A German Transal C160 on final approach for runway 29.

When the anti-missile pods underneath the wings detect anything that might be a heat-seaking missile they drop high-intensity flares that have to distract the missiles heat-seaking warhead.

Those flares create quite some smoke and since the aircraft wings create huge vortexes in the air, the smoke gets stuck in those and as a result we see those beautiful curly smoke patterns.