26 results match your criteria Boundary-layer Meteorology[Journal]

  • Page 1 of 1

A Note on Scalar-Gradient Sharpening in the Stable Atmospheric Boundary Layer.

Boundary Layer Meteorol 2020 10;176(1):149-156. Epub 2020 Apr 10.

Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, The Netherlands.

The scalar front generated by the horizontal self advection of a dipolar vortex through a modest scalar gradient is investigated. This physical scenario is an idealization of the emergence of strong temperature ramps in the stable atmospheric boundary layer. The proposed mechanism is discussed and a two-dimensional analogy is studied in depth using direct numerical simulation. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-020-00516-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7242271PMC

Wind-Turbine and Wind-Farm Flows: A Review.

Boundary Layer Meteorol 2020 20;174(1):1-59. Epub 2019 Sep 20.

1Wind Engineering and Renewable Energy Laboratory (WIRE), École Polytechnique Fédérale de Lausanne (EPFL), EPFL-ENAC-IIE-WIRE, 1015 Lausanne, Switzerland.

Wind energy, together with other renewable energy sources, are expected to grow substantially in the coming decades and play a key role in mitigating climate change and achieving energy sustainability. One of the main challenges in optimizing the design, operation, control, and grid integration of wind farms is the prediction of their performance, owing to the complex multiscale two-way interactions between wind farms and the turbulent atmospheric boundary layer (ABL). From a fluid mechanical perspective, these interactions are complicated by the high Reynolds number of the ABL flow, its inherent unsteadiness due to the diurnal cycle and synoptic-forcing variability, the ubiquitous nature of thermal effects, and the heterogeneity of the terrain. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-019-00473-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946756PMC
September 2019

Volume Averaging for Urban Canopies.

Boundary Layer Meteorol 2019 17;173(3):349-372. Epub 2019 Aug 17.

3Department of Civil Engineering and Engineering Mechanics, Columbia University, New York, NY USA.

When canopy flows are horizontally averaged to obtain mean profiles, the averaging operation can be defined either as an intrinsic average, normalized by the variable fluid volume, or as a superficial average, normalized by the total volume including solid canopy elements. Properties of spatial averages have been explored extensively in the context of flow through plant canopies, albeit with the assumption that the solid volume fraction is negligible. Without this simplification, properties relevant for non-linear terms apply to intrinsic averages while properties of gradients apply to superficial averages. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-019-00470-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822781PMC

Missed Fog?: On the Potential of Obtaining Observations at Increased Resolution During Shallow Fog Events.

Boundary Layer Meteorol 2019 10;173(2):289-309. Epub 2019 Jul 10.

1Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, The Netherlands.

Conventional in situ observations of meteorological variables are restricted to a limited number of levels near the surface, with the lowest observation often made around 1-m height. This can result in missed observations of both shallow fog, and the initial growth stage of thicker fog layers. At the same time, numerical experiments have demonstrated the need for high vertical grid resolution in the near-surface layer to accurately simulate the onset of fog; this requires correspondingly high-resolution observational data for validation. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-019-00462-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6764932PMC

Hybrid Profile-Gradient Approaches for the Estimation of Surface Fluxes.

Authors:
Sukanta Basu

Boundary Layer Meteorol 2019 24;170(1):29-44. Epub 2018 Sep 24.

Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, The Netherlands.

The Monin-Obukhov similarity theory-based wind speed and potential temperature profiles are inherently coupled to each other. We have developed hybrid approaches to disentangle them, and as a direct consequence, the estimation of Obukhov length (and associated turbulent fluxes) from either wind-speed or temperature measurements becomes an effortless task. Additionally, our approaches give rise to two easily measurable indices of atmospheric stability. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0391-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6383842PMC
September 2018
1 Read

Understanding and Reducing False Alarms in Observational Fog Prediction.

Boundary Layer Meteorol 2018 3;169(2):347-372. Epub 2018 Jul 3.

2Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands.

The reduction in visibility that accompanies fog events presents a hazard to human safety and navigation. However, accurate fog prediction remains elusive, with numerical methods often unable to capture the conditions of fog formation, and observational methods having high false-alarm rates in order to obtain high hit rates of prediction. In this work, 5 years of observations from the Cabauw Experimental Site for Atmospheric Research are used to further investigate how false alarms may be reduced using the statistical method for diagnosing radiation-fog events from observations developed by Menut et al. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0374-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6208920PMC
July 2018
2 Reads

Scalar-Flux Similarity in the Layer Near the Surface Over Mountainous Terrain.

Boundary Layer Meteorol 2018 14;169(1):11-46. Epub 2018 Jun 14.

1Department of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innrain 52f, 6020 Innsbruck, Austria.

