Aeolian sediment and dust fluxes during predominant %26quot;background%26quot; wind conditions for unburned and burned semiarid grassland: Interplay between particle size and temporal scale

作者：Merino Martin Luis^*; Field Jason P; Villegas Juan Camilo; Whicker Jeffrey J; Breshears David D; Law Darin J; Urgeghe Anna M

来源：Aeolian Research, 2014, 14: 97-103.

DOI：10.1016/j.aeolia.2014.02.004

• Wind erosion
• Dust measurement
• Particle size
• Aerosol
• Soil

Monitoring of aeolian transport is needed for assessment and management of human health risks as well as for soil resources. Human health risks are assessed based on duration of exposure as well as concentration. Many aeolian studies focus on periods of high wind speed when concentrations are greatest but few studies focus on %26quot;background%26quot; conditions when concentrations are likely lower but which represent the most prevalent conditions. Such %26quot;background%26quot; conditions might be especially important at sites with recent disturbance such as fire. Exposure assessments also require improved understanding relating longer-term (days to weeks) measurements of saltation of larger particles to shorter-term (minutes to hours) measurements of smaller inhalable dust particles. To address these issues, we employed three commonly used instruments for measuring dust emissions for unburned and recently-burned sites: Big Springs Number Eight (BSNE) samplers for larger saltating soil particles (%26gt;50 mu m) with weekly to monthly sampling resolution, DustTraks for suspended particles (diameters %26lt;10 mu m) with 1-s sampling resolution, and Total Suspended Particulate (TSP) filter samplers for measuring with hourly to daily sampling resolution. Significant differences in concentrations between burned and unburned sites were detectable in either short (1-s maximum) interval DustTrak PM10 measurements, or in longer term (weekly) BSNE horizontal sediment flux measurements, but not in intermediate-term (daily 5-h means) for either DustTrak PM10 or TSP measurements. The results highlight ongoing dust emissions during less windy periods and provide insight into the complex interplay among particle-size dependent measures and typical time scales measured.

• 出版日期2014-9
• 单位Los Alamos