def evap_mass_flux_ALOHA(cs, wind_friction, coef):
    """
    Return the evaporative mass flux [kg/m²s]
    source : ALOHA

    Parameters
    ----------
    cs : Chemical vapor phase saturation concentration [kg/m³]
    frict_vel : Friction velocity of the air [m/s]
    coef : Mass transfert coefficient []

    """
    return cs * wind_friction * coef