Research on Observation of Low-altitude Wind Field in Urban Areas in April Based on Coherent Wind Lidar

2021 ◽  
Vol 11 (02) ◽  
pp. 54-62
Author(s):  
峰瑞 张
2016 ◽  
Vol 43 (7) ◽  
pp. 0710004
Author(s):  
唐磊 Tang Lei ◽  
蒋杉 Jiang Shan ◽  
李梓霂 Li Zimu ◽  
郑俊 Zheng Jun ◽  
赵若灿 Zhao Ruocan ◽  
...  

2020 ◽  
Vol 10 (6) ◽  
pp. 1958
Author(s):  
Haitao Gao ◽  
Jin Tao ◽  
Matthias Dehmer ◽  
Frank Emmert-Streib ◽  
Qinglin Sun ◽  
...  

The wind field is an essential factor that affects accurate homing and flare landing of parafoil systems. In order to obtain the ambient wind field during the descent of a parafoil system, a combination method of in-flight wind field identification and prediction is proposed. First, a wind identification method only using global position system information is derived based on the flight dynamics of parafoil systems. Then a wind field prediction model is constructed using the atmospheric dynamics, and the low-altitude wind field is predicted based on the identified wind field of high-altitude. Finally, simulations of wind field identification and prediction are conducted. The results demonstrate that the proposed method can identify the wind fields precisely and also predict the wind fields reasonably. This method can potentially be applied in practical parafoil systems to provide wind field information for homing tasks.


Author(s):  
David S. Nolan ◽  
Brian D. McNoldy ◽  
Jimmy Yunge

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.


2011 ◽  
Vol 71-78 ◽  
pp. 338-341
Author(s):  
Chih Hong Huang ◽  
Kuang Yu Wang

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.


2018 ◽  
Vol 176 ◽  
pp. 01020
Author(s):  
Songhua Wu ◽  
Bingyi Liu ◽  
Guangyao Dai ◽  
Shenguang Qin ◽  
Jintao Liu ◽  
...  

The Compact High-Power Shipborne Doppler Wind Lidar (CHiPSDWiL) based on highspectral-resolution technique has been built up at the Ocean University of China for the measurement of the wind field and the properties of the aerosol and clouds in the troposphere. The design of the CHiPSDWiL including the transceiver, the injection seeding, the locking and the frequency measurement will be presented. Preliminary results measured by the CHiPSDWiL are provided.


2015 ◽  
Vol 8 (2) ◽  
pp. 729-740 ◽  
Author(s):  
A. Sathe ◽  
J. Mann ◽  
N. Vasiljevic ◽  
G. Lea

Abstract. A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method requires measurement of the radial velocity variances at five equally spaced azimuth angles on the base of a scanning cone and one measurement at the centre of the scanning circle, i.e.using a vertical beam at the same height. The scanning configuration is optimized to minimize the sum of the random errors in the measurement of the second-order moments of the components (u,v, w) of the wind field. We present this method as an alternative to the so-called velocity azimuth display (VAD) method that is routinely used in commercial wind lidars, and which usually results in significant averaging effects of measured turbulence. In the VAD method, the high frequency radial velocity measurements are used instead of their variances. The measurements are performed using a pulsed lidar (WindScanner), and the derived turbulence statistics (using both methods) such as the u and v variances are compared with those obtained from a reference cup anemometer and a wind vane at 89 m height under different atmospheric stabilities. The measurements show that in comparison to the reference cup anemometer, depending on the atmospheric stability and the wind field component, the six-beam method measures between 85 and 101% of the reference turbulence, whereas the VAD method measures between 66 and 87% of the reference turbulence.


2009 ◽  
Vol 48 (9) ◽  
pp. 1929-1939 ◽  
Author(s):  
Kyung-Ja Ha ◽  
Sun-Hee Shin ◽  
Larry Mahrt

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.


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

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