Physics Photo of the Week

March 26, 2010

Jones Mountain Trails and Winter Visibility
In honor of the past lingering winter, Physics Photo has to pay tribute to a number of natural winter phenomena.

Here we see some trails on Jones Mountain, near Warren Wilson College, made more visible by snow, sun illumination angle, as well as the lack of leaves.  The Davidson Trail (actually a logging road) can be seen taversing about half-way up Jones Mountain slanting slightly up to the right.  Without the snow cover, the trail is almost invisible.  The embankments on the uphill sides of the trail shields the deposition of snow slightly, thus enhancing the image contrast.  The grazing angle of the sunlight also enhances the contrast.  The trail is much more visible on the zoomed-in image below.

Having hiked up these trails frequently I wished to confirm which trail is which.  Is "Trail 1" the Davidson Trail?  If so, what is "Trail 2"?  The photos below are on-site photos of the trails from an earlier day.  The Davidson Trail is seen winding up the mountain.  See if you can locate the position of the lower photo in the above photo.  "Trail 2" is
not a trail at all, but is a fire break or similar feature made by a bulldozer several decades ago.  The bottom photo on the right is looking down Trail 2 from close to the ridge.

Davidson Trail - Trail 1

Firebreak looking down - Trail 2

Notice that a little bit of snow lies along the up-hill sides of each trail where the shade is greater.  Notice also that the bank of the Davidson Trail is quite steep.  When there is a light snow, the bank stays relatively bare and makes it visible from a distance.

Linear or disturbed features are often visibly enhanced by dustings of snow, oblique lighting, or even by changes in wetness as is often done at archeological sites.

Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department.  These photos feature interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation.  Atmospheric phenomena are especially welcome.  Please send any photos to 

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