@article {Bornstein2013, title = {{Direct temperature and salinity acoustic full waveform inversion}}, journal = {Geophysical Research Letters}, volume = {40}, number = {16}, year = {2013}, month = {aug}, pages = {4344{\textendash}4348}, abstract = {Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed (c), density ($\rho$), temperature (T), and salinity (S) from the weak impedance contrasts associated with the ocean{\textquoteright}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 $\rho$) 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. Key Points T and S can be inverted simultaneously from ocean acoustic data using FWI Local T-S empirical relationships are not required for the inversion Our T and S results have a potential density error of 0.01 kg/m3. {\textcopyright} 2013. American Geophysical Union. All Rights Reserved.}, keywords = {acoustic oceanography, adjoint method, full waveform inversion, thermohaline fine structure}, issn = {00948276}, doi = {10.1002/grl.50844}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84882307211\&partnerID=tZOtx3y1}, author = {Bornstein, G. and Biescas, B. and Sallar{\`e}s, V. and Mojica, J. F.} }