scholarly journals River winds and pollutant recirculation near the Manaus city in the central Amazon

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Tianning Zhao ◽  
Jianhuai Ye ◽  
Igor O. Ribeiro ◽  
Yongjing Ma ◽  
Hui-Ming Hung ◽  
...  
Keyword(s):  
Pollutant Dispersion ◽  
Vertical Profiles ◽  
Fair Weather ◽  
Recirculation Flow ◽  
Wind Speeds ◽  
Synoptic Wind ◽  
Thermally Driven ◽  
Aerial Vehicle ◽  
Northern Brazil ◽  
The Many

AbstractLocal atmospheric recirculation flows (i.e., river winds) induced by thermal contrast between wide Amazon rivers and adjacent forests could affect pollutant dispersion, but observational platforms for investigating this possibility have been lacking. Here we collected daytime vertical profiles of meteorological variables and chemical concentrations up to 500 m with a copter-type unmanned aerial vehicle during the 2019 dry season. Cluster analysis showed that a river-forest recirculation flow occurred for 23% (13 of 56) of the profiles. In fair weather, the thermally driven river winds fully developed for synoptic wind speeds below 4 m s−1, and during these periods the vertical profiles of carbon monoxide and total oxidants (defined as ozone and nitrogen dioxide) were altered. Numerical modeling shows that the river winds can recirculate pollution back toward the riverbank. There are implications regarding air quality for the many human settlements along the rivers throughout northern Brazil.

scholarly journals Wind speed modeling based on measurement data to predict future wind speed with modified Rayleigh model

2021 ◽  
Vol 12 (3) ◽  
pp. 1823
Author(s):  
Suwarno Suwarno ◽  
Rohana Rohana
Keyword(s):  
Wind Speed ◽  
Measurement Data ◽  
Rayleigh Distribution ◽  
Scale Factor ◽  
Percentage Error ◽  
Monthly Data ◽  
Wind Speeds ◽  
Wind Characteristics ◽  
One Year ◽  
The Many

The development of modeling wind speed plays a very important in helping to obtain the actual wind speed data for the benefit of the power plant planning in the future. The wind speed in this paper is obtained from a PCE-FWS 20 type measuring instrument with a duration of 30 minutes which is accumulated into monthly data for one year (2019). Despite the many wind speed modeling that has been done by researchers. Modeling wind speeds proposed in this study were obtained from the modified Rayleigh distribution. In this study, the Rayleigh scale factor (<em>C<sub>r</sub></em>) and modified Rayleigh scale factor (<em>C<sub>m</sub></em>) were calculated. The observed wind speed is compared with the predicted wind characteristics. The data fit test used correlation coefficient (R<sup>2</sup>), root means square error (RMSE), and mean absolute percentage error (MAPE). The results of the proposed modified Rayleigh model provide very good results for users.

Estimation of Wind Vector Profile Using a Hexarotor Unmanned Aerial Vehicle and Its Application to Meteorological Observation up to 1000 m above Surface

2018 ◽  
Vol 35 (8) ◽  
pp. 1621-1631 ◽  
Author(s):  
Tomoya Shimura ◽  
Minoru Inoue ◽  
Hirofumi Tsujimoto ◽  
Kansuke Sasaki ◽  
Masato Iguchi
Keyword(s):  
Wind Speed ◽  
Profile Measurement ◽  
Wind Vector ◽  
Doppler Lidar ◽  
Wind Speeds ◽  
Wide Range ◽  
Lidar Measurements ◽  
Ultrasonic Anemometer ◽  
Aerial Vehicle ◽  
Meteorological Observations

AbstractSmall unmanned aerial vehicles (UAVs), also known as drones, have recently become promising tools in various fields. We investigated the feasibility of wind vector profile measurement using an ultrasonic anemometer installed on a 1-m-wide hexarotor UAV. Wind vectors measured by the UAV were compared to observations by a 55-m-high meteorological tower, over a wide range of wind speed conditions up to 11 m s−1, which is a higher wind speed range than those used in previous studies. The wind speeds and directions measured by the UAV and the tower were in good agreement, with a root-mean-square error of 0.6 m s−1 and 12° for wind speed and direction, respectively. The developed method was applied to field meteorological observations near a volcano, and the wind vector profiles, along with temperature and humidity, were measured by the UAV for up to an altitude of 1000 m, which is a higher altitude range than those used in previous studies. The wind vector profile measured by the UAV was compared with Doppler lidar measurements (collected several kilometers away from the UAV measurements) and was found to be qualitatively similar to that captured by the Doppler lidar, and it adequately represented the features of the atmospheric boundary layer. The feasibility of wind profile measurement up to 1000 m by a small rotor-based UAV was clarified over a wide range of wind speed conditions.

