The insects showed a tendency to head approximately downwind with an acute angle to the wind direction.
Aeolian fractionation can lead to downwind changes in the chemical composition of distal ash fall deposits, connected to changes in the mineralogical composition.
On this day downwind concentrations are calculated at their greatest of the entire emission period.
The layer imitates the profile of the wave, but is displaced downwind about 20".
Such long distance spread requires the emission of large amounts of airborne virus at source and a high density of susceptible animals downwind.
As flies were not able to move downwind from the insertion point, the tests measured upwind displacements only.
A wave-like pattern then becomes established downwind of the mountain range, with the air ' bouncing ' between the surface and the stable layer above.
In the centre of the downwind screen was a round hole circumscribed by a mounting ring to hold a releasing cage.