Just a thought, but why applied math programs?
Control and nonlinear dynamics are equally prominent in both engineering and applied math. In engineering, control will probably have a bit more prominence compared to NLD, whereas applied math might focus more on the math modelling and NLD part. Nevertheless, you can study these as part of engineering.
Scientific computing is more in the computational science and engineering domain, and is not necessarily considered applied math. Most applied math programs I am aware of concentrate on the math modelling part, and do computing only when absolutely necessary. You might be more interested in some of these: https://www.siam.org/students/resources ... ograms.php
Also, scientific computing is sufficiently far removed from control and NLD, that it makes little sense to mention all the three together. Some overlap between sci. comp. and NLD is possible through turbulent fluid flows, weather forecasting etc. but there is little interface between sci. comp. and control. Incidentally, if you are interested in the three topics in the context of biological systems (which seems very plausible), consider an MS/PhD in systems biology or bio-engineering too! For example, the systems biology program in UCSD is excellent and has some facets of all three - control, NLD, and sci. comp.
With regards to GRE score, I wouldn't report it unless the university requires it. I don't see any way in which it can help your admission cause (it's not high enough to be considered a plus) and it could hurt you in a few places (if the adcom is stingy). I wouldn't take the chance. I'll just take a wild guess and say that app math programs at Maryland and Northwestern might interest you. Also see the SIAM link and bio programs like UCSD.