scholarly journals The contribution of snowdrift sublimation to the surface mass balance of Antarctica

1998 ◽  
Vol 27 ◽  
pp. 251-259 ◽  
Author(s):  
Richard Bintanja
Keyword(s):  
Wind Speed ◽  
Mass Balance ◽  
Surface Mass Balance ◽  
Vertical Profiles ◽  
Sublimation Rate ◽  
Model Calculations ◽  
Surface Mass ◽  
Wind Speeds ◽  
Hourly Data ◽  
Sublimation Rates

This paper presents model calculations of snowdrift sublimation rates for year-round automatic weather station (AWS) data in Terre Adélie, Antarctica. The model calculates vertical profiles of wind speed, temperature, humidity and suspended-snow particles in the atmospheric surface layer, and takes into account the buoyancy effects induced by the stably stratified suspended-snow profile by means of an appropriate Richardson number. The model is able to simulate accurately vertical profiles of sublimation rate derived from direct measurements. The model is used to parameterise snowdrift-sublimation rates in terms of wind speed and air temperature. This parameterisation is then used to calculate snowdrift-sublimation rates from 3 hourly data of six AWSs along a transect from Dumont d'Urville to South Pole during one year. Results show that sublimation of suspended snow is negligible in the interior of Antarctica where wind speeds and temperatures are low, whereas near the windy and relatively warm coast its contribution is significant (up to 17cmw.e. a−1). Snowdrift-sublimation rates are highest during summer, when temperatures are highest, in spite of the fact that wind speeds are not as high as in winter. It is concluded that snowdrift sublimation is one of the major terms in the surface mass balance of Antarctica, in particular in the coastal regions.

scholarly journals The Sundowner Winds Experiment (SWEX) Pilot Study: Understanding Downslope Windstorms in the Santa Ynez Mountains, Santa Barbara, California

2020 ◽  
Vol 148 (4) ◽  
pp. 1519-1539 ◽  
Author(s):  
Leila Carvalho ◽  
Gert-Jan Duine ◽  
Charles Jones ◽  
Katelyn Zigner ◽  
Craig Clements ◽  
...  
Keyword(s):  
Pilot Study ◽  
Wrf Model ◽  
Strong Wind ◽  
Vertical Profiles ◽  
Spatial And Temporal Patterns ◽  
Santa Barbara ◽  
Mountain Waves ◽  
Wind Speeds ◽  
Driving Mechanisms ◽  
Downslope Windstorms

Abstract Sundowner winds are downslope gusty winds often observed on the southern slopes of the Santa Ynez Mountains (SYM) in coastal Santa Barbara (SB), California. They typically peak near sunset and exhibit characteristics of downslope windstorms through the evening. They are SB’s most critical fire weather in all seasons and represent a major hazard for aviation. The Sundowner Winds Experiment Pilot Study was designed to evaluate vertical profiles of winds, temperature, humidity, and stability leeward of the SYM during a Sundowner event. This was accomplished by launching 3-hourly radiosondes during a significant Sundowner event on 28–29 April 2018. This study showed that winds in the lee of the SYM exhibit complex spatial and temporal patterns. Vertical profiles showed a transition from humid onshore winds from morning to midafternoon to very pronounced offshore winds during the evening after sunset. These winds accompanied mountain waves and a northerly nocturnal lee jet with variable temporal behavior. Around sunset, the jet was characterized by strong wind speeds enhanced by mountain-wave breaking. Winds weakened considerably at 2300 PDT 29 April but enhanced dramatically at 0200 PDT 29 April at much lower elevations. These transitions were accompanied by changes in stability profiles and in the Richardson number. A simulation with the Weather Research and Forecasting (WRF) Model at 1-km grid spacing was examined to evaluate the skill of the model in capturing the observed winds and stability profiles and to assess mesoscale processes associated with this event. These results advanced understanding on Sundowner’s spatiotemporal characteristics and driving mechanisms.

