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.

Simulation of the wind fields over complex terrain with coupling of CFD and WRF

2021 ◽  
pp. 1-12
Author(s):  
Xiaoyu Luo ◽  
Yiwen Cao
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
Complex Terrain ◽  
Civil Engineering ◽  
Meteorological Data ◽  
Mass Conservation ◽  
Coupling Method ◽  
Wind Fields ◽  
Civil Structures ◽  
Civil Engineers

In the field of civil engineering, the meteorological data available usually do not have the detailed information of the wind near a certain site. However, the detailed information of the wind field during typhoon is important for the wind-resistant design of civil structures. Furthermore, the resolution of the meteorological data available by the civil engineers is too coarse to be applicable. Therefore it is meaningful to obtain the detailed information of the wind fields based on the meteorological data provided by the meteorological department. Therefore, in the present study, a one-way coupling method between WRF and CFD is adopted and a method to keep the mass conservation during the simulation in CFD is proposed. It is found that using the proposed one-way coupling method, the predicted wind speed is closer to the measurement. And the curvature of the wind streamline during typhoon is successfully reproduced.

Influence of the diagnostic wind field model on the results of calculation of the microscale atmospheric dispersion in moderately complex terrain

2013 ◽  
Vol 79 ◽  
pp. 29-35 ◽  
Author(s):  
Ivan V. Kovalets ◽  
Vladimir Y. Korolevych ◽  
Alexander V. Khalchenkov ◽  
Ievgen A. Ievdin ◽  
Mark J. Zheleznyak ◽  
...  
Keyword(s):  
Wind Field ◽  
Complex Terrain ◽  
Field Model ◽  
Atmospheric Dispersion ◽  
Wind Field Model

scholarly journals Inter-community variability in total particle number concentrations in the eastern Los Angeles air basin

2010 ◽  
Vol 10 (23) ◽  
pp. 11385-11399 ◽  
Author(s):  
N. Hudda ◽  
K. Cheung ◽  
K. F. Moore ◽  
C. Sioutas
Keyword(s):  
Los Angeles ◽  
Spatial Variability ◽  
Spatial Variation ◽  
Urban Areas ◽  
Particle Number ◽  
Meteorological Conditions ◽  
Monitoring Station ◽  
Size Distributions ◽  
Central Monitoring ◽  
Seasonal And Diurnal Variations

Abstract. Ultrafine Particles (UFP) can display sharp gradients in their number concentrations in urban environment due to their transient nature and rapid atmospheric processing. The ability of using air pollution data generated at a central monitoring station to assess exposure relies on our understanding of the spatial variability of a specific pollutant associated with a region. High spatial variation in the concentrations of air pollutants has been reported at scales of 10s of km for areas affected by primary emissions. Spatial variability in particle number concentrations (PNC) and size distributions needs to be investigated, as the representativeness of a monitoring station in a region is premised on the assumption of homogeneity in both of these metrics. This study was conducted at six sites, one in downtown Los Angeles and five located about 40–115 km downwind in the receptor areas of Los Angeles air basin. PNC and size distribution were measured using Condensation Particle Counters (CPC) and Scanning Mobility Particle Sizer (SMPS). The seasonal and diurnal variations of PNC implied that PNC might vary significantly with meteorological conditions, even though the general patterns at the sites may remain generally similar across the year due to consistency of sources around them. Regionally transported particulate matter (PM) from upwind urban areas of Los Angeles lowered spatial variation by acting as a "homogenizing" factor during favorable meteorological conditions. Spatial variability also increased during hours of the day during which the effects of local sources predominate. The spatial variability associated with PNC (quantified using Coefficients of Divergence, CODs), averaged about 0.3, which was generally lower than that based on specific size ranges. Results showed an inverse relationship of COD with particles size, with fairly uniform values in the particle range which is associated with regional transport. Our results suggest that spatial variability, even in the receptor regions of Los Angeles Basin, should be assessed for both PNC and size distributions, and should be interpreted in context of seasonal and diurnal influences, and suitably factored if values for exposure are ascertained using a central monitoring station.

scholarly journals Aspects of quality control of wind profiler measurements in complex topography

2014 ◽  
Vol 7 (1) ◽  
pp. 135-148 ◽  
Author(s):  
M. Maruri ◽  
J. A. Romo ◽  
L. Gomez
Keyword(s):  
Complex Terrain ◽  
Meteorological Conditions ◽  
Complex Signal ◽  
Wind Profiler ◽  
Complex Topography ◽  
Homogeneity Study ◽  
Homogeneity Assumption ◽  
Patterns Of Behavior ◽  
Wind Profiler Radar ◽  
Wind Profiles

Abstract. It is well known in the scientific community that some remote sensing instruments assume that sample volumes present homogeneous conditions within a defined meteorological profile. At complex topographic sites and under extreme meteorological conditions, this assumption may be fallible depending on the site, and it is more likely to fail in the lower layers of the atmosphere. This piece of work tests the homogeneity of the wind field over a boundary layer wind profiler radar located in complex terrain on the coast under different meteorological conditions. The results reveal the qualitative importance of being aware of deviations in this homogeneity assumption and evaluate its effect on the final product. Patterns of behavior in data have been identified in order to simplify the analysis of the complex signal registered. The quality information obtained from the homogeneity study under different meteorological conditions provides useful indicators for the best alternatives the system can offer to build wind profiles. Finally, the results are also to be considered in order to integrate them in a quality algorithm implemented at the product level.

