More Like this

1. Geochemical Composition of Aeolian Dust and Surface Deposits from the Qatar Peninsula

   Yigiterhan, Oguz; Turner, Jesse; Al-Ansari, Ebrahim; Murray, James (January 2018, Chemical geology)

   The trace metal geochemistry of atmospheric dust and terrestrial surface particles were studied on the Qatar Peninsula from February 2014 to November 2015. We included samples of the mega dust-storm event on 01–02 April 2015. Atmospheric dust samples were collected using passive dust traps. Terrestrial surface deposits of recent dust accumulation and traffic particulate from roads were also sampled. All samples were total acid digested and analyzed for major and trace elements using ICP-OES analyzer. The concentration of thirteen elements (Ca, Mg, Ag, As, Cd, Cr, Cu, Mo, Ni, Se, Sn, Sr, Zn) were enriched in atmospheric dust samples, relative to upper continental crust (UCC). Calcium was especially enriched by up to 435% relative to UCC. About 33% of the total sample mass was CaCO3, reflecting the composition of surface rocks and soils in the source areas. Of the elements typically associated with anthropogenic activity, Ag, Ni, and Zn were most enriched relative to UCC, with enrichment factors (EF) of 182%, 233%, and 209%, respectively. Other metals, which normally reflect anthropogenic sources, including Pb and V, were not significantly enriched, with enrichment factors of 25% and 3%, respectively. Major elements (Al, Mn, Fe) were depleted (− 58%, − 35%, and − 5%, respectively) relative to UCC due to the large dilution effect of the enrichment of CaCO3. Back trajectories were determined at the date of sampling for each sample using the NOAA HYSPLIT model. These showed that the source of the dust particles was almost equally divided between northerly and southerly sources, except one sample, which appeared to originate from the west. More variability in particle source locations were observed during the winter months (October to March). Samples from the mega-dust storm were solubilized using an acetic acid-hydroxylamine hydrochloride leach procedure to obtain an upper estimate of the potential contribution of bioactive elements to surface seawater. The leach procedure solubilized a significant fraction of almost all elements. Ca was the element most affected (81% removed) because of the carbonate minerals present. Bioactive elements like Fe (25%) and P (58%) were also significantly solubilized. Because river input is so small to the Arabian Gulf, this solubilized fraction of dust is likely a major source of nutrients to surface seawater. Enrichment factors were also calculated with respect to the average composition of terrestrial surface deposits (TSD). Samples are not enriched significantly with respect to major components (EF < 2), with a depletion in Ca, K, Na in dust storm samples, reflecting a different origin. A significant enrichment of the same trace metals is evident in dust deposits and in traffic samples, but not in dust storms: Cu, Mo, Ni, Zn, possibly deriving from local atmospheric sources (traffic, industries). Samples with northern and southern origins were compared to see if the composition could be used to identify source. Only three elements were observed to be statistically different. Pb and Na were higher in samples from the south, while Cr was higher in those from the north. 

   more » « less
2. Aeolian Dust Preserved in the Guliya Ice Cap (Northwestern Tibet): A Promising Paleo-Environmental Messenger

   https://doi.org/10.3390/geosciences12100366  

   Beaudon, Emilie; Sheets, Julia M.; Martin, Ellen; Sierra-Hernández, M. Roxana; Mosley-Thompson, Ellen; Thompson, Lonnie G. (October 2022, Geosciences)

   Asian aeolian dust is a primary factor in Northern Hemisphere atmospheric dynamics. Predicting past and future changes in atmospheric circulation patterns relies in part on sound knowledge of Central Asian dust properties and the dust cycle. Unfortunately for that region, data are too sparse to constrain the variation in dust composition over time. Here, we evaluate the potential of a Tibetan ice core to provide a comprehensive paleo-atmospheric dust record and thereby reduce uncertainties regarding mineral aerosols’ feedback on the climate system. We present the first datasets of the mineralogical, geochemical, and Sr-Nd isotope composition of aeolian dust preserved in pre-Holocene layers of two ice cores from the Guliya ice cap (Kunlun Mountains). The composition of samples from the Summit (GS; 6710 m a.s.l.) and Plateau (GP; 6200 m a.s.l.) cores reveals that the characteristics of the dust in the cores’ deepest ice layers are significantly different. The deepest GS layers reveal isotopic values that correspond to aeolian particles from the Taklimakan desert, contain a mix of fine and coarse grains, and include weathering-sensitive material suggestive of a dry climate at the source. The deep GP layers primarily consist of unusual nodules of well size-sorted grey clay enriched in weathering-resistant minerals and elements typically found in geothermal waters, suggesting that the dust preserved in the oldest GP layers originates from a wet and possibly anoxic source. The variability of the dust composition highlighted here attests to its relevance as a paleo-environmental messenger and warrants further exploration of the particularly heterogenous Guliya glacial dust archive. 

   more » « less
3. Geochemistry of aeolian material from the McMurdo Dry Valleys, Antarctica: Insights into Southern Hemisphere dust sources

   https://doi.org/10.1016/j.epsl.2020.116460  

   Diaz, Melisa A.; Welch, Susan A.; Sheets, Julie M.; Welch, Kathleen A.; Khan, Alia L.; Adams, Byron J.; McKnight, Diane M.; Cary, S. Craig; Lyons, W. Berry (October 2020, Earth and Planetary Science Letters)

   null (Ed.)
4. Aeolian dust weights sampled by BSNE collectors quarterly from the CSIS study at Jornada Basin LTER, 2012-ongoing

   https://doi.org/10.6073/pasta/963467c3263e286f049c4a9449446279  

   Okin, Gregory S; Peters, Debra C (January 2023, Environmental Data Initiative)

   This dataset contains weights of windblown dust collected by BSNE collectors at long-term observation plots that are part of the Jornada Basin LTER Cross-Scale Interaction Study (CSIS) located at the Jornada Experimental Range. There are 15 experimental blocks (or sites) in this study. Within each block, there are 4 plots with different experimental treatments: 1 control, 1 with mesquite herbicide applied, 1 with connectivity modifiers (Conmods) installed, and 1 with Conmods AND mesquite herbicide applied. The intent of Conmods is to decrease gap size between perennial vegetation. The plots are 8 x 8 meters and have an 8 x 8 meter buffer zone on both the upwind and downwind sides of the plot. There are two BSNE (aeolian dust collector) stands per experimental plot positioned at the edge of the upwind and downwind 8m x 8m buffers. Each stand has 3 collectors positioned at heights of 10 cm, 30 cm, and 50 cm, and all collector openings face the prevailing wind direction. Upwind BSNEs collected the amount of dust entering the plot, and the downwind BSNEs collected the amount of dust moving off the plot. These collectors estimate the effectiveness of the plot surface in obstructing wind blown dust. This study is ongoing with data collected quarterly each year. 

   more » « less
5. Deconstructing aeolian landscapes

   https://doi.org/10.1016/j.catena.2018.11.038  

   Barrineau, Patrick; Dobreva, Iliyana; Bishop, Michael P.; Houser, Chris; Forman, Steven L. (March 2019, CATENA)