scholarly journals Extreme wind speed prediction in mountainous area with mixed wind climates

2022 ◽  
Author(s):  
Teng Ma ◽  
Wei Cui ◽  
Lin Zhao ◽  
Yejun Ding ◽  
Genshen Fang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Mountainous Area ◽  
Construction Site ◽  
Wind System ◽  
Mountainous Areas ◽  
Wind Speeds ◽  
Extreme Wind ◽  
Synoptic Wind ◽  
Extreme Wind Speed ◽  
Extreme Wind Speeds

Abstract In addition to common synoptic wind system, the mountainous terrain forms a local thermally driven wind system, which makes the mountain wind system have strong terrain dependence. Therefore, in order to estimate the reliable design wind speeds for structural safety, the samples for extreme wind speeds for certain return periods at mountainous areas can only come from field measurements at construction site. However, wind speeds measuring duration is usually short in real practice. This work proposes a novel method for calculating extreme wind speeds in mountainous areas by using short-term field measurement data and long-term nearby meteorological observatory data. Extreme wind speeds in mountainous area are affected by mixed climates composed by local-scale wind and large scale synoptic wind. The local winds can be recorded at construction site with short observatory time, while the extreme wind speeds samples from synoptic wind climate from nearby meteorological station with long observatory time is extracted for data augmentation. The bridge construction site at Hengduan Mountains in southwestern China is taken as an example in this study. A 10-month dataset of field measurement wind speeds is recorded at this location. This study firstly provides a new method to extract wind speed time series of windstorms. Based on the different windstorm features, the local and synoptic winds are separated. Next, the synoptic wind speeds from nearby meteorological stations are converted and combined with local winds to derive the extreme wind speeds probability distribution function. The calculation results shows that the extreme wind speed in the short return period is controlled by the local wind system, and the long-period extreme wind speed is determined by the synoptic wind system in the mountain area.

scholarly journals Pengujian Performa Payload Video UAV untuk Persiapan Implementasi pemantauan Kapal Illegal Fishing

2020 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Sunar Sunar ◽  
Ari Sugeng Budiyanta
Keyword(s):  
Video Recording ◽  
Target Position ◽  
Operating Conditions ◽  
Wind Speeds ◽  
Illegal Fishing ◽  
Maritime Surveillance ◽  
Fishing Vessels ◽  
Survey System ◽  
Aerial Vehicle ◽  
Zoom In

The Aeronautics Technology Center of LAPAN develops a maritime surveillance system (MSS) based on an unmanned aerial vehicle (UAV) application, specifically to support the handling of illegal fishing vessels. This article discusses video payload testing. The test was carried out in the coastal area, Pamengpeuk, Garut, Indonesia on August 31, 2019. This place was chosen to simulate conditions with wind speeds that are similar to operating conditions in the marine environment during the actual implementation of the operation. The payload used has a video recording feature with the ability to zoom-in, zoom-out and locking-target-positions. UAVs fly loiter at an altitude of 300 m - 500 m above sea level while doing video recording and transmitted in real time to the Ground Control Station (GCS). The test results show the payload shows the zoom-in, zoom-out and locking target position features can operate properly. This feature is very useful to meet the needs of illegal fishing operations in the maritime survey system.  

Prediction of Non-Synoptic Wind Speeds

2020 ◽  
Author(s):  
Franklin T. Lombardo ◽  
Alexander S. Zickar
Keyword(s):  
The United States ◽  
Wind Speeds ◽  
Wind Speed Prediction ◽  
Simulation Techniques ◽  
Step Procedure ◽  
Synoptic Wind ◽  
Spatial Dimensions ◽  
Simple Step ◽  
Speed Prediction ◽  
Future Work

