Category Archives: photography

Fox Mountain Frost

Hollow columnar hoarfrost deposited on leaves and twigs on Fox Mountain in the San Gabriel Mountains, near Los Angeles.

When I see crystals of hoar frost sparkle in the Winter sun it triggers a child-like awe. On Sunday’s Condor Peak Trail Run, several sections of trail glittered as we ran into a low morning sun. On the cold east face of Fox Mountain, a fine, needle-like frost coated the edges and surfaces of leaves and twigs that had collected in pockets on the steep slope.

Digitally magnifying a small section of a 10 Mp image revealed that the frost is comprised of  hollow columns, and further magnification shows that the columns are hexagonal, with lengthwise facets.

This type  of frost – hollow columnar hoarfrost – is described in STUDIES OF FROST AND ICE CRYSTALS by W.A. Bentley, in the Monthly Weather Review, Volume 35, Issue 9 (September 1907), pp. 397-403. Here is an excerpt:

“When formed in the open, they are essentially mild-weather types. They are most common to early autumn and late spring, and the hoarfrost that collects upon the plants and grasses during the so-called destructive frosts at those dates is almost invariably of this type. Hoarfrost deposits of this character form in the open during calm, clear nights when the surface air temperatures range from 56 degrees to 40 degrees at nightfall, and from 33 degrees to 25 degrees during the latter part of the night or early morning.”

Here is a graph of weather data recorded by the Mill Creek (ANF) RAWS on December 1 and December 2. The elevation of the station is 3510′ and it is about 8.5 miles from Fox Mountain (5033′). Parameters graphed are the hourly average wind speed, air temperature, fuel temperature, relative humidity, and dew point.

At Mill Creek the fuel temperature dropped below the frost point at 10:00 p.m Saturday, and did not exceed the frost point again until 8:00 a.m Sunday. For a 5 hour period from 2:00 a.m. to 7:00 a.m. the mean air temperature was 30°F-31°F and the fuel temperature was 22°F-23°F — suggesting strong radiative cooling. Similar conditions probably produced the frost on Fox Mountain.

Condor Peak Trail Run

Trail runner on the Condor Peak Trail as it nears Condor Peak.

The temp was in the 30’s and it took a couple of minutes for my car’s engine to warm enough to thaw the coating of ice on the windshield. I was headed for a run in the San Gabriel Mountains and was wondering how cold it might be.

In a November in which 29 days had been bone dry, it had rained on the 30th, and temps had cooled dramatically. That was day before yesterday. This morning the sky was still a storm-cleansed blue, and except for a few passing high clouds, promised to stay that way. If the winds were not too brisk, it could be one of those invigoratingly crisp late Autumn days — cold in the shadows, but warm and pleasant in the sun.

About an hour later Miklos and I were working our way up the Condor Peak Trail (13W05), not far from the trailhead on Big Tujunga Canyon Road. At the parking area I had shed some extra layers and was now running in shorts and a light long-sleeve top. In the pack were an ultralight shell, gloves, and a headband.

About a 1/4 mile from the parking area we caught up to some hikers and their dogs. They asked us if we were headed “to the top.” I replied that we were doing Fox Mountain and Condor Peak, and would continue on to the Trail Canyon Trail.

“Do you have a car at the Trail Canyon trailhead?”

“Yep…”

“You know it’s 17 miles, right?”

“Yep…”

Twenty minutes into the run, we reached the point where the old trail jumps up from Big T and joins the main trail. From here we turned north, away from the highway, and began a long, winding, uphill course that would eventually reach the divide between Fox Mountain (5033′) and Condor Peak (5440’+). This meandering approach resulted in a very runnable section of trail that gains about 2500′ in 5.5 miles — an average 8.6% grade.

As the trail wound in and out of canyons, and from shadowed to sunny slopes, the temperature contrasts were startling. Within a few feet, we would stride from balmy, solar heated granite alcoves into frosty, refrigerated nooks near freezing. We estimated the difference in temperature to be 30-40 degrees.

Gradually we gained elevation, and in about an hour and a half we crested the broad divide at the base of Fox Mountain. From this point a short — but steep — path leads directly to Fox’s summit. 

Deep in morning shadow, the east side of the peak was cold! The ground was frozen, and heavy frost covered fallen leaves of chaparral. A few strenuous minutes and we were atop the peak, relishing the warmth of the sun and the panoramic view. Mt. Lukens, Josephine Peak, Strawberry Peak and Mt. Wilson loomed nearby. Further to the east, beyond Mt. Waterman and Twin Peaks, Mt. Baldy glistened white with a new coat of snow. Dressed for running, and damp from the climb, chill breezes hurried us from the summit.

Peak to peak the distance from Fox to Condor is over two miles. That’s what the map says, but on the ground Condor looks deceptively close. Several false summits amplify the deception, and many a hiker has been deceived. Even having viewed the route from Fox and climbed the peak before, I still did not fully appreciate the distance.

The scramble up Condor was a little longer than the hike up Fox. The peak has twin summits at very nearly the same elevation. We were curious which summit would have the register and found it on the more westerly summit. To do both Fox and Condor only added about an hour to our run.

Once down from Condor Peak it took about twenty minutes to hoof it over to the Trail Canyon Trail (13W03) junction. From here the trail drops about 3110 ft. in six miles. The grade of the trail is steeper than the Condor Peak trail, and a little more rocky and technical. Where the Condor Peak trail seeks the high lines, the Trail Canyon trail follows a creek and plunges into a deep riparian canyon.

Back at the car we marveled at what an enjoyable run it had been. The perfect weather and nearly ideal grade of the trails seemed to make the run almost effortless. It isn’t always that way.

Here’s a Google Earth image and Google Earth KMZ file of a GPS trace of the route.

Note: Although the Trail Canyon drainage is relatively small, it appears to have generated some sizable flash floods and debris flows. The canyon forms a huge southwest facing “rain catcher.” During Winter storms, the canyon wrings water from moisture laden wind as it is funneled into and up its slopes.

Racing the Sun

Sunset at Ahmanson Ranch.

Racing the sun,
Waiting for rain,
Listening to a meadowlark sing.

From a run at Ahmanson Ranch — now Upper Las Virgenes Canyon Open Space Preserve. Here’s a larger view of the full 16:9 frame.

For an update on this Winter’s austere outlook for rain, see my November 29 Weathernotes.

Comet Holmes 17/P

Image of Comet Holmes 17/P taken in the light pollution of the San Fernando Valley, near Los Angeles, on November 13, 2007.

Image of Comet Holmes 17/P taken in the light pollution of the San Fernando Valley, near Los Angeles. It was photographed through the eyepiece of a 5 in. telescope (SCT) using one of my “running” cameras — a 10 Mp compact digital.

An exposure of 60 seconds was used. The raw format image was pushed 2.5 stops and the tone curve adjusted in Adobe Camera Raw to bring out detail in the diffuse outer coma of the comet. The image was flipped so that it is not reversed and is upright.

The comet’s nucleus is at about 8:00 o’clock, near the head of the more dense and bright inner coma. A hint of a tail can be seen projecting in the 2:00 o’clock direction. The tail of the comet isn’t more obvious because from Earth we’re seeing the comet almost head-on.

This illustration, generated using Starry Night Pro, shows the position of Comet Holmes 17/P on 11/13/07 – beyond the orbit of Mars – and its relationship to the Earth, Sun and the plane of the solar system. An orbit visualization and much more info is available on the Comet 17P/Holmes page on TheSkyLive.

Search Comet Holmes 17/P on Google for more info.