Characterization of surface dust emission potential using a pi swerl
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The document describes the Portable In-Situ Wind Erosion Laboratory (PI-SWERL), which measures dust emission potential from natural surfaces. PI-SWERL has been used at the Engineer Research and Development Center (ERDC) for various applications, including characterizing dust emission by landform type, assessing mitigation techniques, and developing a geomorphic-based dust erodibility parameterization for numerical modeling. The document suggests PI-SWERL could help the Natural Resources Conservation Service estimate soil erodibility under different conditions, produce erodibility maps for management, and support assessments over large areas.
Characterization of surface dust emission potential using a pi swerl
- 1. Characterization of surface dust emission potential using a Portable In- Situ Wind Erosion Laboratory (PI- SWERL) for numerical modeling applications Nancy Parker US Army Corps of Engineers Engineer Research and Development Center 1 August 2018 Nancy.E.Parker@usace.army.mil
- 2. PI-SWERL • Portable In Situ Wind Erosion Lab • Measures PM-10 dust emission potential from natural surfaces • Turn-key device, easy to move, minimal setup, operated by one person Figure 1: Portable In Situ Wind Erosion Lab (PI-SWERL). Image by Desert Research Institute Etyemezian et al.: The Portable In Situ Wind Erosion Laboratory (PI-SWERL): A new method to measure PM10 windblown dust properties and potential for emissions, Atmos. Environ., 41:3789-3796, 2007 Sweeney et al.: Comparison of PI-SWERL with dust emission measurements from a straight-line field wind tunnel, J. Geophys. Res., 113, F01012, 2008.
- 3. PI-SWERL Figure 2: PI-SWERL fan. Image by Desert Research Institute • Open-bottomed chamber with a metal, annular ring that spins ~2.5 in above and parallel to the soil surface • Generates wind shear • Lofted soil and dust particles pass through particulate monitors • Measures the number and size of entrained particles over test cycle.
- 4. PI-SWERL at ERDC Figure 3: Karen Foley collecting PI-SWERL (portable wind shear chamber) samples in the Sonoran Desert. • Mini Pi-SWERL (30 cm diameter) • Can use either DustTrak II 8530 or DustTrak DRX 8533 • Size-resolved dust concentrations
- 5. General Use • Dust emission potential of real world surfaces • Roads • Fields • Training grounds • Assessment of dust mitigation techniques and palliatives
- 6. MODEL RS/GIS FIELD LAB Enhance dust transport modeling capabilities through development of a geomorphic-based, scale-aware dust erodibility parameterization. Generate observational database of spatial and temporal occurrence of dust emission in the southwest US and Mexico. Establish relationships of soil strength and dust emission potential, to geomorphic landform type and age. Small- and large- scale facility lab research to better understand environmental factors that affect soil strength and dust emission. ERDC Dynamic Undisturbed Soils Testbed (DUST) RELATING DUST AND SOIL STRENGTH to GEOMORPHIC TRAITS for DVE and MOBILITY via…
- 7. Figure 4: Indoor macroscale playa-like surface testbed. Engineered Surfaces Bigl, M. F., LeGrand, S. L., Beal, S. A., Sopher, A., and Ringelberg, D. B.: Macro-scale salt crust formation on indoor playa-like test plots for dust emission research applications: Methodology assessment, ERDC/CRREL TR-XX- DRAFT, U.S. Army Engineer Research and Development Center, Hanover, New Hampshire, USA, in review. • Generate indoor, macroscale playa- like soil plots using climate control and brackish water delivery mechanisms • PI-SWERL used to compare soil surface traits to real world analogs
- 8. Figure 5: Biplot of the first two principal components of soil compositional variables and PM10 flux Erodible Material Composition Beal, S. A., Sweeney, M. R., McDonald, E. V., and LeGrand, S. L.: Soil compositional influences on dust emission across landform types in the Sonoran Desert, USA, Aeolian Res., in review. • Influence of soil composition on dust emission by landform type • PI-SWERL used to quantify dust emission potential of different landforms • Measured soil composition variables do not explain the majority of observed variability
- 9. Figure 6: SEM image of fungal hyphae stabilizing soil particles. Erodible Material Biome Barbato, R. A., Jones., R. M., Doherty, S. L., Fisher, A. R., Foley, K. L., McDonald, E. V., and LeGrand, S. L.: Patterns in microbial community structure are influenced by geomorphic landform type in the Southwest USA, in prep. • Microbial dust hitchhikers by landform type • PI-SWERL used to quantify erosion potential of sampling sites • Found patterns in dominant bacteria taxa in select landform types
- 10. Numerical Modeling • ERDC-Geo Scheme • Scale-aware, geomorphic soil erodibility parameterization • Spatially-varying dust emission flux multiplier designed to work with most physics-based dust emission schemes. Figure 7: Erodibility multiplier for a WRF- Chem AFWA-GOCART domain along the AFG/Iran boarder.
