Ice nucleation observation raw data

This study used a novel designed experimental setup to online measure the INPs concurrently for the ambient and heated aerosols (at 350 ℃), using a continuous flow diffusion chamber (CFDC) and other composition measurements. The difference between both measurements reflects the IN activities for non-refractory OA. We found the more oxygenated OA produced by photooxidation at noon preferentially acted as INPs. Our results give first direct evidence that the organic aerosols from anthropogenically polluted region could importantly contribute to the INPs well above the homogeneous ice nucleation temperature, when in high oxidation state and lower ambient relative humidity. Considering the abundant OA loadings over global scale, the role of OA in modulating ice number concentration and its potential consequent impacts on weather and climate should be attended.

本研究采用新颖设计的实验装置，结合连续流扩散室（continuous flow diffusion chamber, CFDC）与其他成分表征手段，对环境气溶胶与350℃加热气溶胶的冰核粒子（Ice Nuclei, INPs）开展同步在线观测。两类测量结果的差值可反映非难熔有机气溶胶（Organic Aerosol, OA）的冰核活性。研究发现，正午光氧化生成的高含氧有机气溶胶更优先充当冰核粒子。本研究首次提供直接证据表明，当有机气溶胶处于高氧化态且环境相对湿度较低时，人为污染区域产生的有机气溶胶可在远高于均质冰核化温度的条件下，对冰核粒子浓度产生重要贡献。考虑到全球范围内广泛存在的有机气溶胶负荷，有机气溶胶在调控冰粒子数浓度方面的作用及其潜在的天气与气候影响值得重点关注。