Meteorological conditions during dust (PM10) emission from a tilled loam soil: Identifying variables and thresholds

摘要

Highlights ? Relationships between weather variables and FVPM10 were analyzed on a loam soil. ? Maximum wind speed and air humidity conditioned more significantly the FVPM10. ? Were estimated threshold values of weather variables for FVPM10. ? Crusting and surface aggregate size distribution influenced PM10 emission process. ? Weather and soil surface conditions interaction produces high variability of FVPM10. Abstract Soil wind erosion and consequent PM10 emission is a complex process that has been related to surface properties and meteorological conditions. Most of the studies have emphasized on the relationship between the surface conditions and the dust emission, in general on deserts and dry lakes or playas. Little is known about the influence of meteorological variables on PM10 emission from agricultural soils. The objective of this study was to identify the most important meteorological variables involved in the emission of PM10, identify their threshold values, and to analyze their interaction with the soil surface conditions. Measurements were made on a loam soil (Entic Haplustoll) in the semiarid Argentinian Pampa. Horizontal mass transport (Q) and PM10 emission were measured during two years on a bare and flat surface that was tilled periodically. The meteorological variables measured were: average and maximum wind speed, wind direction, air temperature, relative humidity and soil temperature. In 30% of the events, the PM10 concentration at 1.8m height exceeded the average values allowed by the World Health Organization (50μgm?3 for a 24h period). Maximum values exceeded 1000μgm?3. The slope of the PM10 concentration gradient changed between spring ? summer and autumn ? winter peri