Jump to content

Talk:Rossby parameter

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Equation Change

[edit]

Per the following discussion posted at WP:RD/S (May 24, 2007):

More atmospheric physics for you! Our article on Rossby waves says that the wave speed is given by

where c is the wave speed, u is the mean westerly flow, is the Rossby parameter, and k and l are the longitudinal and latitudinal wavenumbers. The Rossby parameter is given as

where is the latitude, is the angular speed of the Earth's rotation, and a is the mean radius of the Earth.

Given the above, I cannot see how c is anything other than tiny. Yet it is not.

For example, if I put in u = 3, k = 5, l = 3 and calculate for a latitude of 60 degrees, I get an answer of order , which is far too small.

I am surely misunderstanding something. Can someone check through this and see where I am going wrong? Many thanks, →Ollie (talkcontribs) 01:22, 24 May 2007 (UTC)[reply]


I agree with your assessment. Something must be awry! My understanding of the units in the problem suggest that must be in units of velocity (meters/sec). However, because it is defined as , this does not work out. So, perhaps it ought to be defined as:
This would make beta quite a bit larger (~1012x, which solves our issue quite nicely). I will try to find an alternative source for this equation which may verify my belief. Nimur 15:08, 24 May 2007 (UTC)[reply]
This lecture note seems to corroborate my belief that earth-radius should be multiplied, not divided. I will edit the articles in question. Nimur 15:16, 24 May 2007 (UTC)[reply]

End of copied discussion


Please discuss any issues below this line. Nimur 15:21, 24 May 2007 (UTC)[reply]


Yes, the radius a should be in the denominator, as traditionally defined. You can verify here:

http://amsglossary.allenpress.com/glossary/search?id=rossby-parameter1

Or any GFD texts would tell you the same thing.

Pkamostai (talk) 13:23, 20 December 2007 (UTC)[reply]

Equation

[edit]

Is the current expression of the Rossby parameter really correct? The above equation

suggests has a dimension , since dimension of is and 's is . So the previous equation

seems correct to me.

Am I missing something? 210.174.33.192 19:12, 13 November 2007 (UTC)[reply]

Yes, the radius a should be in the denominator, as traditionally defined. You can verify here: http://amsglossary.allenpress.com/glossary/search?id=rossby-parameter1 Or any GFD texts would tell you the same thing. —Preceding unsigned comment added by Pkamostai (talkcontribs) 13:21, 20 December 2007 (UTC)[reply]

This was the source of confusion some time ago (see the above discussion). I will defer to your more recent edits since I'm not an expert in the field... Nimur (talk) 06:36, 22 December 2007 (UTC)[reply]

No φ in the equation?

[edit]

I'm missing something too. The text says φ represents latitude, but there is not φ in the formula. Or am I just going blind? // Jontew (talk) 13:29, 26 November 2010 (UTC)[reply]

[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Rossby parameter. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 11:46, 23 January 2018 (UTC)[reply]