It seems to exists a correspondence between many (but not all) of the frequency jumps of the misterious peak and temperatures increases detected by the probe, usually due to openings of the WE oven.
In particular the large frequency drop (from 780 to 740 Hz, which onsets in the lock starting July 4 20:10 UTC) coincides with the a large (the largest actually) temperature increase in the oven. This event also coincides with the frequency drop observed on many thermal modes of the WE mirror (see Thermal modes between 5600 and 5900 Hz) and with the jump of some of the violin modes (Entry 18046 by Michele Punturo).
The second plot is just a zoom in between June 10 and 25 when many jumps occurred. Note that temperature increases sometimes coincide with a increase of the peak frequency and sometimes with a drop. It is not at all clear why it should be so.