The scaled standard deviations of temperature and humidity are investigated in complex terrain. The study area is a steep Alpine valley, with six measurement sites of different slope, orientation and roughness (i-Box experimental site, Inn Valley, Austria). Examined here are several assumptions forming the basis of Monin-Obukhov similarity theory (MOST), including constant turbulence fluxes with height and the degree of self-correlation between the involved turbulence variables. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0365-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191036PMC

From Near-Neutral to Strongly Stratified: Adequately Modelling the Clear-Sky Nocturnal Boundary Layer at Cabauw.

Boundary Layer Meteorol 2018 7;166(2):217-238. Epub 2017 Oct 7.

2R&D Observations and Data Technology, Royal Netherlands Meteorological Institute, PO-Box 201, De Bilt, The Netherlands.

The performance of an atmospheric single-column model (SCM) is studied systematically for stably-stratified conditions. To this end, 11 years (2005-2015) of daily SCM simulations were compared to observations from the Cabauw observatory, The Netherlands. Each individual clear-sky night was classified in terms of the ambient geostrophic wind speed with a [Formula: see text] bin-width. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0304-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5775450PMC
October 2017
3 Reads

Gravity Waves and Wind-Farm Efficiency in Neutral and Stable Conditions.

Boundary Layer Meteorol 2018 13;166(2):269-299. Epub 2017 Oct 13.

Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, Box 2421, 3001 Leuven, Belgium.

We use large-eddy simulations (LES) to investigate the impact of stable stratification on gravity-wave excitation and energy extraction in a large wind farm. To this end, the development of an equilibrium conventionally neutral boundary layer into a stable boundary layer over a period of 8 h is considered, using two different cooling rates. We find that turbulence decay has considerable influence on the energy extraction at the beginning of the boundary-layer transition, but afterwards, energy extraction is dominated by geometrical and jet effects induced by an inertial oscillation. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0307-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956888PMC
October 2017

Observations of the Morning Development of the Urban Boundary Layer Over London, UK, Taken During the ACTUAL Project.

Boundary Layer Meteorol 2018 29;166(3):395-422. Epub 2017 Oct 29.

Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading, RG6 6BB UK.

The study of the boundary layer can be most difficult when it is in transition and forced by a complex surface, such as an urban area. Here, a novel combination of ground-based remote sensing and in situ instrumentation in central London, UK, is deployed, aiming to capture the full evolution of the urban boundary layer (UBL) from night-time until the fully-developed convective phase. In contrast with the night-time stable boundary layer observed over rural areas, the night-time UBL is weakly convective. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0300-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6952043PMC
October 2017

Towards Adaptive Grids for Atmospheric Boundary-Layer Simulations.

Boundary Layer Meteorol 2018 14;167(3):421-443. Epub 2018 Feb 14.

1Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, The Netherlands.

We present a proof-of-concept for the adaptive mesh refinement method applied to atmospheric boundary-layer simulations. Such a method may form an attractive alternative to static grids for studies on atmospheric flows that have a high degree of scale separation in space and/or time. Examples include the diurnal cycle and a convective boundary layer capped by a strong inversion. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0335-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560679PMC
February 2018
1 Read

A Note on Spatial Averaging and Shear Stresses Within Urban Canopies.

Boundary Layer Meteorol 2018 23;167(1):171-179. Epub 2017 Nov 23.

Faculty of Engineering and the Environment, University of Southampton, Southampton, SO17 1BJ UK.

One-dimensional urban models embedded in mesoscale numerical models may place several grid points within the urban canopy. This requires an accurate parametrization for shear stresses (i.e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0321-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566258PMC
November 2017
1 Read

Turbulent Flow Over Large Roughness Elements: Effect of Frontal and Plan Solidity on Turbulence Statistics and Structure.

Boundary Layer Meteorol 2018 4;167(1):99-121. Epub 2017 Nov 4.

2University of Southampton, Southampton, SO17 1BJ UK.

Wind-tunnel experiments were carried out on fully-rough boundary layers with large roughness ( , where is the height of the roughness elements and is the boundary-layer thickness). Twelve different surface conditions were created by using LEGO™ bricks of uniform height. Six cases are tested for a fixed plan solidity ( ) with variations in frontal density ( ), while the other six cases have varying for fixed . Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0317-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566281PMC
November 2017
1 Read

Scalar Fluxes Near a Tall Building in an Aligned Array of Rectangular Buildings.

Boundary Layer Meteorol 2018 4;167(1):53-76. Epub 2017 Nov 4.

2EnFlo, University of Surrey, Guildford, GU2 7XH UK.

