SKYWATCH FRIDAY: THE SKY IS FALLING?  At the dramatic conclusion of the season's first thunderstorm, the base of a passing cloud takes on mountainous topography. Meteorologists use the term mammatus to describe these distinctive formations. Warm, moist air in the thundercloud rises in a typical convective updraft. It strikes a layer of cooler, dry air in the atmosphere above and spreads outward to produce an anvil-shaped cloud. Ice crystals fall to the bottom of the cloud where they sublimate, changing state directly from ice to water vapor. As this cool air sinks in pockets across the base of the cloud, localized, reverse convection currents are set up—the puffballs that give mammatus clouds their texture.  "Who-ha-hoo-o-o is Ready for Spring?"Most mornings I awaken to the territorial song of a whip-poor-will. Wait a minute! you might say, if you have some familiarity with this bird. The whip-poor-will rarely performs its namesake song outside the spring mating season. And hey… (you may add suspiciously) whip-poor-wills winter along the Gulf of Mexico and in Central America. They’re hundreds of miles from your frigid Minnesota home in winter! What’s the story, Petersen? The truth is, I cheat. My whip-poor-will waker-upper comes from an alarm clock. During the spring breeding season, local wild birds often make my electronic whip-poor-will redundant. Thanks to its high latitude, Minnesota’s June sunrises take place as early as 5:30 a.m. Humans may have allied dawn and birdsong, but birds don’t seem to consider this such a firm contract. More than two-dozen songbird species nest in our neighborhood, and many appear to consider it slothful to wait until sunrise before singing. Some start as early as 4:00 a.m. In the heart of winter I miss that avian chorus, however inconvenient its timing. Some birds remain here year-round, to be sure. Last year my son’s kindergarten class studied winter birds. Over dinner one evening,  My son's colored pictures from the kindergarten unit on winter birds "Soaring Survivors: Pelican-Watching in San Francisco"  Fog begins to lift above the Golden Gate Bridge I'm standing on the coastal trail just west of San Francisco's Golden Gate. Fog obscures most of the famed structure, though now and then a blazing patch of red is revealed as a gust of wind pushes aside a corner of the low-lying cloud. If I were asked to choose a mascot to represent this grandiose landscape, the brown pelican would have no rivals. To the inexperienced observer this might seem an odd choice. Weighing up to eight pounds, with a wingspan greater than 7 feet and a curving neck that culminates in an improbably long, hooked bill, brown pelicans look like make-believe creatures from a child's storybook: gangly, disproportionate, and comical. Yet airborne pelicans are the epitome of grace—flapping with slow ease; making fast, steep plunges in pursuit of fish; flying in long, curving formations that follow the breaking lines of waves.  Adult brown pelican in non-breeding plumage SKYWATCH FRIDAY: "Head in the Clouds"  Autumn weather is as changeable as a teenager's moods. On Sunday night a heavy bank of clouds rolled in just as the Harvest Moon began to peek over the eastern horizon. The low pressure system parked over our heads and remained in place for two days, bringing two inches of much-needed rain. Wednesday dawned fresh and golden. By early afternoon warmer air had caused unusual cloud formations to build up. Altoculumulus undulatus clouds are named for their resemblance to rippling wave trains along “Actions Speak Louder” I recently read a remarkable, true story about William Kamkwamba, a young man from Malawi, Africa. William was forced to quit school at age 14 because his family could not pay the $80 annual school fee. Instead of becoming dejected or angry, William began to spend time at the library. When he noticed a picture of a windmill, William got the idea to build one. He realized that the windmill could provide a little electricity and pump water, both of which were in short supply in his community. SKYWATCH FRIDAY "Read Across America (or, William's Solar-Powered Adventure)"  The desert of east-central Nevada is lovely, cold, and deep. But as the first sunlight tinges thin clouds above, it’s time for William Grote to get moving. Quickly packing his belongings into the back of his Hauler, he hits the road. This three-wheeled bike looks a bit like an overgrown Mars Rover—and it’s got some of the same features. Wide tires enable the Hauler to traverse off-road terrain. And like the Rover, this vehicle carries a solar panel connected to a battery pack, which stores energy for later use. The battery powers an electric motor to assist the rider through challenging conditions, and also provides connections for AC power. (William’s pedal-power also contributes to battery storage.) The Hauler’s frame is designed to carry 500 pounds, in the form of passengers or cargo behind the recumbent driver’s seat.  William and the Hauler. (All photos in this post courtesy of William Grote) “Peddling Away Down the Road of Life” Raise your hand if you like to ride bikes! Chances are, many of you responded positively to that question. If I could get everyone in the U.S. who purchased an adult-sized bicycle in 2008 to read this blog, there would be more than 13 million hands raised at this moment. America’s love affair with the “dandy horse” goes way back. After its initial wave of popularity in the 1880s, the bicycle experienced a resurgence in the wake of the Great Depression. In 1936 the magazine Popular Science provided a summary of biking in the states. "Four "Passing Thoughts”  "Beauty has as many meanings as man has moods. Beauty is the symbol of symbols. Beauty reveals everything, because it expresses nothing. When it shows us itself, it shows us the whole fiery-colored world." —Oscar Wilde In the early morning hours I stand at the kitchen window, alone with the silence and my thoughts. The last few stars fade overhead as a pale glow touches the treeline across the lake. To my surprise, a late-feeding bat appears over the meadow, making a wide sweep at canopy level. The bat passes just a few meters in front of the window. Suddenly it lurches to the side, down, then rapidly forward. Such maneuvers make bat flight appear haphazard SKYWATCH FRIDAY: "Pull Over, Ma'am" Thankfully, those words—"Pull over, ma'am"—are not the reason I find myself on the shoulder of Interstate 35W at 7:00a.m. Nor is my action the result of car trouble. A different voice has caused me to stop the car on this Sunday morning-quiet stretch of highway. I have heard the call of beautiful scenery. I resisted as long as I could. I’ve been driving through a pervasive layer of ghostly ground fog, which hovers like thin smoke over farm "On the Wing" For weeks the yard has hummed (yes, that's a pun) with ruby-throated hummingbirds. Throughout the day males, females, and juveniles zipped between feeders, flowers, perches, and hideouts. The chase was always on, and tiny birds whizzed past us, in pursuit or retreat, whenever we ventured into the yard. Actual fights between hummingbirds are apparently uncommon, though they seem to expend endless energy keeping each other from nectar sources. In Birds of America, John James Audubon described this habit. “They are quarrelsome,” he wrote, “and have frequent battles in the air, especially the male birds. Should one be feeding on a flower, and another approach it, they are both immediately seen to rise in the air, twittering and twirling in a spiral manner until out of sight.” A few years back I read an article about hummingbirds in Smithsonian magazine. The author commented how fortunate it is that | "Shall I not have intelligence with the earth? Am I not partly leaves and vegetable mould myself?" --Henry David Thoreau, Walden
Christine Petersen is a professional writer, naturalist, and environmental educator who works from her home in Minnesota—when she's not too distracted by the view out the window.
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