College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2020 Nov 1;741:140324. doi: 10.1016/j.scitotenv.2020.140324. Epub 2020 Jun 19.
Several air pollution episodes occurred in China in the past decade, and high levels of aerosols load also caused the changes of radiation, which could further influence the gross primary productivity (GPP) in the terrestrial ecosystem. This paper focuses on the spatiotemporal variations and relationship of aerosol-radiation-GPP in China during a heavy pollution period (2001-2014). For this purpose, the Fu-Liou radiation transfer mechanism model was used to estimate total radiation (TR) and diffuse radiation (DIFR) at the spatial resolution of 1° × 1° based on the satellite aerosol optical depth (AOD) and other auxiliary data. This model shows excellent performance with an R of 0.88 and 0.79 for TR and DIFR, respectively. A significant increasing trend (0.23 W m year) in TR was found in China in this phase, and it was mainly attributed to DIFR. Furthermore, a scenario without aerosols (AOD = 0) was simulated as a comparison to quantify the aerosol radiative forcing, which indicated that aerosols play a catalytic role in DIFR, increasing it by approximately 19.55%. Despite all this, aerosols have weakened the brightening of China due to the negative forcing on direct radiation. Meanwhile, 0.65-4.20 kgC m year increase of GPP was also captured in seven regions of China during this phase.However, the significant negative response of GPP to aerosol was found in most ecosystems in the growing season of vegetation, and the highest correlation of -0.76 (p < .01) existed in the central China forest regions. It suggests although aerosol causes a diffuse fertilization effect, GPP is still lost due to high levels of aerosol load in most areas of China during growing season of vegetation. This paper aims to determine the relationship among the aerosol-radiation-ecosystem productivity in different regions of China, which could provide a reference for the divisional strategy formulation and classification management in different ecosystems.
过去十年，中国发生了数次空气污染事件，高浓度气溶胶负荷也导致辐射变化，从而进一步影响陆地生态系统的总初级生产力（GPP）。本文重点研究了重污染时期（2001-2014 年）中国气溶胶-辐射-GPP 的时空变化及其关系。为此，利用 Fu-Liou 辐射传输机制模型，基于卫星气溶胶光学厚度（AOD）和其他辅助数据，在 1°×1°的空间分辨率上估算总辐射（TR）和漫射辐射（DIFR）。该模型在 TR 和 DIFR 上的 R 值分别为 0.88 和 0.79，表现出优异的性能。在这一阶段，中国的 TR 呈显著增加趋势（0.23 W m year），主要归因于 DIFR。此外，还模拟了一个没有气溶胶（AOD=0）的情景作为对比，以量化气溶胶辐射强迫，结果表明气溶胶在 DIFR 中起催化作用，使其增加了约 19.55%。尽管如此，由于对直射辐射的负强迫，气溶胶减弱了中国的增亮效应。同时，在这一阶段，中国七个地区的 GPP 也增加了 0.65-4.20 kgC m year。然而，在植被生长季，大多数生态系统的 GPP 对气溶胶呈显著负响应，其中中国中部森林地区的相关性最高（-0.76，p <.01）。这表明，尽管气溶胶导致漫射施肥效应，但在植被生长季的大多数地区，由于气溶胶负荷较高，GPP 仍会损失。本文旨在确定中国不同地区气溶胶-辐射-生态系统生产力之间的关系，为不同生态系统的分区战略制定和分类管理提供参考。
