def estimated_inversion_strength(T0,T700):
    '''Compute the Estimated Inversion Strength or EIS,
    following Wood and Bretherton (2006, J. Climate)

    Inputs: T0 is surface temp in Kelvin
           T700 is air temperature at 700 hPa in Kelvin

    Output: EIS in Kelvin

    EIS is a normalized measure of lower tropospheric stability acccounting for
    temperature-dependence of the moist adiabat.
    '''
    # Interpolate to 850 hPa
    T850 = (T0+T700)/2.;
    # Assume 80% relative humidity to compute LCL, appropriate for marine boundary layer
    LCL = lifting_condensation_level(T0, 0.8)
    # Lower Tropospheric Stability (theta700 - theta0)
    LTS = potential_temperature(T700, 700) - T0
    #  Gammam  = -dtheta/dz is the rate of potential temperature decrease along the moist adiabat
    #  in K / m
    Gammam = (g/cp*(1.0 - (1.0 + Lhvap*qsat(T850,850) / Rd / T850) /
             (1.0 + Lhvap**2 * qsat(T850,850)/ cp/Rv/T850**2)))
    #  Assume exponential decrease of pressure with scale height given by surface temperature
    z700 = (Rd*T0/g)*log(1000./700.)
    return LTS - Gammam*(z700 - LCL)
Compute the Estimated Inversion Strength or EIS,
    following Wood and Bretherton (2006, J. Climate)

    Inputs: T0 is surface temp in Kelvin
           T700 is air temperature at 700 hPa in Kelvin

    Output: EIS in Kelvin

    EIS is a normalized measure of lower tropospheric stability acccounting for
    temperature-dependence of the moist adiabat.