scholarly journals Characteristics of Aeolian Dune, Wind Regime and Sand Transport in Hobq Desert, China

2019 ◽  
Vol 9 (24) ◽  
pp. 5543 ◽  
Author(s):  
Hui Yang ◽  
Jiansheng Cao ◽  
Xianglong Hou
Keyword(s):  
Wind Speed ◽  
Meteorological Data ◽  
Sand Dunes ◽  
Temporal Distribution ◽  
Distribution Area ◽  
Sand Transport ◽  
Wind Regime ◽  
The West ◽  
Average Wind Speed ◽  
Drift Potential

A systematic study of the wind regime characteristics in a region can not only accurately grasp the dynamic factors of the development of aeolian geomorphology, but also provide a scientific basis for the prevention and treatment of regional sand disasters. Taking the Hobq Desert as the study area, the basic characteristics of dune are analyzed by using remote sensing images. Based on the annual meteorological data of six meteorological stations from 2009 to 2018, the spatial and temporal distribution characteristics of wind speed were obtained. With the daily wind data of three stations from 2009 to 2018, we have figured out the wind regime and sand transport characteristics of the Hobq Desert. The results show that the sand dune height of the Hobq Desert ranges large, the highest height is 5010 m and the lowest is 10 m. It decreases gradually from the west to the east. The height of dune mainly distributed below 1500 m, followed by 1500–2000 m. Migratory sand dunes in Hobq Desert accounts for 51.8% and is mainly distributed in the west of the desert. The distribution area of fixation sand dunes in Hobq Desert is the least, accounting for 8.3%. The migratory dune pattern is trellis dune, semimigrated dune and semifixed dune patterns include honeycomb dune, parabolic duneand brush dune, and fixation dune pattern is grass dune. Annual wind speed was greatest in the southeast and decreased moving to the northwest. The dominant wind direction was W and SW from 2009 to 2018 in the Hobq Desert, the average wind speed of the prevailing winds mainly distributed at 4–8 m/s. The frequency of wind speed exceeding 10 m/s is very low, with a maximum value of 10% or below. There is a low energy wind environment in the Hobq Desert, with intermediate annual directional variability and obtuse or acute bimodal wind regime. The resultant drift direction (RDD)at Dongsheng station was relatively constant from 2009 to 2018, it was about 350°. RDD differed significantly at Baotou and Linhestations were 181 ± 169° and 231 ± 121°, respectively.The relationship between drift potential (DP) and the average and maximum wind speed was expressed as a power function. DP was strongly correlated with them. There is no significant correlated between the temporal changes in DPandprecipitation and temperature from 2009 to 2018 in the Hobq Desert.

scholarly journals Monitoring Sand Drift Potential and Sand Dune Mobility over the Last Three Decades (Khartouran Erg, Sabzevar, NE Iran)

2021 ◽  
Vol 13 (16) ◽  
pp. 9050
Author(s):  
Mohammad Reza Rahdari ◽  
Andrés Rodríguez-Seijo
Keyword(s):  
Wind Speed ◽  
Sand Dune ◽  
Sand Dunes ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind ◽  
Sand Drift ◽  
Drift Potential ◽  
Long Time ◽  
Ne Iran

Aeolian sediments cover about 6% of the earth’s surface, of which 97% occur in arid regions, and these sediments cover about 20% of the world’s lands. Sand drifts can harm sensitive ecosystems; therefore, this research has aimed to study wind regimes and the monitoring of sand drift potential and dune mobility in the Khartouran Erg (NE Iran). The study investigated 30 years of wind speed and direction to better understand sand dune mobility processes using the Fryberger and Tsoar methods. The results of the wind regime study showed that the eastern (33.4%) and northeastern (14.3%) directions were more frequent, but the study of winds greater than the threshold (6 m/s) in winter, spring, and autumn indicated the dominance of eastern and northern wind directions. Findings of calm winds showed that winters (40.4%) had the highest frequency, and summers (15%) had the lowest frequency; the annual frequency was 30%. The average wind speed in summers was the highest (4.38 m/s), and, in the winters, it was the lowest (2.28 m/s); the annual average wind speed was 3.3 m/s. The annual drift potential (DP = 173 VU) showed that it was categorized as low class, and the winds carried sand to the southwest. The monitoring of drift potential showed that there was a sharp increase between 2003 and 2008, which could have been attributed to a change in wind speeds in the region. Unite directional index, the index of directional variability, has been alternating from 0.3 to 0.6 for 30 years. Furthermore, monitoring of sand mobility recorded a value from 0.1 to 0.4, and the lowest and highest values were registered from 0.08 to 0.9, with an average of 0.27. Finally, it can be concluded that sand dunes have been fixed for a long time, and the intensity of the mobility index is affected by climate changes.

