This question already has an answer here:
Several pictures of the Concorde taking off, show a cloud of water droplets (fog) above the wings. Like this:
I assume the fog is created due to low pressure over the wings. But, doesn't the size location and visible turbulence of this pattern suggest that the wing is stalled? It certainly doesn't look like laminar flow.
I don't recall seeing this on other aircraft at takeoff.
What's going on? Is it unique to the Concorde? Is it exacerbated by ground effect?
This Wikia entry says:
...the undercarriage had to be unusually strong. This was due to the unusual loadings due to the high angle of attack that Concorde needed to take-off due to its delta-wing.
The "high angle of attack" would support my guess that the upper wing is stalled?
I could understand a stall if the aircraft was landing, but these seem to be near stall during takeoff?