Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification. Essentially, lower salinity water (= lower density) floats on top of higher salinity water (= higher density).
Alternative definition, a choice limited to one of two or more possibilities, as of things, propositions, or courses of action, the selection of which precludes any other possibility: You have the alternative of riding or walking. See more.
Augmentative and Alternative Communication (AAC) is the term used to describe various methods of communication that can âadd-onâ to speech and are used to get around problems with ordinary speech. AAC includes simple systems such as pictures, gestures and pointing, as well as more complex techniques involving powerful computer technology.