Sunrise or Sunset - Seeing Gravity Wave Clouds

#2535 "Sunrise on Killbear Light"

This is the next step in applying Creative Scene Investigation (CSI-ing) to "Sunrise on the Killbear Jumping Rocks". The first step explained the colour of the light in Sunrise or Sunset - Seeing Red. The second step explained the clouds. The next step will investigate the gravity waves in those clouds using #2535 "Sunrise on Killbear Light" since that painting includes that portion of the sky depicts the same sunrise, . 

#2534 "Sunrise on the Killbear Jumping Rocks"

Every line in the clouds has a story to tell. The large scale banding in these clouds are gravity waves and they reveal the system relative winds in the free atmosphere away from friction and complicating interactions with the surface of the Earth.  The larger the wavelengths of the gravity waves, the stronger the wind. The system relative wind direction must be perpendicular to those waves. The cloud itself is probably drifting in the same direction as those winds but one cannot discern that motion in a painting. 

The sky in #2535 "Sunrise on Killbear Light" is the same as in
#2534 "Sunrise on the Killbear Jumping Rocks" but I
included more of the clouds in that painting ... so the weather
can be better understood. 

Gravity waves in the sky are exactly like gravity waves on a lake. The wind is blowing perpendicular to those lines. The layer is fairly stable. Waves increase in size and wavelength with the wind. Parcels of air or water deflected upward are pulled back down by gravity. These parcels have momentum and overshoot the average level on their way down. The sinking parcels reach equilibrium and then rise buoyantly. The parcels once again gain momentum and overshoot the average only to be pulled down again by gravity. The process gets repeated again and again and again...

The fact that there are clouds at all tips the balance in favour of that being a southerly wind with moisture from the tropics. If there is not much cloud, then it is likely that the winds are from the north were moisture is more limited. 

The gravity waves also reveal the relatively stable layer in the atmosphere. Parcels displaced from the stable level, always try to return home again. These stable layers can be frontal surfaces typically associated with a southerly flow and more cloud - a warm front in this case. Subsidence inversions are stable layers that typically occur with sinking air and are typical with dry northerly flows. 

Dry northerly flow with gravity waves. A sunset
view looking west over Singleton Lake. 

But there is much more to CSI in this painting … I also see deformation zones and smaller scale gravity waves but will save those for the next day.

Keep you paddle in the water and warmest regards... 

Phil the Forecaster Chadwick