Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Removing compounding factors on u2/v2 boundary conditions in ADC #14

Open
katsmith133 opened this issue May 27, 2021 · 2 comments
Open

Comments

@katsmith133
Copy link
Collaborator

Happy to do this PR, but just want to make sure which one we want to remove...
config_adc_up2_vp2_factor is only used on u2 and v2:

u2(k,1,iCell) = config_adc_up2_vp2_factor*config_adc_bc_const*frictionVelocity**2.0
v2(k,1,iCell) = config_adc_up2_vp2_factor*config_adc_bc_const*frictionVelocity**2.0

config_adc_bc_const is used on u2, v2, tp2, and sp2:
tp2 = 0.4_RKIND * config_adc_bc_const * (wt(i1,1,iCell) / frictionVelocity)**2
sp2 = 0.4_RKIND * config_adc_bc_const * (ws(i1,1,iCell) / frictionVelocity)**2

Do we want separate factors for u2/v2 and tp2/sp2?

@BrodiePearson
Copy link
Collaborator

BrodiePearson commented Jun 1, 2021

If we are following the Andre et al. (1978) paper that Luke linked to in the other thread we should use config_adc_bc_const for both, as the second-order tracer moments should have the same coefficient as u2 and v2 vs. $u_{star}^2$ (but not $w_{star}^2$). But...

  • That paper doesn't have a coefficient of 0.4 out the front of tp2 and sp2. (Should we remove it?)
  • That paper relates tp2 and sp2 to $u_{star}^2$ (sfcFrictionVelocitySquared ) rather than frictionVelocity, which is a combination of $u_{star}^2$ and $w_{star}^2$. (Should we change that to tp2 = config_adc_bc_const * (wt(i1,1,iCell) / sqrt(sfcFrictionVelocitySquared))**2 etc?)
  • At the moment tp2 and sp2 at the surface only affect the splat parameterization but don't affect the model profiles of these properties (t2 and s2). Should we rename them t2 and s2 so they feed into the simulated profiles?

@katsmith133
Copy link
Collaborator Author

@BrodiePearson

  • Andre et al. (1978) does not have this extra coefficient, but the CLUBB implementation that Luke pulled it from does. Not sure where that 0.4 comes from for CLUBB. Perhaps its atmospheric related (?).
  • Again, Andre et al. (1978) does not include the wstar^2 in the tp2 and sp2 term, but the CLUBB implementation does. And again, not sure what the motivation was.
  • I tested this change and there appears to be almost no difference in the results for the cooling case with splatting turned on (both with the w2 BC on and off). Only a very small (~O(-4)) change in the surface value of t2 occurs and that appears to not affect much else.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants