Are the underlined words in the sentence an independent clause, a subordinate clause, or neither?

"since early this morning" my friends and i been riding our bikes every evening.
p.s. the quotation is the underlined words.

It would be a subordinate cause, for it can't stand on its own. Think about it: Since early this morning. What happened since early morning? Since it doesn't provide that information, it wouldn't be able to be an independent cause.

Also, I don't believe that the sentence is grammatically correct :)

From the excerpt above the best answer would be:

 

The aesthetic impact describes what it was like to be a veteran during the Vietnam war, and the experiences of the person taking care of people. In one of the lines that says: “Brushstrokes flash, a red bird's wings cutting across my stare. The sky. A plane in the sky. A white vet's image floats close to me, then his pale eyes look through mine.” It follows how the veteran talks about the death of the victims and how they will be remembered, the description of the plane may even describe bobs that were falling from the sky.