scholarly journals ESTIMATION OF VERTICAL DUST EMISSION FLUX AT A SITE IN THE MONGOLIAN GOBI DURING A DUST STORM PERIOD

2018 ◽  
pp. 25-40
Author(s):  
Jugder D
Keyword(s):  
Soil Moisture ◽  
Wind Speed ◽  
Dust Storm ◽  
Friction Velocity ◽  
Sonic Anemometer ◽  
Dust Emission ◽  
Ground Level ◽  
Gobi Desert ◽  
Moisture Sensor ◽  
Dust Flux

A meteorological and dust monitoring tower with 20 m height set up at a Nomgon site in Umnugobi Aimag in the Mongolian Gobi in 2010. The Nomgon monitoring tower equipped with wind speed sensors at 2, 4, 10 and 20 m height above the ground level (AGL), a wind direction sensor at 10 m height, a sonic anemometer to measure turbulent momentum flux at 8 m height and a soil moisture sensor at 5 cm depth. We had a purpose to measure dust concentration of PM10 at two levels using Dust-Trak instruments during an intensive observation period (IOP) of a dust event in spring. A dust storm was expected in the Mongolian Gobi from 30 April to 1 May 2016 and two Dust-Traks were set at 0.9 and 2.95 m heights in the tower during this IOP for measuring PM10. Wind data at 2 and 10 m height, three wind components at 8 m height by a sonic anemometer, soil moisture (volumetric water content) data in 5 cm depth and dust concentrations of PM10 at two levels are used in this study. These data from the sensors and instruments in the tower were used for estimation friction velocity and vertical dust flux at the Nomgon site. In association with a surface cyclone, its frontal system and a trough aloft, the expected dust storm occurred in the Mongolian Gobi during the IOP period. Dust concentrations of PM10 increased during the dust storm period due to raised wind speed in the dry conditions of air and soil. The present study aimed to estimate friction velocity (u*) and vertical dust flux (F) around Nomgon site in the Mongolian Gobi desert during the dust storm period. The estimation results were presented in this paper.

scholarly journals A dust event in the Mongolian Gobi Desert in spring 2016: Observations and vertical dust flux estimation

2019 ◽  
Vol 99 ◽  
pp. 01009
Author(s):  
Dulam Jugder
Keyword(s):  
Wind Speed ◽  
Dust Storm ◽  
Sonic Anemometer ◽  
Ground Level ◽  
Gobi Desert ◽  
Dust Event ◽  
Moisture Sensor ◽  
Dust Flux ◽  
Dry Conditions ◽  
Set Up

A meteorological and dust monitoring tower with 20 m height set up at a Nomgon site in the Mongolian Gobi Deserts in 2010. The Nomgon monitoring tower equipped with wind speed sensors at 2, 4, 10 and 20 m height above the ground level (AGL), a wind direction sensor at 10 m height, a sonic anemometer to measure turbulent momentum flux at 8 m height and a soil moisture sensor at 5 cm depth. A dust storm was expected in the Mongolian Gobi from 30 April to 1 May 2016 and two aerosol monitors (Dust-Trak) were set at 0.9 and 2.95 m heights in the tower for measuring PM10. Above mentioned data from the tower during an intensive observation period (IOP) of the dust event are used in this study. In association with a surface cyclone, its frontal system and a trough aloft, dust concentrations of PM10 increased during the dust storm period due to raised wind speed in the dry conditions of air and soil. The present study aims to estimate friction velocity (u*) and vertical dust flux (F) around the Nomgon site during the dust storm period. The observations and estimation results are presented.

scholarly journals Design a Monitoring and Control in Irrigation Systems using Arduino Wemos with the Internet of Things

2021 ◽  
Vol 1 (1) ◽  
pp. 53-64
Author(s):  
Lukman Medriavin Silalahi ◽  
Setiyo Budiyanto ◽  
Freddy Artadima Silaban ◽  
Arif Rahman Hakim
Keyword(s):  
Soil Moisture ◽  
Water Level ◽  
Irrigation System ◽  
Ground Level ◽  
Prototype System ◽  
Monitoring And Control ◽  
Moisture Sensor ◽  
Turn On ◽  
Soil Moisture Sensors ◽  
Level Sensor

