Hurricane characterisitcs

Discussion in 'Earth Science' started by kingwinner, Nov 12, 2005.

  1. kingwinner Registered Senior Member

    Messages:
    796
    Hurricane characterisitcs | Coriolis Effect

    1) "The hurricane eye is a calm area with the lowest pressure relative to its surroundings. In there, it is clear and sunny with little or no clouds."

    I was told that high pressure areas have clear and sunny conditions while low pressure ares have rainy conditions. But why while the hurricane eye has low pressure, it is very clam? And also, cold air is descending into the eye, shouldn't that be high pressure instead of low pressure?

    2) I don't get the Coriolis Effect! The earth is rotating from west to east, so wouldn't all winds be deflected to the WEST when their original intention is to move straight north or south? But why in fact, the winds are deflected to the right in the northern hemisphere and deflected to the left in the southern hemisphere, as follows?

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    Last edited: Nov 12, 2005
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  3. D H Some other guy Valued Senior Member

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    The Coriolis acceleration is twice the cross product of the Earth's angular rotation rate vector and the wind velocity vector. Note that because of the curvature of the Earth, all winds blowing parallel to the surface of the Earth have a component normal to the rotation vector except at the Equator.

    Here is what this does to a wind blowing in the Northern Hemisphere:
    • A wind from the south turns to the east -- to the right.
    • A wind from the east turns to the north -- to the right.
    • A wind from the north turns to the west -- to the right.
    • A wind from the west turns to the south -- to the right.
    In other words, the Coriolis effect directs all the winds to the right in the Northern Hemisphere. A low pressure system draws air in from all directions. The rightward deflection results in a counterclockwise flow. (In the Southern Hemisphere, all winds are directed to the left, resulting in clockwise flow around a low pressure system.)

    The eye of a hurricane is clear because cold air is drawn from the upper atmosphere into the eye. This cold air has a much lower absolute humidity than warm air. Adiabatic heating raises the temperature of this air as it falls. Even if the cold air was at 100% relative humidity at the top of the hurricane, by the time it reaches the ground the relative humidity is quite low. The result: the eye is clear.
     
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  5. valich Registered Senior Member

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    Then there's no difference in wind direction between a hurricane and a typhoon, right? But there might there be a slight average difference in strength since the Atlantic is colder and smaller than the Pacific?
     
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  7. kingwinner Registered Senior Member

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    Then why is the eye "a calm area of LOW pressure"? Shouldn't calm areas have high pressure because cool air is sinking?

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    Last edited: Nov 13, 2005
  8. URI IMU Registered Senior Member

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    I am sure no one knows how a hurricane forms, or how its shape is maintained


    If so artificial hurricanes/tornadoes would be very useful for energy generation
    ie couple into the 'spin field' of the Earth.
     
  9. valich Registered Senior Member

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    3,501
    A hurricane is the same thing as a cyclone, except it's called a cyclone in the Pacific:

    When you fill up your bathtub and let it drain out, what do you see? What's in the center? It spins around and the outside revolves faster.

    For a neat diagram of how hurricanes and cyclones form, click on the link at the bottom of this post:

    "Structurally, a tropical cyclone is a large, rotating system of clouds, wind and thunderstorm activity. Its primary energy source is the release of the heat of condensation from water vapor condensing at high altitudes, the heat ultimately derived from the sun. Therefore, a tropical cyclone can be thought of as a giant vertical heat engine supported by mechanics driven by physical forces such as the orbital revolution and gravity of the Earth. Continued condensation leads to higher winds, continued evaporation, and continued condensation, feeding back into itself. This gives rise to factors that give the system enough energy to be self-sufficient and cause a positive feedback loop where it can draw more energy as long as the source of heat, warm water, remains. Factors such as a continued lack of equilibrium in air mass distribution would also give supporting energy to the cyclone. The orbital revolution of the Earth causes the system to spin, giving it a cyclone characteristic and affecting the trajectory of the storm."
    http://en.wikipedia.org/wiki/Hurricanes
     
  10. D H Some other guy Valued Senior Member

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    Just because you don't know doesn't mean nobody does. Do not ascribe your ignorance on the rest of humanity. In fact, we know a <i>lot</i> (but certainly not everything) about how hurricanes form and how their shapes are maintained.

    There is a big difference between knowing how something works and knowing how to harness that knowledge. I suspect we may never harness a hurricane. What happens if our pet hurricane gets free? Hurricanes pack a lot more punch than do nuclear weapons.
     
    Last edited: Nov 13, 2005
  11. kingwinner Registered Senior Member

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    796
    I understand why the eye is a calm area because cold air is sinking there, but would that give a high pressure area? Why is it still a low pressure area?

