[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/conditional-symmetric-instability-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki21\/conditional-symmetric-instability-wikipedia\/","headline":"Conditional symmetric instability – Wikipedia","name":"Conditional symmetric instability – Wikipedia","description":"before-content-x4 Conditional symmetric instability, or CSI, is a form of convective instability in a fluid subject to temperature differences in","datePublished":"2017-12-16","dateModified":"2017-12-16","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki21\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/7e\/Northeast_Snowfall_Impact_Scale.gif\/220px-Northeast_Snowfall_Impact_Scale.gif","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/7\/7e\/Northeast_Snowfall_Impact_Scale.gif\/220px-Northeast_Snowfall_Impact_Scale.gif","height":"165","width":"220"},"url":"https:\/\/wiki.edu.vn\/en\/wiki21\/conditional-symmetric-instability-wikipedia\/","wordCount":6843,"articleBody":"     (adsbygoogle = window.adsbygoogle || []).push({});before-content-x4  Conditional symmetric instability, or CSI, is a form of convective instability in a fluid subject to temperature differences in a uniform rotation frame of reference while it is thermally stable in the vertical and dynamically in the horizontal (inertial stability). The instability in this case develop only in an inclined plane with respect to the two axes mentioned and that is why it can give rise to a so-called “slantwise convection” if the air parcel is almost saturated and moved laterally and vertically in a CSI area. This concept is mainly used in meteorology to explain the mesoscale formation of intense precipitation bands in an otherwise stable region, such as in front of a warm front.[1][2] The same phenomenon is also applicable to oceanography.       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4Table of ContentsPrinciple[edit]Hydrostatic stability[edit]Inertial Stability[edit]Slantwise movement[edit]Potential effects[edit]Slantwise convection[edit]Subsidence[edit]References[edit]External links[edit]Principle[edit]Hydrostatic stability[edit]  An air particle at a certain altitude will be stable if its adiabatically modified temperature during an ascent is equal to or cooler than the environment. Similarly, it is stable if its temperature is equal or warmer during a descent. In the case where the temperature is equal, the particle will remain at the new altitude, while in the other cases, it will return to its initial level4.       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4In the diagram on the right, the yellow line represents a raised particle whose temperature remains at first under that of the environment (stable air) which entails no convection. Then in the animation, there is warming surface warming and the raised particle remains warmer than the environment (unstable air). A measure of hydrostatic stability is to record the variation with the vertical of the equivalent potential temperature (\u03b8e{displaystyle theta _{e}}):[3]If \u03b8e{displaystyle theta _{e}} diminish with altitude leads to unstable airmassIf \u03b8e{displaystyle theta _{e}} remains the same with altitude leads to neutral airmassIf \u03b8e{displaystyle theta _{e}} increase with altitude leads to stable airmass.Inertial Stability[edit]  Dark zones are regions of weak inertial stability in atmospheric circulation.In the same way, a lateral displacement of an air particle changes its absolute vorticity        (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4\u03b7{displaystyle eta }. This is given by the sum of the planetary vorticity, f{displaystyle f}, and \u03b6{displaystyle zeta }, the geostrophic (or relative) vorticity of the parcel:[3][4]\u03b7=[\u2202v\u2202x\u2212\u2202u\u2202y]+f=\u03b6+f{displaystyle eta =left[{frac {partial v}{partial x}}-{frac {partial u}{partial y}}right]+f=zeta +fqquad qquad }Where\u00a0:\u03b7{displaystyle eta } can be positive, null or negative depending on the conditions in which the move is made. As the absolute vortex is almost always positive on the synoptic scale, one can consider that the atmosphere is generally stable for lateral movement. Inertial stability is low only when \u03b7{displaystyle eta } is close to zero. Since f{displaystyle f} is always positive, \u03b7\u22640{displaystyle eta leq 0} can be satisfied only on the anticyclonic side of a strong maximum of jet stream or in a barometric ridge at altitude, where the derivative velocities in the direction of displacement in the equation give a significant negative value.[5]The variation of the angular momentum indicate the stability:[3][5][6]\u0394Mg=0{displaystyle Delta M_{g}=0}, the particle then remains at the new position because its momentum has not changed"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/conditional-symmetric-instability-wikipedia\/#breadcrumbitem","name":"Conditional symmetric instability – Wikipedia"}}]}]