The analysis is carried out for the low frequency (300±30 Hz) intensity fluctuations of the sound pulses propagating in the shallow water waveguide in the presence of nonlinear internal waves (NIW) in the experiment Shallow Water 2006 (Atlantic shelf of USA). Signals were being received by vertical line array (distance to the source ~20 km). NIW train was placed entirely inside of an acoustic track during time period of the sound radiation. Angle between wave front of NIW and direction of an acoustic track was ~10°. Theoretical modeling of spectrum of fluctuations were obtained using theory of authors for the sound fluctuations due to mode coupling. The main feature of the theory is existence of the so called «predominating frequency», corresponding to the spectral component of maximal amplitude. Comparison of modeling results and experimental data allows us to interpret position of the maximum in the spectrum as predominating frequency. Contribution of horizontal refraction is discussed as well.
43.30.Re Signal coherence or fluctuation due to sound propagation/scattering in the ocean
1) Voronezh State University. Universitetskaya pl. 1, Voronezh, 394006, Russia. 2) L. Charney School of Marine Sciences, Haifa University. Mount Carmel, Haifa, 31905, Israel. 3) Woods Hole Oceanographic Institution. Woods Hole, Massachusetts 02543, USA.
Science News of the Faculty of Physics, Lomonosov Moscow State University
This new information publication, which is intended to convey to the staff, students and graduate students, faculty colleagues and partners of the main achievements of scientists and scientific information on the events in the life of university physicists.