    "A hurricane eye is an area of clam, low-pressure center"

    And I was told early in time this relationship:
    low pressure -> bad weather (rainy, cloudy)
    high pressure -> good weather (clear, sunny)

    But it is not working for the eye of a hurricane, it is like the complete opposite........!?
     
  12. D H Some other guy Valued Senior Member

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    2,257
    A hurricane operates on a positive feedback loop. See the cited articles in previous posts. It is this feedback loop that creates the clear eye in the most powerful hurricanes. Also see the National Hurricane Center's FAQ.

    Stop focusing on the eye. Look at the big picture instead (and hurricanes are very big). The rule "Low pressure -> bad weather" is indeed the case when it comes to hurricanes. That is why the National Hurricane Center uses the eye pressure as a key barometer of hurricane intensity.
     
  13. URI IMU Registered Senior Member

    Messages:
    729
    >> Do not ascribe your ignorance on the rest of humanity. >>

    OK, how does a hurricane/tornado maintain its structure..... compact shape if you like ???

    >> And I was told early in time this relationship:
    low pressure -> bad weather (rainy, cloudy)
    high pressure -> good weather (clear, sunny) >>>>

    Air going up -> low pressure ? condensation
    Air going down -> high pressure ? evaporation ?

    In a hurricane air around the eye is going up

    But how can a spiral going at 300km/hr not be blown apart by inertial forces ???

    Solve this and you are into spin gravity.
     
    Last edited: Nov 14, 2005
  14. Facial Valued Senior Member

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    2,217
    Wow. I think you just lost all credibility there.

    You probably mean 'centripetal' forces. And what the heck is spin gravity? Something you coined? Or do you refer to the Coriolis effect? Show me a NOAA website with the term 'spin gravity'. I would like to know what it means.
     
  15. valich Registered Senior Member

    Messages:
    3,501
    Two years ago we had a forum on sciforum under the Astronomy, Exobiology, & Cosmology category called "Electrodynamic Spin Gravity."

    "Due to spin and gravity, the Earth (including its solid part, seas, and atmosphere) takes ellipsoidal form. Force acting on an object on stationary spherical Earth surface is due to gravity, in line with vertical (perpendicular to surface). All verticals meet at the center of Earth. For spinning ellipsoidal Earth, the object is subjected to two forces. Gravity force (to center of ellipsoid) and Centrifugal force (perpendicular to axis of rotation). These two forces combine to form an inward force perpendicular to surface of Earth and zero force tangential to surface."
    http://www.mngogate.com/e13.htm

    "The term describing the specific spin (gravitational moment) interaction effect is recovered in the Hamiltonian. The comparison of the true gravitational coupling with the purely inertial case demonstrates that the spin relativistic effects do not violate the equivalence principle for the Dirac fermions."
    http://arxiv.org/abs/gr-qc/0012102

    also: http://adsabs.harvard.edu/cgi-bin/n...amp;db_key=AST&amp;data_type=HTML&amp;format=
     
  16. URI IMU Registered Senior Member

    Messages:
    729
    Apparently a 'funnel cloud' hit Great Britian recently

    a rare event
    but these incidences in the world are growing in number.
     
  17. URI IMU Registered Senior Member

    Messages:
    729
    Interesting paper

    http://www.math.nsc.ru/directions/tornado-eng.htm

    >> The parent cloud has a three-story structure with rotation in horizontal plane , with middle and lower layer rotating in opposite directions [16], [17]. >>

    Gravity is spiral in structure, IMO.

    >> The interior hollow of a funnel has a clearly defined air walls, with lightning flashing between them. or water surface, then the action of current sharply displays itself. At the same time , when a funnel doesn’t touch the ground, there’s no vertical flow. In 1951 in Texas a funnel passed over an observer at 6 meter height , the interior having diameter about 130 m with walls of 3 meter width.

    Inside the hollow there was a brilliant cloud. There was no vacuum inside, because it was easy to breath . The walls were rotating with a very high speed, ant the rotation might be seen up to the top of the column. A bit later the funnel touched the neighbor’s house and immediately took it off [20].

    This description is similar to many others [21], [22], [23] and require the explanation of the fact that rotation of the air necessarily leads to decrease of pressure. Why, being 6m above the ground, the funnel end causes neither damage nor intense air motion, while, upon touching the ground, destroys and moves off a house?

    Direct measurements show that there is a low pressure area inside the funnel ( 951 mb, Topica June 8, 1966). Such pressure decrease may be resulted at air rotation speed of about 100 m/sec and should make the breath difficult.

    Why the funnel uncovers the river bed sucking out it’s water, while at the same time the observers even do not notice a wind when the funnel passes above them? >>>


    I contend that these are 'spin gravity' manifestations, cause by static electricity.

    I think a similar phemonemon occurred with the space shuttle teather, when the teather 'burnt' out. It was captured on video camera.
     
