Sponsor
At the University of Utah, this work was supported by the National Science Foundation (NSF, PDM-1712538) and the U.S. Department of Energy, Office of Biological & Environmental Research (DOE-SC0022072). The authors also acknowledge the Center for High Performance Computing (CHPC) at the University of Utah for computing, visualization, and storage resources.
Published In
JGR Atmospheres
Document Type
Article
Publication Date
10-2026
Subjects
Vegetated canopies
Abstract
It is well understood that vegetated canopies perturb the atmospheric flow within and immediately above the canopy, deviating from the inertial sublayer (ISL) regime characteristic of non-vegetated rough surfaces. Only above a certain height, denoted as the roughness sublayer height (RSL, π§β), do these flows return to ISL-like behavior. This distinction is critical, as parameterizations in Earth System Models (ESMs) are typically developed for ISL flows. Yet, most π§β estimates stem from studies over flat, homogeneous canopies and may be biased. In contrast, little is known about π§β in non-homogeneous or heterogeneous canopies that are not of agricultural interest, with irregular vegetation arrangements. Given that human activity has increasingly fragmented natural canopies, introducing gaps and multiscale heterogeneities, it is imperative to understand how the RSL height varies under such conditions. To address this gap, Large Eddy Simulations of the atmospheric boundary layer under geostrophic forcing are used to investigate how canopy heterogeneity influences the flow and π§β. Data is analyzed using the turbulent kinetic energy (TKE) budget equation with different averaging approaches. Additionally, the lacunarity metric is applied to measure spatial heterogeneity, and a canopy heterogeneity parameter, βπ, is introduced. Results demonstrate that the effects of canopy heterogeneity on ABL flows are well captured by the dispersive production of TKE, which enables the identification of π§β. Further, a scaling relation between π§β and βπ is established, enabling correction of previously published π§β values for canopy heterogeneity.
Rights
Copyright (c) 2026 The Authors
This work is licensed under a Creative Commons Attribution 4.0 International License.
Locate the Document
DOI
10.1029/2025JD044581
Persistent Identifier
https://archives.pdx.edu/ds/psu/45213
Citation Details
Salmaso, G., Cal, R. B., & Calaf, M. (2025). The Vegetated-Canopy Roughness Sublayer Through a TKE-Budget Lens.