address the need for a long-term research program to meet critical challenges in wind erosion research 8 and management in the United States. The Network has three aims: (1) provide data to support 9 understanding of basic aeolian processes across land use types, land cover types, and management practices, (2) support development and application of models to assess wind erosion and dust emission and their impacts on human and environmental systems, and (3) encourage collaboration among the aeolian research community and resource managers for the transfer of wind erosion technologies. The Network currently consists of thirteen intensively instrumented sites providing measurements of aeolian sediment transport rates, meteorological conditions, and soil and vegetation properties that influence wind erosion. Network sites are located across rangelands, croplands, and deserts of the western US. In support of Network activities, http://winderosionnetwork.org was developed as a portal for information about the Network, providing site descriptions, measurement protocols, and data visualization tools to facilitate collaboration with scientists and managers interested in the Network and accessing Network products.The Network provides a mechanism for engaging national and international partners in a wind erosion research program that addresses the need for improved understanding and prediction of aeolian processes across complex and diverse land use types and management practices.

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Controls on the particle size distribution (PSD) of mineral dust emissions remain poorly understood. Under near‐idealized conditions, dust PSDs can appear invariant with wind friction velocity. However, dryland vegetation attenuates surface friction velocities, and soil crusting reduces the supply of loose erodible material and increases surface resistance to abrasion. Under such conditions, variability in saltation bombardment efficiency and intensity could have a large effect on dust PSDs. We present dust emission measurements from vegetated, supply‐limited aeolian systems that indicate the dependence of emission‐flux PSD on wind friction velocity. We find the fine fraction (<5 μm) of dust particles increases with friction velocity. Results suggest models that assume wind‐invariance of the emission‐flux PSD may not be generalizable for crusted soils with vegetation. There is a need for dust models to represent variability in emission‐flux PSDs for land management, air quality, and climate applications across vegetated and sediment supply‐limited drylands.

To reduce endosulfan (C9H6O3Cl6S; 6,7,8,9,10,10-hexachloro-1,5, 5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide) contamination in rivers and waterways, it is important to know the relative significances of airborne transport pathways (including spray drift, vapor transport, and dust transport) and waterborne transport pathways (including overland and stream runoff). This work uses an integrated modeling approach to assess the absolute and relative contributions of these pathways to riverine endosulfan concentrations. The modeling framework involves two parts: a set of simple models for each transport pathway, and a model for the physical and chemical processes acting on endosulfan in river water. An averaging process is used to calculate the effects of transport pathways at the regional scale. The results show that spray drift, vapor transport, and runoff are all significant pathways. Dust transport is found to be insignificant. Spray drift and vapor transport both contribute low-level but nearly continuous inputs to the riverine endosulfan load during spraying season in a large cotton (Gossypium hirsutum L.)-growing area, whereas runoff provides occasional but higher inputs. These findings are supported by broad agreement between model predictions and observed typical riverine endosulfan concentrations in two rivers.

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