scholarly journals Three-Dimensional Planetary Boundary Layer Parameterization for High-Resolution Mesoscale Simulations

2020 ◽  
Vol 1452 ◽  
pp. 012080 ◽  
Author(s):  
B Kosović ◽  
P Jimenez Munoz ◽  
T W Juliano ◽  
A Martilli ◽  
M Eghdami ◽  
...  
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Planetary Boundary Layer ◽  
Three Dimensional ◽  
Planetary Boundary Layer Parameterization ◽  
Mesoscale Simulations

“Gray Zone” Simulations using a Three-Dimensional Planetary Boundary Layer Parameterization in the Weather Research and Forecasting Model

2021 ◽  
Author(s):  
Timothy W. Juliano ◽  
Branko Kosović ◽  
Pedro A. Jiménez ◽  
Masih Eghdami ◽  
Sue Ellen Haupt ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Planetary Boundary Layer ◽  
Three Dimensional ◽  
Grid Cell ◽  
Weather Research And Forecasting ◽  
Forecasting Model ◽  
Gray Zone ◽  
Pbl Scheme ◽  
3D Effects ◽  
Mesoscale Simulations

AbstractGenerating accurate weather forecasts of planetary boundary layer (PBL) properties is challenging in many geographical regions, oftentimes due to complex topography or horizontal variability in, for example, land characteristics. While recent advances in high-performance computing platforms have led to an increase in the spatial resolution of numerical weather prediction (NWP) models, the horizontal grid cell spacing (Δ x) of many regional-scale NWP models currently fall within or are beginning to approach the gray zone (i.e., Δ x ≈ 100 – 1000 m). At these grid cell spacings, three-dimensional (3D) effects are important, as the most energetic turbulent eddies are neither fully parameterized (as in traditional mesoscale simulations) nor fully resolved [as in traditional large eddy simulations (LES)]. In light of this modeling challenge, we have implemented a 3D PBL parameterization for high-resolution mesoscale simulations using the Weather Research and Forecasting model. The PBL scheme, which is based on the algebraic model developed by Mellor and Yamada, accounts for the 3D effects of turbulence by calculating explicitly the momentum, heat, and moisture flux divergences in addition to the turbulent kinetic energy. In this study, we present results from idealized simulations in the gray zone that illustrate the benefit of using a fully consistent turbulence closure framework under convective conditions. While the 3D PBL scheme reproduces the evolution of convective features more appropriately than the traditional 1D PBL scheme, we highlight the need to improve the turbulent length scale formulation.

scholarly journals A simple three-dimensional canopy – planetary boundary layer simulation model for scalar concentrations and fluxes

Tellus B ◽  
2002 ◽  
Vol 54 (5) ◽  
pp. 784-819 ◽  
Author(s):  
Andrej Sogachev ◽  
Gennady V. Menzhulin ◽  
Martin Heimann ◽  
Jon Lloyd
Keyword(s):  
Boundary Layer ◽  
Simulation Model ◽  
Planetary Boundary Layer ◽  
Three Dimensional

Derivation of Turbulent Kinetic Energy from a First-Order Nonlocal Planetary Boundary Layer Parameterization

2013 ◽  
Vol 70 (6) ◽  
pp. 1795-1805 ◽  
Author(s):  
Hyeyum Hailey Shin ◽  
Song-You Hong ◽  
Yign Noh ◽  
Jimy Dudhia
Keyword(s):  
Boundary Layer ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Planetary Boundary Layer ◽  
Water Cycle ◽  
Convective Boundary ◽  
First Order ◽  
Eddy Simulation ◽  
Pbl Parameterization ◽  
Planetary Boundary Layer Parameterization

Abstract Turbulent kinetic energy (TKE) is derived from a first-order planetary boundary layer (PBL) parameterization for convective boundary layers: the nonlocal K-profile Yonsei University (YSU) PBL. A parameterization for the TKE equation is developed to calculate TKE based on meteorological profiles given by the YSU PBL model. For this purpose buoyancy- and shear-generation terms are formulated consistently with the YSU scheme—that is, the combination of local, nonlocal, and explicit entrainment fluxes. The vertical transport term is also formulated in a similar fashion. A length scale consistent with the K profile is suggested for parameterization of dissipation. Single-column model (SCM) simulations are conducted for a period in the second Global Energy and Water Cycle Experiment (GEWEX) Atmospheric Boundary Layer Study (GABLS2) intercomparison case. Results from the SCM simulations are compared with large-eddy simulation (LES) results. The daytime evolution of the vertical structure of TKE matches well with mixed-layer development. The TKE profile is shaped like a typical vertical velocity (w) variance, and its maximum is comparable to that from the LES. By varying the dissipation length from −23% to +13% the TKE maximum is changed from about −15% to +7%. After normalization, the change does not exceed the variability among previous studies. The location of TKE maximum is too low without the effects of the nonlocal TKE transport.

scholarly journals Marine boundary layer cloud property retrievals from high-resolution ASTER observations: case studies and comparison with Terra MODIS

2016 ◽  
Vol 9 (12) ◽  
pp. 5869-5894 ◽  
Author(s):  
Frank Werner ◽  
Galina Wind ◽  
Zhibo Zhang ◽  
Steven Platnick ◽  
Larry Di Girolamo ◽  
...  
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Marine Boundary Layer ◽  
Thermal Emission ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Retrieval Algorithm ◽  
Research Level ◽  
Boundary Layer Cloud ◽  
Layer Cloud

Abstract. A research-level retrieval algorithm for cloud optical and microphysical properties is developed for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard the Terra satellite. It is based on the operational MODIS algorithm. This paper documents the technical details of this algorithm and evaluates the retrievals for selected marine boundary layer cloud scenes through comparisons with the operational MODIS Data Collection 6 (C6) cloud product. The newly developed, ASTER-specific cloud masking algorithm is evaluated through comparison with an independent algorithm reported in [Zhao and Di Girolamo(2006)]. To validate and evaluate the cloud optical thickness (τ) and cloud effective radius (reff) from ASTER, the high-spatial-resolution ASTER observations are first aggregated to the same 1000 m resolution as MODIS. Subsequently, τaA and reff, aA retrieved from the aggregated ASTER radiances are compared with the collocated MODIS retrievals. For overcast pixels, the two data sets agree very well with Pearson's product-moment correlation coefficients of R > 0.970. However, for partially cloudy pixels there are significant differences between reff, aA and the MODIS results which can exceed 10 µm. Moreover, it is shown that the numerous delicate cloud structures in the example marine boundary layer scenes, resolved by the high-resolution ASTER retrievals, are smoothed by the MODIS observations. The overall good agreement between the research-level ASTER results and the operational MODIS C6 products proves the feasibility of MODIS-like retrievals from ASTER reflectance measurements and provides the basis for future studies concerning the scale dependency of satellite observations and three-dimensional radiative effects.

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