def calc_TB(Sal):
    """
    Calculate total Boron
    
    Directly from CO2SYS:
    Uppstrom, L., Deep-Sea Research 21:161-162, 1974:
    this is 0.000416 * Sal/35. = 0.0000119 * Sal
    TB(FF) = (0.000232 / 10.811) * (Sal / 1.80655) in mol/kg-SW
    """
    a, b = (0.0004157, 35.)
    return a * Sal / b