Mineral Dust Aerosols: Ecological and radiative impacts

矿物粉尘气溶胶：生态和辐射影响

• 批准号: RGPIN-2016-05417
• 负责人: King, James
• 金额: $ 1.82万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=655618
• 关键词: Mineral; Dust; Aerosols; Ecological; radiative

Mineral dust aerosols affect climate directly through the scattering and absorbing of shortwave and thermal radiation and currently account for the largest uncertainty in the radiative forcing within current global climate models. Terrestrial and marine ecosystems in arid regions rely on the atmospheric deposition of mineral aerosols as a result of wind erosion to provide essential soluble nutrients. Currently, mineral dust emission schemes used within global climate models are based on theoretical models parameterized and corrected with highly idealized laboratory results. This simplification leads to simulated emissions that poorly represent actual transported size distributions and therefore mineral dust production and deposition rates. Although mass conservation is maintained in the models, biased rates of flux occur for minerals and nutrients from the source material, resulting in poor estimates of the biological impact of wind erosion. The proposed research program seeks to provide a new approach to the dynamic wind erosion process for measuring and quantifying mineral dust emissions. The program consists of two complementary methodological approaches to establish the role and impact of mineral dust size and chemical distributions throughout the transport process. First, it will evaluate the change in particle size distribution and associated mineralogy of particles as a result from the transport process through a series of laboratory wind tunnel investigations with natural and fabricated soils. These proposed investigations will seek to quantify the enrichment of nutrients in the transportation process to estimate the differences in the radiative and biological properties of mineral aerosols from their parent soils. Secondly, a novel methodology to measure dust emission fluxes is proposed using eddy covariance to provide more reliable estimates over traditional time-averaged methods. A series of comparative field studies in Namibia will utilize these different approaches over a range of surfaces to provide the first such set of this data. The chosen field sites are situated in regions that are directly impacted by the fertilizing component of mineral dust they receive. These results will be tested against current dust emission flux models to improve the performance of existing models and redefine standard procedures for measuring mineral dust emissions. This proposed research program will increase the ability for forecasting dust storms and their impacts on society and the natural environment. This new research will also improve the ability to predict the timing and severity of visibility and associated transport hazard systems within Canadian prairies and other arid zones.**

矿物灰尘气溶胶通过短波和热辐射的散射和吸收直接影响气候，目前是当前全球气候模型中辐射强迫中最大的不确定性。干旱地区的陆地和海洋生态系统依赖于矿物质气溶胶的大气沉积，这是风侵蚀的结果，以提供必需的可溶性营养素。当前，全球气候模型中使用的矿物灰尘发射方案基于理论模型参数化并通过高度理想化的实验室结果进行校正。这种简化导致模拟排放，这些排放代表实际的运输尺寸分布，因此矿物灰尘的产生和沉积速率。尽管模型中维持质量保护，但矿物质和源源材料的养分发生了偏见的通量率，导致对风侵蚀的生物学影响的估计不良。拟议的研究计划旨在为测量和量化矿物灰尘排放的动态风侵蚀过程提供新的方法。该计划包括两种补充方法学方法，以确定整个运输过程中矿物灰尘大小和化学分布的作用和影响。首先，它将评估粒度分布的变化以及颗粒的相关矿物学的变化，这是由于运输过程所致的一系列实验室风隧道调查，该隧道与天然和制造的土壤进行了研究。这些拟议的研究将旨在量化在运输过程中养分的富集，以估计矿物气溶胶与父母土壤的辐射和生物学特性的差异。其次，提出了一种使用涡流协方差来测量粉尘发射通量的新方法，以提供对传统时间平均方法的更可靠的估计。纳米比亚的一系列比较现场研究将在一系列表面上利用这些不同的方法来提供第一组此类数据。所选的现场位置位于受其收到的矿物灰尘的受精成分直接影响的区域。这些结果将针对当前的尘埃发射通量模型进行测试，以改善现有模型的性能，并重新定义测量矿物灰尘排放的标准程序。该建议的研究计划将提高预测沙尘暴及其对社会和自然环境的影响的能力。这项新的研究还将提高预测加拿大大草原和其他干旱地区可见度和相关运输危险系统的时间和严重性的能力。**