Capturing dust deposition in the west
Our lab has developed and tested a new method for dry deposition sampling of particulate aerosols. We have partnered with the National Atmospheric Deposition Program (NADP) to measure the flux of dry deposited materials to remote ecosystems across the Western United States. Our lab has been monitoring dust deposition to approximately 30 sites every month since 2017. The pilot phase of this project run by the EBPL will sadly come to a close in July of 2023. We hope a dry deposition network will become permanently established within the NADP.
This study to date has developed new knowledge of the deposition rate of atmospheric particulates to western ecosystems in the United States, their origin, composition, and freshwater ecosystem impacts. Notably, we have discovered that microplastics make up a nontrivial portion of atmospheric particulates, and that these microplastics can be transported to remote and pristine wilderness areas from both local sources, like nearby cities, or from distal locations, like other continents. The primary global source of microplastics to the atmosphere was identified was the ocean, while within continents, microplastics from road surfaces and agricultural practices were found to be the primary contributors. The research also demonstrated that particulate dust deposition contained bioavailable nutrients, heavy metals, tire wear particles, ash, pollen, plant and bug parts, soil, minerals, bacteria, fungi, and viruses. The composition of dusts varied both seasonally and regionally. The research primarily focussed on constituents that have the potential to influence ecosystems. Of note are the key limiting nutrients to terrestrial ecosystems, nitrogen and phosphorus. Both these nutrients have the potential to negatively impact freshwater and drinking water resources. Deposition rates of these nutrients varied significantly, with seasonal and location-dependent fluctuations spanning two orders of magnitude. To determine the influence of deposited dusts of freshwater biology, we conducted a series of experiments. Our results revealed that dusts can alter the freshwater communities present by both bringing in new nutrient resources as well as new organisms. In some experiments, dust additions led to the proliferation of undesirable algal species. Our findings provide compelling evidence that elevated dust deposition in recent decades is a likely cause of nutrient increases in remote lakes and their contribution to algal blooms. The project findings have been shared with a diverse group of people, including scientists, the general public, students, and lawmakers, through various means such as talks, podcasts, news articles, popular science books, textbooks, videos, and documentaries. The project has also created new learning materials, has been used in policy documents, and has spurred new avenues of research. This work is funded by the National Science Foundation and that Utah Agricultural Experiment Station |
Publications
**Brahney lab student/postdoc
*Student
Evangeliou, N., Tichy, O., Eckhardt, S., Zwaaftink, C.G., Brahney, J. (2022) Global emissions, transport and deposition of atmospheric microplastics revealed from Bayesian inverse modelling. Journal of Hazardous Materials
Brahney, J., Mahowald, N., φPrank, M., Cornwell, G., Klimont, Z., Matsui, H., Prather, K. (2021) Constraining the atmospheric limb of the plastic cycle, Proceedings of the National Academy of Sciences 118 (16) e2020719118
Brahney, J., **Hallerud, M., **Heim, E., Hahnenberger, M. Sukumaran, S. (2020) Plastic rain in Protected Areas of the United States. Science 10.1126/science.aaz5819 [IF:41.845 Cit:13 Altimetric: 1600 (99th perc.)]
Brahney, J., Wetherbee, G., Sexstone, G., Strong, P., Youngbull, C. (2020). A new sampler for the determination of dry deposition with the NADP network. Aeolian Research 45, 100600 [IF:3.345 Cit:1]
**Brahney lab student/postdoc
*Student
Evangeliou, N., Tichy, O., Eckhardt, S., Zwaaftink, C.G., Brahney, J. (2022) Global emissions, transport and deposition of atmospheric microplastics revealed from Bayesian inverse modelling. Journal of Hazardous Materials
Brahney, J., Mahowald, N., φPrank, M., Cornwell, G., Klimont, Z., Matsui, H., Prather, K. (2021) Constraining the atmospheric limb of the plastic cycle, Proceedings of the National Academy of Sciences 118 (16) e2020719118
Brahney, J., **Hallerud, M., **Heim, E., Hahnenberger, M. Sukumaran, S. (2020) Plastic rain in Protected Areas of the United States. Science 10.1126/science.aaz5819 [IF:41.845 Cit:13 Altimetric: 1600 (99th perc.)]
Brahney, J., Wetherbee, G., Sexstone, G., Strong, P., Youngbull, C. (2020). A new sampler for the determination of dry deposition with the NADP network. Aeolian Research 45, 100600 [IF:3.345 Cit:1]