Saltation activity and its threshold velocity in the Gurbantunggut Desert, China

Yang, Xinghua; He, Qing; Liu, Xinchun; Yang, Fan; Huo, Wen; Shen, Shuanghe; Mamtimin, Ali

doi:10.1007/s11069-017-3047-4

Cited by 10 publications

(4 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We considered three measures of the wind: (i) wind drift potential (DP), which captures extreme wind activity and is used as a measure for potential sand transport over sand dunes, (ii) wind speed, and (iii) wind power, which is proportional to the cube of the wind speed. We mainly focus on the timing of the DP maximum and show that over land, especially over the dune regions, the wind peaks during the daytime, whereas it significantly weakens at night; these results are consistent with a recent study regarding the sand activity in the area of White Sands National Park in the US (Gunn et al, 2021) and with studies regarding sand and dust activity in the Taklimakan and Gurbantunggut Deserts (Yang et al, 2013(Yang et al, , 2018Zhou et al, 2019). We attributed the enhanced winds, over land and during the daytime, to the small heat capacity of the ground, which warms and cools quickly, resulting in convection during the daytime and inversion at night; this leads to active upper atmospheric levels that are disconnected from the surface at night, which eventually leads to weaker nighttime surface winds.…”

Section: Summary and Discussionsupporting

confidence: 90%

The diurnal cycle and temporal trends of surface winds

Ashkenazy,

Yizhaq

2022

Preprint

View full text Add to dashboard Cite

Winds play an essential role in the climate system. In this study, we analyze the global pattern of the diurnal cycle of surface (10 m) winds from the ERA5 reanalysis data. We find that over the land and especially over sand dune regions, the maximal wind speed and wind drift potential (DP) occur during the hours around midday. However, over the ocean, the wind also peaks at night. Using the sensible heat flux, we show that the weaker winds over land at night are due to a nocturnal cooling that decouples upper atmospheric levels and their associated stronger winds from the surface-nocturnal cooling is much smaller over the ocean. We also analyze wind data from more than 400 meteorological stations in the USA and find a similar diurnal trend as in the reanalysis data. The timing (during the day) of the maximum wind speed has not varied much over the past 70 years. Yet, the wind speed, wind power, and wind drift potential exhibit significant increases with time over the ocean and, to a much lesser degree, over the land and sand dune regions. We compare the USA DP and wind speed of the ERA5 to that of meteorological stations and find that the ERA5 significantly underestimates the real winds; however, the temporal patterns of the two are similar.

show abstract

Section: Summary and Discussionsupporting

confidence: 90%

The diurnal cycle and temporal trends of surface winds

Ashkenazy,

Yizhaq

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…These threshold values can vary due to multiple factors, such as atmospheric conditions and the characteristics of the soil surface. These factors include air temperature, humidity, soil particle size, moisture level, vegetation, and other conditions (X. Yang et al., 2018 and associated references). Given these variations, the threshold wind speed for saltation is inherently location‐specific.…”

Section: Resultsmentioning

confidence: 99%

“…This method has been proposed and utilized in previous studies, including those by Park and In (2003), Kurosaki and Mikami (2007), and X. Yang et al. (2018). The method is based on the following equation:

{f}_{\text{sal}\vert u}=\frac{{N}_{\text{sal}\vert u}}{{N}_{\text{all}\vert u}}\times 100\%

where f sal| u represents the percentage of saltation occurrence for each wind speed bin, N sal| u denotes the number of saltation occurrences within each wind speed bin, and N all| u is the total count for each wind speed bin.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

The Wind‐Blown Sand Experiment in the Empty Quarter Desert: Roughness Length and Saltation Characteristics

Nelli,

Francis,

Sow

et al. 2024

Earth and Space Science

View full text Add to dashboard Cite

The Empty Quarter Desert, one of Earth's major dust sources, frequently experiences dust storms due to wind erosion. Despite its significance as a primary dust source on a global scale, in‐situ observations from this region had not been reported until very recently. In summer 2022, the WInd‐blown Sand Experiment (WISE) Phase‐1 was initiated in the Empty Quarter Desert of the United Arab Emirates, and continued until 7 February 2023. Utilizing a diverse array of instruments, we measured winds, temperature, humidity, radiation fluxes, saltation, and the physical and optical properties of dust aerosols, atmospheric electric fields, and soil characteristics. A total of 38 distinct sand‐saltation events were recorded from September 2022 to February 2023, with activity peaking between 13:00 and 14:00 local time. Key findings include the identification of dominant wind patterns, and the measurement of the average aerodynamic roughness length (z0) at 0.8 ± 0.6 mm, and the thermal roughness length (zh) at 0.3 ± 0.5 mm—the first estimation of zh for this area. In‐situ observations revealed that dust particle concentrations near the surface increased 1.7‐fold on days with saltation compared to days without it. Moreover, we determined a wind‐speed threshold for initiating saltation at 7.70 m s−1. This comprehensive data set significantly advances our understanding of atmospheric‐soil interactions and sand movement dynamics, providing invaluable insights for ongoing research into desert environments and the global dust cycle.

show abstract