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Title: Coupled mesoscale-LES modeling of a diurnal cycle during the CWEX-13 field campaign: From weather to boundary-layer eddies

Abstract

Multiscale modeling of a diurnal cycle of real-world conditions is presented for the first time, validated using data from the CWEX-13 field experiment. Dynamical downscaling from synoptic-scale down to resolved three-dimensional eddies in the atmospheric boundary layer (ABL) was performed, spanning 4 orders of magnitude in horizontal grid resolution: from 111 km down to 8.2 m (30 m) in stable (convective) conditions. Computationally efficient mesoscale-to-microscale transition was made possible by the generalized cell perturbation method with time-varying parameters derived from mesoscale forcing conditions, which substantially reduced the fetch to achieve fully developed turbulence. In addition, careful design of the simulations was made to inhibit the presence of under-resolved convection at convection-resolving mesoscale resolution and to ensure proper turbulence representation in stably-stratified conditions. Comparison to in situ wind-profiling lidar and near-surface sonic anemometer measurements demonstrated the ability to reproduce the ABL structure throughout the entire diurnal cycle with a high degree of fidelity. The multiscale simulations exhibit realistic atmospheric features such as convective rolls and global intermittency. Also, the diurnal evolution of turbulence was accurately simulated, with probability density functions of resolved turbulent velocity fluctuations nearly identical to the lidar measurements. Explicit representation of turbulence in the stably-stratified ABL was foundmore » to provide the right balance with larger scales, resulting in the development of intra-hour variability as observed by the wind lidar; this variability was not captured by the mesoscale model. Furthermore, multiscale simulations improved mean ABL characteristics such as horizontal velocity, vertical wind shear, and turbulence.« less

Authors:
ORCiD logo [1]; ORCiD logo [2];  [1]; ORCiD logo [1]; ORCiD logo [3]
  1. National Center for Atmospheric Research, Boulder, CO (United States)
  2. Univ. of Colorado, Boulder, CO (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1368587
Report Number(s):
LA-UR-17-25098; NREL/JA-5000-70249
Journal ID: ISSN 1942-2466
Grant/Contract Number:
AC52-06NA25396; AC36-08GO28308
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of Advances in Modeling Earth Systems
Additional Journal Information:
Journal Volume: 9; Journal Issue: 3; Journal ID: ISSN 1942-2466
Publisher:
American Geophysical Union (AGU)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Earth Sciences; Diurnal cycle; LES atmospheric modeling; multiscale modeling; turbulence; atmospheric boundary layers; WRF; large-eddy simulation; CWEX-13; 17 WIND ENERGY

Citation Formats

Munoz-Esparza, Domingo, Lundquist, Julie K., Sauer, Jeremy A., Kosovic, Branko, and Linn, Rodman Ray. Coupled mesoscale-LES modeling of a diurnal cycle during the CWEX-13 field campaign: From weather to boundary-layer eddies. United States: N. p., 2017. Web. doi:10.1002/2017MS000960.
Munoz-Esparza, Domingo, Lundquist, Julie K., Sauer, Jeremy A., Kosovic, Branko, & Linn, Rodman Ray. Coupled mesoscale-LES modeling of a diurnal cycle during the CWEX-13 field campaign: From weather to boundary-layer eddies. United States. doi:10.1002/2017MS000960.
Munoz-Esparza, Domingo, Lundquist, Julie K., Sauer, Jeremy A., Kosovic, Branko, and Linn, Rodman Ray. 2017. "Coupled mesoscale-LES modeling of a diurnal cycle during the CWEX-13 field campaign: From weather to boundary-layer eddies". United States. doi:10.1002/2017MS000960.
@article{osti_1368587,
title = {Coupled mesoscale-LES modeling of a diurnal cycle during the CWEX-13 field campaign: From weather to boundary-layer eddies},
author = {Munoz-Esparza, Domingo and Lundquist, Julie K. and Sauer, Jeremy A. and Kosovic, Branko and Linn, Rodman Ray},
abstractNote = {Multiscale modeling of a diurnal cycle of real-world conditions is presented for the first time, validated using data from the CWEX-13 field experiment. Dynamical downscaling from synoptic-scale down to resolved three-dimensional eddies in the atmospheric boundary layer (ABL) was performed, spanning 4 orders of magnitude in horizontal grid resolution: from 111 km down to 8.2 m (30 m) in stable (convective) conditions. Computationally efficient mesoscale-to-microscale transition was made possible by the generalized cell perturbation method with time-varying parameters derived from mesoscale forcing conditions, which substantially reduced the fetch to achieve fully developed turbulence. In addition, careful design of the simulations was made to inhibit the presence of under-resolved convection at convection-resolving mesoscale resolution and to ensure proper turbulence representation in stably-stratified conditions. Comparison to in situ wind-profiling lidar and near-surface sonic anemometer measurements demonstrated the ability to reproduce the ABL structure throughout the entire diurnal cycle with a high degree of fidelity. The multiscale simulations exhibit realistic atmospheric features such as convective rolls and global intermittency. Also, the diurnal evolution of turbulence was accurately simulated, with probability density functions of resolved turbulent velocity fluctuations nearly identical to the lidar measurements. Explicit representation of turbulence in the stably-stratified ABL was found to provide the right balance with larger scales, resulting in the development of intra-hour variability as observed by the wind lidar; this variability was not captured by the mesoscale model. Furthermore, multiscale simulations improved mean ABL characteristics such as horizontal velocity, vertical wind shear, and turbulence.},
doi = {10.1002/2017MS000960},
journal = {Journal of Advances in Modeling Earth Systems},
number = 3,
volume = 9,
place = {United States},
year = 2017,
month = 4
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/2017MS000960

