Universität zu Köln

Allouche, Mohammad ORCID: 0000-0003-4440-9564, Bou-Zeid, Elie ORCID: 0000-0002-6137-8109, Ansorge, Cedrick, Katul, Gabriel G., Chamecki, Marcelo ORCID: 0000-0003-0576-0597, Acevedo, Otavio, Thanekar, Sham and Fuentes, Jose D. (2022). The Detection, Genesis, and Modeling of Turbulence Intermittency in the Stable Atmospheric Surface Layer. J. Atmos. Sci., 79 (4). S. 1171 - 1191. BOSTON: AMER METEOROLOGICAL SOC. ISSN 1520-0469

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Abstract

Intermittent transitions between turbulent and nonturbulent states are ubiquitous in the stable atmospheric surface layer (ASL). Data from two field experiments in Utqiagvik, Alaska, and from direct numerical simulations are used to probe these state transitions so as to (i) identify statistical metrics for the detection of intermittency, (ii) probe the physical origin of turbulent bursts, and (iii) quantify intermittency effects on overall fluxes and their representation in closure models. The analyses reveal three turbulence regimes, two of which correspond to weakly turbulent periods accompanied by intermittent behavior (regime 1: intermittent; regime 2: transitional), while the third is associated with a fully turbulent flow. Based on time series of the turbulence kinetic energy (TKE), two nondimensional parameters are proposed to diagnostically categorize the ASL state into these regimes; the first characterizes the weakest turbulence state, while the second describes the range of turbulence variability. The origins of intermittent turbulence activity are then investigated based on the TKE budget over the identified bursts. While the quantitative results depend on the height, the analyses indicate that these bursts are predominantly advected by the mean flow, produced locally by mechanical shear, or lofted from lower levels by turbulent ejections. Finally, a new flux model is proposed using the vertical velocity variance in combination with different mixing length scales. The model provides improved representation (correlation coefficients with observations of 0.61 for sensible heat and 0.94 for momentum) compared to Monin-Obukhov similarity (correlation coefficients of 0.0047 for sensible heat and 0.49 for momentum), thus opening new pathways for improved parameterizations in coarse atmospheric models.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Allouche, Mohammad UNSPECIFIED orcid.org/0000-0003-4440-9564 UNSPECIFIED Bou-Zeid, Elie UNSPECIFIED orcid.org/0000-0002-6137-8109 UNSPECIFIED Ansorge, Cedrick UNSPECIFIED UNSPECIFIED UNSPECIFIED Katul, Gabriel G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Chamecki, Marcelo UNSPECIFIED orcid.org/0000-0003-0576-0597 UNSPECIFIED Acevedo, Otavio UNSPECIFIED UNSPECIFIED UNSPECIFIED Thanekar, Sham UNSPECIFIED UNSPECIFIED UNSPECIFIED Fuentes, Jose D. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-688469
DOI:	10.1175/JAS-D-21-0053.1
Journal or Publication Title:	J. Atmos. Sci.
Volume:	79
Number:	4
Page Range:	S. 1171 - 1191
Date:	2022
Publisher:	AMER METEOROLOGICAL SOC
Place of Publication:	BOSTON
ISSN:	1520-0469
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language LOW-LEVEL JET; NOCTURNAL BOUNDARY-LAYER; WIND-SPEED; GLOBAL INTERMITTENCY; SIMILARITY THEORY; CANOPY SUBLAYER; VERTICAL FLUXES; SIMULATIONS; STABILITY; DENSITY Multiple languages Meteorology & Atmospheric Sciences Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/68846