That's the AEGIS system. It works better when land-based, from what I've read; it's dramatically more accurate than the purely naval fleet-defence version.

AEGIS is an integrated, networked system; multiple sensors on multiple platforms (including AWACS) collaborate to detect and hit targets.

There was an AEGIS-equipped ship either in the Black Sea, or trying to get in through the Bosphorus (now closed to naval traffic). The presence of AEGIS ships in the Black Sea would be enough to explain the non-appearance of the Russian airforce.