docs: def chapman_profile(Z0: float, zKM: np.ndarray, H: float):
      """
      Z0: altitude [km] of intensity peak
      zKM: altitude grid [km]
      H: scale height [km]
  
      example:
      pz = chapman_profile(110,np.arange(90,200,1),20)
      """
      return np.exp(.5*(1-(zKM-Z0)/H - np.exp((Z0-zKM)/H)))