# Talk:Monin–Obukhov length

Active discussions
WikiProject Physics / Fluid Dynamics  (Rated Stub-class, Mid-importance)

## Buoyancy flux

I think it is not correct to define the buoyancy flux as in the currently present form:

${\displaystyle {\overline {w^{'}\theta _{v}^{'}}}={\overline {w^{'}\theta ^{'}}}+0.61{\overline {T}}\;{\overline {w^{'}q^{'}}}}$

I would like to discuss the following points:

• This equation is an approximation for the flux that involves Reynolds averaging and some neglections. It is not a definition.
• This approximation is not accurate (see "An Introduction to Boundary Layer Meteorology" by Roland B. Stull, 1988).
• The actual temperature should be replaced by potential temperature.
• Hence, better use the following formulation:
${\displaystyle {\overline {w^{'}\theta _{v}^{'}}}={\overline {w^{'}\theta ^{'}}}(1+0.61{\overline {q}})+0.61{\overline {\theta }}\;{\overline {w^{'}q^{'}}}}$

The above formulation is the "correct" result from the definition of virtual potential temperature, splitting into mean and turbulent state and subsequent Reynolds averaging - but the triple correlation

${\displaystyle {\overline {w^{'}\theta ^{'}q^{'}}}=0}$

has been already neglected. The correction for humidity, however, should be considered. — Preceding unsigned comment added by 130.75.105.113 (talk) 13:50, 31 January 2013 (UTC)

## Related articles

I'm preparing an article on Monin-Obukhov similarity theory as part of an UCLA class project (The Atmospheric Boundary Layer ), which will probably be more comprehensive than this one. I have gathered references and will draft in my sandbox. Let me know if you have any comments or feedback. Thank you. Geoalchimista (talk) 20:30, 29 April 2014 (UTC)

## Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: no consensus to move Kotniski (talk) 11:02, 30 August 2010 (UTC)

Monin–Obukhov LengthObukhov Length — Obukhov first described this length scale in 1946, several years before the work with Monin. It is accepted practice to then only refer to it as the Obukhov length. See here. User:Gibbz84 06:01, 29 July 2010 (UTC)

• What you are saying may be correct, but there are an overwhelming number of literatures calling it Monin–Obukhov Length. 15:51, 29 July 2010 (UTC)
• Quantity of incorrect references does not remove the fact it is still incorrect. —Preceding unsigned comment added by 129.15.109.254 (talk) 19:56, 29 July 2010 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

## Suggested merge

I suggest this page is merged with Monin-Obukhov similarity theory; both are marked as being too technical, and a page on the Obukhov length is inevitably going to be incomprehensible without the context of the similarity theory that it is applied to. When I have time I could help trying to improve a merged page as I taught masters-level Boundary-Layer Meteorology for a number of years. This would also resolve the question of whether to call the page the Obukhov or Monin-Obukhov length (is is more common to call it the former). Rjhogan (talk) 09:16, 23 October 2017 (UTC)

## Monin-Obukhov length

The article now only seems to discuss the Monin-Obukhov length in the atmosphere (with the formula for specific humidity). Should it not also discuss the Monin-Obukhov length in the ocean upper layer (for instance such as described in chapter 14 of Introduction to Geophysical fluid dynamics by Cushman-Roisin, 2011)? Femkemilene (talk) 12:39, 18 March 2014 (UTC)

Sure, you are free to expand the article. 17:08, 18 March 2014 (UTC)