Direct temperature and salinity acoustic full waveform inversion

Abstract

[1] Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed (c), density ( ), temperature (T), and salinity (S) from the weak impedance contrasts associated with the ocean's thermohaline fine structure.The seismic inversion approaches proposed so far are based on the iterative inversion of c from multichannel seismic data, while the rest of parameters (T, S, and ) are determined in a second step using two equations of state and a local T-S empirical relationship. In this work, we present an alternative to this approach. Using 1-D synthetic seismic data, we demonstrate that the direct full waveform inversion of T and S using adjoint methods is feasible without the use of any local T-S relationship and that the models of physical properties obtained with this approach are far more accurate than those inferred from c. Citation: Bornstein, G., B. Biescas, V. Sallarès, and J. F. Mojica (2013), Direct temperature and salinity acoustic full waveform inversion, Geophys. Res. Lett., 40,[4344][4345][4346][4347][4348]

Recovery of temperature, salinity, and potential density from ocean reflectivity

“…Because of that, we consider that the synthetic FWI inversion presented by Bornstein et al . [] is very promising since they do not use any T‐S relation and invert independently temperature and salinity directly from the acoustic wave minimizing the error in potential density. As a final test, we have applied the method of Bornstein et al .…”

“…As a final test, we have applied the method of Bornstein et al . [] to invert potential density from the synthetic reflectivity along a section of a meddy. The result, which is shown in Figure , corroborates that potential density varies along the continuous reflector of the top of the core and hence reflectivity is not isopycnal.…”

“… Isopycnal contours inverted using the FWI method from synthetic seismic data [ Bornstein et al ., ].…”

“…Papenberg et al [2010] inverted stacked reflection sections hundreds of kilometers long that sampled up to 1700 m of the water column into temperature and salinity profiles with accuracies of 0.1 C and 0.1, respectively. Recently, two MCS synthetic data studies that detail methodology and show the potential of using full waveform inversion in oceanographic research have been published by Kormann et al [2011] and Bornstein et al [2013].…”

Characterization of the submesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of high‐resolution MCS data

“…MCS systems are widely used in solid earth exploration and research, and they started to be used in oceanography following the preliminary results of Gonella and Michon [1988] and the seminal work of Holbrook et al [2003], which opened a new branch in operational oceanography that has been called "seismic oceanography." Subsequently, a series of studies have demonstrated the potential of conventional MCS data to image the thermohaline fine structure of the oceans [Biescas et al, 2008;Buffett et al, 2009;Sheen et al, 2012;Ménesguen et al, 2012], to extract water properties such as sound speed, temperature, or salinity [Papenberg et al, 2010;Bornstein et al, 2013;Biescas et al, 2014;Padhi et al, 2015] or to provide information on internal wave dynamics and turbulence [Holbrook and Fer, 2005;Sheen et al, 2009;Krahmann et al, 2008;Falder et al, 2016], all with extraordinary detail in the horizontal dimension.…”