The analytical expressions of radial and the longitudinal components of scintillation index are derived in weak oceanic turbulence.

The effects of off-axis distance, propagation distance, and three oceanic parameters (i.e., the ratio of temperature to salinity contribution to the refractive index spectrum w  , the rate of dissipation of the mean squared temperature lick to view the MathML source">χ_T and the rate of dissipation of the turbulent kinetic energy lick to view the MathML source">ϵ) on radial component of scintillation index are examined.

The influences of propagation distance and three oceanic parameters on the longitudinal component of scintillation index are investigated.

It is shown that the radial component of scintillation increases as off-axis distance increases. Both radial and longitudinal w distance, w   and lick to view the MathML source">χ_T increase while decreases as ɛ increases.

Besides, the longitudinal component of scintillation increases more drastically for plane wave than others, which indicates the plane wave is affected the most at the fixed turbulent strength. The longest weak turbulence distance for a plane wave is shorter than that for a Gaussian or spherical wave.