Sunrise from Pikes Peak

Pikes Peak is one of two Fourteeners in Colorado that have a road to the summit. On Mt. Evans, there is a self-service toll booth, which makes it easy to arrive on the summit in time to shoot sunrise. The Pikes Peak road is also a toll road, but the road is only open when the toll booth is staffed, which makes it impossible to reach the summit before sunrise or to stay until sunset. On one day a year, however, the road opens early to allow photographers and others to arrive on the summit before sunrise. In 2011, the date was September 18. A late-summer snowstorm had dropped six inches of snow on the summit the day before, and a fierce wind was ripping across the summit when I arrived in the pre-dawn twilight. I pulled on my full arctic regalia, everything, in fact, that I would normally wear on a winter sunrise shoot except for plastic double boots. A ranger approached me as I struggled to stay upright while walking across the icy parking lot. "Let's pretend we're playing Jeopardy," he said. "I'll give you the answer, and you give me the question." I nodded assent, wondering where he was going with all this. "The answer is 6," he said. I had gotten up at 2:15 a.m., so I was too sleep-deprived and hypoxic to think fast, and I had no idea what he was talking about. "What is the wind-chill?" he answered for me. "The wind chill is six degrees."

On clear mornings, high peaks that rise abruptly above the plains, such as 14,110-foot Pikes Peak, can be blessed with extraordinarily colorful sunrise light. The light from the rising sun enters the atmosphere, skims the surface of the Earth at a tangent point in the plains of eastern Colorado at about 4,500 feet, then rises back up through the atmosphere to strike the summit of the peak. During that long journey, which is roughly 50 percent longer than it would be if the light was illuminating some object at the tangent point, most of the blue light scatters out of the beam, leaving behind only the reddish rays to light up the foreground. Peaks for which the "horizon" is really another peak of the same elevation get less colorful light because the path length is shorter than those for which the horizon is the plains nearly 10,000 feet below. The shorter path means less opportunities for the blue light to scatter out of the beam as the light interacts with air molecules in a process called Rayleigh scattering. Fortunately, the horizon was free of clouds during my one and only morning on the summit of Pikes Peak, and I was treated to a stunning display of naturally red light playing out across the rough-hewn granite boulders that make up the summit.