Stress modulation account in the problem of the wave spectrum transformation caused by nonuniform currents

The modulation of the momentum flux from turbulent wind flow over the ocean surface caused by the current gradient is considered. Simple estimation shows that the magnitude of such modulation can be up to 100-200% for strong internal waves (IW). A numerical technique is proposed to calculate the stress modulation and simulations are made for periodic IW and solitons. Variable stress is used in the source function of the wave action balance equation and the modulation of the X-band Bragg spectral density is used to calculate typical IW solitons. Momentum flux modulations due to a nonuniform current is incorporated in the theoretical models used for analysis and interpretation of ocean remote sensing from space.