Sun Dogs and Other Things

In the town of Central, 100 air miles northeast of Fairbanks Alaska, we had sun dogs caused by ice crystals in the atmosphere. Both reflection and refraction were involved with refraction producing colored effects and reflection producing white effects. On Tuesday February 19th the reflection effects were minimal and the sun dogs were highly colored while on Wednesday February 20th the reflection effects dominated and overwhelmed the most of the colored effects.

The Olympus XZ-1 was used to capture the ten photographs below. Photos 1, 2 and 7 (full telephoto) were taken using the Sony VCL-DH1756 Tele Conversion Lens (1.7 X) attached to the XZ-1 with the Lensmate XZ-1 adaptor and a 50-->58 mm step ring.


Photo 1 (4:02 pm): The left parhelion (sundog) from Feb. 19th (somehow I was carried away in my attempts to retain the highlights and under-exposed by at least two stops). Times are Alaska Standard time although I keep the camera on Alaska Daylight time year round

 


Photo 2 (4:04 pm): The right parhelion from Feb. 19th. The temperature was -15° C.

 


Photo 3 (10:44 am): The two parhelia just outside of the barely visible 22° halo which surrounds the sun. Also barely visible at the top of the halo is the upper tangent arc. Photos 3-10 were taken on Feb. 20th. Temperature varied from -24° F to -20° F.

 


Photo 4 (10:46 am): The left parhelion with an arc of the parhelic circle emerging from the parhelion. In March 1999, the entire parhelic circle was visible from this location.

 


Photo 5 (11:05 am): The left 120° parhelion on the parhelic circle 120° away from the sun.

 


Photo 6 (11:06 am): The right 120° parhelion on the parhelic circle 120° away from the sun.

 


Photo 7 (11:38 am): The right parhelion. The effect of reflection had faded to the point where the effect of refraction was no longer overwhelmed. Within 15 minutes after this photo was taken, neither effect was visible.

 


Photo 8 (11:16 am): The circumzenithal arc, a section of circle with center directly overhead. This arc was also present with the colored sun dogs on February 19th. It had faded by the time I could get the camera.

 


Photo 9 (2:52 pm): An arc of the parhelic circle just to the right of the right parhelion. By noon the show was over, however two hours later things started up again.

 


Photo 10 (2:56 pm) The right parhelion with the arc of the parhelic circle emerging toward the right. By 3:00 pm everything had faded.