Investigation of the Effect of Persian Gulf Outflow Intrusion into the Oman Sea on the Acoustic Signal Fluctuations

Document Type : Research Article

Authors

1 M.Sc. Graduated, Department of Marine Physic, Faculty of Marine and Oceanic Sciences, University of Mazandaran, Iran

2 Associate Professor, Department of Marine Physic, Faculty of Marine and Oceanic Sciences, University of Mazandaran, Iran

3 Associate Professor, Faculty of Environment, University of Tehran, Tehran, Iran

Abstract

Outflow intrusions are often detected in the vertical profiles of temperature and salinity in the ocean (for example, the Red Sea and Persian Gulf outflow into the India Ocean and Oman Sea, respectively). They are being visible by large fluctuations or inversions within the profiles and as zig-zag patterns in the temperature-salinity plots. In this study, first, using the collected salinity and temperature data in the region of the Oman Sea during spring 1996, the sound speed is calculated via Makenzie formula. Then, by plotting the sound speed profile, it was seen that the vertical structure meet anomaly at depth 200 to 400 meter of the profile. Moreover, the effects of presence and absence of the temperature inversion have been examined on the acoustic signal fluctuations with similar boundary conditions using SPARC model at frequency of 100 Hz. The results show that, when the acoustic source is installed below the inversion layer, receivers that are located in the low temperature inversion layer, receive the signal with time delay, and amplitude is greater than that with the absent inversion temperature. Thereby, the present achievements indicate that the outflow intrusion may affect the shapes and delay times of the received signals.

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Akbarinasab, M., 2015, Plume outflow intrusion impact on acoustical signal fluctuations in a pre-stratified environment. Journal of Theoretical and Applied Vibration and Acoustics, 1(2), 107-121.
Akbarinasab, M., Chegini, V., Ali Akbari Bidokhti, A.A. and Sadrinasab, M., 2012, A Simulation Study of Multi-path Characteristics of Acoustic Propagation in the Strait of Hormuz. Journal of the Persian Gulf, 3(9), 43-51.
Apel, J.R., Ostrovsky, L.A., Stepanyants, Y.A. and Lynch, J.F., 2007, Internal solitons in the ocean and their effect on underwater sound. The Journal of the Acoustical Society of America, 121(2), 695-722.
Baer, R.N., 1980, Calculations of sound propagation through an eddy. The Journal of the Acoustical Society of America, 67(4), 1180-1185.
Hao, J., Chen, Y. and Wang, F., 2010, Temperature inversion in China seas. Journal of Geophysical Research: Oceans, 115(C12).
Holbrook, W.S., Páramo, P., Pearse, S. and Schmitt, R.W., 2003, Thermohaline fine structure in an oceanographic front from seismic reflection profiling. Science,301(5634), 821-824.
Jensen, F.B., Kuperman, W.A., Porter, M.B. and Schmidt, H., 2011, Computational Ocean Acoustics. Springer Science & Business Media.
Jian, Y.J., Zhang, J., Liu, Q.S. and Wang, Y.F., 2009, Effect of mesoscale eddies on underwater sound propagation. Applied Acoustics, 70(3), 432-440.
Lin, Y.T. and Lynch, J.F., 2012, Analytical study of the horizontal ducting of sound by an oceanic front over a slope. The Journal of the Acoustical Society of America, 131(1), EL1-EL7.
Mackenzie, K.V., 1981, Nine‐term equation for sound speed in the oceans. The Journal of the Acoustical Society of America, 70(3), 807-812.
Porter, M.B., 1990, The time‐marched fastfield program (FFP) for modeling acoustic pulse propagation. The Journal of the Acoustical Society of America, 87(5), 2013-2023.
Stojanovic, M. and Preisig, J., 2009, Underwater acoustic communication channels: Propagation models and statistical characterization. IEEE Communications Magazine, 47(1), 84-89.
Tang, D., Moum, J.N., Lynch, J.F., Abbot, P., Chapman, R., Dahl, P.H. and Graber, H., 2007, Shallow Water'06: A joint acoustic propagation/nonlinear internal wave physics experiment. Oceanography, 20(4), 156-167.
Tao, Y. and Xu, X., 2007, Simulation study of multi-path characteristics of acoustic propagation in shallow water wireless channel. In 2007 International Conference on Wireless Communications, Networking and Mobile Computing, 1068-1070, IEEE.
Yuan, D., Li, Y., Qiao, F. and Zhao, W., 2013, Temperature inversion in the Huanghai Sea bottom cold water in summer. Acta Oceanologica Sinica, 32(3), 42-47.
Zhang, L. and Swinney, H.L., 2014, Virtual seafloor reduces internal wave generation by tidal flow. Physical Review Letters, 112(10), 104502.