def stability_parameter_obs(monin, z_obs):
    """
    Computes the stability parameter introduced by Monin and Obukhov. This
    parameter includes effects of both shear stress and buoyancy on turbulence.
    It is applicable to observation height.

    .. math ::

        x_{obs}=1-16\\left(\\frac{z_{obs}}{L}\\right)^{0.25}

    Parameters
    ----------
    monin : float
        monin obukhov length
        :math:`L`
        [m]
    z_obs : float
        observation height
        :math:`z_{obs}`
        [m]

    Returns
    -------
    x_b_obs : float
        stability parameter used in stability correction for observation height
        :math:`x_{obs}`
        [-]
    """
    return (1 - 16 * (z_obs / monin)) ** 0.25
