Discovery of a 150 day period in the Venus condensational clouds

Overview

Using near infrared (NIR) data from the VIRTIS instrument that once traveled aboard the Venus Express spacecraft, Kevin McGouldrick and Constantine C. C. Tsang found a periodic variation in radiance, most intense at the mid-latitudes.  The paper is here.

What Did They Find?

They identified A 150-day periodic variation in radiance within the 1.74 µm and 2.30 µm windows, which is most pronounced between 30° and 60° latitude.  They also found that in these mid-latitudes, radiance at these wavelengths steadily increased throughout the life of the instrument. 

Why Is It Important?

The 150-day timescale is consistent with a model (developed by McGouldrick) of the Venusian condensational clouds vertical structure, driven by radiative-dynamical feedback.  I'm not sure what that means, but thank goodness the paper is open source!

References

• McGouldrick, K., & Tsang, C. (2017). Discovery of a 150 day period in the Venus condensational clouds Icarus, 286, 118-133 DOI: 10.1016/j.icarus.2016.10.005