Turner angle: Difference between revisions

From Glossary of Meteorology
m (Rewrite with Template:Term and clean up)
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
{{TermHeader}}
{{TermSearch}}
<div class="termentry">
  <div class="term">
== Turner angle ==
== Turner angle ==


<div class="definition"><div class="short_definition">A [[parameter]] used to define the local [[stability]] of an inviscid [[water]] column to double-diffusive [[convection]].</div><br/><div class="paragraph">It is defined as  <div class="display-formula"><blockquote>[[File:ams2001glos-Te48.gif|link=|center|ams2001glos-Te48]]</blockquote></div> where tan<sup>&#8722;1</sup> is the four-quadrant arctangent, ''&#x003b1;'' is the [[coefficient of thermal expansion]], ''&#x003b2;'' is the equivalent coefficient for the addition of [[salinity]] (sometimes referred to as saline contraction because the addition of salinity reduces the volume), ''T'' is [[temperature]], and ''S'' is [[salinity]]. If &#8722;45&#x000b0; &lt; Tu &lt; 45&#x000b0;, the  column is [[static stability|statically stable]]. If &#8722;90&#x000b0; &gt; Tu or Tu &gt; 90&#x000b0;, the column is statically unstable to Rayleigh&ndash;Taylor [[instability]]. If &#8722;90&#x000b0; &lt; Tu &lt; &#8722;45&#x000b0;, the column is unstable to [[diffusive convection]]. If 45&#x000b0;  &lt; Tu &lt; 90&#x000b0;, the column is unstable to [[salt fingering]].</div><br/> </div>
A [[parameter]] used to define the local [[stability]] of an inviscid [[water]] column to double-diffusive [[convection]].<br/>It is defined as  <blockquote>[[File:ams2001glos-Te48.gif|link=|center|ams2001glos-Te48]]</blockquote> where tan<sup>&#8722;1</sup> is the four-quadrant arctangent; ''&#x003b1;'' is the [[coefficient of thermal expansion]]; ''&#x003b2;'' is the equivalent coefficient for the addition of [[salinity]], sometimes referred to as the "coefficient of saline contraction;" ''T'' is [[temperature]]; and ''S'' is [[salinity]]. If &#8722;45&#x000b0; &lt; Tu &lt; 45&#x000b0;, the  column is [[static stability|statically stable]]. If &#8722;90&#x000b0; &gt; Tu or Tu &gt; 90&#x000b0;, the column is statically unstable to Rayleigh&ndash;Taylor [[instability]]. If &#8722;90&#x000b0; &lt; Tu &lt; &#8722;45&#x000b0;, the column is unstable to [[diffusive convection]]. If 45&#x000b0;  &lt; Tu &lt; 90&#x000b0;, the column is unstable to [[salt fingering]].<br/>  
 
''Term edited 1 March 2021''
 
{{TermIndex}}
{{TermFooter}}


[[Category:Terms_T]]
''Term edited 8 March 2021''

Latest revision as of 00:06, 29 March 2024

Turner angle

A parameter used to define the local stability of an inviscid water column to double-diffusive convection.
It is defined as

ams2001glos-Te48

where tan−1 is the four-quadrant arctangent; α is the coefficient of thermal expansion; β is the equivalent coefficient for the addition of salinity, sometimes referred to as the "coefficient of saline contraction;" T is temperature; and S is salinity. If −45° < Tu < 45°, the column is statically stable. If −90° > Tu or Tu > 90°, the column is statically unstable to Rayleigh–Taylor instability. If −90° < Tu < −45°, the column is unstable to diffusive convection. If 45° < Tu < 90°, the column is unstable to salt fingering.

Term edited 8 March 2021

Copyright 2025 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.