Rain alters local sea surface physical and biogeochemical properties but its spatiotemporal variability has led to its overlook in global ocean carbon uptake studies. Different physical and chemical processes in the gaseous and liquid phases control the transfer of carbon dioxide (CO₂) between the atmosphere and ocean. Rain impacts the interfacial flux by (1) increasing turbulence in the ocean and (2) modulating the air–sea CO₂ concentration gradient. Concurrently, raindrops inject CO₂ absorbed during their fall into the ocean through wet deposition. Here this study presents a comprehensive estimate of these effects on the global ocean carbon uptake over 2008–2018 based on observational products (satellite and in situ) and reanalysis. Using various representations of the ocean surface response to rainfall and different rain products, we show that rain increases the ocean carbon sink by +0.14–0.19 PgC yr⁻¹ over 2008–2018, representing an increase of 5–7% of the ocean carbon uptake (2.66 PgC yr⁻¹). Rain-induced interfacial flux and wet deposition have comparable orders of magnitude. The former mainly increases the CO₂ sink in the tropics because strong rain rates and weak winds induce noticeable salinity and CO₂ dilution. The latter is important in the tropics, storm track regions and the Southern Ocean.

降雨改变了当地海面的物理和生物地球化学特性，但其时空变化导致其在全球海洋碳吸收研究中被忽视。气相和液相中的不同物理和化学过程控制着二氧化碳(CO ₂ )在大气和海洋之间的转移。降雨通过 (1) 增加海洋湍流和 (2) 调节海气 CO ₂浓度梯度来影响界面通量。同时，雨滴通过湿沉积将其落入海洋时吸收的CO ₂注入其中。本研究根据观测产品（卫星和现场）和再分析，对 2008 年至 2018 年全球海洋碳吸收的影响进行了全面估计。利用海洋表面对降雨和不同降雨产品响应的各种表示，我们发现，2008年至2018年，降雨使海洋碳汇增加了+0.14–0.19 PgC yr ⁻¹ ，相当于海洋碳增加了5–7%吸收（2.66 PgC yr ^-1 ）。降雨引起的界面通量和湿沉降具有相当的数量级。前者主要增加热带地区的CO ₂汇，因为强降雨和弱风会导致明显的盐度和CO ₂稀释。后者在热带、风暴路径地区和南大洋非常重要。