Sunday 17 May 2009

Hurricane



The fact that water-striders use dipolar vortices to move across the surface of the water has intrigued me. These vortices make up half a toroid shape, or one half of a bundt cake, in the water - it's interesting, non? The importance of the toroid structure, and it's significance in the Universe is something to be mulled-over, from the macrocosm to the microcosm. Maxwell thought that atoms were dipolar vortices and that these were responsible for, amongst other things, the dipolar character of the lines of force, and the induction of electric current. Maxwell placed much emphasis on "stress" and "pressure" when dealing with the electromagnetic field; "It appears therefore that the stress in the axis of a line of magnetic force is a tension, like that of a rope..... Excess of pressure in the equatorial direction arises from the centrifugal force of vortices, or eddies, in the medium...."

Pressure, and how it relates to the aether is new to me. I'm trying to think where I can plainly see an example of where all these factors mentioned above are involved. At least I didn't have to look too far for an answer - I had only to look up. It just happens to be Britain's favourite pre-occupation - the weather.

Dipolar vortices are basically a system where two vortices work together - like two spinning discs - one vortex spins clockwise, and it's partner vortex spins counter-clockwise. This is played out in weather systems where air flows from areas of high pressure to areas of low pressure in order to reach fluid equilibrium. These winds move in a spiral: inwards and upwards in low pressure systems, downwards and outwards in high pressure systems. High pressure areas are generally larger and move more slowly than low pressure systems.

In the northern hemisphere, winds circulate around the centre of a high pressure system in a clockwise, 'anticyclonic' movement (in the southern hemisphere the direction is reversed). The winds are generally weaker than those around a low pressure, especially in the centre. High pressure systems tend to cover a greater area than lows, they move more slowly, and have a longer atmospheric lifetime.



In a low pressure system the wind moves in a counter-clockwise, 'cyclonic' direction. As warm humid air spirals upwards, it cools and clouds form. These may be thick enough to give rain or snow. In these low pressure systems the air spirals inwards at the Earth's surface. If the pressure is very low, these spiralling winds may reach storm or hurricane force. In a cyclone, low pressure, denser air is drawn in at low level to replace rising, less dense air.



The winds which we experience in our everyday lives are horizontal flows of air; they are perpendicular to the motion of the air rising and falling from the vortices of the pressure systems. Horizontally, at the Earth's surface, wind always blows from areas of high pressure to areas of low pressure (vertically, winds move from areas of low pressure to areas of high pressure). Wind strength depends on the difference in pressure between the high and low pressure systems, and the distance between them; this is called the pressure gradient; the steeper the gradient, the greater the changes in air pressure, and the stonger the wind. With a high-pressure system, one might conclude that energy is induced vertically, while energy is distributed on the horizontal, while on the other hand, a low-pressure system induces energy horizontally and emits energy on the vertical.

A nice example of dipolar vortices working in tandem is a "bow echo". A bow echo is a term meteorologists use to describe a line of thunderstorms which has a distinct convex shape, like a backward "C", pointing into the direction of movement. The formation of a bow echo requires a strong elevated rear inflow jet at mid-levels. After the rear inflow jet has bowed the storm system, much like an archer's bow, book-end or line end vortices develop on either side of the jet. Due to the small size of the bow echo, the vortices help enhance the mid-level flow between them. This strengthens the rear inflow jet. The strongest gusts, or more rarely tornadoes, thus occur just behind the centre of the bow echo, and are generally comprised of straight line winds which are perpendicular to the bowing segment.



The movement of the bow echo is a reminder of the parabolic shape of the flow of water in an open channel. The current is faster in the middle of a straight stretch of river because there is less friction there than against the banks. This faster current in the middle might be compared to the faster wind in the centre of the bow echo. It might be worth noting that the main current of a river doesn't follow a straight line and the thalweg (the river's "fast lane") meanders from one side to the other even when the river itself runs straight. In the same way perhaps that air moving from high to low pressure does not follow a straight line path, and indeed, follows a spiralling route.

