Li Rui, Dong Xue, Guo Jingchao, Fu Yunfei, Zhao Chun, Wang Yu, Min Qilong
School of Earth and Space Science, University of Science and Technology of China, Hefei, China.
Key Laboratory of Aperture Array and Space Application, Thirty-eight Research Institute of China Electronic Technology Group Corporation, Hefei, China.
Sci Rep. 2017 Oct 23;7(1):13826. doi: 10.1038/s41598-017-12681-0.
Mineral dust is the most important natural source of atmospheric ice nuclei (IN) which may significantly mediate the properties of ice cloud through heterogeneous nucleation and lead to crucial impacts on hydrological and energy cycle. The potential dust IN effect on cloud top temperature (CTT) in a well-developed mesoscale convective system (MCS) was studied using both satellite observations and cloud resolving model (CRM) simulations. We combined satellite observations from passive spectrometer, active cloud radar, lidar, and wind field simulations from CRM to identify the place where ice cloud mixed with dust particles. For given ice water path, the CTT of dust-mixed cloud is warmer than that in relatively pristine cloud. The probability distribution function (PDF) of CTT for dust-mixed clouds shifted to the warmer end and showed two peaks at about -45 °C and -25 °C. The PDF for relatively pristine cloud only show one peak at -55 °C. Cloud simulations with different microphysical schemes agreed well with each other and showed better agreement with satellite observations in pristine clouds, but they showed large discrepancies in dust-mixed clouds. Some microphysical schemes failed to predict the warm peak of CTT related to heterogeneous ice formation.
矿物尘埃是大气冰核（IN）最重要的自然来源，它可能通过异质成核显著调节冰云的特性，并对水文和能量循环产生关键影响。利用卫星观测和云分辨模型（CRM）模拟研究了在一个发育良好的中尺度对流系统（MCS）中潜在的尘埃冰核对云顶温度（CTT）的影响。我们结合了被动光谱仪、有源云雷达、激光雷达的卫星观测以及CRM的风场模拟，以确定冰云与尘埃颗粒混合的位置。对于给定的冰水路径，混合尘埃的云的CTT比相对纯净的云的CTT更高。混合尘埃云的CTT概率分布函数（PDF）向较暖的一端移动，并在约-45°C和-25°C处出现两个峰值。相对纯净云的PDF仅在-55°C处出现一个峰值。采用不同微物理方案的云模拟相互之间吻合良好，并且在纯净云中与卫星观测结果的吻合度更高，但在混合尘埃云中它们显示出较大差异。一些微物理方案未能预测与异质冰形成相关的CTT暖峰。
