A Parametrization of the Convective Boundary Layer with Subgrid Orography.
Saved in:
| Title: | A Parametrization of the Convective Boundary Layer with Subgrid Orography. |
|---|---|
| Authors: | Philippot, Nathan1,2 (AUTHOR) nathan.philippot@univ-grenoble-alpes.fr, Couvreux, Fleur1 (AUTHOR), Rio, Catherine1 (AUTHOR), Ménégoz, Martin2 (AUTHOR) |
| Source: | Journal of the Atmospheric Sciences. May2026, Vol. 83 Issue 5, p1-18. 18p. |
| Subjects: | Convective boundary layer (Meteorology), Large eddy simulation models, Free convection, Heat convection, Uplands |
| Abstract: | Current parameterizations of shallow convection ignore subgrid orography, assuming a flat surface at the mean elevation. Consequently, they often fail in mountainous regions to reproduce realistic profiles and surface temperatures, and to simulate the transition to deep convection. We have produced a set of idealized LES of dry convection with different orographies, including flat cases, to highlight the importance of the subgrid orography on the evolution of the mean profiles, and to characterize the coherent structures contributing to the vertical mixing: the thermal updrafts and the slope winds. From that process analysis of the LES we have developed a generalization of Eddy-Diffusivity Mass-Flux (EDMF) parameterizations for daytime mountainous boundary layers, which unifies the anabatic slope winds and the thermal updrafts within the Mass-Flux framework. The 1D parametrization includes a subgrid orography following an area-height distribution of the atmosphere on which we define the vertical profiles of prognostic variables. It reproduces the daytime evolution of the mean temperature profile, as well as the characteristics of anabatic winds and thermal updrafts simulated in the LES. Further developments are needed to take into account moist processes, nighttime katabatics, as well as the interactions with synoptic winds. To be used in a 3D atmospheric model, this parameterization should be combined to a dynamical core that handles porous mountains, necessitating an adaptation of current models that are based on terrain-following grids. With these additional developments, this parameterization could improve the skill of coarse gridded (>1 km) atmospheric models over mountainous regions. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of the Atmospheric Sciences is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
|---|---|
| Header | DbId: egs DbLabel: Engineering Source An: 194578222 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: A Parametrization of the Convective Boundary Layer with Subgrid Orography. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Philippot%2C+Nathan%22">Philippot, Nathan</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> nathan.philippot@univ-grenoble-alpes.fr</i><br /><searchLink fieldCode="AR" term="%22Couvreux%2C+Fleur%22">Couvreux, Fleur</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Rio%2C+Catherine%22">Rio, Catherine</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Ménégoz%2C+Martin%22">Ménégoz, Martin</searchLink><relatesTo>2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+the+Atmospheric+Sciences%22">Journal of the Atmospheric Sciences</searchLink>. May2026, Vol. 83 Issue 5, p1-18. 18p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Convective+boundary+layer+%28Meteorology%29%22">Convective boundary layer (Meteorology)</searchLink><br /><searchLink fieldCode="DE" term="%22Large+eddy+simulation+models%22">Large eddy simulation models</searchLink><br /><searchLink fieldCode="DE" term="%22Free+convection%22">Free convection</searchLink><br /><searchLink fieldCode="DE" term="%22Heat+convection%22">Heat convection</searchLink><br /><searchLink fieldCode="DE" term="%22Uplands%22">Uplands</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Current parameterizations of shallow convection ignore subgrid orography, assuming a flat surface at the mean elevation. Consequently, they often fail in mountainous regions to reproduce realistic profiles and surface temperatures, and to simulate the transition to deep convection. We have produced a set of idealized LES of dry convection with different orographies, including flat cases, to highlight the importance of the subgrid orography on the evolution of the mean profiles, and to characterize the coherent structures contributing to the vertical mixing: the thermal updrafts and the slope winds. From that process analysis of the LES we have developed a generalization of Eddy-Diffusivity Mass-Flux (EDMF) parameterizations for daytime mountainous boundary layers, which unifies the anabatic slope winds and the thermal updrafts within the Mass-Flux framework. The 1D parametrization includes a subgrid orography following an area-height distribution of the atmosphere on which we define the vertical profiles of prognostic variables. It reproduces the daytime evolution of the mean temperature profile, as well as the characteristics of anabatic winds and thermal updrafts simulated in the LES. Further developments are needed to take into account moist processes, nighttime katabatics, as well as the interactions with synoptic winds. To be used in a 3D atmospheric model, this parameterization should be combined to a dynamical core that handles porous mountains, necessitating an adaptation of current models that are based on terrain-following grids. With these additional developments, this parameterization could improve the skill of coarse gridded (>1 km) atmospheric models over mountainous regions. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of the Atmospheric Sciences is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=194578222 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1175/JAS-D-25-0192.1 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 18 StartPage: 1 Subjects: – SubjectFull: Convective boundary layer (Meteorology) Type: general – SubjectFull: Large eddy simulation models Type: general – SubjectFull: Free convection Type: general – SubjectFull: Heat convection Type: general – SubjectFull: Uplands Type: general Titles: – TitleFull: A Parametrization of the Convective Boundary Layer with Subgrid Orography. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Philippot, Nathan – PersonEntity: Name: NameFull: Couvreux, Fleur – PersonEntity: Name: NameFull: Rio, Catherine – PersonEntity: Name: NameFull: Ménégoz, Martin IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 05 Text: May2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00224928 Numbering: – Type: volume Value: 83 – Type: issue Value: 5 Titles: – TitleFull: Journal of the Atmospheric Sciences Type: main |
| ResultId | 1 |