POSSIBLE CHANGES OF CLIMATE CONDITIONS IN UKRAINE TO THE MIDDLE OF THE XXI CENTURY

2020 ◽  
pp. 94-100
Author(s):  
L.V. Malytska ◽  
V. O Balabukh
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Climate Model ◽  
Temporal Distribution ◽  
Climatic Parameters ◽  
Average Wind Speed ◽  
Climate Conditions ◽  
A1b Scenario

In Ukraine, as in the world, substantial climatic changes have happened throughout past decades. It is a fact that they are manifested in changing of parameters of the thermal regime, regimes of wind and humidity. It is expected that they will be observed also in future that will lead to aggravation of negative effects and risks due to climate change. That determines the relevance of the problem of forecasting such changes in future both globally and regionally. After all, knowledge of climate’s behavior in future is very important in the development of strategies, program and measures to adapt to climate change. The article is devoted to assessing spatio-temporal distribution main climatic indicators (air temperature, wind speed and relative humidity) in Ukraine, their variability and the probable values to the middle of the 21st century (2021-2050). Projection of changes in meteorological conditions was made for A1B scenario of SRES family using data of the regional climate model REMO and data from the hydrometeorological observation network of Ukraine (175 stations). Estimated data obtained from the European FP-6 ENSEMBLES project with a resolution of 25 km. For spatial distribution (mapping) we used open-source Geographic Information System QGIS, type of geographic coordinate system for project is WGS84. In the middle of the XXI century, if A1B scenario is released, it is expected a significant changes of climatic parameters regarding the 1981-2010 climatic norm: air temperature is rise by 1,5 °C, average wind speed is decrease by 5-8%, relative humidity in winter probably drop by 2%, but in summer it rises by 1,5%. The unidirectionality of the changes is characteristic only of air temperature, for wind speed and relative humidity the changes are in different directions. The intensity of changes is also not uniform across the country for all climatic parameters, has its regional and seasonal features. Statistical likelihood for most of highlighted changes for all climatic parameters is 66 % and more, the air temperature change is virtually certain (p-level <0.001).

scholarly journals Effect of meteorological factors on the activity of influenza in Chongqing, China, 2012–2019

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246023
Author(s):  
Li Qi ◽  
Tian Liu ◽  
Yuan Gao ◽  
Dechao Tian ◽  
Wenge Tang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Meteorological Factors ◽  
Meteorological Data ◽  
Warning System ◽  
Absolute Humidity ◽  
Influenza Surveillance ◽  
Average Wind Speed ◽  
Mean Temperature ◽  
Influenza Activity

Background The effects of multiple meteorological factors on influenza activity remain unclear in Chongqing, the largest municipality in China. We aimed to fix this gap in this study. Methods Weekly meteorological data and influenza surveillance data in Chongqing were collected from 2012 to 2019. Distributed lag nonlinear models (DLNMs) were conducted to estimate the effects of multiple meteorological factors on influenza activity. Results Inverted J-shaped nonlinear associations between mean temperature, absolute humidity, wind speed, sunshine and influenza activity were found. The relative risks (RRs) of influenza activity increased as weekly average mean temperature fell below 18.18°C, average absolute humidity fell below 12.66 g/m3, average wind speed fell below 1.55 m/s and average sunshine fell below 2.36 hours. Taking the median values as the references, lower temperature, lower absolute humidity and windless could significantly increase the risks of influenza activity and last for 4 weeks. A J-shaped nonlinear association was observed between relative humidity and influenza activity; the risk of influenza activity increased with rising relative humidity with 78.26% as the break point. Taking the median value as the reference, high relative humidity could increase the risk of influenza activity and last for 3 weeks. In addition, we found the relationship between aggregate rainfall and influenza activity could be described with a U-shaped curve. Rainfall effect has significantly higher RR than rainless effect. Conclusions Our study shows that multiple meteorological factors have strong associations with influenza activity in Chongqing, providing evidence for developing a meteorology-based early warning system for influenza to facilitate timely response to upsurge of influenza activity.

