Talk:Rossby number

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Changed inertial to acceleration because the Coriolis force is the only force in the Navier Stokes equations that can be called inertial. It is inertial because it can be eliminated as a force by a coordinate transformation to a nonrotating system with origin at the earth's center. The acceleration component of the Navier stokes equations is really the sum of all the other forces (both inertial and noninertial, i.e. a piece of the pressure gradient force that is not balanced by coriolis being the most important) that arise in the fluid.

Also removed fictitious as a description of the Coriolis force. The force is no more fictitious than the force of gravity. You can eliminate gravity by boosting to a freely falling frame, does that make it fictitious? No way. Coriolis force is felt and observed in a coordinate system tangent to the earth's surface rotating with the earth and thus is quite real. Calling the force fictitious makes it seem like there are frames of reference that are more "true" than others.

For people that are interested in this enough to read the discussion section, you should realize that a large Rossby number doesn't always mean you can neglect rotation (only very near the equator where models do in fact do that) but it always means you must include the acceleration term in the flow model. That is the annoying part since the acceleration is a sum of frictional stresses (sometimes neglected) and a piece of the pressure gradient force.

--Dba5 21:26, 16 August 2006 (UTC)dba