Thursday, December 31, 2009

The Earth Year

On this last day of 2009, it is important to realize that, beyond our home planet, a year, the cherished span by which we measure our history and our lives, is merely a segment of time. And while the duration of a year correlates with the period of Earth's orbit around the sun, the specific timing of man's calendar year is not tied to any natural cycle; rather, it is a product of human culture, influenced by politics and religion.

It might be argued that our year should begin at the winter solstice (the beginning of the solar cycle as perceived from Earth) but that would produce a 6 month variance of the calendar between the Northern and Southern Hemispheres. Of course, were it not for the tilt of our planet's axis, the seasons would not exist and we would not have solstices. If that were the case, the period of sunlight (for any given location) would not vary through the year and humans would likely be fixated on the moon, measuring our lives and our history in lunar cycles.

Beyond Earth, a year has no more significance than, say, 23 seconds, 51 hours or 813 days; it is just our measure of time based on our planet's orbit and on our experience of seasonal change. If we lived on Mercury, our year would be 88 Earth-days long while, on Neptune, an Earth-year would take us only 1/165 of the way around the sun. When viewed from the perspective of our galaxy, a year becomes even less significant as a period of time; it takes somewhere in the neighborhood of 230-250 million years for our solar system to orbit the center of the Milky Way. As in all aspects of natural science, it is important to acknowledge that our perspective, as observers from planet Earth, can temper our understanding of the Universe. Happy New Year!

Tuesday, December 29, 2009

The Threat of Argument

Argument, the unruly and emotionally-charged cousin of discussion, is often triggered by disrespect, intolerance and selfishness. While arguments are common in human relationships, they seem to be an increasingly common form of public interaction, threatening the welfare of society as a whole.

Recent town meetings to discuss health care policy descended into shouting matches, a Congressman became a folk hero by interrupting a Presidential speech to call him a liar and Capitol Hill has broken into polarized camps. All of this is fueled by an increasing assortment of talk media where bombastic moderators (from the left and right) invite guests from the political fringe and encourage heated argument, all the while interrupting with their own self-righteous remarks. In like manner, "reality shows" of courtroom antics and dysfunctional families entertain us with open combat between attention-starved participants, seeking their brief but fleeting opportunity for fame.

While open debate, dissent and calm discussion are essential to the health of democracy, crass and manufactured arguments have no place in government, entertainment or education. Nothing is accomplished, a poor example is set for our children, disrespect and intolerance are encouraged and stress is induced in participants and viewers alike. Unfortunately, an increasingly large segment of society seems to be entertained by this behavior and by the media programming that supports it; for the rest of us, it is time to vote with our ballots and our remotes.

Monday, December 28, 2009

Formation of Waterfalls

Liquid water, acting under the force of gravity, has sculpted spectacular landscapes across our globe and waterfalls are among the most beautiful and inspiring. Most waterfalls develop where a stream passes a geologic boundary, crossing from a hard, resistant bedrock to a softer, less resistant one; this causes an abrupt drop in the level of the stream flow. The "fall line" of the southeastern U.S. offers an excellent example of this process; here, rivers flowing from the Southern Appalachians to the Atlantic all possess significant waterfalls at the boundary of the Piedmont (underlain with hard igneous and metamorphic rock) and the Coastal Plain (composed of soft sedimentary deposits).

Once waterfalls form at these geologic boundaries, they begin to erode upstream and, over thousands of years, produce rugged gorges through the hard bedrock; an excellent example is provided by the Niagara Gorge, which formed (and continues to develop) as the falls cut their way upstream through the Niagara Escarpment. In other areas, waterfalls form when the walls of river valleys are altered by glaciers or landslides; tributaries that once descended through side canyons now drop precipitously to the valley floor; Yosemite Falls is perhaps North America's most spectacular example.

Some waterfalls occur beneath the surface of our planet, developing at sinkholes where the roof of a cave has collapsed. In these karst landscapes, thick layers of soluble bedrock (limestone or dolomite) lie just beneath the surface, often covered by a relatively thin veneer of sandstone. Cracks in the overlying rock allow rainwater and snowmelt to percolate into the limestone, eventually opening vast, underground networks of streams and caves. Surface streams drain toward these sinkholes and, once the underlying cave is spacious enough, a waterfall forms.

Saturday, December 26, 2009

Window on Winter

While I enjoy winter hikes, on days like today, with frigid air and wind-blown snow, a good novel often sounds more inviting. Fortunately, we have a feeder just outside our picture window and the harsh conditions bring a wide variety of birds to the edge of our family room.

