Climate Change — Chapter 4

More on Natural Variability:

 The Polar Vortex:

)t seems after this past winter and spring, it is a very good time to review the attributes of the Polar Vortex.

Just the words, Polar Vortex, brings thoughts of some sort of alien death-ray or perhaps an extremely powerful washing machine, but what does it have to do with cold weather?

A polar vortex is an area of low pressure—a wide expanse of swirling cold air—that is parked in Polar Regions. The one up north can cause some pretty wild weather and sub-zero temperatures in United States and other parts of the Northern Hemisphere. But it’s not a new thing—this low-pressure system is almost always up there.

The Polar Vortex – an area of low pressure—a wide expanse of swirling cold air—is parked in Polar Regions.  There are two polar vortices in the Earth’s atmosphere, overlying the North and South Poles.

Figure 12. A polar vortex is an upper level low-pressure area lying near theEarth’s poles. There are two polar vortices in the Earth’s atmosphere, overlying the North and South Poles.

The one up north can cause some pretty wild climate, weather, and sub-zero temperatures in the United States as well as other parts of the Northern Hemisphere.  But it actually occurs when the vortex is weaker, not stronger. That might sound weird—but it actually makes sense. Normally, when the vortex is strong and healthy, it helps keep a current of air known as the jet stream traveling around the globe in a pretty circular path. This current keeps the cold air up north and the warm air down south.

Figure 13. The breaking off of part of the vortex is what defines a polar vortex.

Without that strong low-pressure system, the jet stream doesn’t have much to keep it in line. It becomes wavy and rambling. Put a couple of areas of high-pressure systems in its way, and all of a sudden you have a river of cold air being pushed down south along with the rest of the polar vortex system.  When the polar vortex is strong, there is a single vortex with a jet stream that is “well constrained” near the polar front.

Without that strong low-pressure system, the jet stream doesn’t have much to keep it in line. It becomes wavy and rambling. Put a couple of areas of high-pressure systems in its way, and all of a sudden you have a river of cold air being pushed down south along with the rest of the polar vortex system.  When the polar vortex is strong, there is a single vortex with a jet stream that is “well constrained” near the polar front.

We actually want a strong polar vortex to stay warm.

The breaking off of part of the vortex is what defines a polar vortex event. But it actually occurs when the vortex is weaker, not stronger. That might sound weird—but it actually makes sense. Normally, when the vortex is strong and healthy, it helps keep a current of air known as the jet stream traveling around the globe in a pretty circular path. This current keeps the cold air up north and the warm air down south.

But without that strong low-pressure system, the jet stream doesn’t have much to keep it in line. It becomes wavy and rambling. Put a couple of areas of high-pressure systems in its way, and all of a sudden you have a river of cold air being pushed down south along with the rest of the polar vortex system.

That’s what happened in early 2014. The polar vortex suddenly weakened, and a huge high-pressure system formed over Greenland. The high-pressure system blocked the escape of all that cold air in the jet stream, and allowed part of the polar vortex to break off and move southward. Places as far south as Tampa, Florida experienced the wrath of this wandering polar vortex. Most ofCanada and parts of the Midwestern United States had temperatures colder than Alaska at the height of this cold snap!

It’s important to remember that not all cold weather is the result of the polar vortex. While the polar vortex is always hanging out up north, it normally minds its own business. It takes pretty unusual conditions for it to weaken or for it to migrate far south, and other things can cause cold arctic air to travel our way, too.

 

Figure 14. When the northern vortex weakens, it separates into two or more vortices, the strongest of which are near Baffin Island, Canada, and over Northeast Siberia

TheAntarctic vortex of the Southern Hemisphere is a single low-pressure zone that is found near the edge of the Ross Ice Shelf Ross near 160-west longitude. When the polar vortex is strong, the mid-latitude Westerlies (winds at the surface level between 30° and 60° latitude from the west) increase in strength and are persistent. When the polar vortex is weak, high-pressure zones of the mid latitudes may push pole ward, moving the polar vortex jet and polar front toward the equator. The jet stream is seen to “buckle” and deviate south. This rapidly brings cold dry air into contact with the warm, moist air of the mid latitudes, resulting in a rapid and dramatic change of weather known as a “cold snap.”

