Near-surface characteristics of the turbulence structure during a mountain-wave event

Autor(en)
Zeljko Vecenaj, Stephan F. J. De Wekker, Vanda Grubisic
Abstrakt

A case study of mountain-wave-induced turbulence observed during the Terrain-Induced Rotor Experiment (T-REX) in Owens Valley, California, is presented. During this case study, large spatial and temporal variability in aerosol backscatter associated with mountain-wave activity was observed in the valley atmosphere by an aerosol lidar. The corresponding along- and cross-valley turbulence structure was investigated using data collected by three 30-m flux towers equipped with six levels of ultrasonic anemometers. Time series of turbulent kinetic energy (TKE) show higher levels of TKE on the sloping western part of the valley when compared with the valley center. The magnitude of the TKE is highly dependent on the averaging time on the western slope, however, indicating that mesoscale transport associated with mountain-wave activity is important here. Analysis of the TKE budget shows that in the central parts of the valley mechanical production of turbulence dominates and is balanced by turbulent dissipation, whereas advective effects appear to play a dominant role over the western slope. In agreement with the aerosol backscatter observations, spatial variability of a turbulent-length-scale parameter suggests the presence of larger turbulent eddies over the western slope than along the valley center. The data and findings from this case study can be used to evaluate the performance of turbulence parameterization schemes in mountainous terrain.

Organisation(en)
Institut für Meteorologie und Geophysik
Externe Organisation(en)
University of Zagreb, University of Virginia
Journal
Journal of Applied Meteorology and Climatology
Band
50
Seiten
1088-1106
Anzahl der Seiten
19
ISSN
1558-8424
DOI
https://doi.org/10.1175/2010JAMC2450.1
Publikationsdatum
2011
Peer-reviewed
Ja
ÖFOS 2012
105206 Meteorologie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/5fe26255-1f2e-44a5-a4cc-9187e129eed0