scholarly journals Global fluctuations of cerebral blood flow indicate a global brain network independent of systemic factors

2017 ◽  
Vol 39 (2) ◽  
pp. 302-312 ◽  
Author(s):  
Li Zhao ◽  
David C Alsop ◽  
John A Detre ◽  
Weiying Dai
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Networks ◽  
Blood Oxygenation ◽  
Regional Network ◽  
Electrical Measurements ◽  
Regional Networks ◽  
Systemic Factors ◽  
Band Limited ◽  
Global Fluctuations

Global synchronization across specialized brain networks is a common feature of network models and in-vivo electrical measurements. Although the imaging of specialized brain networks with blood oxygenation sensitive resting state functional magnetic resonance imaging (rsfMRI) has enabled detailed study of regional networks, the study of globally correlated fluctuations with rsfMRI is confounded by spurious contributions to the global signal from systemic physiologic factors and other noise sources. Here we use an alternative rsfMRI method, arterial spin labeled perfusion MRI, to characterize global correlations and their relationship to correlations and anti-correlations between regional networks. Global fluctuations that cannot be explained by systemic factors dominate the fluctuations in cerebral blood flow. Power spectra of these fluctuations are band limited to below 0.05 Hz, similar to prior measurements of regional network fluctuations in the brain. Removal of these global fluctuations prior to measurement of regional networks reduces all regional network fluctuation amplitudes to below the global fluctuation amplitude and changes the strength and sign of inter network correlations. Our findings support large amplitude, globally synchronized activity across networks that require a reassessment of regional network amplitude and correlation measures.

scholarly journals The impact of atmospheric dynamics on vertical cloud overlap over the Tibetan Plateau

2017 ◽  
Author(s):  
Jiming Li ◽  
Qiaoyi Lv ◽  
Bida Jian ◽  
Min Zhang ◽  
Chuanfeng Zhao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Wind Shear ◽  
Cloud Cover ◽  
Atmospheric Stability ◽  
Separation Distance ◽  
Atmospheric Dynamics ◽  
The Tibetan Plateau ◽  
Total Cloud Cover ◽  
The Impact ◽  
Overlap Parameter

Abstract. The accurate representation of cloud vertical overlap in atmospheric models is particularly significant for predicting the total cloud cover and for the calculations related to the radiative budget in these models. However, it has received too little attention due to the limited observation, especially over the Tibetan Plateau (TP). In this study, 4 years (2007–2010) of data from the CloudSat cloud product and collocated ERA-Interim reanalysis product were analyzed to examine the seasonal and zonal variations of cloud overlap properties over the TP region, and evaluate the effect of atmospheric dynamics on cloud overlap. Unique characteristics of cloud overlap over the TP have been found. The statistical results show that the random overlap assumption slightly underestimates the total cloud coverage for discontinuous cloud layers over the TP, whereas the overlap parameter α for continuous cloud sharply decrease from maximum to random overlap with an increase of layer distance, eventually trending towards a minimal overlap (e.g., negative α values) as the cloud layer separation distance exceeds 1.5 km. Compared with the global averaged cloud overlap characteristics, the proportion of minimal overlap over the TP is significant high (about 41 %). It may be associated with the unique topographical forcing and thermos-dynamical environment of the TP. As a result, we propose a valid scheme for quantifying the degree of cloud overlap over the TP through a linear combination of the maximum and minimum overlap, and further parameterize decorrelation length scale L as a function of wind shear and atmospheric stability. Compared with other parameterizations, the new scheme reduces the bias between predicted and observed cloud covers. These results thus indicate that effects of wind shear and atmospheric stability on cloud overlap should both be taken into account in the parameterization of overlap parameter to improve the simulation of total cloud cover in models.

scholarly journals Regional wind-field study in complex terrain during summer sea-breeze conditions

1979 ◽  
Author(s):  
W.M. Porch ◽  
P.A. Volker ◽  
K.R. Peterson ◽  
R.L. Weichel ◽  
C. Sherman
Keyword(s):  
Field Study ◽  
Wind Field ◽  
Complex Terrain ◽  
Sea Breeze

Education for the Innovative Development of a Region

2019 ◽  
pp. 284-306
Author(s):  
Mikhail Epshtein ◽  
Sergei Mikhelson
Keyword(s):  
Higher Education ◽  
High Tech ◽  
Innovative Development ◽  
Years Of Experience ◽  
Regional Network ◽  
Regional Networks ◽  
National Network ◽  
Network Program

The chapter describes the possible mechanism of supporting the development of education in a region through an organization of interaction between education and businesses into a regional network of schools and their partners (representatives of science, higher education, high-tech businesses) keen on innovation as the resource of the region's development. Mechanisms for an organization of such a network are based on the model of the innovative complex in education as a mechanism to ensure innovative pedagogical community at the interregional and regional levels through an organization of interaction of scientists, teachers, administrators, and people in a business. The chapter represents five years of experience of implementation of this model in the frameworks of the ROSNANO School League, the Russian national network program, and its influence on the establishment of the regional networks.

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