Observing temperature profile while flying thermals

Temperature as well as static pressure are measured by XC vario. As a results, it is possible to plot temperature as function of pressure altitude. 

Below are plotted a few time slices as recorded. Several observation can be made :

• Flying straight in sink or neutral zone results in measuring a certain gradient of temperature versus altitude - generally steeper than -6.5deg standart atmosphere gradient.
  
• Circling & climbing in a thermal shows a similar temperature gradient versus altitude compared to measured in straight flight, but with an offset corresponding to warmer air
  
• While entering or exiting the thermal, a transition happens in the same order of magnitude : we end up drawing an hysteresis
• The greater the climb, the greater the "warm offset"
• Those observations seem to remain true for strong climb in mountain area as well as weak thermal over flat land on a poor day

Using temperature sensor as a "thermal sniffer" is not the objective here, nevertheless collecting this data could be worthwhile  in term of validating weather models - particularly if coming from a network of gliders flying the same area.

 ----------------------

 Strong thermal at Malaup montain on the 13th of september 2021

• Transition
  
• 3.95m/s mean value over 850m climb
• Transition
  

 

 ----------------------

Good thermal at La Molière (north Vercors) on the 13th of september 2021

• Transition in a uplift area, then sink
  
• 2.1m/s mean value over 320m climb
• Transition
  

 

 

 ----------------------

Soft climb at Gache mountain on the 13th of september 2021

• Transition
  
• 1.1m/s mean value over 370m climb
• Transition
  

 ----------------------

Weak thermal over flat land on the 9th of october 2021

• Transition
• 0.6m/s mean value over 100m climb
• Transition