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  • Multiscale modeling of a diurnal cycle of real-world conditions is presented for the first time, validated using data from the CWEX-13 field experiment. Dynamical downscaling from synoptic-scale down to resolved three-dimensional eddies in the atmospheric boundary layer (ABL) was performed, spanning 4 orders of magnitude in horizontal grid resolution: from 111 km down to 8.2 m (30 m) in stable (convective) conditions. Computationally efficient mesoscale-to-microscale transition was made possible by the generalized cell perturbation method with time-varying parameters derived from mesoscale forcing conditions, which substantially reduced the fetch to achieve fully developed turbulence. In addition, careful design of the simulationsmore » was made to inhibit the presence of under-resolved convection at convection-resolving mesoscale resolution and to ensure proper turbulence representation in stably-stratified conditions. Comparison to in situ wind-profiling lidar and near-surface sonic anemometer measurements demonstrated the ability to reproduce the ABL structure throughout the entire diurnal cycle with a high degree of fidelity. The multiscale simulations exhibit realistic atmospheric features such as convective rolls and global intermittency. Also, the diurnal evolution of turbulence was accurately simulated, with probability density functions of resolved turbulent velocity fluctuations nearly identical to the lidar measurements. Explicit representation of turbulence in the stably-stratified ABL was found to provide the right balance with larger scales, resulting in the development of intra-hour variability as observed by the wind lidar; this variability was not captured by the mesoscale model. Moreover, multiscale simulations improved mean ABL characteristics such as horizontal velocity, vertical wind shear, and turbulence.« less
  • Multiscale modeling of a diurnal cycle of real-world conditions is presented for the first time, validated using data from the CWEX-13 field experiment. Dynamical downscaling from synoptic-scale down to resolved three-dimensional eddies in the atmospheric boundary layer (ABL) was performed, spanning 4 orders of magnitude in horizontal grid resolution: from 111 km down to 8.2 m (30 m) in stable (convective) conditions. Computationally efficient mesoscale-to-microscale transition was made possible by the generalized cell perturbation method with time-varying parameters derived from mesoscale forcing conditions, which substantially reduced the fetch to achieve fully developed turbulence. In addition, careful design of the simulationsmore » was made to inhibit the presence of under-resolved convection at convection-resolving mesoscale resolution and to ensure proper turbulence representation in stably-stratified conditions. Comparison to in situ wind-profiling lidar and near-surface sonic anemometer measurements demonstrated the ability to reproduce the ABL structure throughout the entire diurnal cycle with a high degree of fidelity. The multiscale simulations exhibit realistic atmospheric features such as convective rolls and global intermittency. Also, the diurnal evolution of turbulence was accurately simulated, with probability density functions of resolved turbulent velocity fluctuations nearly identical to the lidar measurements. Explicit representation of turbulence in the stably-stratified ABL was found to provide the right balance with larger scales, resulting in the development of intra-hour variability as observed by the wind lidar; this variability was not captured by the mesoscale model. Furthermore, multiscale simulations improved mean ABL characteristics such as horizontal velocity, vertical wind shear, and turbulence.« less
  • The continuous development of a meso-..beta..-scale boundary layer over sloping terrain upwind of a high mountain barrier was simulated through a complete diurnal cycle using a nonhydrostatic boundary-layer model. The simulation detailed the evolution of a 500--800-m deep nocturnal boundary layer containing 1--3 m s/sup -1/ thermal circulations in the region upwind of a high ridge. Shear between the 5 m s/sup -1/ gradient level winds above the boundary layer and the mesoscale thermal circulations maintained the turbulent mixing of cold air upward against the stable stratification. The nocturnal boundary layer is replaced the following morning by a growing convectivemore » boundary layer containing 3--5 m s/sup -1/ warm thermal flows under its base. A multiple layer structure appears during the morning transition with the coexistence of the synoptic, nocturnal and developing daytime wind systems. As the morning progresses, the downwind edge of the stable layer slowly retreats back toward lower elevations while the convective layer grows under its base. By 5 h after sunrise, the morning transition is complete. Comparisons of the model simulation with field data show that the model accurately simulates the diurnal development of the mesoscale boundary layer.« less