Hayashi, Itoh

Setup

  • Linearize the QHE on an equatorial β\beta plane with rayleigh dampiong of velocity (bizarrely, laplacian diffusion is retained)
  • No base flow.

Scale analysis:

  • Time scale of 10 days.
  • Deep convective heating rate of 10K/day. No source given for where this comes from.
  • Zonal wind is chosen to be 10 m/s
  • Results aren't super relevant for identifying cases.

Linear eigenproblem:

  • Heating profile looks like Qacos(πyHy)cos(πxHx)sin(πzzh)exp(z2H)exp(iωt)Q_a \cos\left(\frac{\pi y}{H_y}\right) \cos\left(\frac{\pi x}{H_x}\right) \sin\left(\frac{\pi z}{z_h}\right) \exp\left(\frac{z}{2H}\right) \exp\left(-i\omega t \right) on [Hx/2,Hx/2]×[Hy/2,Hy/2]×[0,zh][-H_x/2, H_x/2] \times [-H_y/2,H_y/2] \times [0, z_h]
  • Reaches maximum at approx 9km.
  • QaQ_a is 10 K/day.
  • Constant lapse rate atmosphere for base state. No background wind.
  • Relative differences of 10-20 percent (higher when Hx/Hy=2H_x/H_y = 2).
  • Phase speed of 50 days. Results are not sensitive to this.

Explanation of what's happening:

  • Strength of heating determines wdeepy\pder{w_{\textrm{deep}}}{y}, inducing meridional tilting of planetary vorticity.
  • Temperature structure is not coupled to this tilting.

Takeaways:

  • Find places where diabatic heating and wdeepy\pder{w_{\textrm{deep}}}{y} are tighly coupled vs instances where there are other factors driving synoptic structure of vertical motion