| By Steven Foster
Ice Beauty
I’m dreaming of a bright Christmas—sunny with temperatures approaching the low 70s. The iconic “White Christmas” is so 1940s! Forget the fact that Bing Crosby’s version of Irving Berlin’s song is the best-selling single of all time. A white Christmas is a historical song from 1941. We must look on the bright side of global warming as it relates to “climate change.” We just need to change our perspective. Speaking with my 87-yr old dad in Maine, he remarked that as a kid, he and his friends were always skating by Thanksgiving. I reminded him, that we—his kids—were also skating by Thanksgiving! During my Maine childhood a white Christmas was a given. Now, ponds and lakes barely hold ice in some Maine winters. But of course, a Maine winter is why this Maine native lives in the Ozarks.
Every time I experience, feel, and see beauty in nature, I am humbled and awed. I love how water changes into myriad forms of beauty in ice. I also love each and every strand of evolving, changing, adapting, mutating DNA that is The creator’s building block of creation. I don’t believe in DNA, the stuff of The creator’s evolutionary magic. I don’t have to. It exists whether I choose to believe in it or not. Recent religious thought teaches us that the Earth is flat and the Earth is the center of the Universe. And “recent” I define as what historians calls the “early modern era” beginning about 1500. As one historian friend put it, “Anything that happened after 1500 is by definition current affairs.” I don’t believe in global warming. I don’t have to believe in it. Science has blessed me with a magic wand known as a thermometer. Burn me at the stake.
The beauty of snow, sleet and freezing rain
Which brings me to snow, sleet and freezing rain, and what differentiates them. Snow is created when a mass of cold, freezing air is uniformly below freezing from the Earth’s surface to the upper atmosphere. Sleet
is formed when the air aloft is like a sandwich. In this case, the upper levels of the atmosphere are below freezing and when it snows, the snow passes through an atmospheric layer above freezing, causing the snow to partially melt. It then passes through a relatively shallow layer of below-freezing air at the surface, creating sleet. Freezing rain forms when rain from warm air aloft reaches below-freezing surfaces at ground level, caused by a shallow layer of cold air at the surface. Expect to see plenty of all three types of frozen precipitation this winter—courtesy of global warming.
Hoar Frost Beauty
And I love the beauty that all that ice in it’s myriad form creates. Take hoar frost for example. We’ve had beautiful hoar frost (also known as hoarfrost this year. But what is hoar frost? I turned to the website of the National Snow and Ice Data Center for a definition “Hoarfrost: A deposit of interlocking ice crystals (hoar crystals) formed by direct sublimation on objects, usually those of small diameter freely exposed to the air, such as tree branches, plant stems and leaf edges, wires, poles, etc., which surface is sufficiently cooled, mostly by nocturnal radiation, to cause the direct sublimation of the water vapor contained in the ambient air.”
That certainly sounds like definition like that comes from a program with some association with the government. Specifically, the National Snow and Ice Data Center, or NSIDC is part of the University of Colorado Cooperative Institute for Research in Environmental Sciences (UCCIRES), and is affiliated with the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC). NSIDC also supports the National Science Foundation (NSF) through the Arctic System Science Data Coordination Center (ASSDCC [can you say “I work at ASSDCC”]) and the Antarctic Glaciological Data Center (AGDC) or so Wikipedia says. In other words, the good folks at NSIDC know a good deal about frozen water on or about earth. An advance degree in acronyms is required for employment there.
Hoarfrost, therefore, is like dew, except when it’s cold enough outside to freeze water (that is when it’s 32°F or 0°C), and there’s moisture in the air, then hoar crystals (flat crystals that interlock together), form from the moisture in the air when it comes in contact with the edge of the object that is below freezing (or vice versa?). So if you get up early enough, especially after a clear cold night, you can experience the direct sublime beauty of hoarfrost in all its simplicity.