Characteristics of the wind regime of Libya based on NCEP / NCAR reanalysis data and surface weather observations

2020 ◽  
Vol 101-102 (3-4) ◽  
pp. 26-32
Author(s):  
Ellina Agayar ◽  
Ali Saleh Abudawah
Keyword(s):  
Wind Speed ◽  
Wind Field ◽  
General Circulation ◽  
Meteorological Data ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Reanalysis Data ◽  
Average Wind Speed ◽  
Weather Observations ◽  
Surface Weather

The surface wind field are formed by the interaction of general circulation mechanisms with the local physical, geographical and climatic characteristics of the region. The success of the implementation of the different weather models is based on the representativeness of the initial information. The paper presents the results of comparing meteorological data, such as the average monthly speed and direction of the surface wind, from the NCEP / NCAR reanalysis archive with data of surface weather observations for the period from 2015 to 2019. Considering the difficulty of obtaining data, the absence of continuous observations at many meteorological stations in Libya, it was decided to analyze the most complete series of observations for the last period and compare it with the model data of reanalysis. Meteorological stations are located in different geographic regions of Libya (Derna, Zuara, Efren, Misurata, Godames, Jagbub, El-Kufra and Ghat). Based on the monthly average values of the surface wind velocity components for past five years, was done a study of the intrannual structure of the wind field over the territory of Libya and maps of the wind field for this period were constructed. The obtained results of comparison of the NCEP / NCAR reanalysis data with Surface weather observations showed a relatively good agreement between the observed and calculated wind. Noted that the wind, according to NCEP data, is some weaker than observed at the stations. The main reasons for this are the complexity and diversity of the topography around the stations, as well as the representativeness between gridded data and meteorological measurements. Analysis of the distribution of the average monthly wind speed over the territory of Libya indicates a tendency for an increase in the surface wind speed from the southwest to the northeast, both as according to the NCEP / NCAR reanalysis data, where the average wind speed doesn’t exceed 4.7 m/s, and according to actual observations 6.7 m/s.

scholarly journals Millimetre Astronomy from the High Antarctic Plateau: Site Testing at Dome C

1999 ◽  
Vol 16 (2) ◽  
pp. 167-174 ◽  
Author(s):  
L. Valenziano ◽  
G. Dall'Oglio
Keyword(s):  
Wind Speed ◽  
Meteorological Data ◽  
Large Fraction ◽  
Precipitable Water ◽  
South Pole ◽  
Site Testing ◽  
The South ◽  
Precipitable Water Vapour ◽  
Average Wind Speed ◽  
Antarctic Plateau

AbstractPreliminary site testing results at Dome C (Antarctica) are presented, using both Automatic Weather Station (AWS) meteorological data (1986–1993) and Precipitable Water Vapour (PWV) measurements made by the authors. A comparison with the South Pole and other sites is made. The South Pole is a well established astrophysical observing site, where extremely good conditions are reported for a large fraction of time during the year. Dome C, where Italy and France are building a new scientific station, is a potential observing site in the millimetre and submillimetre range. AWS are operating at both sites and they have been continuously monitoring temperature, pressure and wind speed and direction for more than ten years. Site testing instruments are already operating at the South Pole (AASTO, Automated Astrophysical Site-Testing Observatory), while light experiments have been running at Dome C (APACHE, Antarctic Plateau Anisotropy CHasing Experiment) during summertime. A direct comparison between the two sites is planned in the near future, using the AASTO. The present analysis shows that the average wind speed is lower at Dome C (∼1 ms−1) than at the South Pole (∼2 ms−1), while temperature and PWV are comparable.

scholarly journals Climatology of blizzards over Schirmacher Oasis, east Antarctica

MAUSAM ◽  
2021 ◽  
Vol 60 (1) ◽  
pp. 39-50
Author(s):  
R. P. LAL ◽  
SURESH RAM
Keyword(s):  
Wind Speed ◽  
Temperature Rise ◽  
Meteorological Data ◽  
Tropical Storms ◽  
Blowing Snow ◽  
Average Wind Speed ◽  
Average Wind ◽  
Schirmacher Oasis ◽  
Low Visibility ◽  
Strong Winds

