scholarly journals Wind Field Modifications in Habitable Urban Areas

2012 ◽  
Vol 7 (2) ◽  
pp. 267-273 ◽  
Author(s):  
SEEMI AHMED ◽  
ALKA BHARAT
Keyword(s):  
Wind Field ◽  
Urban Areas

Evaluation of the Surface Wind Field over Land in WRF Simulations of Hurricane Wilma (2005). Part I: Model Initialization and Simulation Validation

2021 ◽  
Author(s):  
David S. Nolan ◽  
Brian D. McNoldy ◽  
Jimmy Yunge
Keyword(s):  
Wind Field ◽  
Urban Areas ◽  
Initial Conditions ◽  
Surface Wind ◽  
South Florida ◽  
Wind Fields ◽  
Near Surface ◽  
Hurricane Wilma ◽  
Wind Analysis ◽  
Forecasting System

AbstractWhile global and regional dynamical models are used to predict the tracks and intensities of hurricanes over the ocean, these models are not currently used to predict the wind field and other impacts over land. This two-part study performs detailed evaluations of the near-surface, over-land wind fields produced in simulations of Hurricane Wilma (2005) as it traveled across South Florida. This first part describes the production of two high-resolution simulations using the Weather Research and Forecasting Model (WRF), using different boundary layer parameterizations available in WRF: the Mellor-Yamada-Janjić (MYJ) scheme and the Yonsei University (YSU) scheme. Initial conditions from the Global Forecasting System (GFS) are manipulated with a vortex bogussing technique to modify the initial intensity, size, and location of the cyclone. It is found possible through trial and error to successfully produce simulations using both the YSU and MYJ schemes that closely reproduce the track, intensity, and size of Wilma at landfall. For both schemes the storm size and structure also show good agreement with the wind fields diagnosed by H*WIND and the Tropical Cyclone Surface Wind Analysis (TCSWA). Both over water and over land, the YSU scheme has stronger winds over larger areas than MYJ, but the surface winds are more reduced in areas of greater surface roughness, particularly in urban areas. Both schemes produced very similar inflow angles over land and water. The over-land wind fields are examined in more detail in the second part of this study.

Effect of Adjustable Deflectors on Building Facade on Diverting the Distribution of Aerosol in Micro Climate Wind Field

2011 ◽  
Vol 71-78 ◽  
pp. 338-341
Author(s):  
Chih Hong Huang ◽  
Kuang Yu Wang
Keyword(s):  
Urban Space ◽  
Wind Field ◽  
Urban Areas ◽  
Aerosol Particles ◽  
Building Blocks ◽  
Aerosol Concentration ◽  
Street Canyons ◽  
Wind Environment ◽  
Building Facade ◽  
And Control

Aerosol particles in urban areas are deposited in street canyons due to the wind field generated by building blocks. The purpose of this study was to discuss with CFD software the effect on lowering the aerosol concentration in urban space by means of active and auxiliary adjustable wind deflectors installed on the building facade to divert and control the micro-climate wind environment surrounding the buildings. The results suggested that, the wind deflector could produce an enormous improving efficiency for channelizing the particles.

Spatial Variation of the Regional Wind Field with Land–Sea Contrasts and Complex Topography

2009 ◽  
Vol 48 (9) ◽  
pp. 1929-1939 ◽  
Author(s):  
Kyung-Ja Ha ◽  
Sun-Hee Shin ◽  
Larry Mahrt
Keyword(s):  
Spatial Variation ◽  
Wind Field ◽  
Urban Areas ◽  
Complex Terrain ◽  
Cloud Cover ◽  
Surface Heterogeneity ◽  
Separation Distance ◽  
Complex Topography ◽  
Regional Network ◽  
Regional Networks