Glorious Ice Ribbons
Another winter beauty phenomena I love is frost flowers and ice ribbons. Perhaps new to your natural history vocabulary, we can also call this phenomena “crystallofolia,” a term coined by Bob Harms of the Plant Resource Center, University of Texas, Austin, who has been investigating the phenomena we commonly call “frost flowers”— those beautiful ice formations that are produced at the base of only two native plant species in my Ozark home. Our two native plant species that exhibit this phenomenon are American dittany (Cunila origanoides) and white crownbeard or frostweed (Verbesina virginica) both of which are late-blooming wildflowers. Their frost flowers or twisted ribbons of ice appear for a few days (up to a couple of weeks) after the first hard freezes in autumn. These ephemeral sculptural beauties in ice appear at the base of the plant.
The delicate, elegant ice formations emerge laterally from the stem, just above the ground in the case of American Dittany, but from ground level to two feet up the stem in the case of white crownbeard. Why does this phenomenon only occur in a select few plant species instead of all plants? Speculation is that a combination of characteristics unique to the plant in combination with the external physical forces provides a perfect opportunity for the frost flowers to develop. The xylem, vascular tissue within plants that helps conducts water upward in the stem, is probably quite firm, with secondary rays at a right angle that is strong enough to conduct water during a frost event but its tensile strength reaches a point during the first cold frosts, that freezing water burst through the epidermis at a right angle to the stem. As it does so, it ever so slowly punches moisture into the freezing air extruding ribbons of ice. I love these beauties of nature.
Pennsylvania physician, William Darlington (1782-1863) seems to be one of the first to record observations of frost flowers in Cunila, or as he called it, Maryland Cunila. In the second edition (1837, p. 350) of his Flora Cestrica (an herborizing companion for the young botanists of Chester County, Pennsylvania) he writes: “In the beginning of winter, after a rain, very curious and fantastic ribbands [sic.] of ice may often be observed, attached to the base of the stems of this plant—produced, I presume, by the moisture from the earth rising in the dead stems by capillary attraction, and then being gradually forced out horizontally, through a slit, by the process of freezing. The same phenomenon has been noticed other plants.”
Predicting When Hell will Freeze Over
How do you survive a cold winter? Perhaps the best way, short of a long trip to a tropical location or being condemned to a mythical inferno, is to get a comparative perspective on someone else’s cold winter. In the English-speaking world we can turn to England, which has the longest series of monthly temperature observation datasets recorded back to 1659. This dataset is known as the CET (Central England Temperature), recorded in Celsius.
The winter of 1683-84 is believed to be the coldest winter since records have been kept, with a “great frost” settling in by mid-December for the UK and Central Europe. By January of 1684, the Thames River was frozen all the way up to London Bridge. The Thames itself remained frozen for over two months, with ice measured to a depth of 11 inches. In southwest England, in Somerset, it is said that the ground froze to a depth of four feet. Southwest England, has a relatively mild climate, tempered by the Gulf Stream in the winter months, and Azores high pressure systems in the summer. The winter of 1684 had thee coldest CET at –1.2 deg. C. This period of cold winters lasted for several centuries. From 1408-1814, the Thames froze over 24 times; sometimes the ice was deep enough to support “frost fairs” on the Thames (the last one in 1814).
This is all within a period known as “the Little Ice Age”, a phrase first used in the scientific literature until 1939. It is loosely defined as a period from about 1350-1850, with three particularly cold periods around 1650, 1770 and 1850. Attributed causes include low cycles of solar radiation, increased volcanic activity and variables in ocean circulation.
Fewer sun spots may cause cooling. The years 1645-1715 represent a period of weak solar activity (fewer sun spots) known as the Maunder Minimum period (in which only one-thousandth of “average” expected sun spots occurred). This solar lull is theorized to have trigged regional cooling in the Northern Hemisphere. Since 2008 we have been in a period of “solar maximum” yet only half of the sunspot activity expected has occurred. This has led some scientists to speculate that we could be heading toward a period of “cooler “solar activity within the next 40 years. Add that into the global-warming equation, and you still get climate change
