Impact of Surface Heterogeneity Induced Secondary Circulations on the Atmospheric Boundary Layer

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Sreenath Paleri - , University of Wisconsin-Madison, University of Oklahoma, NOAA/Air Resources Laboratory (Autor:in)
  • Luise Wanner - , Professur für Meteorologie, Karlsruher Institut für Technologie (Autor:in)
  • Matthias Sühring - , Leibniz Universität Hannover (LUH), Pecanode GmbH (Autor:in)
  • Ankur R. Desai - , University of Wisconsin-Madison (Autor:in)
  • Matthias Mauder - , Professur für Meteorologie, Karlsruher Institut für Technologie (Autor:in)
  • Stefan Metzger - , University of Wisconsin-Madison, AtmoFacts, CarbonDew (Autor:in)

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.

Details

OriginalspracheEnglisch
Aufsatznummer3
Seitenumfang32
FachzeitschriftBoundary-Layer Meteorology
Jahrgang191
Ausgabenummer1
PublikationsstatusVeröffentlicht - Jan. 2025
Peer-Review-StatusJa

Externe IDs

ORCID /0000-0002-8789-163X/work/176861763

Schlagworte

ASJC Scopus Sachgebiete

Schlagwörter

  • CHEESEHEAD19, Coupled large eddy simulations, Dispersive fluxes, Diurnal simulations, Energy balance, Land surface heterogeneity