Coriolis effect or force?

[Andrew Clope]

Maybe I'm overthinking this, I understand the Coriolis effect, or so I thought. I've seen it written as both a "force" and an "effect". The way I currently understand it, I don't see how it's a force. It seems to be more of a perception or an effect, depending on vantage point. If on earth, we see the deflection, however, if in space, we would see it as a straight line, with the earth rotating underneath. So I suppose I just don't understand how it would be a force, it doesn't seem to actually be doing any sort of work?

Coriolis effect has always been something that when I think I understand it, it trips me up again with what I thought was a thorough understanding.

If it helps with an explanation, I am trying to understand it in relation to geostrophic winds and gradient winds.

Thanks!

 

[rdale]

It's an "apparent force" so effect also works as a description http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml

 

[Brian G]

I suppose it's a matter of personal preference, but I like to think about it as an actual force. The reason is because most coordinate systems (reference frames) used to describe the atmosphere are accelerating. They are fixed to the surface of the Earth which is rotating. Rotating things are in a constant state of acceleration because their direction is changing even though their tangential velocity may be constant. Because of this the derivation of the primitive momentum equations must take into account the fact that the reference frame itself is accelerating and thus the Coriolis force makes a real and measurable contribution to the movement of air parcels with respect to the coordinate system chosen. I guess what I'm saying is that regardless of whether you call it real or fake it "appears" to be real as derived by the math for a reference framed fix to the surface of the Earth. I guess in that sense "apparent force" seems like a perfectly reasonable description as well. Hopefully someone can correct me if I'm way off base here

 

[Jeff Duda]

I suppose it's a matter of personal preference, but I like to think about it as an actual force. The reason is because most coordinate systems (reference frames) used to describe the atmosphere are accelerating. They are fixed to the surface of the Earth which is rotating. Rotating things are in a constant state of acceleration because their direction is changing even though their tangential velocity may be constant. Because of this the derivation of the primitive momentum equations must take into account the fact that the reference frame itself is accelerating and thus the Coriolis force makes a real and measurable contribution to the movement of air parcels with respect to the coordinate system chosen. I guess what I'm saying is that regardless of whether you call it real or fake it "appears" to be real as derived by the math for a reference framed fix to the surface of the Earth. I guess in that sense "apparent force" seems like a perfectly reasonable description as well. Hopefully someone can correct me if I'm way off base here

This sounds perfectly reasonable to me, and I agree with it.

The Coriolis "force" (I also put the quotes around the word force when I use it in my class) is not technically a force by traditional physics standards since it has no agent. The force is not towards or away from any specific entity. Gravity, for example, is a force because it's a pull towards the center of Earth. The pressure gradient force is a force because it involves a push away from a dense collection of air molecules (i.e., a mass of air) and pull towards a lack thereof.