Yes, if $X$ is a variety over an extension $K$ of $\mathbb Q_p$, then the $\ell$-adic cohomology spaces $H^i(X,\mathbb Q_{\ell})$ are $\ell$-adic representations of $G_{K}$, which give rise to Weil--Deligne representations. (See Tate's Corvallis article, for example.) The resulting Weil--Deligne representation is conjectured to be independent of the choice of $\ell$ (as long as $\ell \neq p$). This is known when $X$ has a smooth proper model over the ring of integers of $K$ (although from the point of view of root numbers this case is not so interesting; in this good reduction situation the associated Weil--Deligne representation is unramified, so the local root number is 1, for the right choice of additive character). It is also known when $X$ is an elliptic curve (in which case $i = 1$ is the interesting choice; this gives the contragredient of the Tate module). Actually computing root numbers is a non-trivial business, especially for instances of very bad reduction at small primes. For examples, see recent work by Mazur and Rubin, and by the Dokchitsers.