**Appendix B. Other SST Observations**

Microwave radiometers observations suffer from poor spatial resolution but have great spatial coverage, since they are not affected by the cloud coverage. Their temporal coverage is good for balanced flows but not for IW. We explored to which extent the information about low-modes stationary internal tides (as well as barotropic tides while we're at it) could be extracted from such data. Figure A2 shows an example of a Microwave SST captured by AMSR2 for the same date than the case study in South Madagascar shown in Section 4.2. As it can be observed by comparing Figures 4 and A2, only stronger gradients can be observed in microwave observations, and its amplitude is reduced by half.

**Figure A2.** (**a**) SST captured by AMSR2 on the 5 June 2014, same date than SST shown in Figure 4 (**b**) Sobel gradient of SST captured by AMSR2.

#### **References**


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