Weather in Antarctica is subject to frequent and sudden changes.  Strong winds and blizzards dominate Antarctic weather. A combination of blowing snow, gale force wind and very low visibility is normally defined as blizzard. Meteorological data recorded at Indian Antarctic Station Maitri, in respect of blizzards recorded during the period 1990-2005 has been studied to find out climatological features of blizzards affecting Schirmacher Oasis.       At Maitri the blizzard is mostly associated with extra-tropical storms and is normally preceded by precipitation. On average during the year about 21 blizzards affects the station for 45 days during the year. During the month of April to August 3 to 4 blizzards affects the station. Maximum number of blizzards occurs in the month of August with about 7 blizzard days. Average wind speed recorded during the blizzard is about 52 kt but it exceeded 100 kt on several occasions. The duration may vary from hours to days with average of 25 hours. Longest duration of 168 hours was recorded in June 1997. There are about 12 such occasions when blizzard lasted more than 72 hours. No correlation has been found between maximum wind speed and temperature rise during blizzard and the speed is also not correlated with pressure departure during the period.

scholarly journals Energy and power estimation for three different locations in Palestine

2019 ◽  
Vol 14 (3) ◽  
pp. 1049 ◽  
Author(s):  
Ahmed S A Badawi ◽  
Nurul Fadzlin Hasbullaha ◽  
Siti Hajar Yusoff ◽  
Aisha Hassan Hashim
Keyword(s):  
Renewable Energy ◽  
Wind Speed ◽  
Wind Energy ◽  
Meteorological Data ◽  
Gaza Strip ◽  
Energy Potential ◽  
Average Wind Speed ◽  
Average Wind ◽  
Mean Wind Speed ◽  
Power And Energy

In this paper power energy estimated based on wind speed records in three different areas in Palestine Nablus, Ramallah and Gaza. The main aims of this study to calculate the total amount of power and energy that can produce and to encourage investment in renewable energy in Palestine. Available meteorological data from local weather stations are used to study the wind energy potential in the West Bank (WB) for two sites and Gaza Strip (GS) for one site. The daily average wind speed data for three sites in Palestine analyzed, and fitted to the Weibull probability distribution function. The parameters of Weibull have been calculated by author using Graphical method. This study shed lights on the relationship between the wind energy and power versus the mean wind speed (MWS). The total gathered energy per unit area during 2006 in WB from Nablus site is 927.1 kwhr/m<sup>2</sup>, whereas 2008.0141 kwhr/m<sup>2</sup> from Ramallah site.This significant study to assess the wind energy production in Palestine to encourage investment in renewable energy sectors.

scholarly journals Current distribution of wind in Morocco

2017 ◽  
pp. 61-69
Author(s):  
M.O. Slizhе ◽  
A.B. Semergei-Chumachenko ◽  
El Hadri Youssef
Keyword(s):  
Wind Speed ◽  
Annual Variation ◽  
Atlantic Coast ◽  
Extreme Weather Events ◽  
Wind Regime ◽  
Mountain Areas ◽  
Average Wind Speed ◽  
Trade Winds ◽  
Weather Patterns ◽  
Average Wind

Information about wind is widely used in many sectors of the economy. Wind also causes many dangerous and extreme weather events. Modern climate changes require a certain revision of weather patterns previously accepted for the area. This article provides information on the current space and time distribution of wind characteristics within the territory of Morocco. During the period of 2005-2014 some monthly average wind speed values and data on repeatability of wind directions by gradations were obtained on the basis of physical and statistical analysis of results of observations of wind speed and directions performed at 26 stations. The authors defined the character of distribution of monthly averages of wind speed within the territory and its seasonal changes. Most of the territory is covered by mountains of Morocco which encourages development of local winds. At central and northern regions of Morocco predominance of weak winds due to complex orography of terrain is observed. In the central part of Morocco there is a region with the lowest values of wind speed. Formation of the wind regime at the coastal stations takes place in a developed breeze circulation. Wind speed and direction are significantly different at the nearby stations, such as Larache and Chefchaouen, Meknes and Fez. Increase of wind during the warmer half of a year was revealed at all stations. Nature of annual variation of average wind speed at the stations allows us to split the stations into two groups. The first group includes the stations where the average wind speed increases in summer and decreases in winter. The second group includes the stations where the average wind speed increases in spring and decreases in autumn. In the southern part and along the coast, where the terrain is flat, an increase of wind speed is observed. On open plains of the southern part of Atlantic coast during all seasons wind has a direction corresponding to direction of trade winds of the Northern hemisphere. It should be noted that the main factor forming air circulation within the territory of Morocco is represented by trade winds the intensity of which nearly doubles from summer to winter. Formation of wind directions at the stations takes place mainly under the influence of terrain of the area. At many stations predominant wind direction in January changes by 180º in comparison to the respective July values. Therefore, characteristics of the wind regime of Morocco in 2005-2014 consist in increase of wind speed in the coastal zone and decrease thereof in mountain areas together with presence of two types of annual variation of wind speed depending on physical and geographical conditions.

