Saturday, March 23, 2013

Wrapping the Flag in Canadian Humour

An earlier post told a portion of the story of the design of the painting for the “50 Years of Our Flag Project”. The project wraps the Canadian Flag in history, art and science. Using artistic licence I have also tried to wrap the flag in a little bit of humour.
As a society we move too fast. We may be really connected around the Globe but remain disconnected from what is in front of us. The little pleasures that surround us every day and every where are typically missed. These little pleasures include taking the time to look up at the sky and the clouds. Who sees the back lit bunny? For most people, read no further, just take time to enjoy the clouds. For those who want a bit of meteorology feel free to forge ahead.

The lifted condensation level (LCL) of the fall air mass was quite high – probably 2 to 3 thousand feet above ground level. The parcels of air lifted from the drying surfaces and autumn crops all condense at the same level above the ground – the LCL. That is why these cloud bases are level since heating of the ground is the main reason providing convective lift. The southerly winds increase with height and slope the towers of cumulus cloud toward the north as they grow. The “Bunny Cloud” has gotten tall enough to start the precipitation processes. The bunny is thus called a “towering cumulus”. This also tells us that the temperatures within the higher portions of the cloud are near minus 15 Celsius. Ice crystals grow very well at these colder temperatures due to the high saturation vapour pressure over ice. The ice crystals grow, get heavier and begin to fall. Some crystals collide and aggregate together. By the time the snow flakes are fully developed they are falling at 1 metre per second and exit the bottom of the bunny. In this case the air temperatures closer to the ground are well above freezing. The air is also drier. The snow flakes melt into rain drops which fall much faster closer to 10 metres per second. This increased fall rate decreases the density of the hydrometeor per a given volume and this partially explains why the snow flakes disappear after they have fallen a certain distance from the base of the cloud. The rain drops could also be evapourating into oblivion and thus never reach the ground. Meteorologists call this type of precipitation that doesn’t quite make it to earth “virga”. I suspect this was all virga as I don’t remember getting any moisture on my canvas.
There is humour and even science around us all. We just need to slow down to enjoy it.

1 comment:

zz said...

Phil, thank you for the painting and the explanation. And for sure humor makes science more fun.