Within MAP, one of the scientific projects was devoted to ‘Boundary Layers in Complex Terrain’. In a number of subprojects, boundary-layer issues were addressed and detailed high-resolution multi-sensor observations were combined with simulation by models allowing for adequate parametrization of turbulence processes. In this contribution, the projects are briefly introduced and an attempt is made to summarize their key findings and to put them into a joint perspective. Spatial variability is found to be large but strictly related to topography and therefore allowing for possible parametrization. Traditional boundary-layer scaling approaches cannot simply be applied over highly complex topography, but some of the MAP findings suggest the potential for suitable extensions of those scaling relations to cover various cases of complex terrain. The mean boundary-layer structure and thermally driven flows in narrow valleys are found not to be generally in line with previous results from larger valleys elsewhere. Furthermore, local circulations are reported to contribute considerably to exchange between valley and free troposphere. In particular, the range of their effects on the lower atmosphere seems to be larger than just turbulent transport within the planetary boundary layer would suggest. Thus in larger-scale numerical models where the topography is not resolved, possible sub-grid parametrizations for local exchange seem to be in order.

On the boundary layer structure over highly complex terrain: Key findings from MAP and related projects / Rotach, Mathias Walter; Zardi, Dino. - In: HRVATSKI METEOROLOSKI CASOPIS - CROATIAN METEOROLOGICAL JOURNAL. - ISSN 1330-0083. - STAMPA. - 40:(2005), pp. 124-127.

On the boundary layer structure over highly complex terrain: Key findings from MAP and related projects

Rotach, Mathias Walter;Zardi, Dino
2005-01-01

Abstract

Within MAP, one of the scientific projects was devoted to ‘Boundary Layers in Complex Terrain’. In a number of subprojects, boundary-layer issues were addressed and detailed high-resolution multi-sensor observations were combined with simulation by models allowing for adequate parametrization of turbulence processes. In this contribution, the projects are briefly introduced and an attempt is made to summarize their key findings and to put them into a joint perspective. Spatial variability is found to be large but strictly related to topography and therefore allowing for possible parametrization. Traditional boundary-layer scaling approaches cannot simply be applied over highly complex topography, but some of the MAP findings suggest the potential for suitable extensions of those scaling relations to cover various cases of complex terrain. The mean boundary-layer structure and thermally driven flows in narrow valleys are found not to be generally in line with previous results from larger valleys elsewhere. Furthermore, local circulations are reported to contribute considerably to exchange between valley and free troposphere. In particular, the range of their effects on the lower atmosphere seems to be larger than just turbulent transport within the planetary boundary layer would suggest. Thus in larger-scale numerical models where the topography is not resolved, possible sub-grid parametrizations for local exchange seem to be in order.
2005
Rotach, Mathias Walter; Zardi, Dino
On the boundary layer structure over highly complex terrain: Key findings from MAP and related projects / Rotach, Mathias Walter; Zardi, Dino. - In: HRVATSKI METEOROLOSKI CASOPIS - CROATIAN METEOROLOGICAL JOURNAL. - ISSN 1330-0083. - STAMPA. - 40:(2005), pp. 124-127.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/93379
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? ND
social impact