Abstract This study examines the spatial variation of the wind field observed in the coastal zone of southeast Korea with its complex terrain, using measurements from a regional network 75 km across and centered about Busan. Results are compared with observations from an inland regional network centered around Daegu, Korea, with less dramatic, but still significant, surface heterogeneity. The coherency between stations is examined in terms of the between-station correlations of the wind components for all pairs of stations as a function of separation distance between stations. A mesovelocity scale is defined as a measure of the spatial variability of the wind field within the network. This variability is related to wind speed and cloud cover for the two contrasting regional networks. Additional comparisons are made with a homogenous rural network in Iowa. The results underscore the complexity of flow with topography, urban areas, and land–sea contrasts and demonstrate the inadequacy of existing network strategies.

scholarly journals ANÁLISE DAS CARACTERÍSTICAS DO VENTO SOBRE A FLORESTA NACIONAL DO TAPAJÓS, PARÁ, BRASIL

2016 ◽  
Vol 38 ◽  
pp. 204
Author(s):  
Raphael Pablo Tapajós ◽  
Rodrigo Da Silva ◽  
Wilderclay Barreto Machado ◽  
Raoni Silva de Santana ◽  
Roseilson Do Vale ◽  
...  
Keyword(s):  
Wind Direction ◽  
Wind Field ◽  
Urban Areas ◽  
Rainy Season ◽  
Agricultural Fields ◽  
National Forest ◽  
The North ◽  
River Region ◽  
Westerly Winds ◽  
North And South

The atmospheric circulation of the Tapajós River region has unique characteristics due to influences of forests, agricultural fields, rivers and urban areas. The study with regard to the wind field in two different points in National Forest Tapajós (FNT) shows that there are significant differences in wind direction at those points. Identifying and quantify of the North and South canalization, and westerly winds, give important indications for studying the influence of different areas on the FNT. The results show that the occurrences of drains and west winds are more present during the rainy season and occur more during the day. Furthermore, in Jamaraquá station nearest to the River, the influence of channeling and west winds are greater, which can be due not only proximity of river but also the topographical features.

Wind field simulations in urban areas

2001 ◽  
Author(s):  
R. Koomullil ◽  
B. Soni
Keyword(s):  
Wind Field ◽  
Urban Areas

scholarly journals Worsening urban ozone pollution in China from 2013 to 2017 – Part 1: The complex and varying roles of meteorology

2020 ◽  
Author(s):  
Yiming Liu ◽  
Tao Wang
Keyword(s):  
Wind Field ◽  
Urban Areas ◽  
Emission Control ◽  
Meteorological Conditions ◽  
Specific Humidity ◽  
Biogenic Emissions ◽  
Anthropogenic Emissions ◽  
Ozone Pollution ◽  
The Impact ◽  
Ozone Levels

Abstract. China has suffered from increasing levels of ozone pollution in urban areas despite the implementation of various stringent emission reduction measures since 2013. In this study, we conducted numerical experiments with an up-to-date regional chemical transport model to assess the contribution of the changes in meteorological conditions and anthropogenic emissions to the summer ozone level from 2013 to 2017 in various regions of China. The model can faithfully reproduce the observed meteorological parameters and air pollutant concentrations and capture the increasing trend in the surface maximum daily 8-hour average (MDA8) ozone (O3) from 2013 to 2017. The emission control measures implemented by the government induced a decrease in MDA8 O3 levels in rural areas but an increase in urban areas. The meteorological influence on the ozone trend varied by region and by year and could be comparable to or even more significant than the impact of changes in anthropogenic emissions. Meteorological conditions can modulate the ozone concentration via direct (e.g., increasing reaction rates at higher temperatures) and indirect (e.g., increasing biogenic emissions at higher temperatures) effects. As an essential source of volatile organic compounds that contributes to ozone formation, the variation in biogenic emissions during summer varied across regions and was mainly affected by temperature. China’s midlatitude areas (25° N to 40° N) experienced a significant decrease in MDA8 O3 due to a decline in biogenic emissions, especially for the Yangtze River Delta and Sichuan Basin regions in 2014 and 2015. In contrast, in northern (north of 40° N) and southern (south of 25° N) China, higher temperatures after 2013 led to an increase in MDA8 O3 concentrations via an increase in biogenic emissions. We also assessed the individual effects of changes in temperature, specific humidity, wind field, planetary boundary layer height, clouds, and precipitation on ozone levels from 2013 to 2017. The results show that the wind field change made a significant contribution to the increase in surface ozone over China by transporting the ozone downward from the upper troposphere and the lower stratosphere. The long-range transport of ozone and its precursors outside the modeling domain also contributed to the increase in MDA8 O3 in China, especially on the Tibetan Plateau (an increase of 1 to 4 ppbv). Our study represents the most comprehensive and up-to-date analysis of the impact of changes in meteorology on ozone across China and highlights the importance of considering meteorological variations when assessing the effectiveness of emission control on changes in the ozone levels in recent years.

