Sunday, October 19, 2025

Cloudy iridescence

 
iridescence in clouds
Thin clouds of ice crystals

Thin clouds with small and uniformly-shaped ice crystals passing close to the sun diffract the sunlight and produce iridescence.  
 
 
clouds with iridescent
A train of clouds

The intensity of the irisation increases as the clouds get nearer to the sun.  The clouds on the left are about 10 degrees away from the sun.  As this formation moves to the left, the clouds on the right will soon get to show off their pastel colors.
 
 

Monday, October 6, 2025

Three setting suns


The cold clouds of a passing weather front afford the sight of three suns setting.
 
sun digs and sun
Close to the horizon

The sun dogs on either side of the sun are caused by the refraction of the sunlight through the ice crystals in the clouds.   These parhelia are approximately 22 degrees to either side of the sun.  The red is closest to the sun with the blue to the outside.
 
For the stereogrammers,
 
3d triple sun
At sunset in 3d
 
this sundog scene is presented as a relaxed view stereograph.

  

Wednesday, October 1, 2025

Contrail in the front

 
clouds with contrail before
There is an airplane there

This twin jet engine aircraft is transiting from the clear skies of a cold front for the cloudier ones of the warm front. 
 
 
clouds with contrail entry
Visible in silhouette

Having entered the warm front, the contrail from the jet plane began getting longer.