The Coriolis "force" and its effect

The quick explanation

• 
  When you exert a force on an object in a certain way to set it in motion, you expect it to move in a certain direction. If you had some control like Tony Gwynne, you could hit a baseball to go a certain way.
  
  Some things like air, water, and long-range projectiles, set in motion by forces we know about, end up moving in unexpected directions. They're deflected from their intended paths. But there's a pattern to the deflection and it's not random. Distinct objects and masses of air and water swerve to the right in the northern hemisphere and to the left in the southern hemisphere, looking in the direction of forward motion.
  
  But - we know of no force that's nudging these things to the right or left. So why does it go that way?
  
  It's due to our point of view, stuck to the surface of our rotating planet. The object once it's set in motion is moving in the expected path. It's our own motion that makes the path of the object ...
  
  But - it's important because we want to know where objects will end up on our rotating frame of reference. If there's a mysterious force that pulls a baseball to the right, I'd need to make an adjustment.
  
  But no one makes a correction for a moving baseball. What kinds of things are affected? Technically, everything. But the effect isn't important for some things. http://blog.saxongifts.com/?q=Erzgebirge-Christmas-Pyramids In detail, the motion is not absolutely free of other effects like gravtiy centrifugal.

What you need to know

How to make the correction

When it's important or not. People will tell you lots of things are important, but some things are going to be more important than others. Judgment

You need to pass the test.

This is a core process that ...

Will it make you rich and famous?

Concepts you've to get a grip on in Earth science

1. How solar radiation heats air and makes it move 2. Convection 3. How air circulates on the surface of our planet 4. How surface ocean currents (the gyres) move 5. How air circulates in a cyclone http://blog.saxongifts.com/?q=Erzgebirge-Christmas-Pyramids http://ams.allenpress.com/archive/1520-0477/79/7/pdf/i1520-0477-79-7-1373.pdf http://www.usatoday.com/weather/resources/basics/coriolis-understanding.htm

Fun stuff

How to make the correction

When it's important or not. People will tell you lots of things are important, but some things are going to be more important than others. Judgment

You need to pass the test.

This is a core process that ...

Will it make you rich and famous?

http://blog.saxongifts.com/?q=Erzgebirge-Christmas-Pyramids

Seeing for yourself

1. Solar heating
   • Because of the greater concentration of solar heating at the equator than the poles, air rises near the equator (at the ITCZ) and sinks at the poles.
   • This sets up the first-order (most general) circulation pattern in the Earth's atmosphere (sometimes called the Hadley cells).
   • In this pattern, two circular cells of circulation set up, one in each hemisphere.
   • In the northern hemisphere, air rises at the ITCZ, moves northward, descends near 30° N, then returns southward to the ITCZ as the NE Trade Winds (NE Trades).
   • The arms of these vertical circulation cells that touch the Earth's surface are the surface winds.
   Key points
   
   • The trade winds should blow directly north-to-south. We see that the actual winds don't. Instead a wind such as the NE Trades blows mysteriously from NE-to-SW along a diagonal and curved path. When we launch projectiles along the same path as the NE Trades, straight southward towards the equator from 30°N, the same deflection occurs. Looking in the direction of motion, the path of the projectile is deflected to the right and moves from the NE to the SW. It does this in the absence of any force that could have caused the deflection.
   • The deflection of all winds, looking in the direction that the wind is moving, is to the right in the northern hemisphere and to the left in the southern hemisphere.
   • This mysterious deflection is due to our perspective of the situation standing on a rotating spherical Earth. The deflection is the Coriolis Effect.
   • If we look at the moving air or projectile from outer space. We would see no mysterious deflection at all. The air mass or projectile would be moving in a direction consistent with the initial forces that set it in motion.
   • But we look at the situation from a point of view on the Earth, and to us the air mass or projectile moves in a different way. We care about where that air mass or projectile will be relative to places on the rotating Earth's surface, not with respect to outer space.
   • Because we need to be able to predict the deflectiion in order to forecast winds and deliver projectiles to precise targets, scientists have quantified the force required to cause these deflections and called it the Coriolis Force. The Coriolis isn't a true force, instead it is adjustment factor that's needed to quantify the deflection for our rotating frame of reference. The details of that force are part of a stsndard course in physics. Oceanographers, atmospheric scientists, long-range weapons and satellite engineers need to be able to apply the Coriolis Force correctly in their work.
   What the non-scientist needs to know
   
   • The Coriolis Force causes some moving objects on the Earth to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere.
   • Some kinds of moving objects are unexpected deflected from their expected paths by the Coriolis Force.
   • The deflection of Coriolis Effect occurs because of our rotating reference frame.
   • The kinds of masses affected by Coriolis are ...
   Common misconceptions and difficulties
   
   • Knowing which moving objects are significantly affected by the Coriolis Force.
   • Knowing when it's appropriate to describe the direction of motion as to the left, right, clockwise, counterclockwise, and by a compass direction.
   Difficult concepts for the advanced student
   
   • Understanding the relationship between the definition of the Coriolis equation and ...

Questions for thought

1. If one atom of carbon weighs ~12 u, and it contains 6 protons that each weigh about 1 u,how many neutrons does an unbound atom of ¹²C contain?
2. How many atoms of ¹²C make up 12.011 g of carbon-12?
3. How many atoms of ¹²C make up 12.011 g of carbon-12?

Standards addressed

1. ES4. Energy enters the Earth system primarily as solar radiation and eventually escapes as heat.
   Energy in the Earth System
   
   • Solar radiation warms ground and heats air.
   • Air does eventually radiate energy back to space. Heat is a transfer of energy as radiation. Heat and solar radiation are shades of the same thing.
2. ES5. a. Students know how differential heating of Earth results in circulation patterns in the atmosphere and oceans that globally distribute the heat.
   Energy in the Earth System
   
3. ES5. b. Students know the relationship between the rotation of Earth and the circular motions of ocean currents and air in pressure centers.
   Energy in the Earth System
   
   • Air moves in pattern that is unexpected in the absence of the Coriolis force.
   • Surface ocean currents (the gyres) move in a way tnat is expected based on being moved by surface winds.
   • As a response to forces that include the Coriolis force, water moves around a short hill of water that makes up each ocean gyre.
ESIE1. d. Formulate explanations by using logic and evidence. ESIE1. k. Recognize the cumulative nature of scientific evidence. More solar energy reaches the equatorial regions than the polar regions because the equatorial regions A are covered by a greater area of land. B have more vegetation to absorb sunlight. C have days with more hours of light. D receive sun rays closest to vertical. CSS 41-43

Related topics

1. Avogadro's number
2. Mole

Earth science topics where the periodic table is referenced

1. Salinity and dissolved ions in seawater
2. Minerals
3. Composition of objects and matter in space
4. Photosynthesis and nutrients