So, longer-lasting bubble could be your suggestion for testing the possible thermal activity over the treatment vats! My toy bubbles disappear too soon and drop too soon. I'd like to follow up on your formula. Binocular study of the bubbles downwind could possibly reveal wanted data.
With your good lead, BillC, here is a lead to anothr formula
http://sciencebob.com/the-ultimate-bubble-solution/Additionally, I am thinking of making and releasing bubbles at altitude (not from ground) from a long-tether kite-system platform. If the bubbles fall ordinarily, then perhaps no thermal. But if the bubbles rise especially noticeably, then that would be interesting. And then notice this over some intervals of time to see the constancy of flow behavior.
Would a tiny bit of the soap bubbles dropping into the vats bother the bacteria used in the treatment plant? Maybe the experiment would need to be approved by chemical engineers of the operation. What grace could the experiment give to the public besides our hang gliding wind flows?
Maybe the potential therms could be detective by other wind-reading methods.
https://en.wikipedia.org/wiki/Wind_profilerhttps://en.wikipedia.org/wiki/SODARMaybe a long kited line with scores of tell tales on the tether could profile what is happening. Skilled kiting to keep the line below the near tower heights will be needed.
At Sylmar at the Markus S. service on June 14, 2015, I suggested a movement to put continued energy into gaining ever better visibility of wind.