An updated Irwin sensor for measurement of surface shear velocity

• Spatial patterns of surface wind shear velocity ( u s *) drive aeolian processes. • New Irwin sensors make measuring u s * practical in the field. • Robust sensor calibration is demonstrated using wind tunnel and PI-SWERL data. • Wireless Irwin sensors reduce deployment workload and enable areal u s * measurement. • Sensor improvements expand opportunities to parameterize new aeolian models. Accurate and efficient collection of field data related to aeolian processes is critical for improving wind erosion predictions and related management decisions. The Irwin sensor ( Irwin, 1981 ) has been used in numerous wind tunnel and field studies to indicate surface shear velocity. However, the sensitivity of the sensor makes them difficult to maintain in a range of environmental conditions (e.g., moisture/high sand flux). This study presents a new generation of Irwin sensor incorporating updated electronics, battery operation, wireless data transmission, and streamlined field deployment and removal. A total of 20 sensors were manufactured and calibrated in a wind tunnel at the Engineer Research and Development Center (ERDC). A subset of the sensors was calibrated using a PI-SWERL, which confirmed the two calibration methods converge on similar values for flat smooth test surfaces. The updated sensors were installed around a mesquite shrub at the Jornada Experimental Range, New Mexico, USA from February to July 2023. We found that initial data from the sensors accurately captured spatial patterns of surface shear velocity surrounding the shrub. The improvements to the sensor reduced workload for both deployment and maintenance, and reduced disturbance at the field site. We discuss potential opportunities to use the improved sensor network in a range of geomorphological research areas including quantifying aeolian sediment transport, building and parameterizing wind erosion models that incorporate spatial dependencies, and improving predictive tools for landform change.