An Analytical Model of Co-oscillating Tide under Frictional Effect in the Yellow Sea

Abstract

The response of the tidal waves to friction effect is investigated in terms of deformation of Kelvin and Poincare modes, The 1st Poincare mode does not exist over the low frequency region less than the critical frequency of omega ω <√2f , with γ /f=0.0, but the mode comes to exist in the presence of friction. When friction exists and its magnitude increases, the wave number increases, indicating that the wave length of the Poincare mode becomes increasingly short with increasing friction. The damping coefficient gradually increases with increasing friction over the high frequency region, but the trend is reversed over the low frequency region. In case of Kelvin wave the present study substantiates the characters of Kelvin wave examined by Mofjeld (1980) and Lee (1988). Based on the examination of frictional effects on the tidal wave propagation, the co-oscillating tides in the Yellow Sea are examined by considering both the head opening and bottom friction effects. As friction is introduced and increased in addition to partial opening at bay head, the location of the amphidromic point near the Shantung Peninsula moves more southwestward. This southwestward movement of the amphidromic point is increasingly compatible with the observed location of Ogura&apos;s or Nishida&apos;s tidal chart of the M 2 tide.