Hard to find anything about this in US news sites--we are a bit preoccupied with ourselves right now, it seems. I just happened to see reports of Turkish armored columns, etc. One report says the "entire" Turkish Second Army (about 10,000 soldiers) is conducting the operation. Seems hard to believe that 10,000 troops would move against US supported forces and the US media would ignore it. Perhaps it is a much smaller operation, and the reports I'm seeing are propaganda.
In one report, the Russians are blaming the US for the action (reason: the US armed the Kurds). "Blame" is an interesting word in politics (domestic or international).
Link: https://al-sura.com/turkey-invades-syria-goal-to-destroy-ypg/