Notices
Results 1 to 10 of 10

Thread: Wind?

  1. #1 Wind? 
    Forum Freshman AlphaParticle's Avatar
    Join Date
    Oct 2010
    Location
    Australia
    Posts
    16
    this is probably going to sound like a ridiculously simple question with so many answers, but, it's been boggling me...
    where, how, or by what means is wind made???


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Freshman freeyourmind's Avatar
    Join Date
    Oct 2010
    Posts
    13
    By high and low pressure.

    You need to think big here, like massive scale. Remember, the planet is not just where you are, what you see, and what you feel.

    Wind is created by high and low pressures. Hot air rises, and cool air is forced downwards. This creates what is referred to as a convection current. Imagine a heater in your room, and you can feel the hot air rising from it. The cold air above is pushed aside to make room for the hotter air rising.

    If you think of this on a huge scale, like the sun heating the deserts of this world, and the massive alp mountain ranges cooling the rising air, and sending it back down to earth. On these scales, you can feel the air being moved around in the convention current as 'wind'.


    Reply With Quote  
     

  4. #3  
    Forum Freshman AlphaParticle's Avatar
    Join Date
    Oct 2010
    Location
    Australia
    Posts
    16
    thank you, that was really helpful!
    Reply With Quote  
     

  5. #4  
    Geo
    Geo is offline
    Forum Junior
    Join Date
    Nov 2009
    Location
    New Zealand
    Posts
    273
    There's also debri avalanches, snow avalanches, volcanism, waterfalls, fire...
    Reply With Quote  
     

  6. #5  
    Forum Professor jrmonroe's Avatar
    Join Date
    Mar 2010
    Posts
    1,444
    Quote Originally Posted by AlphaParticle
    where, how, or by what means is wind made???
    Solar power. The major winds patterns are caused by the sun’s heating of the earth’s surface, particularly near the equator due to the sun’s effect being strongest there.

    And think massive, as FYM said. Six major air circulation “cells” (or thermal loops) exist: two Hadley cells roughly on either side of the equator, two Ferrel cells in the temperate zones, and two polar cells near the poles. The northern and southern hemispheres contain one of each pattern, and neighboring cells mesh together somewhat like gears in a huge machine.

    Hadley cells. These cells are the major driver of the Ferrel and Polar cells. Heating near the equator causes the air to rise, causing neighboring air masses to move horizontally toward the equator to take its place. The rising air splits and travels pole-ward, cools, then drops down at about ±30° latitude to replace the air masses traveling horizontally toward the equator, and again flows toward the equator to complete the loop.

    Ferrel cells. These cells mesh with the Hadley and Polar cells, but rotate in the opposite direction. Air rises at about ±60° with air moving pole-ward to replace it. The risen air travels toward the equator, drops at about ±30°, and again flows toward the poles. The Ferrel cells are more chaotic, and their surface weather patterns are not as predictable as those of the Hadley and Polar cells.

    Polar cells. These cells follow Hadley cells rotation, with relatively warmer air rising at about ±60° with air moving from the polar region to replace it. The risen air travels toward the poles, cools, then descends near the poles, and ultimately flows toward the ±60° latitude to complete the loop.

    Due to other physics involved, these cells create other general air movements at the earth’s surface. The Hadley cells contain surface air masses that travel toward the equator and from the east, called the “trade winds”. The Ferrel cells generally produce surface winds that travel toward the poles from the west, called the “westerlies”. And the Polar cells produce winds traveling toward the equator from the east. The jet streams also form at altitude where the cells “mesh together”.

    The northern trade winds worried European explorers who feared traveling south of about 30°N (at the westernmost parts of Africa) because the winds were blowing them out to sea, instead of along the coast of Africa. These trade winds, and the Sahara and other geography separated sub-Saharan Africans from Europeans for many years.

    Yet, because Columbus found he couldn’t sail easily against the westerlies at Spain's latitude, he found it easier to sail toward the equator and sail west with the trade winds, and it explains why he discovered the Caribbean (further to the south) instead of the North American continent (Spain is about the same latitude as New Jersey!).

    Also, deserts tend to form at about ±30° where the descending air becomes dry.
    Grief is the price we pay for love. (CM Parkes) Our postillion has been struck by lightning. (Unknown) War is always the choice of the chosen who will not have to fight. (Bono) The years tell much what the days never knew. (RW Emerson) Reality is not always probable, or likely. (JL Borges)
    Reply With Quote  
     

  7. #6  
    Forum Junior
    Join Date
    Dec 2009
    Location
    New England
    Posts
    223
    [quote="freeyourmind"]

    Hot air rises, and cool air is forced downwards. This creates what is referred to as a convection current. Imagine a heater in your room, and you can feel the hot air rising from it. The cold air above is pushed aside to make room for the hotter air rising.

    /quote]

    Forgive this hairsplitting, but gravity is the force. It gives heavier air first grabs as it pulls that down displacing the hot air up out of the way
    "Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense." --Buddha (563BC-483BC)
    Reply With Quote  
     

  8. #7  
    Forum Freshman Siberian Fox's Avatar
    Join Date
    Jan 2011
    Location
    California, USA
    Posts
    20
    It causes high and low pressure. For example if the pressure is high you could be blown away, and if the pressure is low then you will not move.
    Reply With Quote  
     

  9. #8 Re: Wind? 
    Suspended
    Join Date
    Jan 2011
    Posts
    108
    Quote Originally Posted by AlphaParticle
    this is probably going to sound like a ridiculously simple question with so many answers, but, it's been boggling me...
    where, how, or by what means is wind made???
    Next time you boil pasta for lunch have a look at the hot bubbles of water forming on the hot base of the pan (the earth surface) they break away and float up, cooler water flows under them to fill the vacuum they leave behind, that downward movement of cooler water is wind to us humans on the base of the pan. Add to that earths spin causing two prevailing currents in opposite directions and beastly eddie currents where both meet near the equatorial part of the globe and you have climate and 'prevailing winds'.
    Reply With Quote  
     

  10. #9  
    Moderator Moderator
    Join Date
    Apr 2007
    Location
    Washington State
    Posts
    8,416
    To add a new wrinkle, at everything but near the equator horizontal wind is mostly a balance between pressure gradient, Coriolis force and friction near the surface.
    Meteorologist/Naturalist & Retired Soldier
    “The Holy Land is everywhere” Black Elk
    Reply With Quote  
     

  11. #10 Wind 
    Suspended
    Join Date
    Jan 2011
    Posts
    13
    Heat is a form of energy. The more heat absorbed by the air cause it to rise (in broad terms). Cooler air, is more dense and will sink, relative to warmer air mass'. The difference in pressure between two bodies of air, is called a pressure gradient. The air moves from an area of high pressure to an area of low pressure. this causes wind. The coriolus effect is a force, caused by the rotation of the planet, which deflects the motion of the wind by approx. 45 degrees, to the right or left, depending on which hemisphere the pressure gradient exists.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •