  Searches for phosphine in Venus' atmosphere have sparked a debate. Cordiner
et al. 2022 analyse spectra from the Stratospheric Observatory For Infrared
Astronomy (SOFIA) and infer <0.8 ppb of PH3. We noticed that some spectral
artefacts arose from non-essential calibration-load signals. By-passing these
signals allows simpler post-processing and a 5.7{\sigma} candidate detection,
suggesting approx. 3 ppb of PH3 above the clouds. Compiling six phosphine
results hints at an inverted abundance trend: decreasing above the clouds but
rising again in the mesosphere from some unexplained source. However, no such
extra source is needed if phosphine is undergoing destruction by sunlight
(photolysis), to a similar degree as on Earth. Low phosphine values/limits are
found where the viewed part of the super-rotating Venusian atmosphere had
passed through sunlight, while high values are from views moving into sunlight.
We suggest Venusian phosphine is indeed present, and so merits further work on
models of its origins.
