Guest opinion: Dr. Tim Ball
The central theme of purveyors of environmental and climate deception is to take normal events and present them as normal. Here are examples of the most frequently used stories involving ice in Antarctica. A 2017 New York Times (NYT) story titled “Miles of Ice ColIapsing into the Sea.” Or one from an agency that should know better but is among the worst for alarmist’s misinformation about ice. Without any evidence whatsoever they title an article, “Antarctic Ice Shelf Disintegration Underscores a Warming World.” It begins with the false assumption that CO2 causes global warming and extrapolates that to the claim of increased disasters.
The recently released Fourth US National Climate Assessment is a broader example. The historical records show no increase in natural disasters, but they point to recent hurricanes as evidence when they are all within any natural variability. As I said many times all this is possible because most people, including those in the media and environmentalists who exploit the stories, don’t know about or ignore the fundamental components of the natural world.
Few know that ice forms and behaves in many different ways and causes a variety of effects in the atmosphere and on the land. It was lack of knowledge about sea ice formation and variation that allowed Al Gore to exploit naturally changing amounts of Arctic ice. Add false claims of declining polar bear populations to create a full-blown alarmist deception.
In 1768 William Wales and Joseph Dymond, appointed by the Astronomer Royal, Nevil Maskelyne, took a scientific expedition to Churchill, Manitoba to measure the Transit of Venus. They were charged to make extensive measurements and answer important scientific questions of the day. One of those was a question many can’t answer today. Is sea ice salt or fresh?
The first form of ice is created when water freezes. People assume that it occurs at 32°Fahrenheit, 0°Celsius, or 273.15 Kelvin. Freshwater density begins to increase at 4°C, and ice forms as fusion occurs at 0°C. However, saltwater fusion occurs around -2°C, but that varies with the level of salinity. This means polar sea water can cool as much as 6°C before ice forms. However, the Arctic Ocean has the lowest salinity of any of the oceans because of low evaporation and high inflows of freshwater from massive rivers, like the Mackenzie, Ob, Yenisei, and Lena.
Sea ice forms from seawater. It expands when it freezes, so the volume of ice is greater than the water from which it is formed. It floats with most of the ice, about 7/8th underwater, so the volumetric changes between when it forms, and melt has virtually no impact on sea level. It is difficult to draw any conclusions about variations in volumes of sea ice from year to year because we only have satellite data since 1980. In addition, we only recently learned the effect of wind on moving the ice around and changing the melt rates in different regions. All the evidence is that sea ice variations are well within any normal range. All the fear about polar bears surviving and the disaster of loss of ice are given lie by the existence of a fossilized White Spruce (Picea Glauca) of considerable dimension some 100 km north of the current tree line radiocarbon dated to 4949 ± 140 years. This empirical evidence requires a world some 3°C warmer than today, yet the polar bear survived.
Most precipitation in middle and high latitudes begins as snow and melts into rain before it reaches the surface. A variety of stages and forms, some of them unique, occur while this is happening. For example, water can occur in all three phases, ice (solid) water (liquid) and water vapor (gas) at the same temperature. Water can also exist as a liquid well below the freezing point, a condition known as super-cooled water.
If the freezing level is at or very close to the ground, the precipitation will remain as snow. If it continues to accumulate it will add a positive feedback by changing the albedo that lowers the ambient air temperature. Most people are familiar with the direct freezing of water, however, all other ice, which is the majority on the planet, occurs in glaciers and begins life as snow. The process of transformation from snow to ice begins when a portion of the annual snowfall survives the summer melt. This occurs in two ways; the temperature of a region declines, or the amount of snowfall increases. It is surprising how close a large part of the world is to the impact of a temperature decline. For example, in 1816 snow stayed in the forest across central and northern Canada through the entire summer. Ice covered Lake Winnipeg until July 20th. Some areas are affected more than others. As the temperature cools, snow accumulates and survives more easily on the poleward side of high-altitude valleys.
The diagram shows a simple cross-section through an Alpine glacier, Glaciologists distinguish these from continental glaciers like Greenland and Antarctica, but the formation and mechanisms are the same.
Snow accumulates in the zone above the Equilibrium Line. Some call it the permanent snow line. More snow falls than melts, so layers build up. The snow gradually changes to granules and the air is trapped in bubbles and eventually mostly expelled. For the air to become enclosed takes a long time, at least 70 years before the bubble is enclosed, which makes the claim that the layer in the ice represents a given year is nonsense. When snow accumulates to about 50 m, the ice layers begin to meld and become indistinguishable. At this point the ice changes from brittle to plastic, and from rigid to flowing. The “Direction of flow” arrow in the diagram illustrates the pattern.
Temperature affects the rate of melting in the Ablation zone, but overall the size and advance of the glacier is as much about changing snowfall in the accumulation zone, and that is true of all glaciers. With continental glaciers, especially the Antarctic, when the ice pushes out into the ocean it begins to float and create a unique ice feature known as Tabular ice shelves. They are at the center of most global warming alarmist stories like those in the first paragraph. When the glacier grows due to increased snowfall in the Accumulation zone, it moves downslope in “the Direction of Flow.” This occurs in the Antarctic and Arctic, but those in the Antarctic are much larger. The largest of these shelves in the world is the Ross Ice Shelf named after James Ross who wrote on February 5, 1775
“That there may be a Continent or large tract of land near the Pole, I will not deny,” “On the contrary I am of the opinion there is, and it is probable that we have seen a part of it. The excessive cold, the many islands and vast floats of ice all tend to prove that there must be land to the South.
He is referring to the icebergs, large irregular blocks of ice that calve from glaciers all the time, but also the vast flat-topped ice islands that break off the Ice Shelf. These break away because of pressure from advancing ice behind, the up and down movement of the tides, the constant battering of large waves, and the extremely strong winds blowing out of the continent. These are called Katabatic winds and are the downslope flow from the height of Antarctica (3000 m in the center) and the density of the very cold air. At Cape Dennison on the edge of the continent, the mean wind velocity is 19.3 meters per second (43 mph) and an average for July (midwinter) is 24.5 m/s (55 mph). That pushes the ice away from the continent rapidly.
Proximity of Cape Dennison, “windiest place on earth” to Ross Shelf.
These floating ice islands are a navigational hazard south of 50° latitude. They also offer potential water supply. Australia, Saudi Arabia, and California all investigated towing these slabs, preferably carved out for easier towing. You then ground them along the shore, surround them with plastic curtains and pump the meltwater into onshore holding tanks. The California studies estimated a 50% melt in transit would still leave enough water for Los Angeles for a three-month supply. They made no mention of the ecologic damage as it melts in transit. What about the impact on local climate with a massive block of grounded ice and the fog that it would create? The French engineering company hired to look at the Saudi Arabia plan talked about wrapping the island in plastic to reduce the melt rate because of the higher air and water temperatures involved.
Meanwhile, the alarmists report these islands as a new phenomenon when they are perfectly natural and vary in size and frequency as a result of a growing Antarctic glacier, not a one that is melting.
via Watts Up With That?
December 3, 2018 at 09:07AM