How Weird Is Winter? The Science of Cold and Ice

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How Weird Is Winter?  The Science of Cold and Ice 
By Heath Shive 

As House Stark would say: Winter is coming.  Or, depending on where you live, winter is already there.  So it might help to “know thine enemy.”

The Weird Stuff About Winter

1. Ice and snow are technically minerals, just like rubies or emeralds.  They fit the official geological definition.  And just like other minerals…
2. Ice and snow come in a variety of colors!  The color depends on the impurities.  Volcanic particulates of the Tambora Eruption of 1815 produced blue, brown and red snows in Maryland; and red and yellow snow in Taranto, Italy.  In 2010, the Stavropol region of southern Russia experienced a light purple snow, attributed to Saharan dust.  There has even been…
3. Pink snow!  Pink snow is regularly found in the Sierra Nevada and is called “Watermelon Snow” due to its pink color.  It even smells like watermelon - though you shouldn’t eat it!  The color is the result of Chlamydomonas nivalis, a species of cold-loving green algae that has a secondary red carotenoid pigment (astaxanthin).  But the true color of pure ice and snow is…
4. Blue!  Pure ice is blue, for the same reason the sky and oceans are blue.  Water absorbs more light from the red spectrum and reflects more blue.  However, snow looks white because trapped air reflect back all light.  If an ice cube doesn’t look blue, it’s because large quantities are required to make the effect obvious…and beautiful.  But you don’t want too much ice or otherwise we could have another…
5. Ice Age! Starting about 2.5 million years ago (the Pleistocene Epoch) glaciers grew rapidly and spread across the world.  At their peak, glaciers covered as much as 30% of Earth’s current land area.  Summer temperatures were 10ºC (18ºF) colder than present.  Sea levels dropped by more than 90 meters (250 feet), resulting in an extra eighteen percent increase in dry land, in turn creating land bridges across the Bering Strait, the English Channel, and Indonesia.  The last Ice Age ended 15 thousand years ago, and the Pleistocene ended almost 12 thousand years ago.  But to this day, no one is really sure…
6. Why the Ice Age began in the first place!  Theories abound.  The foremost theory involves the Milankovitch cycles, a term for how the Earth’s “wobble” (precession), axial tilt (obliquity), and planetary orbit (eccentricity) all vary with a regular cycle of every 20 thousand, 40 thousand and 100 thousand years respectively.  Those variations affect how the Earth is exposed to the Sun’s heat.  Milankovitch cycles have operated since the Earth was turning, but the Ice Age was a geologically recent event, only in the last couple million years.  For the majority of Earth’s history, the planet has been considerably warmer. 
7. So, what else could have cooled the planet?  Did the erosion of the newborn Himalayas absorb and remove vast quantities of carbon dioxide, an important greenhouse gas?  Did the connection of the North and South American continents provide the catalyst?  When the two continents joined, the Gulf Stream now carried much warmer and wetter waters farther north.  This would increase precipitation (snow), and so increase glacier growth.  Other scientists say that continental drift plays a factor, as Ice Ages don’t really occur until there were large ice caps on the North and South Poles (which only occur when large landmasses are near the Poles to serve as climatic “anchors”).  No one is certain how the Ice Ages were born, or when they’ll return again.  But what is known for sure is...
8. The coldest spot in the universe is here on planet Earth!  In 2003, MIT scientists led by Wolfgang Ketterle were able to come within 810 trillionths of a degree of absolute zero (-273.15 Celsius).  Absolute zero is the coldest temperature known to science - so cold that even atoms stop moving.  But this super-cold spot was only a thousandth of an inch across.  In 2018, Italian physicists were able to bring an entire cubic meter to a temperature of 6 milliKelvin - or -273.144 degrees Celsius!  This is still colder than anywhere else in the known universe!  ​

Conclusion
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Winters come and go.  But humans have tackled winters - and worse - and we still survive.  We have fought every crisis that Mother Nature brings to us.  And we have what it takes to overcome…or move to Florida.

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Sources:
"Southern Russia overwhelmed with purple snow 09/03/2010." YouTube. Uploaded by czesio95, 8 Jul. 2012, https://www.youtube.com/watch?v=ty8kWGhWyYU. Accessed 22 January 2017

Armstrong, W.P. "Watermelon Snow." Environment Southwest. Number 517, 1987, pp. 20-23.

Officer, Charles & Jake Page. Tales of the Earth: Paroxyms and Pertubations of the Blue Planet. New York City: Oxford University Press, 1993.
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Fagan, Brian, ed. The Complete Ice Age: How Climate Change Shaped the World. New York City: Thames & Hudson, 2009.

Rafferty, John P, ed. The Cenozoic Era: Age of Mammals. New York City: Britannica Educational Publishing, 2011.

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