scholarly journals Modelling studies of wind field on urban environment

2002 ◽  
Vol 2 (6) ◽  
pp. 1979-2001 ◽  
Author(s):  
K. Radics ◽  
J. Bartholy ◽  
R. Pongrácz
Keyword(s):  
Urban Environment ◽  
Wind Field ◽  
Urban Areas ◽  
Strong Dependence ◽  
Urban Climate ◽  
Modelling Studies ◽  
Wind Measurements ◽  
Wind Characteristics ◽  
Climate Station ◽  
Wind Profiles

Abstract. Increasing load of air pollution in urban environment emphasises the need for detailed evaluation of wind characteristics that significantly affect the air quality of urban areas, especially, in large agglomerations. This paper includes analysis of urban wind climatology and estimation of wind profiles based on measurements of the new urban climate station located at the Eötvös University, observations of the meteorological station network of the Budapest agglomeration area, and multi-level wind measurements near Hegyhátsál. Furthermore, wind field modelling (using the WAsP linear spectral wind flow model) is presented over selected representative complex areas that demonstrates strong dependence between wind, height, topography, and roughness.

scholarly journals Urban wind field calculation through the Röckle based method: the basics for a GIS implementation

2021 ◽  
Author(s):  
Jérémy Bernard ◽  
Fredrik Lindberg ◽  
Sandro Oswald
Keyword(s):  
Wind Speed ◽  
Urban Planning ◽  
Open Source ◽  
Wind Field ◽  
Urban Areas ◽  
Urban Setting ◽  
World Population ◽  
Industrial Complex ◽  
Field Calculation ◽  
Los Alamos

<p>Wind speed is one of the key parameter affecting human thermal comfort: high wind speed during winter and low wind speed during summer may exacerbate respectively cold and heat stress. In urban areas, where more than 50% of the world population is currently living, the wind field is strongly affected by the size and the organization of the obstacles (mainly buildings and trees). Simple and quick estimation of the wind speed and direction in an urban setting could then be an interesting information for urban planning purpose. To calculate a high resolution three-dimensional wind field in an urban setting, Computational Fluid Dynamic (CFD) models are mostly used. They usually solve advection and turbulence equations by an iterative process which is too long for most of the urban planning applications. To reduce this time, Röckle (1990) proposed:</p><ul><li>to decrease the number of iteration by initializing the wind field around buildings: this is done by modeling empirically the wind speed and direction using results from wind tunnel observations,</li> <li>to solve only the advection equation from this initial wind field since the turbulence is supposed roughly “solved” by the initialization.</li> </ul><p>At our knowledge, at least two models have been developed using this approach: QUIC-URB (Brown et al. 2018) and the second is part of the SkyHelios software (Fröhlich and Matzarakis, 2018). However: (i) none of these softwares are open-source (i.e. source code is not freely available), it is then rather complicated to propose scientific improvements and (ii) none of them are integrated in a commonly used GIS-based urban planning tool which would popularize their use by urban planners.</p><p>Our presentation will focus on the development of our tool called URock, an open-source application of the Röckle methodology. If the results produced by this tool are consistent with observation, it should be included in QGIS (a commonly used urban planning GIS) through the plug-in UMEP (Lindberg et al. 2017).</p><p><strong>References</strong></p><p>Brown, Michael John. Quick Urban and Industrial Complex (QUIC) CBR Plume Modeling System: Validation-Study Document. No. LA-UR-18-29993. Los Alamos National Lab.(LANL), Los Alamos, NM (United States), 2018.</p><p>Fröhlich, Dominik, and Andreas Matzarakis. "Spatial estimation of  thermal indices in Urban Areas—Basics of the SkyHelios Model." Atmosphere 9.6 (2018): 209.</p><p>Lindberg F, Grimmond CSB, Gabey A, Huang B, Kent CW, Sun T, Theeuwes N, Järvi L, Ward H, Capel-Timms I, Chang YY, Jonsson P, Krave N, Liu D, Meyer D, Olofson F, Tan JG, Wästberg D, Xue L, Zhang Z (2018) Urban Multi-scale Environmental Predictor (UMEP) - An integrated tool for city-based climate services. Environmen tal Modelling and Software.99, 70-87 https://doi.org/10.1016/j.envsoft.2017.09.020</p><p>Röckle, R., 1990: Bestimmung der Strömungsverhältnisse im Bereich komplexer Bebauungsstruk-turen. PhD thesis Fachbereich Mechanik der Technischen Hochschule Darmstadt Darmstadt.</p>