- 11. Numerical Modeling Figure 8: 1:750K scale geomorphic landform map for Southwest Asia • PI-SWERL used to create landform-based dust emission potential look- up tables. • Ratio of physically modeled to analog-based dust emission potential used to generate spatially varying multiplier. LeGrand, S. L.: A geomorphic, scale-aware approach to erodible material parameterization in dust transport models, in prep.
- 12. Summary • PI-SWERL is a turn-key device, easy to set up and use • Measures PM-10 dust emission potential from natural surfaces • PI-SWERL can be used to • Measure dust emission potential, and • Assess dust mitigation techniques • Currently used in many applications at ERDC including large-scale testbed work, landform characterization, and numerical modeling
- 13. Applications for the NRCS • PI-SWERL used to estimate in situ erodibility of soils under different disturbance conditions • Produce maps of soil erodibility that can be used in management, and wind erosion and dust emission modeling • PI-SWERL can provide robust sampling to support assessments of erodibility over large areas
- 14. Questions ?
Editor's Notes
- #3: Originally developed by DRI and used by several agencies and universities – we know of at least 17 in the world that exist Quick way to measure PM-10 from real world surfaces Particulate matter size 10 and smaller Literally just turn it on, easy to move Almost an order of magnitude more measurements than if you used a traditional wind tunnel
- #4: Typical test cycle lasts about 10 minutes Optical gates are inside the chamber so that you can monitor saltation activity
- #5: We have #17 Ours is a mini pi-swerl – 30 cm opening at the bottom, previous generations are larger Ours is special because it can use 2 different DustTrak – the DustTrak DRX can look at multiple size bins (particle size) all at once (MODIFIED for this dual capability)
- #6: What do people use it for? Assessing dust emission potential – natural hazard conditions Dust mitigation techniques – stuff you’re trying to stop
- #7: We have a large multidisciplinary group at ERDC Deterministic product for characterizing soil erodibility Product validation and uncertainty characterization Activities to better understand physical processes controlling variability From Jimmy: To determine the uncertainty needed to optimize operational risk management decision support tools.
- #8: Large scale testbed Avoid having to do costly fieldwork in remote areas Reduce costs and be more efficient before we do our large scale field testing Compare engineered soil traits to real world analogues
- #9: We’ve been looking at whether or not we can describe the influence of soil composition on dust emission by landform type Pi-Swerl used to quantify dust emission potential of landforms IN THE FIELD PCA shows there is no real correlation between PM-10 dust emission flux and soil composition by landform
- #10: Looking at ways that you can look at microbial dust hitchhikers and relate them to landform Pi-Swerl used to quantify erosion potential of fieldwork sites Where did the dust come from?
- #11: New name ERDC-Geo Scheme Scale-aware meaning that it accounts for how good your information is Additional information about how loose your soil is that most dust emission schemes don’t have Most physical dust emission schemes say dust blew, assume based on your psd, this much stuff was knocked loose This gives you an estimate based on geomorphic landform characteristics (e.g. how tightly the particles are bound) BLEND of physics of the model and real-world analogues In theory, as we improve our model physics over time, the need for this will go away
- #12: Landform map and dust-emission potential field measurements (Pi-SWERL) Apply spatially varying multiplier to your simulated dust emission flux (model)
- #14: Insert comments Nick mentioned on sampling