Gao Kunfeng, Vogel Franziska, Foskinis Romanos, Vratolis Stergios, Gini Maria I, Granakis Konstantinos, Zografou Olga, Fetfatzis Prodromos, Papayannis Alexandros, Möhler Ottmar, Eleftheriadis Konstantinos, Nenes Athanasios
Laboratory of Atmospheric Processes and Their Impacts, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Present Address: Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland.
NPJ Clim Atmos Sci. 2025;8(1):160. doi: 10.1038/s41612-024-00817-9. Epub 2025 May 5.
We report the drivers of spatiotemporal variability of ice nucleating particles (INPs) for mixed-phase orographic clouds (~-25 °C) in the Eastern Mediterranean. In the planetary boundary layer, pronounced INP diurnal periodicity is observed, which is mainly driven by biological (and to a lesser extent, dust) particles but not aerosols from biomass burning. The comparison of size-resolved and fluorescence-discriminated aerosol particle properties with INPs reveals the primary role of fluorescent bioaerosol. The presence of Saharan dust increases INPs during nighttime more than daytime, because of lower boundary layer height during nighttime which decreases the contribution of aerosols (including bioaerosols) from the boundary layer. INP diurnal periodicity is absent in the free troposphere, although levels are driven by the availability of bioaerosol and dust particles. Given the effective ice nucleation ability of bioaerosols and subsequent effects from ice multiplication at warm temperatures, the lack of such cycles in models points to important and overlooked drivers of cloud formation and precipitation in mountainous regions.
我们报告了东地中海混合相地形云（约-25°C）中冰核粒子（INPs）时空变化的驱动因素。在行星边界层，观测到明显的INP昼夜周期性，其主要由生物（以及程度较轻的沙尘）粒子驱动，而非生物质燃烧产生的气溶胶。将尺寸分辨和荧光区分的气溶胶粒子特性与INPs进行比较，揭示了荧光生物气溶胶的主要作用。撒哈拉沙尘的存在使夜间的INPs增加幅度大于白天，这是因为夜间边界层高度较低，减少了边界层气溶胶（包括生物气溶胶）的贡献。在自由对流层中不存在INP昼夜周期性，尽管其水平受生物气溶胶和沙尘粒子的可获得性驱动。鉴于生物气溶胶有效的冰核形成能力以及暖温下冰增殖的后续影响，模型中缺乏此类循环表明山区云形成和降水的重要驱动因素被忽视了。
