Description
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Data distributed here are part of the data acquired during the 2 field campaigns that were carried out in springs 2017 and 2018 in south Tunisia during the WIND-O-V project (https://www6.inrae.fr/anr-windov/) funded by the ANR.
The distributed data document the characteristics of the 1) surface of the eroding field, 2) aerodynamic conditions (wind speed, stability of the surface boundary layer), 3) saltation flux (intensity and size-distribution), and 4) vertical dust flux (intensity and size-distribution) determined by the gradient method. The objective was to explore in depth and understand the links between all these parameters.
Data include: (1) minimally-dispersed soil size distribution: soil samples were dried at 105°C during 24h before to be slowly sieved on a column of 14 sieves (<50, 50-63, 63-80, 80-100, 100-125, 125-160, 160-200, 200-250, 250-300, 300-400, 400-500, 500-800, 800-1000, >1000 µm). The duration of sieving was 20 minutes and the intensity 40 on a Retsch AS200 vibratory sieve shaker. Each fraction was then weighted on an electronic balance (0.0001 g of precision). (2) saltation flux: they were measured using five sand traps, the design of which was adapted from the Big Spring Number Eight (BSNE) of Fryrear (1986). Each sand trap had an opening of 5 x 10 cm². They were mounted on a mast with their centers positioned at 5.5, 20.25, 36.45, 51.20, and 87.25 cm above ground level (agl). The mast was equipped with a large wind vane so that the opening of all sand traps always faced the wind. After accounting for the collection efficiency of the sand traps, the saltation flux was computed by vertical integration of the cumulative masses collected at the 5 heights using the exponential formula proposed by Williams (1964). (3) aerodynamic parameters (16-min. average): aerodynamic roughness length, and stability parameters were estimated from the wind and temperature profiles using the iterative procedure designed by Frangi and Richard (2000). Wind speed and air temperature vertical profiles were determined using respectively 7 cup anemometers (A100R Vector Instrument®) positioned at 0.22, 0.65, 1.33, 1.83, 3.01, 4.00, and 5.24 m agl, and 4 thermocouples (type T cupper/Constantan) positioned at 0.48, 1.66, 3.83, and 5.07 m agl on the same mast. (4) vertical dust flux intensity and size distribution (16-min. average) were determined by the gradient method. Dust concentrations were measured using two identical Optical Particle Counters (OPC) welas® (White Light Spectrometer 2300, PALAS), each equipped with an omnidirectional total suspended particles (TSP) sampling head (BGI by Mesa Labs, Butler, NJ USA) installed at 2.04 m and 4.10 m agl.
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