Irrigation door is a big issue for farmers. The factor that became a hot issue at the irrigation gate was the irresponsible attitude of the irrigation staff regarding the schedule of opening/closing the irrigation door so that it caused the rice fields to becoming dry or submerged. In this research, an automatic prototype system for irrigation system will be designed based on integrating several sensors, including water level sensors, soil moisture sensors, acidity sensors. This sensor output will be displayed on Android-based applications. The integration of communication between devices (Arduino Nano, Arduino Wemos and sensors supporting the irrigation system) is the working principle of this prototype. This device will control via an Android-based application to turn on / off the water pump, to open/close the irrigation door, check soil moisture, soil acidity in real time. The pump will automatically turn on based on the water level. This condition will be active if the water level is below 3cm above ground level. The output value will be displayed on the Android-based application screen and LCD screen. Based on the results of testing and analysis of the prototype that has been done in this research, the irrigation door will open automatically when the soil is dry. This condition occurs if the water level is less than 3 cm. The calibrated Output value, including acidity sensor, soil moisture sensor and water level sensor, will be sent to the server every 5 seconds and forwarded to an Android-based application as an output display.

scholarly journals Detecting Ground Level Enhancements using Soil Moisture Sensor Networks

Space Weather ◽  
2021 ◽  
Author(s):  
A. D. P. Hands ◽  
F. Baird ◽  
K. A. Ryden ◽  
C. S. Dyer ◽  
F. Lei ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Sensor Networks ◽  
Ground Level ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Ground Level Enhancements

scholarly journals Testing the performance of state-of-the-art dust emission schemes using DO4Models field data

2015 ◽  
Vol 8 (2) ◽  
pp. 341-362 ◽  
Author(s):  
K. Haustein ◽  
R. Washington ◽  
J. King ◽  
G. Wiggs ◽  
D. S. G. Thomas ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Field Data ◽  
Dust Emission ◽  
Shear Velocity ◽  
Box Model ◽  
Wind Speeds ◽  
Dust Flux ◽  
Dry Lake ◽  
Order Of Magnitude ◽  
Emission Threshold

Abstract. Within the framework of the Dust Observations for Models (DO4Models) project, the performance of three commonly used dust emission schemes is investigated in this paper using a box model environment. We constrain the model with field data (surface and dust particle properties as well as meteorological parameters) obtained from a dry lake bed with a crusted surface in Botswana during a 3 month period in 2011. Our box model results suggest that all schemes fail to reproduce the observed horizontal dust flux. They overestimate the magnitude of the flux by several orders of magnitude. The discrepancy is much smaller for the vertical dust emission flux, albeit still overestimated by up to an order of magnitude. The key parameter for this mismatch is the surface crusting which limits the availability of erosive material, even at higher wind speeds. The second-most important parameter is the soil size distribution. Direct dust entrainment was inferred to be important for several dust events, which explains the smaller gap between modelled and measured vertical dust fluxes. We conclude that both features, crusted surfaces and direct entrainment, need to be incorporated into dust emission schemes in order to represent the entire spectra of source processes. We also conclude that soil moisture exerts a key control on the threshold shear velocity and hence the emission threshold of dust in the model. In the field, the state of the crust is the controlling mechanism for dust emission. Although the crust is related to the soil moisture content to some extent, we are not as yet able to deduce a robust correlation between state of crust and soil moisture.

scholarly journals The Baja California Peninsula, a Significant Source of Dust in Northwest Mexico

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 582 ◽  
Author(s):  
Enrique Morales-Acuña ◽  
Carlos Torres ◽  
Francisco Delgadillo-Hinojosa ◽  
Jean Linero-Cueto ◽  
Eduardo Santamaría-del-Ángel ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Wind Speed ◽  
Interannual Variability ◽  
Baja California ◽  
Southern Oscillation ◽  
Dust Emission ◽  
Baja California Peninsula ◽  
Significant Source ◽  
Enso Events ◽  
Desert Regions

