1695-1707<span style="font-size:9.0pt;line-height:
150%;font-family:" times="" new="" roman";mso-fareast-font-family:calibri;mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">Time series temperature and salinity (at 1 hour
interval) and currents data (10 min interval) at surface (3 m) and bottom (14
m), collected in the Gautami-Godavari
estuary during 25-27 September 2008 were utilized to document the characteristics
of Internal waves (IWs) and to infer their generation mechanism. Based on the stability criteria, two High
Frequency (HF) significant modes in the Internal Wave (IW) field at frequencies
96.67 cph (10 m depth) and 71.15 cph (14 m depth) have been identified. At
these modes, IW parameters viz., wave
length (L), wave number (κ), potential
energy (PE), baroclinic potential energy (BPE)
and phase speed (ci)
and
displacement function (η(z,t)) have been
computed (with salinity and currents data) objectively by adopting well known
harmonic technique through Principal Component Analysis (PCA). Results revealed
that (1) first mode: IW was found to move with a phase speed of 0.13 m s-1
and wave length of 0.0056 km (wave number=178.64 cycles km-1) having
energies of 0.0006 J m-2 (potential) and 0.0027 J m-2
(baroclinic) whereas (2) second mode:
0.09 m s-1, 0.0076 km, 131.48 cycles km-1, 0.0055
J m-2, 0.020 J m-2 and 0.094 m s-1 for L, κ, PE, BPE and ci respectively. η(z,t) was found to be
positive (elevation-type IWs) and negative values (oscillation-type) during IW
propagation of two modes respectively wherein
mode 2 is more energetic (8 times) than mode 1. Tidally-modulated force
may be the possible mechanism to generate HF IWs under ebb period.</span