Winter is coming? Winter will never leave.
- photo by Mitch Waxman
For the record, my fear is that a new glacial age has begun, and TV weather reports back up my suspicions. Problem is that I’m not that good with a spear, and when the mastodons return I’m going to get bossed around by a group of hirsute Pachyderms. This sort of humiliation would be fairly typical for me, as your humble narrator is extremely easy to bully, especially by those megafauna which prosper during Ice Ages. Luckily, I can definitely do the cave paintings, so there will be some rationalized utility by which the strong can justify keeping me alive. Of course, this scenario isn’t all that much different from normal life, as there’s always someone trying to boss me around.
The energy balance of the snowpack itself is dictated by several heat exchange processes. The snowpack absorbs solar shortwave radiation that is partially blocked by cloud cover and reflected by snow surface. A long-wave heat exchange takes place between the snowpack and its surrounding environment that includes overlying air mass, tree cover and clouds. Heat exchange takes place by convection between the snowpack and the overlaying air mass, and it is governed by the temperature gradient and wind speed. Moisture exchange between the snowpack and the overlying air mass is accompanied by latent heat transfer that is influenced by vapor pressure gradient and air wind. Rain on snow can add significant amounts of thermal energy to the snowpack. A generally insignificant heat exchange takes place by conduction between the snowpack and the ground. The small temperature change from before to after a snowfall is a result of the heat transfer between the snowpack and the air. As snow degrades, its surface can develop characteristic ablation textures such as suncups or penitentes.
- photo by Mitch Waxman
It’s my own fault, being bullyable, as I was born “less than.” Vast physical cowardice, combined with a naturally ugly mind, renders one somewhat less than a “leader.” It has never been my joy to hit the game running home run, rather I’m the fellow who fouls out and sets up the hero for his or her savior moment at the bottom of the ninth. In an ice age overrun by giant Moose and hairy Elephants, it would be vainglorious to suggest that I’d be of much use to society, and admission is offered that one such as myself would have made a terrible Viking.
Ice was originally thought to be slippery due to the pressure of an object coming into contact with the ice, creating heat, melting a thin layer of the ice and allowing the object to glide across the surface. For example, the blade of an ice skate, upon exerting pressure on the ice, would melt a thin layer, providing lubrication between the ice and the blade. This explanation, called “pressure melting”, originated in 19th century. It however did not account for skating on ice temperatures lower than −3.5 °C, which skaters often skate upon.
In the 20th century an alternative explanation, called “friction heating,” was proposed, whereby friction of the material was the cause of the ice layer melting. However, this theory also failed to explain skating at low temperature. Neither sufficiently explained why ice is slippery when standing still even at below-zero temperatures.
It is now believed that ice is slippery because ice molecules in contact with air cannot properly bond with the molecules of the mass of ice beneath (and thus are free to move like molecules of liquid water). These molecules remain in a semi-liquid state, providing lubrication regardless of pressure against the ice exerted by any object. However, the significance of this hypothesis is disputed by experiments showing a high coefficient of friction for ice using atomic force microscopy.
- photo by Mitch Waxman
Perhaps my bag in this new Cryosphere, or snowball Earth, will be to handle the weaker animals which will populate the nooks and crannies of our world. This wouldn’t put any meaningful protein on the table, but would be a service sought out by others by which some occupation could be found. Squashing bugs and chasing rodentine manifestations would at least keep me busy enough to stay warm. Also, like the Mongols, I could wear clothes made of sewn up amalgamations of Mouse leather.
Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.
Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams.
The present-day polar ice sheets are relatively young in geological terms. The Antarctic Ice Sheet first formed as a small ice cap (maybe several) in the early Oligocene, but retreating and advancing many times until the Pliocene, when it came to occupy almost all of Antarctica. The Greenland ice sheet did not develop at all until the late Pliocene, but apparently developed very rapidly with the first continental glaciation. This had the unusual effect of allowing fossils of plants that once grew on present-day Greenland to be much better preserved than with the slowly forming Antarctic ice sheet.
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