Feeding groups of chickadees, titmice, white-breasted nuthatches and downy woodpeckers appear on a regular basis and northern cardinals, especially bright against the bleak, winter landscape, are more than welcome visitors. Now and then, an unruly mob of house sparrows and starlings invades the scene; though not overly fond of the sunflower seed, they are voracious scavengers and, while searching through the contents, scatter much of the seed for our ground feeders. The latter include juncos, white-throated sparrows, cardinals, mourning doves and an occasional fox sparrow. Among other visitors are red-bellied woodpeckers, house finches, purple finches, Carolina wrens, hairy woodpeckers and those erratic red-breasted nuthatches. Of course, gray and fox squirrels grab what they can and, toward dusk, an opossum may wander in to scour the site for fallen seed.

Amateur naturalists and beginning bird watchers are often surprised to discover the variety of birds that inhabit our residential areas. All it takes is a well-placed feeder and cold, snowy weather to provide an entertaining window on nature's diversity.

Friday, December 25, 2009

Christmas Pinwheel

Yesterday's winter storm is centered over Iowa this morning and its counterclockwise winds are producing dramatic and ironic variations in the holiday weather. Strong southerly winds ahead of the storm are pushing relatively warm, moist air far to the north while cold, northerly winds to its west are bringing frigid air to the deep south. At this hour, the temperature in Dallas sits at 31 degrees F while it is five degrees warmer in northern Wisconsin; Chicago enjoys a balmy 42 degrees though, half a State to the southwest, Des Moines shivers at 19.

Northwest of the central low, the warm, humid air is being pushed over the dense, Arctic air, producing heavy snow which, combined with strong north winds behind the cold front, has created blizzard conditions across western Minnesota, the eastern Dakotas and down the Nebraska-Iowa border. Here in Missouri, wrap-around flurries, caught in a gusty, west wind, have arrived just in time for Christmas; the temperature is 17 F and is forecast to remain near 20 degrees throughout the day.

Powerful, slow moving storms often produce a marked contrast in weather over short distances and, as is evident today, one's latitude neither rules out nor guarantees a snowy Christmas. Like giant pinwheels, these massive systems can mix north with south in a sudden and dramatic fashion.

Thursday, December 24, 2009

From April to December

Last evening, as a massive winter storm swirled over the Central Plains, thunderstorms rolled across Missouri, swept northward in advance of the cold front. Dropping torrential rain, the storms were accompanied by balmy, spring-like air and, by dawn, the thermometer sat at 50 degrees F.

Though such balmy interludes are common here during the winter months, the potency of the thunderstorms was a bit unusual, confirming the tremendous amount of energy in this latest storm system; to our southwest, the trailing cold front ignited tornadic supercells in east Texas while, north of the storm, blizzards raged across Minnesota and the Dakotas.

Contrary to the original forecast, the Midwest low has apparently weakened while a secondary low, which developed over Oklahoma, has strengthened, bringing heavy snow to central Oklahoma, northern Texas and southeastern Kansas. As this low tracks northeastward, we will remain in the warm (rainy) sector today but, as its front sweeps in from the west, our temperature will plummet; in concert, snow will develop, northwest winds will strafe the Heartland and December will reclaim Missouri.

Wednesday, December 23, 2009

The Evolution of Thought

Nervous systems first appeared in primitive marine life, billions of years ago. These earliest systems were reflexive in nature; stimuli (light, touch, pressure waves, etc.) would trigger a response (movement toward or away from the stimulus). Such mechanisms were essential to survival, playing an important role in feeding, defense and reproductive behavior.

As evolution produced more complex life forms, the neurological system developed in concert. Special sensory organs permitted more sophisticated forms of sight, hearing, smell and coordination; we can easily identify this progression in the modern representatives of animal families, from mollusks to mammals. Up through birds and most mammals, the neurologic system is primarily limited to peripheral nerves, spinal cord, brain stem and cerebellum; the brain stem controls basic functioning (such as respiration) while the cerebellum is critical to balance and coordination. The cerebral cortex, with its highly complex network of neurons, is the latest product of neurologic evolution, adding the capacity to think, reason, interpret, remember, learn, create and communicate in sophisticated ways.

While a primitive cerebral cortex is found in all birds and mammals, it has reached its highest form of development in primates; of course, humans are the most advanced primates and our cerebrum is, by far, the most complex. Indeed, our brain power has developed to the point where many humans conclude that we are divine creatures, superior to and separated from all lower forms of animal life. Yet, anatomic evidence demonstrates a clear evolutionary progression of the nervous system and medical science has shown a convincing correlation between specific brain injuries (via trauma, stroke, tumor, congenital deformity) and the loss of specific neurologic capabilities. Though difficult for many to accept, our thoughts, memories and emotions are the products of neuronal pathways and brain chemistry.

