Monday, July 29, 2013

The Crow Asks: Can you explain these odd contrails?


Last week near sunset I noticed some contrails about (as typically in the YXU at this time of year). But check these out. If you look at the photos you’ll see that “above” each trail the trail looks normal but “below” it is a series of round, puffy clouds, not unlike cirrocumulus clouds. Definitely not billow shaped clouds ones would expect from some kind of gravity wave interaction.

Can anyone tell me is this an altitude affect, dynamics, or is it a function of the type of airplane engine which emitted the water vapour?

Monday, July 1, 2013

PCL’s transmitted laser beam in the rain

In case you wondered what does the PCL’s transmitted laser beam look like when it is drizzling out. The answer is weird, instead of a steady bright green column you get all this “carbonated” bubbling in the beam from the water droplets.

Laser Beam in Drizzle from Robert Sica on Vimeo.

PCL makes the Ontario Physics Grade 12 textbook

Crow Andy joined us at the lidar last night and showed us this page from the Ontario Grade 12 Physics text: the PCL is now appearing in backpacks all over the province.

(this photo dates back to our location at the Delaware Observatory and was taken by Honorary Crow for Life Luc Girard).

Physics 12 textbook - PCL photo