Details
Originalsprache | Englisch |
---|---|
Aufsatznummer | 3 |
Fachzeitschrift | Boundary-Layer Meteorology |
Jahrgang | 191 |
Ausgabenummer | 1 |
Publikationsstatus | Veröffentlicht - 28 Dez. 2024 |
Abstract
We investigate how effective surface length scales (Leff) and atmospheric boundary layer stability modulate surface-induced secondary circulations over a realistic heterogeneous surface. The evolution of the circulations and their impact on surface-atmosphere fluxes are studied using coupled large eddy simulations of the CHEESEHEAD19 field campaign. The heterogeneity-induced circulations were diagnosed using time and ensemble averaging of the atmospheric fields. Simulations were performed for summer (August) and autumn (September) Intensive Observation Periods of the field campaign, characterised differently in terms of normalised surface length scales and ABL stability. Quasi-stationary and persistent circulations were diagnosed in the daytime ABL that span the entire mixed layer height (zi). Their variation in time and space are presented. Homogeneous control runs were also performed to compare and contrast spatial organisation and validate the time-ensemble averaging operation. In the convective boundary layers simulated during the summer time simulations, wavelengths that scale as the effective surface heterogeneity length scales contribute the most to the heterogeneity-induced transport. Contributions from surface-induced circulations were lower in the simulated near-neutral BL for the autumn simulations. We find that both Leff/zi and ABL static stability control the relative contribution of surface-induced circulations to the area averaged vertical transport. This scale analysis supports prior work over the study domain on scaling tower measured fluxes by including low frequency contributions. We believe that the conceptual framework presented here can be extended to include the effects of sub-grid land surface heterogeneity in numerical weather prediction and climate models and also to further explore scale-aware scaling methodologies for near surface-atmosphere exchanges.
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- Erdkunde und Planetologie (insg.)
- Atmosphärenwissenschaften
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in: Boundary-Layer Meteorology, Jahrgang 191, Nr. 1, 3, 28.12.2024.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Impact of Surface Heterogeneity Induced Secondary Circulations on the Atmospheric Boundary Layer
AU - Paleri, Sreenath
AU - Wanner, Luise
AU - Sühring, Matthias
AU - Desai, Ankur R.
AU - Mauder, Matthias
AU - Metzger, Stefan
N1 - Publisher Copyright: © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
PY - 2024/12/28
Y1 - 2024/12/28
N2 - We investigate how effective surface length scales (Leff) and atmospheric boundary layer stability modulate surface-induced secondary circulations over a realistic heterogeneous surface. The evolution of the circulations and their impact on surface-atmosphere fluxes are studied using coupled large eddy simulations of the CHEESEHEAD19 field campaign. The heterogeneity-induced circulations were diagnosed using time and ensemble averaging of the atmospheric fields. Simulations were performed for summer (August) and autumn (September) Intensive Observation Periods of the field campaign, characterised differently in terms of normalised surface length scales and ABL stability. Quasi-stationary and persistent circulations were diagnosed in the daytime ABL that span the entire mixed layer height (zi). Their variation in time and space are presented. Homogeneous control runs were also performed to compare and contrast spatial organisation and validate the time-ensemble averaging operation. In the convective boundary layers simulated during the summer time simulations, wavelengths that scale as the effective surface heterogeneity length scales contribute the most to the heterogeneity-induced transport. Contributions from surface-induced circulations were lower in the simulated near-neutral BL for the autumn simulations. We find that both Leff/zi and ABL static stability control the relative contribution of surface-induced circulations to the area averaged vertical transport. This scale analysis supports prior work over the study domain on scaling tower measured fluxes by including low frequency contributions. We believe that the conceptual framework presented here can be extended to include the effects of sub-grid land surface heterogeneity in numerical weather prediction and climate models and also to further explore scale-aware scaling methodologies for near surface-atmosphere exchanges.
AB - We investigate how effective surface length scales (Leff) and atmospheric boundary layer stability modulate surface-induced secondary circulations over a realistic heterogeneous surface. The evolution of the circulations and their impact on surface-atmosphere fluxes are studied using coupled large eddy simulations of the CHEESEHEAD19 field campaign. The heterogeneity-induced circulations were diagnosed using time and ensemble averaging of the atmospheric fields. Simulations were performed for summer (August) and autumn (September) Intensive Observation Periods of the field campaign, characterised differently in terms of normalised surface length scales and ABL stability. Quasi-stationary and persistent circulations were diagnosed in the daytime ABL that span the entire mixed layer height (zi). Their variation in time and space are presented. Homogeneous control runs were also performed to compare and contrast spatial organisation and validate the time-ensemble averaging operation. In the convective boundary layers simulated during the summer time simulations, wavelengths that scale as the effective surface heterogeneity length scales contribute the most to the heterogeneity-induced transport. Contributions from surface-induced circulations were lower in the simulated near-neutral BL for the autumn simulations. We find that both Leff/zi and ABL static stability control the relative contribution of surface-induced circulations to the area averaged vertical transport. This scale analysis supports prior work over the study domain on scaling tower measured fluxes by including low frequency contributions. We believe that the conceptual framework presented here can be extended to include the effects of sub-grid land surface heterogeneity in numerical weather prediction and climate models and also to further explore scale-aware scaling methodologies for near surface-atmosphere exchanges.
KW - CHEESEHEAD19
KW - Coupled large eddy simulations
KW - Dispersive fluxes
KW - Diurnal simulations
KW - Energy balance
KW - Land surface heterogeneity
UR - http://www.scopus.com/inward/record.url?scp=85213523919&partnerID=8YFLogxK
U2 - 10.21203/rs.3.rs-3439181/v1
DO - 10.21203/rs.3.rs-3439181/v1
M3 - Article
AN - SCOPUS:85213523919
VL - 191
JO - Boundary-Layer Meteorology
JF - Boundary-Layer Meteorology
SN - 0006-8314
IS - 1
M1 - 3
ER -