Go to http://u2.dmhy.org to register an account on the external site, and then post a message asking for invitations. You should be invited to the site on the same day. This is the U2 Animation Park. There are many animation resources in it, including the one you want, The Day After Tomorrow. There are two high-definition versions, both in 720P and more than 5G
If you just want to download this one, then don’t bother!