Atacama Desert Dust Emission Research (ADDER): Resolving aeolian dust source dynamics

阿塔卡马沙漠粉尘排放研究 (ADDER)：解决风沙源动态

• 批准号: NE/X002896/1
• 负责人: Joanna Nield
• 金额: $ 10.61万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX002896%2F1
• 关键词: Atacama; Desert; Dust; Emission; Research

Understanding when, where, and how windblown dust is emitted from deserts is important because dust can be detrimental to human health, can pollute downwind environmental systems, and, when airborne, can influence climate. Desert dust can also be rich in iron and other nutrients so when it falls into oceans downwind of its desert source, it can stimulate the productivity of marine biota in the surface waters. The impact of this is especially important in certain sensitive coastal areas where the mixing of cold water occurs close to the shore, such as at the Atacama and Namib Desert coastlines. These coastal waters can be particularly receptive to the nutrients that deposited dust might be providing.The UK Team have undertaken research on windblown dust in southern African deserts for many years. Our approach has been to use satellite observations to identify the sources of dust in different areas of the desert landscape, and then install state-of-the-art monitoring and survey equipment in these 'hot-spots' of dust emission to measure the wind and surface characteristics that control how and when dust is eroded by the wind. Our data have allowed improvements to be made in models of windblown dust emission into the atmosphere, and have also shown the significance of deposited dust in the fertilisation of the South Atlantic Ocean.The Atacama Desert is similar in many interesting respects to the Namib Desert in southern Africa. Both deserts are located on continental west coasts, fringed by cold ocean currents to the west and steep topography to the east. They have similar types of landscapes with a mix of dry river valleys, stony plains, and salty dry lakes. In the Namib, such surfaces have been shown to be prone to wind erosion and the generation of dust storms. However, whilst we know that winds generate dust in the Atacama Desert, we know very little about when and where such storms occur, or whether the dust contains iron which might affect the nutrient levels in the adjacent ocean waters. Our aim is to start a new collaboration of scientists from Chile, the UK, and Namibia to begin to answer these questions and determine the impacts of and controls on windblown dust in the Atacama Desert. We wish to achieve an understanding of the relevant processes in the Atacama which is as good as that which we have gained in the Namib.This research will bring together researchers from the UK and Namibia who have expertise in identifying sites of dust erosion (termed emission 'hot-spots') in Namibia, and a Chilean researcher who has expertise on the Atacama wind erosion system. Together this new team will establish, for the first time and at high resolution, where dust in the region comes from (using satellite images to identify 'hot-spots'), and how frequently dust storms occur. The team will then undertake fieldwork to explore the surface ground conditions at these 'hot-spots' and, at specific sites, install instruments to directly measure the amount of dust that is being eroded. Based on the outputs from this project, the team will develop a long-term collaborative relationship that will explore the effects of dust in the Atacama region in more detail through additional grant proposals. This will include investigating the influence of climate cycles on the efficiency of wind erosion, how important dust in this region is for ocean productivity, and the significance of human impact, such as mining, on generating windblown dust.

了解沙漠中风吹尘埃何时、何地以及如何排放非常重要，因为灰尘可能有害人类健康，可能污染顺风环境系统，并且在空气中传播时可能影响气候。沙漠尘埃还富含铁和其他营养物质，因此当它落入沙漠源头下风的海洋时，它可以刺激地表水域海洋生物群的生产力。这种影响在某些敏感的沿海地区尤其重要，这些地区的冷水混合发生在靠近海岸的地方，例如阿塔卡马和纳米布沙漠海岸线。这些沿海水域特别容易接受沉积灰尘可能提供的营养物质。英国团队多年来一直对南部非洲沙漠的风吹灰尘进行研究。我们的方法是利用卫星观测来识别沙漠景观不同区域的沙尘来源，然后在这些沙尘排放“热点”安装最先进的监测和调查设备来测量风速以及控制灰尘被风侵蚀的方式和时间的表面特征。我们的数据可以改进风吹尘埃排放到大气中的模型，并且还显示了沉积尘埃在南大西洋肥沃过程中的重要性。阿塔卡马沙漠在许多有趣的方面与纳米布沙漠相似。南部非洲。这两个沙漠都位于大陆西海岸，西边是寒冷的洋流，东边是陡峭的地形。它们有着相似的地貌类型，包括干涸的河谷、多石的平原和咸干的湖泊。在纳米布，这些表面已被证明容易遭受风蚀并产生沙尘暴。然而，虽然我们知道风会在阿塔卡马沙漠中产生灰尘，但我们对此类风暴发生的时间和地点知之甚少，也不知道灰尘中是否含有可能影响邻近海水营养水平的铁。我们的目标是与来自智利、英国和纳米比亚的科学家展开新的合作，开始回答这些问题，并确定阿塔卡马沙漠中风尘的影响和控制措施。我们希望对阿塔卡马的相关过程有一个与我们在纳米布中所获得的一样好的了解。这项研究将汇集来自英国和纳米比亚的研究人员，他们在识别沙尘侵蚀地点（称为排放）方面具有专业知识。纳米比亚的“热点”），以及一位在阿塔卡马风蚀系统方面拥有专业知识的智利研究人员。这个新团队将首次以高分辨率确定该地区灰尘的来源（使用卫星图像识别“热点”）以及沙尘暴发生的频率。然后，该团队将进行实地考察，探索这些“热点”的地表条件，并在特定地点安装仪器来直接测量被侵蚀的灰尘量。根据该项目的成果，该团队将建立长期合作关系，通过额外的拨款提案更详细地探讨灰尘对阿塔卡马地区的影响。这将包括调查气候循环对风蚀效率的影响、该地区的灰尘对海洋生产力的重要性，以及采矿等人类影响对产生风吹灰尘的重要性。