气候变化领域集成服务门户(CCPortal): The effect of wind speed averaging time on the calculation of sand drift potential: New scaling laws

CCPortal

DOI	10.1016/j.epsl.2020.116373
	The effect of wind speed averaging time on the calculation of sand drift potential: New scaling laws
	Yizhaq H.; Xu Z.; Ashkenazy Y.
发表日期	2020
ISSN	0012821X
卷号	544
英文摘要	Drift potential (DP) is a key factor used to quantify aeolian sand transport, and it is often used for predicting wind erosion and dune mobility under climate change scenarios. It is proportional to the mean of the cube of the wind speed at a 10-m height when that wind speed is above 6.2 m/s (12 knots), a speed threshold above which sand can be transported by the wind. DP depends on the temporal resolution and the averaging time of the wind velocity measurements. Usually, either a 10-min or 1-h mean wind speed is used to calculate the DP, although different studies have used different averaging periods for calculating the mean wind speed and, consequently, the DP. Here, we perform a comprehensive analysis of an extensive, long-term wind speed database from different locations around the world and from reanalysis data sources, and show that DP decreases with the averaging time of the wind speed. The decrease of DP versus the averaging time interval can be approximated by a stretched exponential function. In addition, the relative decrease of DP, as a function of the maximum DP, is smaller for high wind speed sites. This result is a consequence of the fact that high DP sites are characterized by longer clusters of successive wind speed events above the threshold velocity; they are thus less affected by the time averaging process. Interestingly, the clusters' lengths decay exponentially with wind speed and faster for low DP sites. Our new results have important implications for calculating the effective DP and for better estimating the biases that result from using wind data with different averaging times, which is a common problem in aeolian research. We also found an approximate linear relation between DP and the wind power that is close to the analytic approximation for the relation between the two. This new finding has many important applications since it will allow one to calculate DP from wind power data and vice versa. In addition, it implies that the same scaling laws found for DP also exist for the wind power. © 2020 Elsevier B.V.
关键词	averaging time drift potential reanalysis data stretched exponential Weibull distribution wind power
英文关键词	Climate change; Exponential functions; Speed; Wind power; Analytic approximation; Climate change scenarios; Comprehensive analysis; Mean wind speed; Stretched exponential functions; Temporal resolution; Threshold velocity; Wind velocity measurement; Wind; database; drift behavior; eolian process; sand; temporal variation; wind forcing; wind velocity
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202990
作者单位	Department of Solar Energy and Environmental Physics, BIDR, Ben-Gurion University, Midreshet Ben-Gurion, Israel; School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
推荐引用方式 GB/T 7714	Yizhaq H.,Xu Z.,Ashkenazy Y.. The effect of wind speed averaging time on the calculation of sand drift potential: New scaling laws[J],2020,544.
APA	Yizhaq H.,Xu Z.,&Ashkenazy Y..(2020).The effect of wind speed averaging time on the calculation of sand drift potential: New scaling laws.Earth and Planetary Science Letters,544.
MLA	Yizhaq H.,et al."The effect of wind speed averaging time on the calculation of sand drift potential: New scaling laws".Earth and Planetary Science Letters 544(2020).