Despite their impacts on ecosystems, climate, and human health, atmospheric emissions of mineral dust from deserts have been scarcely studied. This work estimated dust emission flux (E) between 1979 and 2014 from two desert regions in the Baja California Peninsula (BCP) using a modified dust parameterization scheme. Subsequently, we evaluated the processes controlling the variability of E at intra- and interannual scales. During the period 1979–2014 peak E were generally recorded in summer (San Felipe) and spring (Vizcaino), and the lowest emissions occurred in autumn (San Felipe) and winter (Vizcaíno). Intra- and interannual variability in E was associated with fluctuations in wind speed and direction, precipitation, and soil moisture, which, in turn, were controlled by the seasonal displacement of the North Pacific high-pressure center. Key drivers of the interannual variability of E are strong El Niño Southern Oscillation (ENSO) events. These climatic events and the hydrometeorological variables mentioned above played a major role in the onset and occurrence of dust events, with the highest annual emissions at Vizcaíno. Besides, a lag of 19 months (San Felipe) and 21 months (Vizcaino) was recorded between the occurrence of relevant E and ENSO events, apparently in response to the effect of this climatic event on precipitation. The climate variability of E in both desert regions was evidenced by the positive trends associated with increases in wind speed and air temperature, and with decreases in precipitation and soil moisture. Finally, our findings suggest that the BCP should be considered as a significant source of dust for the regional inventory of particulate matter emissions from the Earth’s surface.

Investigation of the effect of wind speed fluctuation on the drag coefficient

2020 ◽  
Author(s):  
Naoya Suzuki ◽  
Takuji Waseda ◽  
Naohisa Takagaki
Keyword(s):  
Wind Speed ◽  
Drag Coefficient ◽  
Friction Velocity ◽  
Sonic Anemometer ◽  
Correlation Method ◽  
Eddy Correlation ◽  
Large Fluctuation ◽  
Speed Fluctuation ◽  
Period Data ◽  
The University

<p>The drag coefficient is generally expressed as functions only of the wind speed U<sub>10</sub>. However, there exists considerable disagreement among the observed values of the drag coefficient. In this study, we observed the wind stress at the coastal tower of Hiratsuka Offshore Experimental Tower of the University of Tokyo in Japan. The 3-axis sonic anemometer was installed on the top of the tower, which was 20 m above mean sea level. The observation periods were from September 15, 2015 to December 31, 2019. The eddy correlation method was used to calculate the friction velocity every 10 minutes. The variation of the drag coefficient plotted against the wind speed U<sub>10</sub> has very large using the all period data. The variation of the drag coefficient was reduced by excluding large fluctuation of wind speed in time series within one hour. Furthermore, the sudden changes of the wind speed and direction was also found to affect the variation of the drag coefficient. These results show that the wind speed fluctuation influenced the variation of the drag coefficient. We also investigate the effect of waves on the drag coefficient.</p>

scholarly journals Comparison of turbulence measurements by a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar

2020 ◽  
Vol 13 (2) ◽  
pp. 969-983 ◽  
Author(s):  
Matthias Mauder ◽  
Michael Eggert ◽  
Christian Gutsmuths ◽  
Stefan Oertel ◽  
Paul Wilhelm ◽  
...  
Keyword(s):  
High Resolution ◽  
Wind Speed ◽  
Friction Velocity ◽  
Sonic Anemometer ◽  
Vertical Wind ◽  
Doppler Lidar ◽  
Flow Distortion ◽  
Sonic Anemometers ◽  
Vertical Wind Speed ◽  
Standard Deviations

Abstract. Accurate measurements of turbulence statistics in the atmosphere are important for eddy-covariance measurements, wind energy research, and the validation of atmospheric numerical models. Sonic anemometers are widely used for these applications. However, these instruments are prone to probe-induced flow distortion effects, and the magnitude of the resulting errors has been debated due to the lack of an absolute reference instrument under field conditions. Here, we present the results of an intercomparison experiment between a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar, which is inherently free of any flow distortion. This novel remote sensing instrument has otherwise very similar spatial and temporal sampling characteristics to the sonic anemometer and hence served as a reference for this comparison. The presented measurements were carried out over flat homogeneous terrain at a measurement height of 30 m. We provide a comparative statistical analysis of the resulting mean wind velocities, the standard deviations of the vertical wind speed and the friction velocity and investigate the reasons for the observed deviations based on the turbulence spectra and co-spectra. Our results show an agreement of the mean wind velocity measurements and the standard deviations of the vertical wind speed with a comparability of 0.082 and 0.020 m s−1, respectively. Biases for these two quantities were 0.003 and 0.012 m s−1, respectively. Slightly larger differences were observed for friction velocity. Analysis of the corresponding co-spectra showed that the CSAT3B underestimates this quantity systematically by about 3 % on average as a result of co-spectral losses in the frequency range between 0.1 and 5 s−1. We also found that an angle-of-attack-dependent transducer-shadowing correction does not improve the agreement between the CSAT3B and the Physikalisch-Technische Bundesanstalt (PTB) lidar effectively.

