bispectra to understand how scales interact

[Sylviabohnenstengel]

Calculate bispectra either using existing PyBispectra package or direct from FFT based code.

• Calculate bispectra in spatial domain and then average over time
• Calculate bispectra at a point for a timeseries

[Sylviabohnenstengel]

spatial bispectra:

• load data into cubes
• ensure data are on unifrom cartesian grid
• rotate/unrotate if necessary
• radially bin
• take 2D FFT(kx,ky)
• define radial wave number bins for k
• For each (k1_bin,k2_bin)(k_1_bin, k_2_bin)(k1​_bin,k2​_bin), randomly sample wavevectors k1​ in bin1 and k2​ in bin2, compute
  F(k1)F(k2)F∗(k1+k2)
• Average over samples and over time → B(k1,k2)