Winds generated from non-synoptic events cause significant losses globally. This chapter focuses specifically on winds generated from thunderstorms. Thunderstorm-generated winds produce the highest recorded wind speeds in many worldwide locations, which makes them important for the design of structures. Prediction of these wind speeds is then a crucial step in the design process. This chapter discusses a simple, step-by-step procedure for predicting thunderstorm-generated wind speeds using a location in the United States as an illustrative example. This procedure includes data recording/archival, storm-type classification, reducing data dependence, estimating a rate of occurrence, and fitting a probability distribution, including consideration of multiple storm types. Examples from the existing literature are also shared to give the reader a comprehensive look at what has been done on the topic to this point. Based on the illustrative example and the existing literature, physical and probabilistic differences from synoptic prediction methods and analysis are also elucidated. These differences include higher variability of thunderstorm-generated winds, regionality of the wind climate, and topics such as wind directionality and changes in frequency and intensity. Rarely used simulation techniques that help address robustness of current predictions as well as handle the finite spatial dimensions in the analysis and prediction of non-synoptic winds are also covered. Future work on non-synoptic wind speed prediction is touched on, including additional parsing of non-synoptic storms into subtypes and a comprehensive non-synoptic model similar to what has been done for tropical cyclones.

scholarly journals River Breezes for Pollutant Dispersion in GoAmazon2014/5

2018 ◽  
Author(s):  
Adan S. S. Medeiros ◽  
Igor O. Ribeiro ◽  
Marcos V. B. Morais ◽  
Rita V. Andreoli ◽  
Jorge A. Martins ◽  
...  
Keyword(s):  
Pollutant Dispersion ◽  
Atmospheric Composition ◽  
Horizontal Wind ◽  
Data Sets ◽  
Plume Dispersion ◽  
Wind Fields ◽  
Wind Speeds ◽  
Pollutant Concentrations ◽  
First Case ◽  
Apparent Influence

Abstract. The effect of river breezes on pollutant plume dispersion or canalization in the central Amazon was evaluated. A pollution plume changes atmospheric composition downwind of Manaus, a city of 2 million people positioned at the confluence between two wide rivers. Herein, to evaluate the effects of river breezes, two cases were modeled at the mesoscale for March 2014. The first case, "with rivers" (wR), simulated the transport and chemistry of the Manaus pollution plume as the rivers were in reality. The second case, "without rivers" (woR), carried out simulations for which all rivers and floodable areas were replaced by forest. The three main conclusions are as follows: (1) Between the two cases, alterations in wind speeds were maximum at local noon, and river breezes influenced horizontal wind fields from surface up to 150 m in altitude, suggesting a capping height of 150 m on most days for the influence of river breezes on pollutant concentrations. In agreement with this modeling result, data sets collected at 500 m by aircraft flights showed no apparent influence of the underlying rivers on plume dispersion. The flights traversed the plume downwind of Manaus during the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment. (2) Between the wR and wOR cases, changes to downwind concentrations of O3, NOx, and CO pollutants were

scholarly journals Unmanned aerial vehicle control costs mirror bird behaviour when soaring close to buildings

2020 ◽  
Vol 12 ◽  
pp. 175682932094100
Author(s):  
Ana Guerra-Langan ◽  
Sergio Araujo-Estrada ◽  
Shane Windsor
Keyword(s):  
Flight Control ◽  
Radial Distance ◽  
Urban Environments ◽  
Strong Wind ◽  
Control Effort ◽  
Wind Speeds ◽  
Flight Costs ◽  
Dynamics And Control ◽  
Aerial Vehicle ◽  
And Control

Small unmanned aerial vehicles (SUAVs) are suitable for many low-altitude operations in urban environments due to their manoeuvrability; however, their flight performance is limited by their on-board energy storage and their ability to cope with high levels of turbulence. Birds exploit the atmospheric boundary layer in urban environments, reducing their energetic flight costs by using orographic lift generated by buildings. This behaviour could be mimicked by fixed-wing SUAVs to overcome their energy limitations if flight control can be maintained in the increased turbulence present in these conditions. Here, the control effort required and energetic benefits for a SUAV flying parallel to buildings whilst using orographic lift was investigated. A flight dynamics and control model was developed for a powered SUAV and used to simulate flight control performance in different turbulent wind conditions. It was found that the control effort required decreased with increasing altitude and that the mean throttle required increased with greater radial distance to the buildings. However, the simulations showed that flying close to the buildings in strong wind speeds increased the risk of collision. Overall, the results suggested that a strategy of flying directly over the front corner of the buildings appears to minimise the control effort required for a given level of orographic lift, a strategy that mirrors the behaviour of gulls in high wind speeds.

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