Tuesday, December 22, 2009

Creeping toward Spring

Now that we have crossed the winter solstice, the Northern Hemisphere begins its long, steady march toward spring. Too slow for many humans, the sun's angle will inch higher in the southern sky and, as a consequence, its rays will more directly impact the lands north of the equator. By the summer solstice, on or about June 21, it will reach its zenith (as our Hemisphere is at its maximum tilt toward the sun) and we will enjoy the longest day of the year.

Though our days will lengthen incrementally, we will not appreciate significant warming for another couple of months; in fact, at central latitudes of North America, the coldest days of the year (by average highs and lows) occur during the third week in January. While the sun angle will be too low to provide significant warming until mid February, we still enjoy balmy interludes as weather systems pump mild air up from the south.

Over time, the frozen ground will thaw, plants will germinate, birds will sing and our faith will be restored. Until then, we can enjoy the snowscapes, star gaze on clear winter nights, listen for the hoot of owls and dream of spring.

Sunday, December 20, 2009

Just House Sparrows

Casual backyard birders know them as those little brown birds that crowd the feeder, aggressively denying access to competi-tors. Avid, experienced birders know that they are "just house sparrows," prolific and alien residents of our cities, suburbs and farmlands.

Actually members of the weaver family, these common birds were introduced to North America from Europe and, to say the least, have adapted well to our natural and man-made environments; though they look and act like our native sparrows, they have shorter legs and thicker bills. Rather dull in plumage and too abundant to interest veteran bird watchers, they are the beneficiaries of farmers and sympathetic suburbanites, who provide them with waste grain, bread crumbs, millet and other commercial bird seed.

While these immigrants have messy nesting habits and compete with native birds for natural food, one must admire their hardiness and adaptability. And, when it comes to their basic physiology and anatomy, they are just as interesting as any other bird species. But looks, habits and country of origin have a lot to do with acceptance, just as occurs in human society.

Friday, December 18, 2009

Merging Lows

Light snow has developed in central Missouri this afternoon as a low pressure trough has dropped down from the north, dragging a pocket of cold air in its wake. Sitting over the mid Mississippi Valley, this low is pulling warm, moist air up from the south and lifting it over the cold air to its north and west. Falling through a thick blanket of subfreezing atmosphere, the precipitation is reaching the ground as snow; since the ground is relatively warm, little accumulation is expected.

Meanwhile, a stronger low is swirling over the Panhandle of Florida, bringing heavy rains to the Southeast. As this low moves to the northeast and our current storm moves to the east, the two systems will merge off the Southeast Coast. Since cold air will drop behind the Midwest low, a cold front will pass through the Mid Atlantic region just as the the storms combine, setting the stage for heavy snow from Virginia to New York.

As with all of these weather events, the track of the heavy snowfall will depend upon the relative positions of the cold front and the new, combined low. If the latter churns slowly to the northeast, paralleling the coast, significant snow will blanket the urban corridor, from Washington, D.C., to New York; if, on the other hand, it's course is more north or more east, the swath of heavy snow will shift accordingly. Either way, its going to look a lot like Christmas across the Mid Atlantic States.

Thursday, December 17, 2009

Geology of Big Bend

Protected as a National Park in 1944, the Big Bend of West Texas harbors one of the best concentrations of geologic formations on the planet. Spanning 500 million years of Earth's history, these rock layers represent the last three chapters of geologic time: the Paleozoic, Mesozoic and Cenozoic Eras.

In the early Paleozoic, some 500 million years ago (MYA), a seaway curved into the south-central region of North America, from Mexico to the latitude of Oklahoma and Arkansas. Over the following 200 million years, this shallow arm of the sea filled with sand, mud and gravel which hardened into layers of sandstone, shale and conglomerate rock. When North America and South America collided during the assembly of Pangea, 300-270 MYA, these sediments were lifted and folded into the Ancestral Ouachitas, which have since eroded into relatively low ridges across this region; stumps of the ancient mountains represent the oldest rocks in Big Bend National Park. About 135 MYA, a broad sea cut across North America, from eastern Mexico to northwest Canada, covering what is now the High Plains and Rocky Mountain corridor; after depositing thick layers of limestone, this Cretaceous Sea retreated, leaving younger sandstones and mudstones (with their cargo of dinosaur and marine life fossils) atop the limestone. The Cretaceous limestone now forms towering cliffs along the Rio Grande River and is the primary component of Big Bend's Deadhorse Range.

