Light-absorbing carbonaceous aerosols (LACs), including black carbon and light-absorbing organic carbon (brown carbon, BrC), have an important role in the Earth system via heating the atmosphere, dimming the surface, modifying the dynamics, reducing snow/ice albedo, and exerting positive radiative forcing. The lifecycle of LACs, from emission to atmospheric evolution further to deposition, is key to their overall climate impacts and uncertainties in determining their hygroscopic and optical properties, atmospheric burden, interactions with clouds, and deposition on the snowpack. At present, direct observations constraining some key processes during the lifecycle of LACs (e.g., interactions between LACs and hydrometeors) are rather limited. Large inconsistencies between directly measured LAC properties and those used for model evaluations also exist. Modern models are starting to incorporate detailed aerosol microphysics to evaluate transformation rates of water solubility, chemical composition, optical properties, and phases of LACs, which have shown improved model performance. However, process-level understanding and modeling are still poor particularly for BrC, and yet to be sufficiently assessed due to lack of global-scale direct measurements. Appropriate treatments of size- and composition-resolved processes that influence both LAC microphysics and aerosol–cloud interactions are expected to advance the quantification of aerosol light absorption and climate impacts in the Earth system. This review summarizes recent advances and up-to-date knowledge on key processes during the lifecycle of LACs, highlighting the essential issues where measurements and modeling need improvement.

吸收光的碳质气溶胶（LAC），包括黑碳和吸收光的有机碳（棕碳，BrC），通过加热大气层，调暗表面，改变动力，减少积雪/冰，在地球系统中具有重要作用。反照率，并施加正辐射强迫。从排放到大气演变再到沉积，LAC的生命周期是其整体气候影响和确定其吸湿和光学特性，大气负担，与云的相互作用以及积雪上的沉积的不确定性的关键。目前，对LAC生命周期中某些关键过程的直接观测（例如，LAC与水凝物之间的相互作用）受到限制。在直接测量的LAC属性和用于模型评估的属性之间也存在很大的不一致。现代模型开始结合详细的气溶胶微观物理学来评估水溶性，化学组成，光学性质和LAC相的转化率，这些转化率已显示出改进的模型性能。但是，过程级的理解和建模仍然很差，特别是对于BrC而言，由于缺乏全局规模的直接测量而尚未得到充分评估。对影响LAC微观物理学和气溶胶-云相互作用的尺寸和成分分解过程进行适当的处​​理有望促进量化地球系统中的气溶胶吸收光和气候影响。