Trajectory modeling of modern dust transport to the Southern Ocean and Antarctica
Trajectory modeling of modern dust transport to the Southern Ocean and Antarctica
复制标题
DOI：
10.1002/2015jd023304
复制
发表时间：
2015-09-27
影响因子：
4.4
通讯作者：
Bertler, Nancy A. N.
中科院分区：
文献类型：
--
作者：
Neff, Peter D.;Bertler, Nancy A. N.
南大洋和南极洲上空的气溶胶沉降有可能改变海洋生产力，进而影响海洋碳吸收，同时由于大气颗粒物的散射和吸收，还会影响辐射平衡。由于排放水平低以及遥感平台探测效果不佳，对南半球来源的陆地沙尘和其他空气传播物质的现代排放、传输和沉降进行量化具有挑战性。在此，利用前向轨迹模型研究了1979年至2013年期间不依赖沉降过程的大气传输。轨迹从南美洲（巴塔哥尼亚）、澳大利亚和南部非洲已知的干旱沙尘源区开始，并详细考虑了新西兰作为一个潜在源区的情况。结果表明，巴塔哥尼亚和新西兰的沙尘及其他气溶胶排放物在所有季节都有强烈的大气传输，这使得即使新西兰潜在的少量排放也能对南大洋和南极的气溶胶负荷有显著贡献。我们发现，控制沙尘和其他气溶胶分布的大气传输呈现出明显的空间变异性。新西兰和巴塔哥尼亚的轨迹在短时间内有很大比例到达西南极洲，而在东南极洲内陆，源区的贡献有限且混合程度高。讨论了现有深冰芯站点对现代大气传输的敏感性。最后，南大洋太平洋和大西洋区域向极轨迹延伸的年际变异性凸显了热带太平洋海表温度和高纬度风变异性（例如，南半球环状模）与沙尘和其他气溶胶向南大洋和南极洲传输之间的关联。
Aerosol deposition over the Southern Ocean and Antarctica has the potential to alter marine productivity and thus ocean carbon uptake while also impacting radiative balance due to scattering and absorption from atmospheric particulates. Quantification of modern emission, transport, and deposition of terrestrial dust and other airborne material from Southern Hemisphere sources is challenging due to low emission levels and poor detection from remote sensing platforms. Here forward trajectory modeling is used to explore atmospheric transport, independent of deposition processes, from 1979 to 2013. Trajectories are initiated from known arid dust source areas in South America (Patagonia), Australia, and southern Africa, with detailed consideration of New Zealand as a potential source. Results suggest that Patagonian and New Zealand dust and other aerosol emissions share strong atmospheric transport during all seasons, allowing even potentially small New Zealand emissions to contribute significantly to Southern Ocean and Antarctic aerosol loading. We find that atmospheric transport controlling distribution of dust and other aerosols shows distinct spatial variability. New Zealand and Patagonia rapidly contribute a high proportion of trajectories to West Antarctica, while in interior East Antarctica, source contributions are limited and highly mixed. The sensitivity of existing deep ice core sites to modern atmospheric transport is discussed. Finally, interannual variability of poleward trajectory extension over the Pacific and Atlantic sectors of the Southern Ocean highlights the association of both tropical Pacific sea-surface temperature and high-latitude wind variability (e.g., the Southern Annular Mode) with transport of dust and other aerosols to the Southern Ocean and Antarctica.