Figure 15. Southern Hemisphere Polar Vortex – Geopotential Height and Vorticity – Approximately 5500 meters (18,000 feet)

The topography and circular shape of Antarctic is such that an extremely cold stratospheric air vortex stagnant (to -148°F (-100°C) in the Antarctic stratosphere, distinct from the rest of the atmosphere, which is formed above the region during the long polar nights. The polar vortex is established in the middle and lower stratosphere above 9,9 miles (16 km) altitude. The wind blowing around the polar vortex can attain a speed of 0,0622 miles (100 meters) per second. The air flows into the polar vortex all winter, becoming cold enough to allow the formation of polar stratospheric clouds. The vortex is generally very stable above Antarctica during the austral winter, because it is a fairly homogeneous continent, well centered at the South Pole.

Let’s review one more Natural Variability issue that does not get its share of review and discussion, and that is volcanoes.

The National Center for Atmospheric Research explains it this way: The gases and dust particles thrown into the atmosphere during volcanic eruptions have influences on climate. Most of the particles spewed from volcanoes cool the planet by shading incoming solar radiation. The cooling effect can last for months to years depending on the characteristics and magnitude of the eruption.

Volcanoes have also caused climate change over millions of years during times in Earth’s history when extreme amounts of volcanismoccurred, releasing gases into the atmosphere.  Climate change does not cause increased volcano activity. Volcano activity causes Climate Change.   Attila Kilinc, head of the geology department at the University of Cincinnati, explains it this way: “As rock inside the earth melts, its mass remains the same while its volume increases–producing a melt that is less dense than the surrounding rock. This lighter magma then rises toward the surface by virtue of its buoyancy. If the density of the magma between the zone of its generation and the surface is less than that of the surrounding and overlying rocks, the magma reaches the surface and erupts.”

Figure 16. The gases and dust particles thrown into the atmosphere during volcanic eruptions have influences on climate. Most of the particles spewed from volcanoes cool the planet by shading incoming solar radiation. The cooling effect can last for months to years depending on the characteristics of the eruption.

It seems we could go on and on about Natural Variability.  Our scientists are indeed still learning about our planet, our solar system, and the never-ending cosmos and the impact they all have on our planet’s climate.

The point is; these Natural Variability attributes are complex, extremely significant, and not well understood by many people and not sufficiently considered in our Climate Change debates. Lets review a few comments that scientist have said about Climate Change complexity.

It seems Philip Stott, Emeritus Professorof Biogeographyat the School Oriental and AfricanStudies in London totally understands. He says; “climate change is too complicated to be caused by one factor whether CO 2 or clouds.”

Phil Chapman, an astronautical engineer, NASA astronaut, staff physicist at MIT says:  “All those urging action to curb global warming need to take off the blinkers and give some thought to what we should do if we are facing global cooling instead.”

Professor Plimer, Professor of Geology and Earth Sciences at the University of Adelaide, stated;“the idea of taking a single trace gas in the atmosphere, accusing it and finding it guilty of total responsibility for climate change, is an “absurdity”

Richard Lindzen, Professor of Atmospheric Science at Massachusetts Institute of Technology, wrote: “The notion of a static, unchanging climate is foreign to the history of the Earth or any other planet with a fluid envelope.   Such hysteria (over global warming) simply represents the scientific illiteracy of much of the public, the susceptibility of the public to the substitution of repetition for truth.”

Dr. Lidzen brings up an extremely valuable point when he mentions scientific illiteracy and the substitution of repetition for truth.

In upcoming Chapter Five, we will review the concept of substitution of repetition for truth. A phenomenon that has plagued the Climate Change discussion for the last several years.