Following the Laramide Orogeny (Rocky Mountain uplift, 65 MYA), volcanism developed in the Big Bend region and occurred intermittently from the Eocene to the Miocene (from 42 to 22 MYA). The earliest eruptions formed the Christmas Mountains, in the northwest area of the Park, while later volcanism formed the Chisos Mountains, which include Big Bend's highest point, Emory Peak (7832 feet). Further uplift of the Mountain West during the Miocene has stretched the crust between Big Bend and the Colorado Plateau, triggering formation of the Rio Grande Rift and producing fault-block ranges across West Texas and eastern New Mexico. Finally, heavy precipitation during the Pleistocene molded the varied strata of Big Bend and the dry climate of the Holocene has served to protect and highlight the Park's geologic wonders.

Tuesday, December 15, 2009

Polar Plunge

A dome of cold, dry air has dropped into the Heartland, bringing a morning low of 14 degrees F to central Missouri. Across the Midwest, temperatures range from the teens to 20 below zero, with dew points from the single digits to near 30 below. Sunny skies accompany the dome but the low angle of the winter sun produces little warmth.

Along the southern edge of this dome, from east Texas to the Florida Panhandle, a clash with warm, humid air is producing heavy rain and flooding. Dew points across this boundary rise by 50 degrees in some areas, from the mid teens in Arkansas in the mid sixties along the Gulf Coast. As the dense, cold air knifes below the warm, soupy air, the latter is forced to rise, dropping its temperature below the dew point and triggering the heavy rain. Since the boundary is stationary, this precipitation continues to fall over the same areas and flooding results.

A milder, Pacific high will nudge this dome to the northeast over the next few days and the Midwest should return to more seasonal conditions. But, from now until mid March, these polar outbreaks will invade the Heartland on a regular basis.

Sunday, December 13, 2009

December Sunset

A few days ago, driving south across the flat glacial plain of Illinois, we watched the sun set behind a white sea. The retreating winter storm had spread a few inches of snow on the fields that stretched away to the Illinois River and its backside winds sent ground blizzards across the bleak landscape.

Less than two weeks from its winter solstice, the sun disappeared below the southwest horizon and an orange glow spread above the fields, contrasting with the slate blue of the clear, cold sky; the thermometer read 17 degrees F. Skeins of geese drifted toward the river but nothing else moved in the late afternoon twilight.

Before long, the last glow of dusk retreated with the sun and a bowl of stars covered the vast till plain. It would be a long, frigid night for the wildlife of central Illinois.

Saturday, December 12, 2009

Faith & Courage

There is a well known saying that you will never find an atheist in a foxhole. And, I would add, you will never find an atheist in a suicide vest. Most who engage in combat, for whatever cause, are comforted by the conviction that, should they pay the ultimate price, they will be rewarded in the afterlife. In other words, their religious beliefs, if not their rationale for war, provide the courage to participate.

Humans often lean on faith to deal with a variety of struggles in their lives, including illness, addiction and personal loss; of course, the ultimate certainty of death is the primary threat that we all face. Many would argue that religious belief is an essential source of courage, providing emotional support as we endure the many trials and tribulations of life; were it not for the self-delusion and secondary consequences (discrimination, zealotry, anti-science rhetoric) I might agree that religious faith is a benign form of adaptation.

There is another relationship between courage and faith that most humans are unwilling to consider. Immersed in a world of religious conviction and mysticism, the individual is infused with beliefs at an early age and remains under pressure to retain them throughout his life. It takes courage to question the tenets of faith and, in the end, most choose to comply rather than adopt a life of intellectual honesty.

Friday, December 11, 2009

Ohio Gray

Ohio harbors a wealth of beautiful landscapes: rustic farms, wooded hills, tallgrass prairie, hemlock groves, scenic lakeshores and rugged gorges, to mention a few. But the winter weather of the Buckeye State rarely brings such accolades. Visiting family this week, my memories of Ohio's gray season were strongly reinforced.

Located at the confluence of moisture flow from the Gulf of Mexico and the Great Lakes, Ohio receives more than its fair share of annual precipitation and, during the colder months, what doesn't fall creates a dense overcast of flat, gray clouds. Adding to the moisture flow, the State's terrain gradually climbs toward the east, producing a mild "upslope" as the air rises, cools and condenses. This orographic precipitation is especially evident in Northeastern Ohio where northwest winds, developing behind cold fronts, sweep across Lake Erie, saturate with moisture and dump their cargo of heavy snow on the higher terrain southeast of the Lake.

Of course, this winter precipitation nourishes the rich forests, wetlands, meadows and productive farmlands of the State. But, in the midst of a cold, gray winter, those benefits are often hard to appreciate.