Hydrostatic pressure also varies with depth, where the pressure that exists at any place in a body of fluid due to the weight of the fluid above, so that the fluid at the bottom moves downhill a little slower than the sheet immediately beneath it. Water is much heavier than air, and therefore water at even a moderate depth in the ocean has enormous pressure. This pressure, in turn, creates a buoyant force that pushes upward.

While conducting experiments with liquids, Bernoulli observed that when the diameter of a pipe is reduced, the water flows faster. This suggested to him that some force must be acting upon the water, a force that he reasoned must arise from differences in pressure. Specifically, the slower moving fluid in the wider area of pipe had a greater pressure than the portion of the fluid moving through the narrower part of the pipe. As a result, he concluded that pressure and velocity are inversely related - in other words, as one increases, the other decreases. The fluid pressure is lowest in the centre where the velocity is greatest.... hang on, that sounds familiar. You'll have to exuse me a mo', but I need to make a quick re-cap on smoke rings....

A smoke-ring is a spinning-doughnut-shaped mass of air (a "torodial vortex") spinning in an inside-out kind of way, so the air in the middle of the ring is always being blown forwards. The fluid pressure in a vortex is lowest in the centre where the speed is greatest, and rises progressively with distance from the centre. When air exits the hole, friction with the rim retards it, causing the air in the centre to move forward faster than the air at the edge. Friction causes the torus to tractor itself forward. The energy that is used to move it forward and keeps the vortex rotating is taken from the inertia of the rotating air in the vortex. Inertia is the tendency of anything in motion to keep moving. Only thing is, matter does not hold potential energy, this energy is a property of the aether. Inertia is really describing the induction of energy from the aether field; this energy being an electrical fluid.



With these pressure systems, I think there is a lot more than meets the eye. You start to get the feeling that the forces inside the atmosphere work as a seething, infinite mass of invisible toroidal knots. Moisture not only helps to feed these systems, it also helps them to become visible. Even the wind is invisible - we only notice it when we get to feel it against our skin, or see it interact with other objects like the leaves on a tree, or dust blown from the ground. These effects are much more noticeable as the weather conditions grow more extreme.

Vortex motions in an invisible fluid medium like air are in themselves invisible; nevertheless, parts of a tornado funnel become visible due to moisture condensation in the core and dirt and debris caught up in the swirling winds. Tornadoes start as a horizontal column of air that rotates, and for whatever reason, some of these turn vertical. A horizontal column of air that rotates? That's a smoke ring, right? Meteorologists have known that the long swift river of air called the jet stream has helped breed tornadoes in conjunction with masses of warm air and of cold air. Tornadoes are caused by the rapid dropping of a cold air through a lighter warm air mass - a sinkhole.



On a larger scale, hurricanes and their counterparts the typhoon or cyclone, are large swirls on the move attempting to equalize air pressure. With hurricanes, moist air gets sucked into the low pressure region at the centre, rises and condenses into clouds at the eyewall, and is expelled outwards at the top into high cirrus clouds. In the eyewall, large changes in pressure create the hurricane's strongest winds. These winds can reach nearly 200 miles (320 kilometers) per hour. Damaging winds may extend 250 miles (400 kilometers) from the eye. In the eyewall, warm air spirals upward, creating the hurricane's strongest winds. The speed of the winds in the eyewall is related to the diameter of the eye. Just as ice skaters spin faster when they pull their arms in, a hurricane's winds blow faster if its eye is small. If the eye widens, the winds decrease.

In the largest and most intense hurricanes (like Hurricane Katrina in 2005), the strongest winds are located in the eyewall that surrounds the nearly calm eye. If the hurricane is stationary (spinning, but with no forward motion) the field of winds is shaped like a torus, with a calm center and the fastest winds forming a ring around the center. Concentric rings of incrementally weaker winds are analyzed outward from the core of strongest winds.

While the wind just above the ocean surface spirals anticlockwise toward the center, the air at high altitudes blows outward in a clockwise spiral. This outward flowing air produces thin cirrus (feathery) clouds that extend great distances (thousands of kilometers) from the center of circulation and the presence of these clouds may be the first sign that a hurricane is approaching.

