UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Mass-Flux Characteristics of Reactive Scalars in the Convective Boundary Layer

Petersen, AC; Beets, C; van Dop, H; Duynkerke, PG; Siebesma, AP; (1999) Mass-Flux Characteristics of Reactive Scalars in the Convective Boundary Layer. Journal of the Atmospheric Sciences , 56 (1) pp. 37-56. 10.1175/1520-0469(1999)056<0037:MFCORS>2.0.CO;2. Green open access

[thumbnail of Petersen_ Journal of the Atmospheric Sciences.pdf]
Preview
Text
Petersen_ Journal of the Atmospheric Sciences.pdf

Download (306kB) | Preview

Abstract

The transport of nonreactive and reactive bottom-up and top-down diffusing scalars in a solid-lid convective boundary layer is studied using large-eddy simulation (LES). The chemistry considered consists of an irreversible, binary reaction involving the bottom-up and top-down diffusing scalars. The mass-flux or top-hat characteristics of the reactive flow are determined. Also, several mass-flux schemes are run in an off-line mode, that is, with prescribed profiles of the mass flux and the updraft area fraction, and are compared to the LES. Top-hat approximations are found to capture about 25% of the covariance between two arbitrary (nonreacting or reacting) scalars and about 65% of the flux. Subplume fluxes are located either in the updraft for bottom-up diffusing scalars or in the downdraft for top-down diffusing scalars. The mass-flux scheme that is nearly identical to the exact plume-budget equations gives the best performance. For the parameterization of lateral exchange this mass-flux scheme includes gross exchange across the interface between updrafts and downdrafts, that is, includes also subinterface-scale exchange processes (like the other dynamical quantities also prescribed in an off-line mode using LES data). A simpler mass-flux scheme, which does not include the more sophisticated parameterizations of subplume fluxes and subinterface-scale lateral exchange, is found to perform only slightly worse. The results of this paper are also valid for the surface layer and lower mixed layer of the entraining convective boundary layer but not for the entrainment zone.

Type: Article
Title: Mass-Flux Characteristics of Reactive Scalars in the Convective Boundary Layer
Open access status: An open access version is available from UCL Discovery
DOI: 10.1175/1520-0469(1999)056<0037:MFCORS>2.0.CO;2
Publisher version: https://doi.org/10.1175/1520-0469(1999)056<0037:MF...
Language: English
Additional information: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
UCL classification: UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science
URI: https://discovery.ucl.ac.uk/id/eprint/1458334
Downloads since deposit
97Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item