Satellites reveal Earth's seasonally shifting dust emission sources

Reducing Resolution Dependency of Dust Emission Modeling Using Albedo‐Based Wind Friction

“…The amount of F cal for the year 2022, by region and by resolution is shown in Table 1 (uncalibrated F TEM are shown in Text S4 in Supporting Information ; Table S1 in Supporting Information ). At 0.5 km resolution, the total F cal is 19 Tg y −1 , broadly consistent with the recent global albedo‐based average (2001–2020) F cal and its uncertainty (29.1 ± 14.9 Tg y −1 ; Chappell, Web, Hennen, Schepanski, et al., 2023; Chappell, Webb, Hennen, Zender, et al., 2023). The amount estimated here is smaller than that recent estimate because we consider only the year 2022 and because the 278 km spatial restriction excludes coastal regions (Figure 2).…”

“…This scaling issue at least partially explains why there are several orders of magnitude difference in updated global F estimates (29–4,313 Tg y −1 up to 20 μm particle diameter (Chappell, Webb, Hennen, Schepanski, et al., 2023; Huneeus et al., 2011)). Ridley et al.…”

“…(2013) suggested that the fidelity of F modeling may benefit from better representation of these roughness and texture properties and consideration of their sub‐grid distribution. The arising hypothesis is therefore that compatibility between areal wind fields and areal u s * should improve the performance of F modeling across scales (Chappell, Webb, Hennen, Schepanski, et al., 2023).…”

Using Field Measurements Across Land Cover Types to Evaluate Albedo‐Based Wind Friction Velocity and Estimate Sediment Transport

“…Accurate estimation of the areal u s * / U h is a critical issue that large‐scale sediment transport and dust emission prediction studies have been endeavoring to address for more than 20 years since large scale aeolian transport models were first developed (Marticorena & Bergametti, 1995). The values of ω ns can be retrieved and applied at a range of scales, including wind tunnels, pyranometer‐based field measurements, and surface albedo data from satellites, thereby enabling the monitoring of spatial and temporal variations in u s * / U h at local, regional, and even global scales (Chappell, Webb, Hennen, Schepanski, et al., 2023; Hennen et al., 2022, 2023; Ziegler et al., 2020). Our results demonstrate the good performance of albedo‐based models across land surfaces and scales in comparison with field measurements at multiple investigation sites across a large area of northern China, thereby providing support for the parameterization of sediment transport and dust emission models.…”

“…(2020) demonstrated the scale invariance of this approach at the field (plot) scale. This scale invariance has been assumed to hold over large areas when the albedo‐based approach has been applied to dust emission studies in North America (Hennen et al., 2022, 2023) and globally (Chappell, Webb, Hennen, Schepanski, et al., 2023). Considering the existence of multiple, very different, roughness element types, such as plants and gravel, and different spatial combinations (density variation, non‐homogeneous spatial distribution) in arid and semi‐arid landscapes, it is necessary to further evaluate the applicability of this new approach based on albedo across a representative range of cover types.…”