Scalar dispersion from ground-level sources in arrays of buildings is investigated using wind-tunnel measurements and large-eddy simulation (LES). An array of uniform-height buildings of equal dimensions and an array with an additional single tall building (wind tunnel) or a periodically repeated tall building (LES) are considered. The buildings in the array are aligned and form long streets. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0308-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566286PMC
November 2017
2 Reads

Wind-Tunnel Simulation of Weakly and Moderately Stable Atmospheric Boundary Layers.

Boundary Layer Meteorol 2018 21;168(1):29-57. Epub 2018 Feb 21.

EnFlo Laboratory, Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH UK.

The simulation of horizontally homogeneous boundary layers that have characteristics of weakly and moderately stable atmospheric flow is investigated, where the well-established wind engineering practice of using 'flow generators' to provide a deep boundary layer is employed. Primary attention is given to the flow above the surface layer, in the absence of an overlying inversion, as assessed from first- and second-order moments of velocity and temperature. A uniform inlet temperature profile ahead of a deep layer, allowing initially neutral flow, results in the upper part of the boundary layer remaining neutral. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0337-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6438612PMC
February 2018
1 Read

The Impact of Three-Dimensional Effects on the Simulation of Turbulence Kinetic Energy in a Major Alpine Valley.

Boundary Layer Meteorol 2018 23;168(1):1-27. Epub 2018 Feb 23.

3Meteorology and Air Quality Section, Wageningen University, Wageningen, The Netherlands.

The correct simulation of the atmospheric boundary layer (ABL) is crucial for reliable weather forecasts in truly complex terrain. However, common assumptions for model parametrizations are only valid for horizontally homogeneous and flat terrain. Here, we evaluate the turbulence parametrization of the numerical weather prediction model COSMO with a horizontal grid spacing of for the Inn Valley, Austria. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0341-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6438614PMC
February 2018
1 Read

Effects of a Fence on Pollutant Dispersion in a Boundary Layer Exposed to a Rural-to-Urban Transition.

Boundary Layer Meteorol 2018 3;169(2):185-208. Epub 2018 Jul 3.

1Laboratory for Aero and Hydrodynamics, Department Process and Energy, Delft University, Leeghwaterstraat 21, 2628 CA Delft, The Netherlands.

Simultaneous particle-image velocimetry and laser-induced fluorescence combined with large-eddy simulations are used to investigate the flow and pollutant dispersion behaviour in a rural-to-urban roughness transition. The urban roughness is characterized by an array of cubical obstacles in an aligned arrangement. A plane fence is added one obstacle height upstream of the urban roughness elements, with three different fence heights considered. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-018-0367-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6413630PMC
July 2018
8 Reads

Large-Eddy Simulation of Thermally Stratified Atmospheric Boundary-Layer Flow Using a Minimum Dissipation Model.

Boundary Layer Meteorol 2017 Dec;165(3):405-419

Center for Turbulence Research, Stanford University, Stanford, California 94305, USA.

A generalized form of a recently developed minimum dissipation model for subfilter turbulent fluxes is proposed and implemented in the simulation of thermally stratified atmospheric boundary-layer flows. Compared with the original model, the generalized model includes the contribution of buoyant forces, in addition to shear, to the production or suppression of turbulence, with a number of desirable practical and theoretical properties. Specifically, the model has a low computational complexity, appropriately switches off in laminar and transitional flows, does not require any ad hoc shear and stability corrections, and is consistent with theoretical subfilter turbulent fluxes. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0288-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6800680PMC
December 2017

Early Warning Signals for Regime Transition in the Stable Boundary Layer: A Model Study.

Boundary Layer Meteorol 2017 11;162(2):283-306. Epub 2016 Oct 11.

4Department of Remote Sensing and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands.

The evening transition is investigated in an idealized model for the nocturnal boundary layer. From earlier studies it is known that the nocturnal boundary layer may manifest itself in two distinct regimes, depending on the ambient synoptic conditions: strong-wind or overcast conditions typically lead to weakly stable, turbulent nights; clear-sky and weak-wind conditions, on the other hand, lead to very stable, weakly turbulent conditions. Previously, the dynamical behaviour near the transition between these regimes was investigated in an idealized setting, relying on Monin-Obukhov (MO) similarity to describe turbulent transport. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-016-0199-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7154886PMC
October 2016

Are Urban-Canopy Velocity Profiles Exponential?

Authors:
Ian P Castro

Boundary Layer Meteorol 2017 8;164(3):337-351. Epub 2017 Jun 8.

Aerodynamics and Flight Mechanics, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ UK.

Using analyses of data from extant direct numerical simulations and large-eddy simulations of boundary-layer and channel flows over and within urban-type canopies, sectional drag forces, Reynolds and dispersive shear stresses are examined for a range of roughness densities. Using the spatially-averaged mean velocity profiles these quantities allow deduction of the canopy mixing length and sectional drag coefficient. It is shown that the common assumptions about the behaviour of these quantities, needed to produce an analytical model for the canopy velocity profile, are usually invalid, in contrast to what is found in typical vegetative (e. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0258-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979513PMC

Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas.

