Vertical-Velocity Skewness in the Buoyancy-Driven Boundary LayerSource: Journal of the Atmospheric Sciences:;1989:;Volume( 047 ):;issue: 009::page 1149DOI: 10.1175/1520-0469(1990)047<1149:VVSITB>2.0.CO;2Publisher: American Meteorological Society
Abstract: A number of puzzling features of the skewness of the vertical velocity field, Sw(z), are found in observations and large-eddy simulations (LES) of the buoyancy-driven planetary boundary layer (PBL). For example, observations of Sw(z) in cases where the air is heated from below indicate that Sw(z) > 0 and remains relatively constant for z ? 0.3zi, whereas all large-eddy simulations of these cases show a continuing increase of Sw(z) with height. In cases where the air is both heated from below and cooled from above, as in some of the stratus-topped PBL cases, large-eddy simulations show a rather curious feature: Sw is positive in the upper layer and negative in the lower layer. In considering these features, it occurred to us that a theoretical model of what one should expect of the skewness distribution, even in simple situations, did not exist. Hence in the present paper we examine the skewness distributions from direct numerical simulations of several simple archetypes of buoyancy-driven turbulent flow. While these simulations do not resolve the discrepancy between LES and observations, they help in understanding the LES results, and suggest avenues for future research.
|
Collections
Show full item record
contributor author | Moeng, Chin-Hoh | |
contributor author | Rotunno, Richard | |
date accessioned | 2017-06-09T14:29:42Z | |
date available | 2017-06-09T14:29:42Z | |
date copyright | 1990/05/01 | |
date issued | 1989 | |
identifier issn | 0022-4928 | |
identifier other | ams-20317.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4156532 | |
description abstract | A number of puzzling features of the skewness of the vertical velocity field, Sw(z), are found in observations and large-eddy simulations (LES) of the buoyancy-driven planetary boundary layer (PBL). For example, observations of Sw(z) in cases where the air is heated from below indicate that Sw(z) > 0 and remains relatively constant for z ? 0.3zi, whereas all large-eddy simulations of these cases show a continuing increase of Sw(z) with height. In cases where the air is both heated from below and cooled from above, as in some of the stratus-topped PBL cases, large-eddy simulations show a rather curious feature: Sw is positive in the upper layer and negative in the lower layer. In considering these features, it occurred to us that a theoretical model of what one should expect of the skewness distribution, even in simple situations, did not exist. Hence in the present paper we examine the skewness distributions from direct numerical simulations of several simple archetypes of buoyancy-driven turbulent flow. While these simulations do not resolve the discrepancy between LES and observations, they help in understanding the LES results, and suggest avenues for future research. | |
publisher | American Meteorological Society | |
title | Vertical-Velocity Skewness in the Buoyancy-Driven Boundary Layer | |
type | Journal Paper | |
journal volume | 47 | |
journal issue | 9 | |
journal title | Journal of the Atmospheric Sciences | |
identifier doi | 10.1175/1520-0469(1990)047<1149:VVSITB>2.0.CO;2 | |
journal fristpage | 1149 | |
journal lastpage | 1162 | |
tree | Journal of the Atmospheric Sciences:;1989:;Volume( 047 ):;issue: 009 | |
contenttype | Fulltext |