Bandwidth scale for frequency spectrum of sea waves

It is well known that energy spectrum bandwidth should be able to reflect t he degree of energy concentration. However, the commonly used bandwidth fac tors defined by Longuet-Higgins could not fit the concept satisfactorily. A new kind of spectrum bandwidth scale factor with a clear physical meaning is given in the present paper and a constant is obtained which reveals the intrinsic characteristics of sea waves. Thereby a universal relationship be tween significant wave height of sea waves and spectrum bandwidth is establ ished.