Ice-nucleating particles (INPs) can initiate cloud ice formation, influencing cloud radiative effects (CRE) and climate. However, the knowledge of INP sources, concentrations, and their impact on CRE over the Tibetan Plateau (TP)—a highly climate-sensitive region—remains largely hypothetical. Here, we integrated data from multisource satellite observations and snowpack samples collected from five glaciers to demonstrate that dust particles constitute primary INP sources over the TP. The springtime dust influxes lead to seasonally elevated ice concentrations in mixed-phase clouds. Furthermore, the decadal reduction in dustiness from 2007 to 2019 results in decreased springtime dust INPs, thereby amplifying the cooling effect of clouds over the TP, with a 1.98 ± 0.39–watt per square meter reduction in surface net CRE corresponding to a 0.01 decrease in dust optical depth. Our findings elucidate previously unidentified pathways of climate feedback from an atmospheric INP perspective, especially highlighting the crucial role of dust in aerosol-cloud interactions.

中文翻译：

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减少的尘埃颗粒通过调节青藏高原云冰的形成来放大云冷却效应


冰核粒子 （INPs） 可以引发云冰的形成，影响云辐射效应 （CRE） 和气候。然而，关于青藏高原 （TP）（一个高度气候敏感地区）的 INP 来源、浓度及其对 CRE 的影响的知识在很大程度上仍然是假设的。在这里，我们整合了来自多源卫星观测的数据和从五个冰川收集的积雪样本，以证明尘埃颗粒构成了青藏高原上的主要 INP 来源。春季沙尘涌入导致混合相云中的冰浓度季节性升高。此外，从 2007 年到 2019 年，沙尘的年代际减少导致春季沙尘 INP 降低，从而放大了高原上云的冷却效应，表面净 CRE 每平方米减少了 1.98 ± 0.39 瓦，相当于尘埃光学深度减少了 0.01。我们的研究结果从大气 INP 的角度阐明了以前未确定的气候反馈途径，特别强调了尘埃在气溶胶-云相互作用中的关键作用。