Atmospheric boundary layer: Difference between revisions

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(Abbreviated ABL; <br/>''also called'' boundary layer, planetary boundary  layer.) The bottom layer of the [[troposphere]] that is in contact with the surface of the earth.<br/> It is often turbulent and is capped by a [[static stability|statically stable]] layer of air or [[temperature inversion]].  The ABL depth (i.e., the [[inversion]] height) is variable in time and space, ranging from tens of  meters in strongly statically stable situations, to several kilometers in convective conditions over  deserts. During [[fair]] weather over land, the ABL has a marked [[diurnal]] cycle. During daytime, a  [[mixed layer]] of vigorous [[turbulence]] grows in depth, capped by a statically stable [[entrainment zone|entrainment  zone]] of intermittent turbulence. Near [[sunset]], turbulence decays, leaving a [[residual layer]] in place  of the mixed layer. During nighttime, the bottom of the residual layer is transformed into a statically  [[stable boundary layer]] by contact with the radiatively cooled surface. [[cumulus|Cumulus]] and [[stratocumulus]]  clouds can form within the top portion of a humid ABL, while [[fog]] can form at the bottom of a  stable boundary layer. The bottom 10% of the ABL is called the [[surface layer]]. <br/>''Compare'' [[Ekman layer|Ekman  layer]].<br/> Stull, R. B. 1988. An Introduction to Boundary Layer Meteorology.  666 pp. <br/>  
(Abbreviated ABL; <br/>''also called'' boundary layer, planetary boundary  layer.) The bottom layer of the [[troposphere]] that is in contact with the surface of the earth.<br/> It is often turbulent and is capped by a [[static stability|statically stable]] layer of air or [[temperature inversion]].  The ABL depth (i.e., the [[inversion]] height) is variable in time and space, ranging from tens of  meters in strongly statically stable situations, to several kilometers in convective conditions over  deserts. During [[fair]] weather over land, the ABL has a marked [[diurnal]] cycle. During daytime, a  [[mixed layer]] of vigorous [[turbulence]] grows in depth, capped by a statically stable [[entrainment zone|entrainment  zone]] of intermittent turbulence. Near [[sunset]], turbulence decays, leaving a [[residual layer]] in place  of the mixed layer. During nighttime, the bottom of the residual layer is transformed into a statically  [[stable boundary layer]] by contact with the radiatively cooled surface. [[cumulus|Cumulus]] and [[stratocumulus]]  clouds can form within the top portion of a humid ABL, while [[fog]] can form at the bottom of a  stable boundary layer. The bottom 10% of the ABL is called the [[surface layer]]. <br/>''Compare'' [[Ekman layer|Ekman  layer]].<br/> Stull, R. B. 1988. An Introduction to Boundary Layer Meteorology.  666 pp. <br/>  



Latest revision as of 09:20, 19 April 2024


(Abbreviated ABL;
also called boundary layer, planetary boundary layer.) The bottom layer of the troposphere that is in contact with the surface of the earth.
It is often turbulent and is capped by a statically stable layer of air or temperature inversion. The ABL depth (i.e., the inversion height) is variable in time and space, ranging from tens of meters in strongly statically stable situations, to several kilometers in convective conditions over deserts. During fair weather over land, the ABL has a marked diurnal cycle. During daytime, a mixed layer of vigorous turbulence grows in depth, capped by a statically stable entrainment zone of intermittent turbulence. Near sunset, turbulence decays, leaving a residual layer in place of the mixed layer. During nighttime, the bottom of the residual layer is transformed into a statically stable boundary layer by contact with the radiatively cooled surface. Cumulus and stratocumulus clouds can form within the top portion of a humid ABL, while fog can form at the bottom of a stable boundary layer. The bottom 10% of the ABL is called the surface layer.
Compare Ekman layer.
Stull, R. B. 1988. An Introduction to Boundary Layer Meteorology. 666 pp.


capa límite atmosférica[edit | edit source]

(Se abrevia como ABL;
también se conoce como capa límite, capa límite planetaria). Es la capa inferior de la tropósfera que se encuentra en contacto con la superficie de la Tierra.

Con frecuencia es turbulenta y está delimitada por una capa de aire estáticamente estable o por inversión térmica. La profundidad de la ABL (es decir, la altura de la inversión) es variable en el tiempo y el espacio, con un rango de decenas de metros en situaciones de estabilidad estática sólida, a varios kilómetros en condiciones de convección encima de los desiertos. Durante el buen tiempo sobre territorio, la ABL tiene un ciclo diurno evidente. Durante el día, una capa mixta de turbulencia vigorosa se hace más profunda, delimitada por una zona de arrastre estáticamente estable de turbulencia intermitente. Hacia el ocaso, la turbulencia declina y deja una capa residual en lugar de la capa mixta. Durante la noche, la parte inferior de la capa residual se transforma en una capa límite estáticamente estable por contacto con la superficie enfriada radiativamente. Se pueden formar nubes cúmulo y estratocúmulo dentro de la parte superior de una ABL húmeda, en tanto que en la parte inferior de una capa límite estable, se puede formar niebla. El 10 % inferior de la ABL se denomina capa superficial.
Compare con capa de Ekman.


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