Explicitly construct a differentiable vector field $W$ in the torus.
Meridians of $T^2$ parameterized by arc length, for all $p \in T^2$, define $W (p)$ as the velocity vector of the meridian passing through $p$.
Maybe could help
$x=(R+r \cos \phi)\cos \theta$;
$y=(R+r \cos \phi)\sin \theta$;
$z=r \sin \phi$
Where $\theta, \phi \in [0, 2\pi[$ Thanks