Atmospheric Transport and Photo-chemical Transformation of Iron: Model Development, Application, and Verification with Surface and Satellite Data

在这个项目中，将开发一个环境颗粒中水溶性铁（DFe）产生的耦合化学-气溶胶-云-辐射模型，并将其应用于DFe在全球海洋不同地区的运输和沉积。主要的假设是，矿物气溶胶的大气运输和转化在将铁从高度不溶的矿物相转移到可被浮游植物生物吸收的水溶性形式方面发挥了重要作用。本研究的目的是减少与粉尘矿物组成、铁的地壳和燃烧源、铁氧化物的光化学还原溶解、气溶胶的云处理、铁的化学循环和模型网格分辨率相关的海洋DFe通量评估中的不确定性。GEOS-Chem（戈达德地球观测系统-化学）模型将与最近实施的尘铁动员机制一起使用。该模式将用于提供(1)粗网格模拟，以估计全球海洋不同部分的DFe平均通量；(2)嵌套网格模拟，表征沿海地区Fe溶解和DFe沉积的区域特征；(3)粉尘矿物组成及溶解机理敏感性研究；(4)矿物气溶胶模拟能力评估。这项研究将使人们更好地了解环境颗粒中DFe产生的过程，并将有助于评估粉尘在海洋生产力和碳循环中的作用。这项研究将支持不同群体的大气科学本科生和研究生的教育。北卡罗莱纳州立大学科学之家组织的外展项目将与K-12教师合作，促进以实践为基础的科学学习，以提高学生对科学的热情。

In this project, a coupled chemistry-aerosol-cloud-radiation model for the production of water-soluble iron (DFe) in ambient particles will be developed and applied to the transport and deposition of DFe to different parts of the global oceans. The main hypothesis is that atmospheric transport and transformation of mineral aerosols play an important role in mobilizing Fe from highly insoluble mineral phases to water-soluble forms that are available for biological uptake by phytoplankton. The objectives of this study are to reduce uncertainties in assessments of DFe fluxes to the oceans associated with the mineralogical composition of dust, crustal and combustion sources of Fe, photochemical reductive dissolution of Fe oxides, cloud processing of aerosols, chemical cycling of Fe, and model grid resolution. The GEOS-Chem (Goddard Earth Observing System-Chemistry) model will be used with a recently implemented dust iron mobilization mechanism. The model will be used to provide (1) coarse grid simulations to estimate average fluxes of DFe to different parts of the global ocean; (2) nested grid simulations to characterize regional features of Fe dissolution and deposition of DFe in coastal regions; (3) sensitivity studies of dust mineralogical composition and dissolution mechanisms; and (4) an assessment of capabilities in modeling mineral aerosols.This study will lead to an improved understanding of processes responsible for the production of DFe in ambient particles and will facilitate the assessment of the role of dust in ocean productivity and the carbon cycle. This research will support the education of a diverse group of undergraduate and graduate students in atmospheric science. Outreach projects organized by the Science House of North Carolina State University will be carried out with a goal of increasing student enthusiasm for science by partnering with K-12 teachers to promote hands-on inquiry-based science learning.