Turbulent flow structures over a gobi surface and their impact on aeolian sand transport
Description
This dataset was designed to examine the behavior of turbulent flow structures over gobi surfaces and the impact of these structures on the sand transport rate. Synchronous high-frequency measurements of two time series of 3-D wind speed (20Hz) and saltating particle count rate (1Hz) over a gobi surface (39°8.062´N, 88°59.967´E) in two transport events (10:00 to 16:49 on May 4, 2018, and 18:30-20:19 on May 7, 2018) have been presented. Wind velocity was measured by a RM Young 81000 Ultrasonic anemometer, situated at the height of 0.7 m above the gobi surface at a time interval of 0.05 s, recorded by a Campbell CR 1000 datalogger. The profile of saltating grain number was measured by a vertical array of five piezoelectric impact sensors (H11-LIN, Sensit) at heights of 0.05, 0.12, 0.38, 0.8 and 1.38 m above the gobi surface with a measurement frequency of 1 Hz, also recorded by a Campbell CR 1000 datalogger. The piezoelectric impact sensors at heights of 0.12, 0.8 and 1.38 m were in a vertical profile, while due to the bulk limitation sensors, the piezoelectric impact sensors at heights of 0.05 and 0.38 m were 0.34 m and 0.24 m horizontally apart, respectively, from the vertical array of the other three sensors. The vertical array of the piezoelectric impact sensors was located 0.53 m in the spanwise direction from the anemometer to minimize their influence on airflow. Aeolian saltation flux profiles over gobi were measured by a vertical array of BSNE sand traps deployed at heights of 0.025, 0.175, 0.285, 0.585, 1.155, 1.785 and 3.000 m (midpoints of the trap inlet). A sand trap at the height of 0.275 m was separated 1.22 m horizontally from the left array to decrease the bulk effect of the sand traps from each other as rotating, while the sand trap at 0.025 m was put between the 0.275-m high sand trap and the vertical array and set flush with the gobi surface to measure the saltation flux on the surface, yet it could not rotate. Sand transport rate at 1 Hz can be obtained based on high-frequency time series of Sensit particle counts and low-frequency flux measurements of BSNE traps.