Wednesday, December 14, 2005

More Cloud Bows

The truly inimitable Julie reports on a recent adventure. As usual the geography is a little, well, vague. There are two trails to Mumford Bar, one from the south, near Westville, on the Foresthill Divide, the other from the north, near Government Springs, on Sawtooth Ridge.

The former is reached via Foresthill, the latter via Emigrant Gap and Forest Road 19, turning left onto the Helester Point Road. Julie went in via Government Springs.

To reach the North Fork is a hike of a few miles. The canyon is 3000 feet deep here and is deepening as one goes east.

She fords the river, and ventures up the American River Trail to the base of the Beacroft Trail, the next trail east, going up the Foresthill Divide from Mumford.

This is a hike of a few miles.

Then she and her friend return.

About cloud bows: the best treatment I have found was in a coffe-table book full of gorgeous color plates titled "Clouds of the World," by an airline pilot who always flew with his camera. This book came out around 1978 or so and is likely long out of print. Essentially, there are many types of ice crystals, in cirrus clouds, and related clouds. Each type has its own peculiar angle of refraction. Hence each type of cloud bow is located a certain angular measure from the sun; we call the line from our eye to the sun, zero degrees, and on the same line, produced behind us to infinity, is the anti-solar point, at 180 degrees. A particular type of cloud bow may be found only at an angular distance of 57.xxx degrees, for instance.

Sun dogs are those commonest cloud bows located on the "ring around the sun," the angular separation of which, I am embarassed to report, I do not recall; it might be 35.26 degrees.

*******
So familiar sounding, the nature mystisism and cloud bows. Now when I see
them, they are still just as magical, but in a different way. Not because
they mean something, but just because they exist and I am lucky enough to
see them sometimes. I saw one yesterday (Tuesday) after a magnificent hike
down Mumford Bar with Kathi. We were in full sun almost all the way down,
and there was no snow in Emigrant Gap. At the river it was cold and shady ,
naturally, and it was painful to cross the water. 34 steps to take and the
pain sets in after 24! We proceeded up past the Mumford cabin, and lunched
at the wonderful roaring and thundering grotto near the bottom of Beacroft.
The day did warm finally in the bottom of the canyon and our crossing on the
ruturn trip was much more pleasant. Then back into the warm sun up the
slope. We decided to top off the day with a visit to Big Valley Bluff, and
that is where we were treated to a sight of the sun dogs. One on either side
of the sun, as it settled into some low clouds. The moon was high and quite
large. The snow on surrounding peaks took on a peculiar steel blue color as
the sunset dwindled to dusk, truly one of the more dramatic sights I've
seen. And sun dogs too! Julie
*******

Quite a nice long walk! Thanks, Julie!

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