbles, etc.)

  • Break the hemispheric symmetry of the bubbles (pert_latc).

  • Change the PHYSICS time step. Do the models display temporal convergence of the expected order? 

  • Mark Taylor: Change the resolution used to produced the initial conditions (nz and nphi). The initialization routine uses an iteration procedure on a an initial grid of size nz  (height) and nphi (latitude). The initial data is then computed by interpolating onto the actual horizontal and vertical grid supplied by the model. Does the resolution of this initial grid impact the results?

  • (Jishi) change the small earth factor X and timesteps