Poppies and Circumhorizon Arc

June 08, 2017

PoppiesandCHA_IMG_20170409_130936_scaled (1)

Photographer: Jussi Leinonen
Summary Authors: Jussi Leinonen; Jim Foster

As shown above, a bloom of bright orange California poppies (Eschscholzia californica) blankets the ground near the Antelope Valley Poppy Reserve in Southern California. Meanwhile, a patch of sky above the Santa Monica Mountains, to the south, displays beautiful coloration. This circumhorizon arc (CHA) forms when hexagonal plate ice crystals in cirrus clouds are oriented so that that sunlight enters the side face of these crystals and then exits through the lower basal face. Both the poppies and the CHA have limits as to when they can be appreciated; the poppies bloom only in early spring and the CHA can only be observed when the Sun is higher than 57.8 degrees above the horizon -- or near midday during the spring and summer seasons. Photo taken on April 9, 2017.

Photo Details: Camera Maker: LGE; Camera Model: Nexus 5X; Focal Length: 4.67mm; Aperture: ƒ/2.0; Exposure Time: 0.0003 s (1/3185); ISO equiv: 60; Software: GIMP 2.8.16.