Boundary Layer Meteorol 2017 28;164(2):183-213. Epub 2017 Apr 28.

1Department of Meteorology, Reading University, RG6 6UR Reading, UK.

Nine methods to determine local-scale aerodynamic roughness length and zero-plane displacement are compared at three sites (within 60 m of each other) in London, UK. Methods include three anemometric (single-level high frequency observations), six morphometric (surface geometry) and one reference-based approach (look-up tables). A footprint model is used with the morphometric methods in an iterative procedure. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0248-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979542PMC

The Effects of Heat Advection on UK Weather and Climate Observations in the Vicinity of Small Urbanized Areas.

Boundary Layer Meteorol 2017 12;165(1):181-196. Epub 2017 Jun 12.

1School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK.

Weather and climate networks traditionally follow rigorous siting guidelines, with individual stations located away from frost hollows, trees or urban areas. However, the diverse nature of the UK landscape suggests that the feasibility of siting stations that are truly representative of regional climate and free from distorting local effects is increasingly difficult. Whilst the urban heat island is a well-studied phenomenon and usually accounted for, the effect of warm urban air advected downwind is rarely considered, particularly at rural stations adjacent to urban areas. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-017-0263-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961505PMC

A Mesoscale Model-Based Climatography of Nocturnal Boundary-Layer Characteristics over the Complex Terrain of North-Western Utah.

Boundary Layer Meteorol 2016;159:495-519. Epub 2015 May 30.

National Center for Atmospheric Research, Boulder, CO USA.

Nocturnal boundary-layer phenomena in regions of complex topography are extremely diverse and respond to a multiplicity of forcing factors, acting primarily at the mesoscale and microscale. The interaction between different physical processes, e.g. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-015-0044-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948760PMC
May 2015
2 Reads

The Variability of Refractivity in the Atmospheric Boundary Layer of a Tropical Island Volcano Measured by Ground-Based Interferometric Radar.

Boundary Layer Meteorol 2016 22;161(2):309-333. Epub 2016 Jun 22.

1Department of Meteorology, University of Reading, Reading, RG66AL UK.

For 24 h we measured continuously the variability of atmospheric refractivity over a volcano on the tropical island of Montserrat using a ground-based radar interferometer. We observed variations in phase that we interpret as due to changing water vapour on the propagation path between the radar and the volcano and we present them here in the context of the behaviour of the atmospheric boundary layer over the island. The water vapour behaviour was forced by diurnal processes, the passage of a synoptic-scale system and the presence of a plume of volcanic gas. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-016-0168-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175716PMC

Spatial Characteristics of Roughness Sublayer Mean Flow and Turbulence Over a Realistic Urban Surface.

Boundary Layer Meteorol 2016 22;160(3):425-452. Epub 2016 Apr 22.

5Civil Engineering, Faculty of Applied Sciences, University of British Columbia, Vancouver, BC Canada.

Single-point measurements from towers in cities cannot properly quantify the impact of all terms in the turbulent kinetic energy (TKE) budget and are often not representative of horizontally-averaged quantities over the entire urban domain. A series of large-eddy simulations (LES) is here performed to quantify the relevance of non-measurable terms, and to explore the spatial variability of the flow field over and within an urban geometry in the city of Basel, Switzerland. The domain has been chosen to be centered around a tower where single-point turbulence measurements at six heights are available. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-016-0157-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175723PMC

Eddy covariance measurements of carbon dioxide, latent and sensible energy fluxes above a meadow on a mountain slope.

Boundary Layer Meteorol 2007 Feb;122(2):397-416

Institut für Ökologie, Universität Innsbruck, Sternwartestr. 15, 6020 Innsbruck, Austria.

Carbon dioxide, latent and sensible energy fluxes were measured by means of the eddy covariance method above a mountain meadow situated on a steep slope in the Stubai Valley/Austria, based on the hypothesis that, due to the low canopy height, measurements can be made in the shallow equilibrium layer where the wind field exhibits characteristics akin to level terrain. In order to test the validity of this hypothesis and to identify effects of complex terrain in the turbulence measurements, data were subjected to a rigorous testing procedure using a series of quality control measures established for surface layer flows. The resulting high-quality data set comprised 36 % of the original observations, the substantial reduction being mainly due to a change in surface roughness and associated fetch limitations in the wind sector dominating during nighttime and transition periods. Read More

View Article

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10546-006-9109-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898019PMC
February 2007
1 Read
  • Page 1 of 1