elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Kontakt | English
Schriftgröße: [-] Text [+]

Observations and Numerical Simulations of Subrotor Vortices during T-REX

Doyle, James D. und Grubišić, Vanda und Brown, William O. J. und De Wekker, Stephan F. J. und Dörnbrack, Andreas und Weissmann, Martin und Jiang, Qingfang und Mayor, Shane D. (2009) Observations and Numerical Simulations of Subrotor Vortices during T-REX. Journal of the Atmospheric Sciences, 66 (5), Seiten 1229-1249. DOI: 10.1175/2008JAS2933.1.

[img]
Vorschau
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
10MB

Offizielle URL: http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F2008JAS2933.1

Kurzfassung

High-resolution observations from scanning Doppler and aerosol lidars, wind profiler radars, as well as surface and aircraft measurements during the Terrain-induced Rotor Experiment (T-REX) provide the first comprehensive documentation of small-scale intense vortices associated with atmospheric rotors that form in the lee of mountainous terrain. Although rotors are already recognized as potential hazards for aircraft, it is proposed that these small-scale vortices, or subrotors, are the most dangerous features because of strong wind shear and the transient nature of the vortices. A life cycle of a subrotor event is captured by scanning Doppler and aerosol lidars over a 5-min period. The lidars depict an amplifying vortex, with a characteristic length scale of ∼500–1000 m, that overturns and intensifies to a maximum spanwise vorticity greater than 0.2 s−1. Radar wind profiler observations document a series of vortices, characterized by updraft/downdraft couplets and regions of enhanced reversed flow, that are generated in a layer of strong vertical wind shear and subcritical Richardson number. The observations and numerical simulations reveal that turbulent subrotors occur most frequently along the leading edge of an elevated sheet of horizontal vorticity that is a manifestation of boundary layer shear and separation along the lee slopes. As the subrotors break from the vortex sheet, intensification occurs through vortex stretching and in some cases tilting processes related to three-dimensional turbulent mixing. The subrotors and ambient vortex sheet are shown to intensify through a modest increase in the upstream inversion strength, which illustrates the predictability challenges for the turbulent characterization of rotors.

Dokumentart:Zeitschriftenbeitrag
Titel:Observations and Numerical Simulations of Subrotor Vortices during T-REX
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Doyle, James D.Naval Research Lab., Monterey, CA, USA
Grubišić, VandaDesert Research Inst., Reno, NE, USA
Brown, William O. J.NCAR, Boulder, CO, USA
De Wekker, Stephan F. J.Univ. of Virginia, Charlottesville, VA, USA
Dörnbrack, AndreasNICHT SPEZIFIZIERT
Weissmann, MartinNICHT SPEZIFIZIERT
Jiang, QingfangNaval Research Lab., Monterey, CA, USA
Mayor, Shane D.California State Univ., Chico, CA, USA
Datum:2009
Erschienen in:Journal of the Atmospheric Sciences
Referierte Publikation:Ja
In SCOPUS:Ja
In ISI Web of Science:Ja
Band:66
DOI :10.1175/2008JAS2933.1
Seitenbereich:Seiten 1229-1249
Status:veröffentlicht
Stichwörter:rotor, subrotor, downslope wind, lidar
HGF - Forschungsbereich:Luftfahrt, Raumfahrt und Verkehr
HGF - Programm:keine Zuordnung
HGF - Programmthema:keine Zuordnung
DLR - Schwerpunkt:Luftfahrt
DLR - Forschungsgebiet:L - keine Zuordnung
DLR - Teilgebiet (Projekt, Vorhaben):L -- keine Zuordnung
Standort: Oberpfaffenhofen
Institute & Einrichtungen:Institut für Physik der Atmosphäre > Lidar
Hinterlegt von: Martin Weissmann
Hinterlegt am:27 Aug 2009 14:48
Letzte Änderung:12 Dez 2013 20:41

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Copyright © 2008-2013 Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.