Contemporary and future dust sources and emission fluxes from gypsum- and quartz-dominated eolian systems, New Mexico and Texas, USA
Contemporary and future dust sources and emission fluxes from gypsum- and quartz-dominated eolian systems, New Mexico and Texas, USA
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美国新墨西哥州和德克萨斯州以石膏和石英为主的风成系统的当代和未来灰尘源和排放通量
DOI：
10.1130/g49488.1
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发表时间：
2021
期刊：
影响因子：
5.8
通讯作者：
McDonald, Eric V.
中科院分区：
文献类型：
--
作者：
Sweeney, Mark R.;Forman, Steven L.;McDonald, Eric V.
最近关于风成沙丘粉尘排放的研究旨在改善区域和全球排放量估计和粉尘来源的知识，特别是在气候变化的情况下。当考虑到由活动沙丘到稳定沙丘、沙丘间、沙层和干盐湖组成的整个风成系统时，沙丘场的粉尘排放量可以更准确地估计。每种地貌都可以排放不同浓度的灰尘，这取决于淤泥和粘土的供应、土壤表面特性以及地貌的动态和相互作用程度。我们使用便携式原位风蚀实验室（PI-SWERL）来测量两个端元风成系统中地貌的PM10（颗粒物<10 μm）粉尘排放潜力：新墨西哥州（美国）的白色沙滩沙丘场，由石膏组成，以及德克萨斯州西部的莫纳汉斯沙丘场，由石英组成。白色沙地是粉尘排放的热点，沙丘和邻近的干盐湖产生高达8.3 mg/m2/s的粉尘通量。相比之下，活跃的莫纳汉斯沙丘含有100%的沙子，并产生低粉尘通量高达0.5毫克/平方米/秒，而相邻的稳定的沙层和沙丘含有淤泥和粘土，如果重新激活气候变化或人为干扰，可产生高达17.7毫克/平方米/秒。这些发现对大平原到美国西南部的风沙系统目前和未来的粉尘排放潜力具有影响，未实现的排放量>300 t/km 2/yr。
Recent research on dust emissions from eolian dunes seeks to improve regional and global emissions estimates and knowledge of dust sources, particularly with a changing climate. Dust emissions from dune fields can be more accurately estimated when considering the whole eolian system composed of active to stabilized dunes, interdunes, sand sheets, and playas. Each landform can emit different concentrations of dust depending on the supply of silt and clay, soil surface characteristics, and the degree to which the landforms are dynamic and interact. We used the Portable In Situ Wind Erosion Laboratory (PI-SWERL) to measure PM10 (particulate matter <10 μm) dust emission potential from landforms in two end-member eolian systems: the White Sands dune field in New Mexico (USA), composed of gypsum, and the Monahans dune field in west Texas, composed of quartz. White Sands is a hotspot of dust emissions where dunes and the adjacent playa yield high dust fluxes up to 8.3 mg/m2/s. In contrast, the active Monahans dunes contain 100% sand and produce low dust fluxes up to 0.5 mg/m2/s, whereas adjacent stabilized sand sheets and dunes that contain silt and clay could produce up to 17.7 mg/m2/s if reactivated by climate change or anthropogenic disturbance. These findings have implications for present and future dust emission potential of eolian systems from the Great Plains to the southwestern United States, with unrealized emissions of >300 t/km2/yr.