Total deposition flux of insoluble atmospheric particles, Banizoumbou, Niger

Total deposition flux of insoluble atmospheric particles is collected with a passive collector of an inverted “Frisbee” shape (Hall and Waters, 1986; Hall and Upton, 1988), equipped with a flow deflector ring, as tested by Wiggs et al. (2002) and full with marbles to limit dust resuspension and rain splashing. The “Frisbee” collector is installed at 6.8 m height. The samples are collected manually with a weekly time-step. In case of rainfall during the rainy season, water and deposited particles are collected in a 5-litter bottle connected to the bottom of the sampler. The collection procedure is decomposed into three main phases: (1) rinsing with a large volume of water, (2) decantation during more than 6 hours and siphoning of excess water; (3) drying in an oven at 70°C until complete water evaporation. The collected dust is finally weighed in a pre-weighted pillbox with a balance having a precision of 0.0001 g. Total deposition flux of insoluble atmospheric particles is expressed as g/m² per sampling period and as g/m²/day by dividing the collected mass by surface of collection and sampling duration (dates of start and end of sampling are given in the data files in UTC). Fluxes are given after subtracting blanks; the blank value is given in the header of each file.

不溶性大气颗粒总沉积通量的采集采用倒置"飞盘"形被动采样器（passive collector），该采样器由Hall与Waters（1986）、Hall与Upton（1988）提出，并经Wiggs等（2002）验证，配备导流环（flow deflector ring），内部填充大理石以抑制粉尘再悬浮与雨水溅蚀。该飞盘形采样器安装于6.8米高度处。采样以周为时间间隔，采用人工方式完成。雨季降雨时，雨水与沉降颗粒物将被收集至连接采样器底部的5升储瓶中。样品前处理流程分为三个主要阶段：(1) 用大量清水冲洗采样器；(2) 静置沉降不少于6小时后，虹吸去除多余水分；(3) 置于70℃烘箱中烘干至水分完全蒸发。最终将收集得到的粉尘转移至已预称重的称量盒中，使用精度达0.0001 g的分析天平进行称重。不溶性大气颗粒总沉积通量的表达形式包括两种：以单采样周期内的克每平方米（g/m²）为单位，或通过将采集到的粉尘质量除以采样面积与采样时长，换算为克每平方米每天（g/m²/d）（采样起止时间以协调世界时（UTC）标注于各数据文件内）。所有通量值均已扣除空白对照值，空白对照值标注于各数据文件的表头中。