With the high-pressure and low-pressure weather systems, we've seen it work as dipolar vortices. These dipolar vortices expose the wind system as being part of a vortex ring, which for the most part remains invisible. The position of the dipolar vortices reveal the torus as moving over the face of the planet with the ring in the vertical position - in the same way a smoke ring moves across a room. However, with the tornado or hurricane, we are seeing the vortex ring adopt a horizontal position -more like a flying saucer, or frisbee.

With the tornado, or hurricane, we're seeing the low pressure system wreak havoc at ground level. The strongest vertical, or nearly vertical, up-currents developed in the most unstable air require a system of converging horizontal wind currents at the ground to supply them. Horizontal winds speeds as great as 50 - 100 m/sec (100 - 200 knots) and more, may be briefly attained in the ring of fastest moving air 5 - 50m or so from the centre. These horizontal winds are referred to as secondary flow. The secondary flow is toward the centre of the tornado and is then drawn upward by the significantly lower pressure several thousands of feet above the surface.

If the funnel of the tornado is seen as the primary flow, and the intake of air at ground level being known as the secondary flow - is it possible these then make up the double cone of a torus? It could look like one cone was being stretched, and elongated reaching from the ground to the clouds. The other cone, which makes up the other half of the double cone, is a vortex which appears to be virtually flattened-out, almost as if it has been steam-rollered into something like a pancake over the surface of the land.



Inside the tornado the low rain clouds rotate counter-clockwise and the high cirrus clouds at the peak rotate in a clockwise direction. To me, the change in direction signifies the existence of another torus. This high level outflow in the upper troposphere occurs where the centrifugal forces of the cyclone meet the centrifugal forces of an opposing anticyclone. One would assume that this anticyclone belongs to a seperate system. We've now got two toroids reacting with one another; it's one donut piled ontop of another, and apparently sucking energy from either end. Are we now looking at a dipole?

High pressure systems are steered by upper-level winds in the stratosphere. Do these high pressure systems then in turn activate low-pressure systems so that they appear to act as some type of "idle wheel"? Is the tropopause defining a boundary where the behaviour of systems in the troposphere are mirrored by systems in the stratosphere? There's a very important engine at work in here somewhere - now to find it. And did anyone else notice that I never mentioned the Coriolis force?



Many thanks:
http://science.howstuffworks.com/hurricane2.html http://www.flickr.com/photos/cgandolfo/296822045/http://www.singularvortex.com/UVS%20on%20clear%20air%20vortex.htm
http://www.scienceclarified.com/everyday/Real-Life-Chemistry-Vol-3-Physics-Vol-1/Fluid-Mechanics.html
http://hurricaneclimate.blogspot.com/2008/06/physical-geography-of-hurricanes.html
http://en.wikipedia.org/wiki/Bow_echo
http://www.solarviews.com/eng/cloud1.htm
http://www.milli-bar.com/wsoldani/Katrina/Katrina6.htm
http://www.absoluteastronomy.com/topics/Dust_devil
http://www.sciencestorm.com/award/0233178.html
http://earthsci.org/education/teacher/basicgeol/windes/windes.html http://www.whoi.edu/science/AOPE/people/tduda/isww/text/apel/apel.htm
http://www.eeb.ucla.edu/test/faculty/nezlin/PhysicalOceanography.htm
http://www.worldandi.com/subscribers/searchdetail.asp?num=16893http://www.theweatherprediction.com/radared/radarfaq2/
http://jeb.biologists.org/cgi/content/figsonly/207/22/3945
http://science.nasa.gov/headlines/y2000/ast12dec_1.htm
http://www.youtube.com/watch?v=vPPMaDH7L7I
http://www.nasa.gov/worldbook/hurricane_worldbook.html
http://www.esa.int/esaCP/SEMIZFM5NDF_index_1.html
http://www.upi.com/Science_News/2002/07/27/Massive-research-effort-eyes-high-clouds/UPI-38211027749600/








1 comment:

batt said...

hehe i bet we both or converging at the same point :-)