Abstract. Aerosols can enhance ecosystem productivity by increasing diffuse radiation. Such diffuse fertilization effects (DFEs) vary among different aerosol compositions and sky conditions. Here, we apply a suite of chemical, radiation, and vegetation models in combination with ground- and satellite-based measurements to assess the impacts of natural and anthropogenic aerosol species on gross primary productivity (GPP) through DFE during 2001–2014. Globally, aerosols increase GPP by 8.9 Pg C yr^-1 at clear skies but only 0.95 Pg C yr^-1 at all skies. Anthropogenic aerosols account for 41% of the total GPP enhancement though they contribute only 25% to the increment of diffuse radiation. Sulfate/nitrate aerosols from anthropogenic sources make dominant contributions of 33% (36%) to aerosol DFE at all (clear) skies, followed by the ratio of 18% (22%) by organic carbon aerosols from natural sources. In contrast to other species, black carbon aerosols decrease global GPP by 0.28 (0.12) Pg C yr^-1 at all (clear) skies. Long-term simulations show that aerosol DFE is increasing 2.9% yr^-1 at all skies mainly because of a downward trend in cloud amount. This study suggests that the impacts of aerosols and cloud should be considered in projecting future changes of ecosystem productivity under varied emission scenarios.

中文翻译：

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通过扩散施肥效应区分自然和人为气溶胶对全球总初级生产力的影响

摘要。气溶胶可以通过增加漫射辐射来提高生态系统生产力。这种扩散施肥效应 (DFE) 因气溶胶成分和天空条件不同而异。在这里，我们应用一套化学、辐射和植被模型，并结合基于地面和卫星的测量，评估 2001-2014 年期间通过 DFE 的自然和人为气溶胶物种对总初级生产力 (GPP) 的影响。在全球范围内，在晴朗的天空下，气溶胶使 GPP 增加 8.9 Pg C yr ^-1但仅增加 0.95 Pg C yr ^-1在所有的天空。人为气溶胶占总 GPP 增强的 41%，尽管它们对扩散辐射的增量仅贡献 25%。来自人为来源的硫酸盐/硝酸盐气溶胶在所有（晴朗）天空中对气溶胶 DFE 的贡献率为 33% (36%)，其次是来自天然来源的有机碳气溶胶的比例为 18% (22%)。与其他物种相比，黑碳气溶胶使所有（晴朗）天空的全球 GPP 降低 0.28 (0.12) Pg C yr ^-1。长期模拟表明，所有天空的气溶胶 DFE均以2.9% yr ^{-1 的}速度增长，这主要是由于云量呈下降趋势。这项研究表明，在预测不同排放情景下生态系统生产力的未来变化时，应考虑气溶胶和云的影响。