scholarly journals Worsening urban ozone pollution in China from 2013 to 2017 – Part 1: The complex and varying roles of meteorology

2020 ◽  
Vol 20 (11) ◽  
pp. 6305-6321 ◽  
Author(s):  
Yiming Liu ◽  
Tao Wang
Keyword(s):  
Wind Field ◽  
Urban Areas ◽  
Emission Control ◽  
Meteorological Conditions ◽  
Specific Humidity ◽  
Biogenic Emissions ◽  
Anthropogenic Emissions ◽  
Ozone Pollution ◽  
The Impact ◽  
Ozone Levels

Abstract. China has suffered from increasing levels of ozone pollution in urban areas despite the implementation of various stringent emission reduction measures since 2013. In this study, we conducted numerical experiments with an up-to-date regional chemical transport model to assess the contribution of the changes in meteorological conditions and anthropogenic emissions to the summer ozone level from 2013 to 2017 in various regions of China. The model can faithfully reproduce the observed meteorological parameters and air pollutant concentrations and capture the increasing trend in the surface maximum daily 8 h average (MDA8) ozone (O3) from 2013 to 2017. The emission-control measures implemented by the government induced a decrease in MDA8 O3 levels in rural areas but an increase in urban areas. The meteorological influence on the ozone trend varied by region and by year and could be comparable to or even more significant than the impact of changes in anthropogenic emissions. Meteorological conditions can modulate the ozone concentration via direct (e.g., increasing reaction rates at higher temperatures) and indirect (e.g., increasing biogenic emissions at higher temperatures) effects. As an essential source of volatile organic compounds that contributes to ozone formation, the variation in biogenic emissions during summer varied across regions and was mainly affected by temperature. China's midlatitude areas (25 to 40∘ N) experienced a significant decrease in MDA8 O3 due to a decline in biogenic emissions, especially for the Yangtze River Delta and Sichuan Basin regions in 2014 and 2015. In contrast, in northern (north of 40∘ N) and southern (south of 25∘ N) China, higher temperatures after 2013 led to an increase in MDA8 O3 via an increase in biogenic emissions. We also assessed the individual effects of changes in temperature, specific humidity, wind field, planetary boundary layer height, clouds, and precipitation on ozone levels from 2013 to 2017. The results show that the wind field change made a significant contribution to the increase in surface ozone over many parts of China. The long-range transport of ozone and its precursors from outside the modeling domain also contributed to the increase in MDA8 O3 in China, especially on the Qinghai–Tibetan Plateau (an increase of 1 to 4 ppbv). Our study represents the most comprehensive and up-to-date analysis of the impact of changes in meteorology on ozone across China and highlights the importance of considering meteorological variations when assessing the effectiveness of emission control on changes in the ozone levels in recent years.

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