Substantial large-scale feedbacks between natural aerosols and climate
Substantial large-scale feedbacks between natural aerosols and climate
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DOI：
10.1038/s41561-017-0020-5
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发表时间：
2018-01-01
影响因子：
18.3
通讯作者：
Spracklen, D. V.
中科院分区：
文献类型：
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作者：
Scott, C. E.;Arnold, S. R.;Spracklen, D. V.
陆地生物圈是天然气溶胶的重要来源。天然气溶胶源改变了气候，但也受到气候的强烈控制，导致了自然气溶胶-气候反馈的可能性。在这里，我们使用全球气溶胶模式来评估陆地自然气溶胶-气候反馈，受气溶胶数量观测的限制。我们发现，温度高于平均水平与大颗粒（直径100纳米）的浓度高于平均水平有关，特别是在夏季。该模式很好地再现了这种关系，并受到气象变率和来自生物源和景观火源的自然气溶胶变率的驱动。计算得到的温带年平均气溶胶辐射效应（直接和间接）与观测到的全球温度异常呈负相关，并受温度与天然气溶胶排放呈正相关关系的驱动。温带气溶胶-气候反馈估计为景观火气溶胶的-0.14 W m(-2) K-1，大于生物源次生有机气溶胶的-0.03 W m(-2) K-1。这些反馈在量级上与其他生物地球化学反馈相当，突出了将自然气溶胶反馈纳入气候模拟的必要性。
The terrestrial biosphere is an important source of natural aerosol. Natural aerosol sources alter climate, but are also strongly controlled by climate, leading to the potential for natural aerosol-climate feedbacks. Here we use a global aerosol model to make an assessment of terrestrial natural aerosol-climate feedbacks, constrained by observations of aerosol number. We find that warmer-than-average temperatures are associated with higher-than-average number concentrations of large (>100 nm diameter) particles, particularly during the summer. This relationship is well reproduced by the model and is driven by both meteorological variability and variability in natural aerosol from biogenic and landscape fire sources. We find that the calculated extratropical annual mean aerosol radiative effect (both direct and indirect) is negatively related to the observed global temperature anomaly, and is driven by a positive relationship between temperature and the emission of natural aerosol. The extratropical aerosol-climate feedback is estimated to be -0.14 W m(-2) K-1 for landscape fire aerosol, greater than the -0.03 W m(-2) K-1 estimated for biogenic secondary organic aerosol. These feedbacks are comparable in magnitude to other biogeochemical feedbacks, highlighting the need for natural aerosol feedbacks to be included in climate simulations.