Sunday, December 6, 2009

Myths & Children

For the sake of tradition, we deceive our children with a variety of myths, from flying reindeer to a giant Easter bunny to the tooth fairy. While most consider this practice to be harmless childhood fantasy, stimulating imagination and bringing happiness into their lives, it may produce unintended consequences, if only at the subconscious level.

Would the holiday season be less joyful if we eliminated these myths? Are we unable to celebrate peace, charity and good will without the jolly man in the red suit? Are gifts less appreciated if we are honest about their source? All of this may sound like psycho-babble from a holiday humbug but I'm not sure we need to protect our children from the realities of life by creating fantasies that we must debunk as they begin to mature. Trust is fragile and should be handled with care.

There are certainly good reasons to protect our children from fear and worry during their formative years and their understanding of life must progress in a gradual, non-threatening and age-appropriate manner. But our willingness to sustain traditional myths, however cute and entertaining, says more about our own discomfort with reality than it does about our devotion to childhood fantasy. After all, we have adult myths that are difficult to abandon.

Saturday, December 5, 2009

The Nature of Infidelity

The scandal involving Tiger Woods has flashed across the globe this week, covered by tabloids, sports networks and major news organizations. The fact that Woods, admired for his skill and his devotion to golf, has been unfaithful in his marriage was not a surprise to me. What was a surprise was the that, after centuries of similar episodes, humans were shocked to hear the story.

There is no excuse for infidelity but there are reasons. The first and overriding reason is that human males are not naturally monogamous. Like most males in the animal kingdom, we were designed to spread our genes through as many females as possible; part of that design is a sexual drive that creates interest in having a variety of partners (especially attractive females of child-bearing age). Despite legal, religious and social constraints, many men cannot (or choose not to) contain this natural tendency. Though highlighted by the lives of celebrities, marital infidelity is widespread among all socioeconomic levels, all professions, all religions and all cultures, resulting in a high rate of divorce and the associated painful consequences.

Lesser causes include marital problems, psychological disorders and, far down the list, predatory females (a favorite villain for many unfaithful males). Given the selfish nature of human beings, there are few (if any) ways to prevent the common occurrence of infidelity. But I'm sure that women can suggest a cure.

Thursday, December 3, 2009

Winter Plunges South

The first major cold front of the season pushed through Missouri yesterday morning and, behind the front, strong north winds brought winter to the Heartland. Though temperatures fell through the day, there was not enough moisture in the air to produce rain or snow.

This morning, with a bright full moon in the clear, western sky, the thermometer reads 27 degrees F. Fortunately, the winds have abated and my walk to work in the predawn darkness was pleasantly invigorating. Though cold, the air is dry, offering a welcome change from the chilly, damp weather of recent weeks.

With little solar heating at this time of year, we are at the mercy of the jet stream. Its dips (troughs) allow Canadian air to plunge southward while its northern oscillations (ridges) bring interludes of balmy weather from the south. But the tide has turned and cold spells will dominate for the next few months.

Wednesday, December 2, 2009

Highway Evangelists

The farmers of the American Heartland certainly know a great deal about corn, wheat and soybeans. Many have experience raising cattle, hogs and sheep. Some also fancy themselves as preachers.

Conscious of the captive audience that streams past their fields, these highway evangelists promote their beliefs with a self-righteous zeal. Scripture verse adorns the side of barns, images of Jesus rise above the corn stalks, anti-abortion signs line the fences and makeshift billboards advise us to repent and prepare for eternity.

As private landowners, they certainly have the right to take advantage of the exposure and express their beliefs. Of course, the great majority of these roadside preachers are Conservative Republicans, in favor of the death penalty, opposed to gun control and enraged by any "socialist ideas" that the government might propose; one wonders if Jesus would share their views. And, most disturbing, their underlying message is that America is a Christian nation; all others are unwelcome.

Tuesday, December 1, 2009

Into the Dark

Humans are not naturally equipped to deal with cold or darkness. We do not have enough body fat (in most cases) or hair cover to provide adequate insulation and our night vision is very limited. One can only imagine the stress imposed by these factors prior to the advent of modern technology; death from exposure or nocturnal predators was surely common.

As we descend into the cold and darkness of winter, we get a taste of these environmental threats and, despite our access to electricity and heated homes, we retain the fear of our ancestors, buried in the collective human psyche. We are, after all, tropical creatures, not designed for polar or subpolar climates. And, as a species, we "remember" the advantage that nocturnal hunters have during these winter months; the hoot of the owl and the howl of the wolf, while inspiring, are also chilling.

So, following the lead of our threatened ancestors, we conduct our seasonal rituals. Using lights to ward off the darkness, we pray and hope that our saviour, the sun, will return.