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Acta Geophysica

, Volume 56, Issue 1, pp 100–113 | Cite as

Nocturnal basin low-level jets: an integrated study

  • Joan Cuxart
Article

Abstract

Low-level jets (LLJs) are a very common feature in the nocturnal stably stratified boundary layer. Many factors can intervene in their generation, linked basically to effects of baroclinity. A special kind of low-level jets is composed by the nocturnal katabatic and basin flows, generated over terrain slopes. A study of observed LLJs in the Duero Basin is shown here, combining observational data and modelling experiments. Normalized in respect to the maximum wind height, the dynamic characteristics of the jets are similar: a two-layer system, with a stably stratified layer below the jet maximum and a near neutral layer above, with a very stable layer separating them at the level of the wind maximum. There is vertical mixing above and below the jet, and the connection between these layers takes place occasionally in a very turbulent manner.

Key words

low-level jet katabatic flows Duero Basin vertical mixing two-layer system large-eddy simulation mesoscale modelling 

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Copyright information

© Institute of Geophysics, Polish Academy of Sciences 2008

Authors and Affiliations

  1. 1.Departament de FisicaUniversitat de les Illes BalearsMallorcaSpain

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