View Single Post
  #2   Report Post  
Old May 5th 13, 11:50 PM posted to uk.sci.weather
Len Wood Len Wood is offline
external usenet poster
 
First recorded activity by Weather-Banter: Oct 2009
Posts: 1,730
Default Eddies, waves etc: definitions

On May 5, 8:20*pm, Liam Steele wrote:
Hi all.

I'm reading up on types of atmospheric motion, and when discussing the
meridional transport of various properties the motion is generally split
into three components:

1. Mean meridional circulation
2. Transient eddies
3. Stationary waves

However, depending on what book, article or website I read, I come
across the terms transient eddies, stationary eddies, travelling waves,
stationary waves and non-travelling waves. Is this just a case of
different terminology for the same thing, or are there specific differences?

Are transient eddies and travelling waves the same? Are stationary
eddies, stationary waves and non-travelling waves the same?

Thanks in advance!

--
Liam


Depends a bit on scale.
Transient eddies usually refer to things like mid-latitude
depressions. Sometimes called baroclinic eddies.
These are embedded in larger planetary scale waves which may or may
not be stationary.

Rossby waves (barotropic waves) are planetary scale waves which derive
from the variation of the Coriolis parameter with latitude.
You could average out the transient eddies (noise) over a long enough
period to just leave the Rossby waves.
But the hemispheric flow you see at a given instant depends on
feedback across all scales.

Len
Wembury