Modifications of a Valley Wind System by an Urban Area - Experimental Results

1999 ◽  
Vol 71 (1-2) ◽  
pp. 117-125 ◽  
Author(s):  
M. Piringer ◽  
K. Baumann
Keyword(s):  
Urban Area ◽  
Experimental Results ◽  
Wind System ◽  
Valley Wind

Intercomparison of Mesoscale Model Simulations of the Daytime Valley Wind System

2011 ◽  
Vol 139 (5) ◽  
pp. 1389-1409 ◽  
Author(s):  
Juerg Schmidli ◽  
Brian Billings ◽  
Fotini K. Chow ◽  
Stephan F. J. de Wekker ◽  
James Doyle ◽  
...  
Keyword(s):  
Land Surface ◽  
Mesoscale Model ◽  
Numerical Models ◽  
Surface Wind ◽  
Sensible Heat Flux ◽  
Surface Wind Speed ◽  
Time Shift ◽  
Wind System ◽  
Valley Wind ◽  
The Mean

Three-dimensional simulations of the daytime thermally induced valley wind system for an idealized valley–plain configuration, obtained from nine nonhydrostatic mesoscale models, are compared with special emphasis on the evolution of the along-valley wind. The models use the same initial and lateral boundary conditions, and standard parameterizations for turbulence, radiation, and land surface processes. The evolution of the mean along-valley wind (averaged over the valley cross section) is similar for all models, except for a time shift between individual models of up to 2 h and slight differences in the speed of the evolution. The analysis suggests that these differences are primarily due to differences in the simulated surface energy balance such as the dependence of the sensible heat flux on surface wind speed. Additional sensitivity experiments indicate that the evolution of the mean along-valley flow is largely independent of the choice of the dynamical core and of the turbulence parameterization scheme. The latter does, however, have a significant influence on the vertical structure of the boundary layer and of the along-valley wind. Thus, this ideal case may be useful for testing and evaluation of mesoscale numerical models with respect to land surface–atmosphere interactions and turbulence parameterizations.

scholarly journals Interactions Between the Nighttime Valley-Wind System and a Developing Cold-Air Pool

2016 ◽  
Vol 161 (1) ◽  
pp. 49-72 ◽  
Author(s):  
Gabriele Arduini ◽  
Chantal Staquet ◽  
Charles Chemel
Keyword(s):  
Wind System ◽  
Valley Wind ◽  
Cold Air

Site Effect Study in Urban Area: Experimental Results in Grenoble (France)

2002 ◽  
pp. 2543-2557 ◽  
Author(s):  
Benoît Lebrun ◽  
D. Hatzfeld ◽  
P. Y. Bard
Keyword(s):  
Urban Area ◽  
Site Effect ◽  
Effect Study ◽  
Experimental Results

Diurnal Mountain Winds

2000 ◽  
Author(s):  
C. David Whiteman
Keyword(s):  
Large Scale ◽  
Blow Up ◽  
Thermal Structure ◽  
Temperature Inversion ◽  
Return Flow ◽  
Wind System ◽  
Valley Wind ◽  
Deep Layers ◽  
Horizontal Pressure ◽  
Upper Level

Diurnal mountain winds develop over complex topography of all scales, from small hills to large mountain massifs and are characterized by a reversal of wind direction twice per day. As a rule, winds flow upslope, up-valley, and from the plain to the mountain massif during daytime. During nighttime, they flow downslope, down-valley, and from the mountain massif to the plain. Diurnal mountain winds are strongest when skies are clear and winds aloft are weak. Diurnal mountain winds are produced by horizontal temperature differences that develop daily in complex terrain. The resulting horizontal pressure differences cause winds near the surface of the earth to blow from areas with lower temperatures and higher pressures toward areas with higher temperatures and lower pressures. The circulations are closed by return, or compensatory, flows higher in the atmosphere. Four wind systems comprise the mountain wind system, which carries air into a mountain massif at low levels during daytime and out of a mountain massif during nighttime. The slope wind system (upslope winds and downslope winds) is driven by horizontal temperature contrasts between the air over the valley sidewalls and the air over the center of the valley. The along-valley wind system (up-valley winds and down-valley winds) is driven by horizontal temperature contrasts along a valley’s axis or between the air in a valley and the air over the adjacent plain. The cross-valley wind system results from horizontal temperature differences between the air over one valley sidewall and the air over the opposing sidewall, producing winds that blow perpendicular to the valley axis and toward the more strongly heated sidewall. The mountain-plain wind system results from horizontal temperature differences between the air over a mountain massif and the air over the surrounding plains, producing large-scale winds that blow up or down the outer slopes of a mountain massif. The mountain-plain circulation and its upper level return flow are not confined by the topography but are carried over deep layers of the atmosphere above the mountain slopes. Because diurnal mountain winds are driven by horizontal temperature differences, the regular evolution of the winds in a given valley is closely tied to the thermal structure of the atmospheric boundary layer within the valley, which is characterized by a diurnal cycle of buildup and breakdown of a temperature inversion.

Soil contaminated with PAHs and nitro-PAHs: contamination levels in an urban area of Catania (Sicily, southern Italy) and experimental results from simulated decontamination treatment

2016 ◽  
Vol 19 (4) ◽  
pp. 1121-1132 ◽  
Author(s):  
Guido De Guidi ◽  
Pietro P. Falciglia ◽  
Alfio Catalfo ◽  
Giorgio De Guidi ◽  
Sonia Fagone ◽  
...  
Keyword(s):  
Urban Area ◽  
Southern Italy ◽  
Experimental Results ◽  
Contamination Levels

Investigation of optical turbulence over an urban area: comparison between experimental results and simulation

2020 ◽  
Author(s):  
Detlev Sprung ◽  
Carmen Ullwer ◽  
Erik Sucher ◽  
Thomas Kociok ◽  
Alexander M. J. van Eijk ◽  
...  
Keyword(s):  
Urban Area ◽  
Experimental Results ◽  
Optical Turbulence

scholarly journals Mountain-Valley Wind System in the Khumbu Himal, East Nepal

1981 ◽  
Vol 59 (5) ◽  
pp. 753-762 ◽  
Author(s):  
T. Ohata ◽  
K. Higuchi ◽  
K. Ikegami
Keyword(s):  
Wind System ◽  
Valley Wind ◽  
Mountain Valley

Site Effect Study in Urban Area: Experimental Results in Grenoble (France)

2001 ◽  
Vol 158 (12) ◽  
pp. 2543-2557 ◽  
Author(s):  
B. LeBrun ◽  
D. Hatzfeld ◽  
P. Y. Bard
Keyword(s):  
Urban Area ◽  
Site Effect ◽  
Effect Study ◽  
Experimental Results

Managing groundwater rise: Experimental results and modelling of water pumping from a quarry lake in Milan urban area (Italy)

2004 ◽  
Vol 45 (5) ◽  
pp. 600-608 ◽  
Author(s):  
Giovanni Pietro Beretta ◽  
Monica Avanzini ◽  
Adelio Pagotto
Keyword(s):  
Urban Area ◽  
Experimental Results ◽  
Water Pumping ◽  
Groundwater Rise ◽  
Quarry Lake
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