scholarly journals Comparison of turbulence measurements by a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar

2019 ◽  
Author(s):  
Matthias Mauder ◽  
Michael Eggert ◽  
Christian Gutsmuths ◽  
Stefan Oertel ◽  
Paul Wilhelm ◽  
...  
Keyword(s):  
High Resolution ◽  
Wind Speed ◽  
Friction Velocity ◽  
Sonic Anemometer ◽  
Vertical Wind ◽  
Doppler Lidar ◽  
Flow Distortion ◽  
Sonic Anemometers ◽  
Vertical Wind Speed ◽  
Standard Deviations

Abstract. Accurate measurements of turbulence statistics in the atmosphere are important for eddy-covariance measurements, wind energy research, and the validation of atmospheric numerical models. Sonic anemometers are widely used for these applications. However, these instruments are prone to probe-induced flow distortion effects, and the magnitude of the resulting errors has been debated due to the lack of an absolute reference instrument under field conditions. Here, we present the results of an intercomparison experiment between a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar, which is inherently free of any flow-distortion. This novel remote sensing instrument has otherwise very similar spatial and temporal sampling characteristics as the sonic anemometer and hence served as a reference for this comparison. The presented measurements were carried out over flat homogeneous terrain, at a measurement height of 30 m. We provide a comparative statistical analysis of the resulting mean wind velocities, the standard deviations of the vertical wind speed and the friction velocity and investigate the reasons for the observed deviations based on the turbulence spectra and cospectra. Our results show a very good agreement of the mean wind velocity measurements and the standard deviations of the vertical wind speed, with comparabilities of 0.082 and 0.017 m s−1, respectively. Biases for these two quantities were very low, being smaller than 0.01 m s−1, which corresponds to about 1 % in relative terms. Slightly larger differences were observed for friction velocity. Analysis of the corresponding cospectra showed that the CSAT3B underestimates this quantity systematically by about 3 % on average as a result of too steep a drop-off in the inertial sub-range. We also found that an angle-of-attack dependent transducer-shadowing correction does not improve this agreement effectively because it leads to an artificial correlation between the three wind components and therefore severely distorts the shape of the cospectra.

scholarly journals Dust Emission from Gobi under Different Dust Content Conditions: A Wind Tunnel Study atop the Mogao Grottoes

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1498
Author(s):  
Linhao Liang ◽  
Weimin Zhang ◽  
Lihai Tan ◽  
Shuyi Chen
Keyword(s):  
Wind Tunnel ◽  
Atmospheric Aerosols ◽  
Friction Velocity ◽  
Dynamic Condition ◽  
Dust Emission ◽  
Dust Content ◽  
Gobi Desert ◽  
Wind Force ◽  
Surface Dust ◽  
Mogao Grottoes

Dust emission from the Gobi desert is one of the major sources of global atmospheric aerosols. However, the main factors affecting dust emission from Gobi remain poorly understood. In this paper, field wind tunnel experiments were performed atop the Mogao Grottoes to determine the variation characteristics of the vertical dust flux (F) of particulate matter less than 10 μm (PM10) for Gobi surfaces with different dust content and wind speeds under external sand supply. The results demonstrate that F obeyed a power function with increasing friction velocity (U∗), and increased exponentially with the increasing surface dust content (C). The index of n-value in the formula F∝U∗n is taken in the range of 2.02–2.63 under the surface of 27.3–47.3% dust content (<100 µm), and the dust emission rate was significantly enhanced when the surface dust content exceeded approximately 37%. This study indicates that wind force is the primary dynamic condition affecting Gobi dust emission, and that surface dust content is a significant factor in determining the quantity of dust emission. Furthermore, the contribution of wind force to PM10 emission is greater than the surface dust content, and the higher the height, the greater the weight of friction velocity.

Sign in / Sign up

Export Citation Format

Share Document