    Last edited: Nov 14, 2005
  18. Light Registered Senior Member

    Messages:
    2,258
    It's confusing, Kingwinner, because you are overlooking one major part of the action. As the colder air falls, it's warmed and pulled rapidly into the hurricane wall. So rapidly, in fact that it never quite makes it down to the surface. That's why surface conditions are so calm and why the pressure drops to such low values.
     
  19. URI IMU Registered Senior Member

    Messages:
    729
    from link

    >> According to our model a parent cloud of tornado beside its observable part has an unobservable part in the form of a vacuum domain. Under a joint action of gravitational and electrical field, which in a storm-cloud achieves a value in a hundreds of millions of volts, thin long vacuum domains with high density of defects are being stretched out from a domain. Spin polarisation of such a domain causes the rotation of a tornado's funnel. The calculations made by V.L.Dyatlov as applied to a vacuum with 100% defect density show that tangential stresses can achieve in it hundreds of kilograms per centimeter [11].

    In the air when a funnel doesn't touch solid objects, unstable momentum is compensated by the rotation of a funnel and the air connected with this funnel. And in a solid body these momenta cause the large tangential stresses which are sufficient for cutting off the wheels of a car or for turning a brick church from the west to the east.

    A positive mass localized on a lower end of a funnel explains a fast extension of a funnel and a subsequent blow against the surface of the earth or water.

    A vacuum domain as well as a vacuum doesn't have the conductivity of self-gravitational current, it doesn't possess a free gravitational charges. Therefore while touching the surface only the surface gravitational charges go in the ground. At that a funnel is detached from the ground. Whereupon the process of polarisation again extends a funnel and it again touches the ground. In such a way it may be explained an observable dotted contact of a funnel with the earth.

    The energy source as in the experiment of Einstein-de-Haas is energy of the magnetic field, in this case - energy of the polarisation. Thus a gravitational energy is transformed into a spin energy.

    A cloud always rises through a height of 20 km above a funnel of tornado. Since an upper boundary of the troposphere passing in a middle latitudes at a height of 10-11 km confines all thermobaric processes in the atmosphere, a manifestation of tornado at such a height can't have a meteorological explanation, but it can have a gravidynamical explanation. A stretched and strongly polarized vacuum domain contains at its upper end a large positive mass and positive electrical charge. And both charges repel from the earth and rushes together with the air outside the troposphere. The entrapped moisture makes a domain visible.

    The most widespread and the most inexplicable manifestation of tornado as a picking of solid objects by soft ones
    ( straws pick boards, chips pick trunks, a board penetrates a wall of a house, a thick steel plate) also can be explained by the accepted model, see Fig.5.

    Image of straws penetrating more solid matter at
    http://www.math.nsc.ru/directions/Figure5.jpg

    (image too big ..... how does one reduce the size of a large image ??? )
     
  20. protostar Registered Senior Member

    Messages:
    98
    Another tornado devistated some homes in Iowa. Iowa does not generally have tornados. I have spoken with some people in regards to the tornado there as well as Indiana. These storms "have come from no where" and it is likely that they will happen again. On another note, tropical storm Gamma
    is likely to turn into another hurricane.
    Hopefully everyone is paying attention to these "global earth changes" and what is happening here in the United States.
    Proto
     
  21. valich Registered Senior Member

    Messages:
    3,501
    And then I quoted that a hurricane or typhoon "is subjected to two forces: Gravity force (to center of ellipsoid) and Centrifugal force (perpendicular to axis of rotation). These two forces combine to form an inward force perpendicular to surface of Earth."

    We're drifting here a bit but we all seem to agree that both the center of a hurricane and the center of a tornado are due to the center low pressure area within and and the upward convection. And we both seem to have cited sources that account for the source and/or origin of both hurricanes and tornadoes as due to both gravity and the centrifugal force due to the rotation of the Earth: "gravidynamical explanation."

    So what makes the two different? Or why doesn't a hurricane turn into a tornado when it hits land? Actually I know that a hurricane does sometimes spawn tornadoes on land.
     
  22. Light Registered Senior Member

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    2,258
    Actually, I'd quickly change that last statement to : "it's very rare that a hurricane does NOT spawn tornadoes." I've lived in the Southeastern U.S. for over 50 years and every single one those beasts that's made landfall (as far back as I can remember) has spawned at least one or two and sometimes as many as a dozen or more tornadoes.
     
  23. valich Registered Senior Member

    Messages:
    3,501
    Yeah, I agree. So why does a hurricane spawn tornadoes when our above scenario attributes tornadoes to a gravitational AND "electrical field" ["which in a storm-cloud achieves a value in a hundreds of millions of volts, thin long vacuum domains with high density of defects are being stretched out from a domain"], while hurricanes are produced by gravitational and centrifugal force (the Corriolis effect?)?
     

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