Convective movement of multi-component fluid flow initiated by joint heat and salt stratification referred to as the thermohaline system was studied in this job. Motion analysis study plays a key role in oceanography, meteorology, and chemical engineering. Tidal impacts in coastal areas bring hot saltwater under cold freshwater. In this model, it is considered a viscous incompressible thermohaline fluid confined within a distance between two parallel rigid planes. The system in the x-y plane is of infinite extent. The lower border is heated regularly and the upper border is kept at a temperature of zero degrees. At the lower limit, the concentration remains greater than at the upper limit. The advanced mathematical model is a modified Stern model version. Having evaluated vertical instability in the presence of sinusoidal heating, assuming the modal alternatives in the horizontal layer. Salinity has been shown to enhance the stability domain or sinusoidal heating with fluctuating power equilibrium in the presence of salinity. It obtains numerical alternatives and compares them with previous research.