scholarly journals Wind Dynamic Environment and Wind Tunnel Simulation Experiment of Bridge Sand Damage in Xierong Section of Lhasa–Linzhi Railway

2020 ◽  
Vol 12 (14) ◽  
pp. 5689 ◽  
Author(s):  
Shengbo Xie ◽  
Jianjun Qu ◽  
Qingjie Han ◽  
Yingjun Pang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Prevention And Control ◽  
Simulation Experiment ◽  
Dynamic Environment ◽  
Windward Side ◽  
Sand Transport ◽  
Wind Tunnel Simulation ◽  
Drift Potential ◽  
And Control

The Lhasa–Linzhi Railway is located in the sandy area of the South Tibet valley, with high elevation and cold temperature. The Xierong section is a bridge section where blown sand hazards are severe. However, the disaster-causing mechanism of blown sand hazards in this section is currently unclear, thereby hindering targeted sand prevention and control. To address this problem, the wind dynamic environment of and causes of sand damage in this section are investigated through the field observation of the locale and a wind tunnel simulation experiment. Results show that the dominant sand-moving wind direction in the Xierong section is SSE. The wind speed, frequency of sand-moving wind, sand drift potential (DP), and maximum possible sand transport quantity (Q) in this section are relatively high during spring (March to May) and low during other seasons. The yearly resultant sand transport direction (RDD, RA) is SW. The angle between the route trend of this section and the sand transportation direction is 30°–45°, and the sand source is located in the east side of the railway. During spring, sand materials are blown up by the wind, forming blown sand flow and movement from the NE to SW direction. Increased wind speed area is formed between the top of the slope shoulder of the windward side of the bridge and the downwind direction of 3H, causing blown sand erosion. Meanwhile, weakened wind speed areas are formed within the distance of -3H at the upwind direction and from the downwind direction of the 3H to 20H of the bridge. These areas accumulate sand materials at the upwind and downwind directions of the bridge, thereby resulting in blown sand hazards. This research provides a scientific basis for the prevention and control of sand damage in the locale.

scholarly journals Effect of meteorological factors on the activity of influenza in Chongqing, China, 2012–2019

2020 ◽  
Author(s):  
Li Qi ◽  
Tian Liu ◽  
Yuan Gao ◽  
Dechao Tian ◽  
Qin Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Meteorological Factors ◽  
Meteorological Data ◽  
Warning System ◽  
Break Point ◽  
Influenza Surveillance ◽  
Average Wind Speed ◽  
Mean Temperature ◽  
Influenza Activity

Abstract Background: The effects of multiple meteorological factors on influenza activity remain unclear in Chongqing, the largest municipality in China. We aimed to fix this gap in this study.Methods: Weekly meteorological data and influenza surveillance data in Chongqing were collected from 2012 to 2019. Distributed lag nonlinear models (DLNMs) were conducted to estimate the effects of multiple meteorological factors on influenza activity.Results: Inverted J-shaped nonlinear associations between mean temperature, wind speed, sunshine and influenza activity were found. The relative risks (RRs) of influenza activity increased as weekly average mean temperature fell below 18.18℃, average wind speed fell below 1.55 m/s and average sunshine fell below 2.36 hours. Taking the median values as the references, lower temperature and windless could significantly increase the risks of influenza activity and last for 4 weeks. A J-shaped nonlinear association was observed between relative humidity and influenza activity; the risk of influenza activity increased with rising relative humidity with 78.26% as the break point. Taking the median value as the reference, high relative humidity could increase the risk of influenza activity and last for 3 weeks. In addition, we found the relationship between aggregate rainfall and influenza activity could be described with a U-shaped curve. Rainfall effect has significantly higher RR than rainless effect.Conclusions: Our study shows that multiple meteorological factors have strong associations with influenza activity in Chongqing, providing evidence for developing a meteorology-based early warning system for influenza to facilitate timely response to upsurge of influenza activity.

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