Hi Bill,

I think the tracks are just left by the very recent movement of aircraft and people on what appears to be a damp flight deck.

The sun is low in the sky, perhaps morning or evening - but after colours and before sunset.

If it's morning, perhaps they've just had a washdown of the flightdeck, or it's the morning dew, and we're seeing the tracks of the first flight-deck movements of the day leaving the marks on the deck. But I'll admit this is just a lot of supposition...

Simon